A method for inhibiting candida albicans and its use

Abstract

This invention relates to the technical field of inhibiting Candida albicans, specifically a method for inhibiting Candida albicans. The method includes the step of irradiating Candida albicans with visible light during its growth process, wherein the visible light includes blue light. This invention provides a method for inhibiting Candida albicans using blue light, which can effectively inhibit the fungus. This method has no risks of secondary pollution or radiation pollution, and is low in cost and simple to operate, making it highly valuable for widespread application. It is particularly suitable for inhibiting the growth of Candida albicans in existing pigeon breeding environments, helping to improve the pigeon breeding environment and reduce the workload of breeders.

Description

Technical Field

[0001] This invention relates to the technical field of inhibiting Candida albicans, specifically a method for inhibiting Candida albicans using blue light and the application of using blue light to inhibit Candida albicans. Background Technology

[0002] Candida albicans, also known as white candidiasis, is a fungus widely found in nature and within organisms. This fungus is highly pathogenic and exhibits strong drug resistance, easily causing poultry candidiasis, also called thrush, in pigeons with weakened immune systems. It is a fungal disease caused by Candida albicans in the upper digestive tract of poultry, characterized by white pseudomembranes and ulcers on the upper digestive tract mucosa, leading to intestinal mucosal shedding and subsequent invasion of tissues such as the heart, lungs, brain, and spleen, ultimately resulting in the death of the pigeon.

[0003] This type of Candida albicans, originating from pigeons, causes disease by infecting the host (pigeon) to varying degrees due to its excellent adaptability to the environment and numerous virulence factors. Currently, there is a lack of effective treatments for fungal diseases caused by Candida albicans infection in pigeon breeding environments. Simple treatments are often ineffective. While using feed mixed with medication, it is also necessary to improve feeding and management conditions and strengthen hygiene measures to achieve better results. Breeders need to regularly clean and disinfect the breeding environment, which increases their workload and can easily disturb the pigeons. Summary of the Invention

[0004] The main purpose of this application is to provide a light-based antibacterial method that can effectively inhibit Candida albicans. This method has no risks of secondary pollution or radiation pollution, and is low in cost and simple to operate, making it highly valuable for widespread application. It is particularly suitable for inhibiting the growth of Candida albicans in existing pigeon breeding environments, which can help improve the breeding environment of pigeons and reduce the workload of breeders. Through research, the applicant has discovered and clarified the following conclusions: Blue light and its combination of light have a significant inhibitory effect on Candida albicans.

[0005] The specific technical solution of the present invention is as follows: A method for inhibiting Candida albicans, the method comprising the step of irradiating Candida albicans with visible light during its growth process, wherein the visible light includes blue light.

[0006] In one method for inhibiting Candida albicans as described above, the peak wavelength of the blue light is 440 nm to 465 nm.

[0007] In one method for inhibiting Candida albicans as described above, the power of the blue light is 22W to 28W.

[0008] In the method for inhibiting Candida albicans described above, the exposure time of visible light to Candida albicans is not less than 2 hours.

[0009] In the method for inhibiting Candida albicans as described above, the visible light includes a first visible light and a second visible light, wherein the first visible light is blue light and the second visible light is one of red light, yellow light, green light, or pink light.

[0010] In one method for inhibiting Candida albicans as described above, the second visible light is pink light.

[0011] One method for inhibiting Candida albicans, as described above, involves irradiating Candida albicans with blue light in a well-ventilated breeding space that blocks external light.

[0012] In one method for inhibiting Candida albicans as described above, the culture space is provided with a reflective surface for reflecting the visible light, the reflective surface being arranged to surround the irradiation range of the visible light.

[0013] The application of monochromatic visible light to inhibit Candida albicans, wherein the visible light is blue light.

[0014] The application of dual-color visible light to inhibit Candida albicans includes a first visible light and a second visible light, wherein the first visible light is blue light and the second visible light is one of red light, yellow light, green light, or pink light. Attached Figure Description

[0015] Figure 1 This is a comparison diagram of the antibacterial effects of light irradiation with different powers according to the present invention. Detailed Implementation

[0016] The embodiments of the technical solution of this application will be described in detail below with reference to the accompanying drawings. The described embodiments are only some embodiments of the technical solution of this application, and not all embodiments. Based on the embodiments of the technical solution of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the technical solution of this application.

[0017] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of the technical solution of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0018] Furthermore, the descriptions involving "first," "second," etc., in the technical solutions of this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0019] This invention presents experimental studies on the effects of different monochromatic visible light on Candida albicans. The following details the experimental analysis of this invention on the effects of monochromatic visible light on Candida albicans.

[0020] I. Experimental Section (1) Prepare the light source Existing commercially available light source emitting devices or lighting equipment can be used. These devices can be connected to mains power or continuously emit 10W to 30W of visible light with a specific color via an independent power source. Preferably, the light source emitting devices or lighting equipment have a controller or control unit that allows users to easily adjust the light source parameters. The visible light includes any one of blue light, red light, yellow light, green light, and pink light, or a combination of two of them. To save on equipment costs, the visible light is preferably provided by an LED light source.

[0021] The specific light source parameters are as follows: Blue light, with a peak wavelength of 450.7nm and a power of 10W; Blue light, with a peak wavelength of 455.8nm and a power of 26.5W; Red light, with a peak wavelength of 632.0nm and a power of 10W; Green light, with a peak wavelength of 518.8nm and a power of 10W; Yellow light, with a peak wavelength of 580.6nm and a power of 10W; Powder light, peak wavelength 449.6nm, power 10W; (2) Test strains Candida albicans (ATCC10231) was purchased from the China Medical Microbial Culture Collection Center.

[0022] In addition, strains can also be sampled from the throat secretions of existing diseased pigeons. The lesions of Candida albicans in pigeons are mainly found in the oral cavity and throat. The oral cavity of diseased pigeons is dirty, containing transparent mucus-like substances, white raised ulcers with blood streaks, and easily peeled yellowish-white contents. There is swollen tissue near the trachea. The sampled throat secretions from diseased pigeons are inoculated into Sabouraud agar medium and incubated at 28-37℃ for 24-72 hours. Colonies suspected of containing Candida albicans are then picked out for purification culture. The purification process is repeated 2-3 times or more using the streak dilution method or physiological saline serial dilution plating method. Finally, the purified colonies are inoculated into Sabouraud dextrose liquid medium and incubated on a shaker at 30℃ for 48 hours.

[0023] Fungal DNA was extracted using a fungal genomic DNA extraction kit. The suspected Candida genome was then amplified using PCR. The PCR products were sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing. The sequencing results were then compared for homology in the NCBI database, and a phylogenetic tree was constructed using MEGA12. This identified strain was then used in an artificial reinfection experiment with healthy pigeons, which developed symptoms similar to those of Candida albicans.

[0024] (3) Culture medium preparation Prepare physiological saline, and prepare Sabouraud dextrose liquid medium and Sabouraud dextrose agar medium according to the standard formula and sterilize them at 115℃ for 20 minutes. Store them at 4℃ for later use.

[0025] Accurately weigh 10.00g of the pretreated culture medium sample and place it in a sterile 50mL centrifuge tube. Add a measured amount of deionized water or ultrapure water to achieve a solid-liquid ratio of 1:5 (W:V). Tightly cap the centrifuge tube. Place the centrifuge tube in an incubator and shake at 37℃ for 40min. After shaking, place the centrifuge tube in a centrifuge and centrifuge at 6000r / min for 10min to remove the precipitate. Use a sterile dropper to aspirate the supernatant and transfer it to a 50mL beaker for later use.

[0026] (4) Activation of Candida albicans Remove the bacterial strain stored at -80℃ and thaw it at room temperature for 15 minutes. Then, place it in a vortex mixer and shake for 1 minute. Under aseptic conditions, take 300 μl of the thawed, refrigerated inoculum and inject it into pre-autoclaved Sabouraud broth. Flame the bottle opening with an alcohol lamp for several seconds, and also flame the inside of the wrapping paper covering the cap (be careful not to ignite the wrapping paper). Then, wrap the bottle opening with the wrapping paper and seal it with a rubber band. Place the bottle on a shaker and incubate at 150 rpm and 37℃. This is the first generation. After 18 hours, take 300 μl of the activated first-generation bacterial solution and inject it into pre-sterilized Sabouraud broth. Incubate in an incubator. This is the second generation. Repeat the above procedure to cultivate the third generation bacterial solution. After three generations of continuous cultivation, the most active and optimal bacterial solution is obtained.

[0027] (5) Standardized operating procedures and determination of inoculation materials for Candida albicans plating experiment To ensure consistency of subsequent light treatment experimental conditions and accuracy of colony counting, the standardized inoculation material for Candida albicans was first determined. Regarding the selection of the bacterial growth phase, based on relevant literature analysis, when Candida albicans is cultured for approximately 16 hours, the bacteria are in the logarithmic growth phase. At this stage, the colony morphology is typical, and the physiological activity is stable, making it most suitable for coating experiments.

[0028] Inside the clean bench, a concentration of 10 was prepared using a 10-fold gradient dilution method. -1 ~10 -7 A series of bacterial suspensions with CFU / mL were prepared. 1 mL of the third-generation activated bacterial suspension was placed in a centrifuge tube, and then 9 mL of sterile physiological saline was added. The mixture was vortexed to obtain 10... -1 Diluted bacterial solution, from 10 -1 Pipette 1 mL of bacterial culture into a centrifuge tube containing CFU / mL and add 10 mL of 10 -2 Add 9 mL of sterile physiological saline to a centrifuge tube containing CFU / mL, vortex to mix, and prepare 10 CFU / mL centrifuge tubes. -2 CFU / mL bacterial culture. Dilute sequentially as described above until a 10⁻⁶ CFU / mL solution is obtained. -7 For each concentration gradient of CFU / mL bacterial culture, a sterile pipette should be used to avoid cross-contamination.

[0029] Take each concentration gradient (10 -1 ~10 -70.1 mL of bacterial suspension (CFU / mL) was evenly spread onto the surface of Sabouraud dextrose agar plates, with three parallel plates corresponding to each concentration. Using a sterile L-shaped glass rod, the bacterial suspension was evenly spread over the entire surface of the plate in a zigzag pattern, ensuring complete coverage without any liquid accumulation. After the bacterial suspension was completely absorbed, the plates were inverted and placed in a 36±2℃ incubator for 24 hours. After incubation, the plates were removed, and the colony-forming units (CFU) of each concentration gradient parallel plate were counted using a colony counter. The optimal spreading concentration was determined based on the colony count results.

[0030] Candida albicans culture solution was subjected to 10 -2 CFU / ml, 10 -3 CFU / ml, 10 -4 CFU / ml, 10 -5 CFU / ml, 10 -6 CFU / ml, 10 -7 After dilution to CFU / ml, 0.1 mL was spread onto a petri dish and incubated at 37℃ for 24 hours. The number of colonies grown on the plate was then obtained. According to the requirements for colony counting in GB4789.2-2022 National Food Safety Standard for Microbiological Examination of Food: Determination of Total Colony Count, a dilution with a colony count between 30 and 300 CFU per plate should be selected for counting. In this experiment, 10 -4 Based on a bacterial concentration of 800 CFU / mL and a plating volume of 0.1 mL, the theoretical colony count per plate is approximately 80 CFU, which falls within the optimal counting range of 30–300 CFU. This dilution avoids sampling errors caused by insufficient colony counts and prevents overlapping growth due to excessive colony counts. All subsequent light treatment experiments uniformly used a bacterial suspension cultured for 16 hours and diluted to 10⁻⁴ times as the standardized inoculum.

[0031] (6) Experimental procedures for different monochromatic visible light on Candida albicans 1. Illumination Experiment Setup: This embodiment uses a closed rectangular box structure as the culture space. A light source emitter or lighting device is installed on one side of the box, while the other five sides are covered with reflective film to improve light uniformity. A ventilated platform is provided at the bottom of the box for placing culture dishes. The distance between the light source emitter or lighting device and the culture dishes is maintained at a stable 10cm. A light-blocking cloth is placed on the outside of the box structure to prevent interference from other light sources and ensure a stable culture space and adequate ventilation.

[0032] 2. Five 10W Monochromatic Light Irradiation Experiments: Five culture spaces were set up to correspond to five monochromatic lights (10W red, yellow, green, pink, and blue light), and the distance between the light source and the culture dish was adjusted to 10cm. Twelve light time gradients were applied to each monochromatic light (2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 hours), with three parallel culture dishes for each time gradient. After the timing was completed, the culture dishes were removed and placed in a constant-temperature, sealed, light-free incubator at 37℃ for 24 hours. The total bacterial count was then determined.

[0033] 3.10W and 26.5W Blue Light Irradiation Experiments: Two incubation spaces were set up, each using a blue light source with a power of 10W and 26.5W respectively, with the distance between the light source and the petri dishes adjusted to 10cm. Twelve illumination time gradients were set for each power light source (2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24h), with three parallel petri dishes for each time gradient. After the timing was completed, the petri dishes were removed and placed in a constant-temperature, sealed, light-free incubator at 37℃ for 24h of incubation, followed by total bacterial count determination.

[0034] 4. Blank control group experiment: The blank control group culture dishes (3 parallel culture dishes per time gradient) were placed in a light-proof environment covered with black light-blocking cloth to ensure complete isolation from external light sources. The culture temperature conditions of the blank control group were also kept consistent with those of the light-illuminated experimental groups. After timing, the culture dishes were removed and placed in a constant-temperature, sealed, light-free incubator at 37℃ for 24 hours. The total bacterial count was then determined.

[0035] 5. Total colony count determination: Count colonies visually or with a magnifying glass. Select plates with colony counts between 30-300 CFU and no non-spreading colonies for counting. For plates with colony counts below 30 CFU, record the specific values ​​for subsequent analysis; plates with colony counts exceeding 300 CFU are not included in the statistics due to excessive density.

[0036] This invention provides a method for inhibiting Candida albicans, the method comprising the step of irradiating Candida albicans with visible light during its growth process, the specific implementation of which is as follows: Example 1 The culture medium inoculated with Candida albicans was placed in a culture space and cultured. The light source emitting device or lighting equipment was modulated to emit blue light with a power of 10W and a peak wavelength of 450.7nm and directed toward the culture medium. Twelve light time gradient treatments were performed (2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24h). Three parallel culture dishes were set up for each time gradient. After the time was completed, the culture dishes were taken out and placed in a constant temperature, sealed, light-free incubator for culture. After culturing at 37℃ for 24h, the total number of colonies was determined.

[0037] Example 2 Based on Example 1, the difference is that the light source emitting device or lighting equipment is modulated to red light with a power of 10W and a peak wavelength of 632.0nm.

[0038] Example 3 Based on Example 1, the difference is that the light source emitting device or lighting equipment is modulated to emit powder light with a power of 10W and a peak wavelength of 449.6nm.

[0039] Example 4 Based on Example 1, the difference is that the light source emitting device or lighting equipment is modulated to green light with a power of 10W and a peak wavelength of 518.8nm.

[0040] Example 5 Based on Example 1, the difference is that the light source emitting device or lighting equipment is modulated to emit yellow light with a power of 10W and a peak wavelength of 580.6nm.

[0041] Example 6 Based on Example 1, the difference is that the light source emitting device or lighting equipment is modulated to blue light with a power of 26.5W and a peak wavelength of 455.8nm.

[0042] Comparative Example 1 The culture medium inoculated with Candida albicans was placed in the culture space and cultured. The light source or lighting equipment was turned off, and the total number of colonies was determined after culturing at 37°C for 24 hours.

[0043] The structures of Examples 1, 2, 3, 4, 5, 6 and Comparative Example 1 are shown in Table 1. It can be seen that there are significant differences between the Examples and the Comparative Example. Among them, blue light (especially high-power blue light) has a stronger inhibitory effect on Escherichia coli than other colors of visible light, and is the most effective monochromatic light for inhibiting Candida albicans.

[0044] Table 1:

[0045] II. Research Results After the culture period ended, the data in Table 1 was processed using Origin software, and the results are as follows: Comparative Example 1 (without light treatment): 0–8h: The colony count decreased from 342 CFU at 2h to 229 CFU at 4h, rebounded to 320 CFU at 6h, and further increased to 333 CFU at 8h. This fluctuating change is consistent with the natural growth characteristics of microorganisms under no-intervention conditions and may be related to the initial inoculation density, nutrient consumption, and accumulation of metabolites.

[0046] 8–18 h: Colony count fluctuated between 232–305.67 CFU, decreasing to 257 CFU at 10 h, rising to 283 CFU at 12 h, decreasing to 240 CFU at 14 h, decreasing slightly to 232 CFU at 16 h, and rising to 302 CFU at 18 h. This fluctuation range is consistent with the variability of natural growth, and no obvious trend of continuous growth or inhibition was observed.

[0047] 18–24 h: The colony count decreased to 269 CFU at 20 h, slightly decreased to 250 CFU at 22 h, and rebounded to 363 CFU at 24 h, returning to near the initial level. This rebound is consistent with the natural growth pattern of microorganisms under uninterrupted conditions, indicating that its growth was not inhibited by external factors, but only exhibited normal growth cycle fluctuations.

[0048] Example 1 (significantly antibacterial wavelength): 0–12h: The colony count decreased significantly from 277 CFU at 2h, down to 256 CFU at 4h, 165 CFU at 6h, 57 CFU at 8h, 36 CFU at 10h, and 4 CFU at 12h, reaching the lowest point of the entire cycle. During this stage, blue light exhibited a strong time-dependent bactericidal effect on microorganisms.

[0049] 12–18h: The colony count rapidly increased from 4 CFU at 12h to 20 CFU at 14h, 179 CFU at 16h, and 248 CFU at 18h, returning to near the initial level, indicating that the microorganisms have adapted to blue light.

[0050] 18–24h: The colony count dropped to 167 CFU at 20h, rebounded to 183 CFU at 22h, and surged to 316 CFU at 24h, significantly higher than the initial level, indicating that the inhibitory effect was reversed after long-term blue light irradiation and microorganisms exhibited hyperproliferation rebound.

[0051] Experiments have shown that blue light is the strongest antibacterial wavelength for Candida albicans.

[0052] Example 2 (mixed wavelengths, no significant antibacterial effect): 0–10 h: The colony count rapidly increased from 117 CFU at 2 h, to 247 CFU at 4 h, to 263 CFU at 6 h, and reached a peak of 380 CFU at 8–10 h. This sustained rapid growth indicates that red light has a strong proliferative effect on microorganisms in the early stage.

[0053] 10–18 h: Colony counts continued to decline from their peak, dropping to 247 CFU at 12 h, slightly increasing to 251 CFU at 14 h, decreasing to 223 CFU at 16 h, and further decreasing to 180 CFU at 18 h. This trend indicates that the promoting effect of red light significantly diminishes over time, and the microorganisms enter a growth inhibition phase, which may be related to photo-oxidative damage or the accumulation of metabolites.

[0054] 18–24 h: The colony count rebounded to 212 CFU at 20 h, slightly decreased to 200 CFU at 22 h, and rebounded again to 277 CFU at 24 h, returning to a relatively high level. This rebound indicates that the inhibitory effect of red light gradually weakened, and the microorganisms resumed growth through repair mechanisms, showing an overall "initially suppressed and then rebounded" characteristic.

[0055] Experiments showed that red light, being a mixed wavelength for Candida albicans, had no significant effect.

[0056] Example 3 (mixed wavelengths, no significant antibacterial effect): 0–12h: The colony count started at 127 CFU at 2h, rose to 218 CFU at 4h, and further increased to 255 CFU at 6h. It then briefly dropped to 162 CFU at 8h, rebounded to 198 CFU at 10h, and reached a peak of 293 CFU at 12h. This phase showed an overall fluctuating increase, indicating that light had a certain promoting effect on microbial proliferation in the early stages. The brief drop at 8h may be related to the microbial metabolic cycle or environmental adaptation.

[0057] 12–18 h: The colony count gradually decreased from the peak at 12 h, dropping to 235 CFU at 14 h, 207 CFU at 16 h, and further to 191 CFU at 18 h. This continuous downward trend suggests that as the irradiation time increases, the proliferation-promoting effect of the powder gradually weakens, and may even turn into a certain degree of inhibition, with a significant slowdown in the microbial growth rate.

[0058] 18–24 h: The colony count rebounded to 290 CFU at 20 h, close to the peak at 12 h, then dropped to 157 CFU at 22 h, and rebounded again to 218 CFU at 24 h. The overall pattern was a "rise-fall-rise" fluctuation, without a continuous decline, indicating that the inhibitory effect of light on microorganisms is time-limited, and microorganisms can recover their proliferative capacity through adaptive adjustments.

[0059] Experiments showed that the mixed wavelength of the light was not effective against Candida albicans.

[0060] Example 4 (moderate antibacterial wavelength): 0–12 h: The colony count increased rapidly from 84 CFU at 2 h, to 123 CFU at 4 h, 131 CFU at 6 h, 201 CFU at 8 h, 259 CFU at 10 h, and reached a peak of 389 CFU at 12 h. This continuous increase indicates that green light has a strong proliferation-promoting effect on microorganisms in the early stage, possibly by accelerating cell division through optimizing photosynthetic efficiency or energy metabolism.

[0061] 12–20 h: Colony counts decreased continuously from the peak, dropping to 339 CFU at 14 h, 255 CFU at 16 h, 187 CFU at 18 h, and remaining at 192 CFU at 20 h. This trend indicates that the promoting effect of green light significantly diminishes over time, and the microorganisms enter a growth inhibition phase, which may be related to light-induced oxidative damage or metabolic imbalance.

[0062] 20–24 h: The colony count rebounded to 301 CFU at 22 h, then slightly decreased to 277 CFU at 24 h, but remained at a high level. This rebound indicates that the inhibitory effect of green light gradually weakened, and the microorganisms resumed growth through repair mechanisms. The overall count did not show a continuous decline, suggesting that its inhibitory effect is reversible.

[0063] Experiments have shown that green light is a moderately inhibitory wavelength for Candida albicans.

[0064] Example 5 (weak antibacterial wavelength): 0–10 h: The colony count rapidly increased from 119 CFU at 2 h, reaching 252 CFU at 4 h, then decreased to 223 CFU at 6 h, further decreasing to 112 CFU at 8 h, and finally to 96 CFU at 10 h. This "increase followed by decrease" trend indicates that yellow light can promote microbial proliferation in the short term, but prolonged exposure leads to inhibition, which may be related to the enhanced light-induced oxidative stress response.

[0065] 10–20 h: The colony count gradually increased from 96 CFU at 10 h to 192 CFU at 12 h, 229 CFU at 14 h, and stabilized at 225–215 CFU at 16–20 h. This process of recovery and stabilization indicates that the microorganisms have adapted to the inhibitory effect of yellow light, and the growth rate has returned to a relatively stable level.

[0066] 20–24 h: The colony count dropped to 176 CFU at 22 h and rebounded to 264 CFU at 24 h, remaining at a relatively high level overall. This fluctuation did not show a sustained decline, indicating that the inhibitory effect of yellow light on microorganisms is not long-lasting, and microorganisms can resume proliferation through metabolic adjustments.

[0067] Experiments have shown that yellow light is the weakly effective wavelength for Candida albicans.

[0068] For blue visible light, which showed the best antibacterial effect, further studies were conducted on the antibacterial effects of different powers on Candida albicans, specifically a comparative analysis of Example 1 and Example 6. The data in Table 1 were processed using Origin software and combined with… Figure 1 A direct comparison yields the following results: Example 1 (10W Blue Light) Initial response (0 to 4 hours): Colony counts begin to decrease from the initial level, but the rate of decrease is relatively slow.

[0069] Mid-term trend (4 to 12 hours): The curve shows a continuous but relatively gentle decreasing trend, indicating that 10W blue light has continuous antibacterial activity, but the inactivation efficiency is limited.

[0070] Endpoint prediction: Based on the curve trend, it is inferred that within the experimental time, this power may not be able to reduce the colony count to an extremely low level or achieve complete sterilization, and the antibacterial effect will have a plateau period.

[0071] Example 6 (26.5W Blue Light) Rapid killing period (0 to 8 hours): The curve shows a steep drop in the initial stage, indicating that high-power blue light can quickly produce a strong inhibitory or killing effect on Candida albicans, and the initial inactivation rate is significantly higher than that of the 10W group.

[0072] The inhibition period (8 to 24 hours): As the irradiation time increased, the downward trend continued, and the colony count remained at the lowest level after 10 hours; and it was lower than that of the 10W treatment group during the same period throughout the observation time.

[0073] Based on the comparison of the effects of Example 1 and Example 6, at any given time point, the number of colonies corresponding to the 26.5W blue light treatment was significantly lower than that of the 10W blue light treatment, which directly demonstrates the power-dependent enhancement effect.

[0074] III. Conclusion Experiments were conducted to analyze the inhibitory effects of monochromatic light of different wavelengths (blue, red, pink, green, and yellow), powers (10W and 26.5W blue light), and durations (gradual changes from 2 to 24 hours) on Candida albicans. The results showed that blue light (especially high-power 26.5W blue light) had a significant antibacterial effect after irradiation for at least 2 hours, while red and pink light showed moderate inhibition, and green and yellow light had weaker inhibitory effects. Blue light (440-465nm) exhibited the strongest antibacterial effect in this experiment, especially under high-power conditions of 26.5W, where short-term irradiation (2-6 hours) significantly reduced colony counts. Red and pink light showed some inhibitory trends after 8-12 hours, but their effects were significantly weaker than blue light, indicating that longer-wavelength photons have lower energy and may mainly affect bacterial metabolism through indirect pathways or have weaker interactions with specific photoreceptors. Green and yellow light had the weakest antibacterial effects, which may be related to the lack of pigments that effectively absorb light in these wavelengths, suggesting that wavelength selection is a key parameter for light-induced antibacterial activity.

[0075] Furthermore, this invention also presents experimental studies on the effects of different dual-color visible light on Candida albicans. The following details the experimental analysis of this invention on the effects of dual-color visible light on Candida albicans.

[0076] I. Experimental Section (1) Prepare the light source Existing commercially available light source emitting devices or lighting equipment can be used. They can be connected to mains power or continuously emit 10W to 30W of visible light through an independent power source and emit at least two specific colors of light. Preferably, the light source emitting device or lighting equipment has a controller or control unit that allows users to easily adjust the light source parameters. The visible light includes any one of blue light, red light, yellow light, green light, and pink light, or a combination of two of them. In order to save equipment costs, the visible light is preferably provided by an LED light source.

[0077] The specific light source parameters are as follows: Blue light, with a peak wavelength of 450.7nm and a power of 10.7W; Red light, with a peak wavelength of 632.0nm and a power of 9.7W; Green light, with a peak wavelength of 518.8nm and a power of 10.7W; Yellow light, with a peak wavelength of 580.6nm and a power of 10.7W; The light source has a peak wavelength of 449.6nm and a power of 10.7W. (2) For the test strain, culture medium preparation, Candida albicans activation, standardized operating procedures for Candida albicans coating experiment and determination of inoculation materials, refer to the aforementioned experimental study on the effects of different monochromatic visible light on Candida albicans and its related settings, which will not be repeated here.

[0078] (6) Experimental procedures for different combinations of two-color visible light on Candida albicans 1. Illumination Experiment Setup: This embodiment uses a closed rectangular box structure as the culture space. A light source emitter or lighting device is installed on one side of the box, while the other five sides are covered with reflective film to improve light uniformity. A ventilated platform is provided at the bottom of the box for placing culture dishes. The distance between the light source emitter or lighting device and the culture dishes is maintained at a stable 10cm. A light-blocking cloth is placed on the outside of the box structure to prevent interference from other light sources and ensure a stable culture space and adequate ventilation.

[0079] 2. Two-color light grouping experiment: This experiment used blue, red, pink, yellow, and green light in 10 combinations (blue / red, blue / pink, blue / yellow, blue / green, red / pink, red / yellow, red / green, pink / yellow, pink / green, green / yellow). Ten culture spaces were set up to correspond to each of the ten two-color light groups, and the distance between the light source and the culture dishes was adjusted to 10 cm. After coating, each culture dish was directly transferred to the light source for the light experiment. Twelve light time gradients were applied to each two-color light group's culture space (2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 h), with three parallel culture dishes for each time gradient. After timing, the culture dishes were removed and placed in a constant-temperature, sealed, light-free incubator at 37℃ for 16 h, after which the total bacterial count was determined.

[0080] 3. Blank control group experiment: The blank control group culture dishes (3 parallel culture dishes per time gradient) were placed in a light-proof environment covered with black light-blocking cloth to ensure complete isolation from external light sources. The culture temperature conditions of the blank group were also kept consistent with those of the light-illuminated experimental groups. After timing, the culture dishes were removed and placed in a constant-temperature, sealed, light-free incubator at 37℃ for 16 hours. The total bacterial count was then determined.

[0081] 4. Total colony count determination: Count colonies visually or with a magnifying glass. Select plates with colony counts between 30-300 CFU and no non-spreading colonies for counting. For plates with colony counts below 30 CFU, record the specific values ​​for subsequent analysis; plates with colony counts exceeding 300 CFU are not included in the statistics due to excessive density.

[0082] This invention provides a method for inhibiting Candida albicans, comprising the step of irradiating Candida albicans with visible light during its growth process. The visible light includes a first visible light and a second visible light; the first visible light is blue light, and the second visible light is one of red light, yellow light, green light, or pink light. Specific implementation details are as follows: Example 11 The culture medium inoculated with Candida albicans was placed in a culture space and cultured. The light source emitting device or lighting equipment was modulated to a dual-color visible light combination of blue light and red light and irradiated towards the culture medium. Twelve light time gradient treatments were carried out (2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24h). Three parallel culture dishes were set up for each time gradient. After the timing was completed, the culture dishes were taken out and placed in a constant temperature sealed incubator without light contact for culture. After culturing at 37℃ for 16h, the total number of colonies was determined.

[0083] Example 12 Based on Example 11, the difference is that the light source emitting device or lighting device is modulated to a dual-color visible light combination with a power of blue light + pink light.

[0084] Example 13 Based on Example 11, the difference is that the light source emitting device or lighting device is modulated to a dual-color visible light combination with a power of blue light + yellow light.

[0085] Example 14 Based on Example 11, the difference is that the light source emitting device or lighting device is modulated to a dual-color visible light combination with a power of blue light + green light.

[0086] Comparative Example 15 Based on Example 11, the difference is that the light source emitting device or lighting device is modulated to a dual-color visible light combination with red light and pink light power.

[0087] Comparative Example 16 Based on Example 11, the difference is that the light source emitting device or lighting device is modulated to a dual-color visible light combination with red light + yellow light power.

[0088] Comparative Example 17 Based on Example 11, the difference is that the light source emitting device or lighting device is modulated to a dual-color visible light combination with a power of red light + green light.

[0089] Comparative Example 18 Based on Example 11, the difference is that the light source emitting device or lighting device is modulated to a dual-color visible light combination with a power of pink light + yellow light.

[0090] Comparative Example 19 Based on Example 11, the difference is that the light source emitting device or lighting device is modulated to a dual-color visible light combination with a power of pink light + green light.

[0091] Comparative Example 20 Based on Example 11, the difference is that the light source emitting device or lighting device is modulated to a dual-color visible light combination with a power of green light + yellow light.

[0092] Comparative Example 2 The culture medium inoculated with Candida albicans was placed in the culture space and cultured. The light source or lighting equipment was turned off, and the total number of colonies was determined after culturing at 37°C for 16 hours.

[0093] The structures of Examples 11 to 20 and Comparative Example 2 are shown in Tables 3 and 4. Significant differences exist between the examples and the comparative examples. Overall, the dual-color light combinations based on blue light (i.e., blue-based combinations: blue / pink, blue / yellow, blue / green) exhibited stronger antibacterial effects, with the blue / pink combination showing the most prominent antibacterial effect, confirming that dual-color light irradiation can effectively inhibit the growth of Candida albicans.

[0094] Example 21 Based on any of the above embodiments, this embodiment further preferably uses blue light or a combination of blue light to irradiate Candida albicans in a breeding space that can block external light and is breathable. This can further effectively inhibit the impact of Candida albicans on the growth of pigeons and reduce the interference and impact of external light factors on the antibacterial effect of blue light or a combination of blue light in the breeding space. The breeding space can be further provided with a reflective surface for reflecting visible light. The reflective surface can be a curved structure or a planar structure. A reflective surface with a curved structure or several reflective surfaces with a planar structure are arranged in a circle within the visible light irradiation range, which can cover the irradiation range of blue light or a combination of blue light to the dead corners, achieve full light coverage, and ensure the effective range of light-based antibacterial treatment.

[0095] Table 3:

[0096] Table 4:

[0097] II. Research Results After the culture period ended, the data in Table 1 was processed using Origin software, and the results are as follows: Blank control group (i.e., Comparative Example 2, without light treatment): The colony count in the control group exhibited a typical logarithmic growth trend over time. From 2 to 8 hours, the growth lag phase occurred, with the colony count slowly increasing from 50 to 150, as the bacteria adapted to the culture environment. From 8 to 20 hours, the rapid logarithmic growth phase occurred, with the colony count linearly increasing to over 350, indicating a high-speed proliferation phase. From 20 to 24 hours, a growth plateau phase was reached, with the colony count maintaining a peak of 363±23, showing no downward trend. No antimicrobial stress was applied throughout the process, providing a growth benchmark for all two-color light experimental groups and validating the effectiveness of the experimental system.

[0098] Blue / Red Group (i.e., Example 11) This group exhibited the weakest antibacterial effect among the blue light-based combinations, showing early onset of action, slight fluctuations in the middle stage, and stabilization in the later stage. From 2 to 8 hours, the colony count decreased to approximately 80, indicating a significant antibacterial effect. From 8 to 16 hours, the colony count fluctuated slightly (80-100), with a brief balance between bacterial proliferation and inhibition. From 16 to 24 hours, it stabilized at around 100. The difference in colony count between the 24-hour group and the control group was 131.972, indicating that the synergistic antibacterial effect of blue and red light was weaker than other blue light-based combinations, showing early onset of action but with a slightly weaker inhibitory intensity.

[0099] Blue / Pink group (i.e., Example 12) This combination exhibits the strongest antibacterial effect, demonstrating strong inhibition of colony growth throughout its entire growth cycle without any distinct growth stages. Significant antibacterial effect was observed after 2 hours of light exposure, with only approximately 30 colonies, far lower than the control group at the same time point. From 2 to 24 hours, the colony count showed no significant increase, remaining at an extremely low level of 30-80 colonies, with no lag phase, no logarithmic growth phase, and no plateau phase; the growth curve was almost a horizontal straight line. The difference in colony count between this combination and the control group at 24 hours reached 211.194, indicating the earliest onset of antibacterial effect among all combinations, and the inhibitory effect showed no time decay, achieving complete suppression of Candida albicans growth.

[0100] Blue / Yellow group (i.e., Example 13) The antibacterial effect ranked third, with the following characteristics: rapid onset of action, peak antibacterial effect in the middle stage, and slight rebound in the later stage. From 2 to 6 hours, the colony count decreased from approximately 50 to 30, demonstrating a rapid and significant antibacterial effect; the peak antibacterial period was from 6 to 16 hours, with the colony count remaining at a minimum level of 30-50; from 16 to 24 hours, the colony count slightly rebounded to around 60, without a significant increase. The difference in colony count between the 24-hour group and the control group was 185.583, indicating that a small number of bacteria adapted to the alkaline microenvironment and underwent slight proliferation in the later stage, but overall, a strong antibacterial level was maintained.

[0101] Blue / Green group (i.e., Example 14) The antibacterial effect was moderately strong, with growth characteristics of rapid early inhibition followed by slight stabilization in the later stages. From 2 to 4 hours, the colony count rapidly decreased to approximately 40, demonstrating a rapid onset of the antibacterial effect and reflecting the rapid blocking effect of cell membrane damage on bacterial proliferation. From 4 to 24 hours, the colony count showed a very slow, slight increase, eventually stabilizing at 60-90, with no significant upward trend, and consistently remained far lower than the control group. The difference in colony count between the 24-hour group and the control group was 173.778; the slight increase in colony count in the later stages was only due to the slow growth of a small number of undamaged bacteria, and the overall inhibitory effect remained stable.

[0102] Red / Pink Group (Comparative Example 15) This group exhibited the strongest antibacterial effect among the non-blue light-based combinations, characterized by a slightly delayed onset of action, rapid inhibition in the mid-stage, and a slight rebound in the later stage. From 2 to 10 hours, the colony count was close to the control group (increasing from 60 to 120), showing no significant antibacterial effect, indicating initial bacterial proliferation. From 10 to 16 hours, the colony count rapidly decreased to 80, highlighting the concentrated antibacterial effect. From 16 to 24 hours, it slightly rebounded to around 90. At 24 hours, the colony count difference from the control group was 183.472, close to the blue light-based combination. However, due to the absence of blue light, early bacterial proliferation was not inhibited, and a slight rebound occurred later, indicating a weaker inhibitory effect compared to the blue light-based combination.

[0103] Red / Yellow Group (Comparative Example 16) The antibacterial effect was moderate, with growth characteristics of slow growth throughout, no significant onset of action, and strong inhibitory persistence. From 2 to 24 hours, the colony count showed a consistently slow increasing trend, increasing from 50 to 90, without a significant rapid proliferation phase. The difference in colony count between the combination and the control group gradually widened over time, with the antibacterial effect becoming increasingly significant after 10 hours. The difference in colony count between the combination and the control group at 24 hours was 143.278, indicating that this combination had a sustained inhibitory effect on the proliferation rate of Candida albicans, with the bacteria remaining in a slow growth state throughout, without a significant growth burst phase.

[0104] Red / Green combination (Comparison Example 17) This group exhibited the weakest antibacterial effect among all experimental groups, characterized by continuous growth throughout the entire process with only a slight inhibition of the proliferation rate. The colony count showed a continuous increasing trend from 80 to 250 cells / day from 2 to 24 hours, making it the group with the highest colony count among all experimental groups. There was no obvious point of inhibition throughout the process, with only the colony count growth rate being slightly lower than the control group. The difference in colony count between the 24-hour group and the control group was 89.500, indicating the weakest synergistic antibacterial effect of red and green light, which only slightly slowed bacterial proliferation and could not achieve effective colony count inhibition.

[0105] Pink / Yellow combination (comparison ratio 18) The antibacterial effect was weak, with growth characteristics of rapid proliferation in the early stage, followed by only slowed growth and no decrease in colony count in the later stage. From 2 to 10 hours, the colony count increased rapidly (from 70 to 200), highly consistent with the growth trend of the control group, indicating normal bacterial proliferation. From 10 to 24 hours, the colony count growth slowed down, remaining at 200-220, showing only a slight antibacterial effect. The difference in colony count between the 24-hour group and the control group was 98.056, indicating that this combination could only slow down the proliferation rate of Candida albicans, but could not effectively block bacterial growth, and there was no obvious antibacterial onset stage.

[0106] Pink / Green Group (Comparison Example 19) The antibacterial effect ranked second among non-blue light-based combinations, with growth characteristics of delayed onset, stable inhibition in the mid-term, and no significant rebound. From 2 to 8 hours, the colony count increased synchronously with the control group (from 50 to 130), with no antibacterial effect; from 8 to 14 hours, the colony count rapidly decreased to 70, indicating antibacterial efficacy; from 14 to 24 hours, the colony count remained stable at 70-80, with no significant rebound trend. The difference in colony count between the 24-hour group and the control group was 172.444. Although the onset of action was delayed, bacterial proliferation was completely blocked after mid-term inhibition, demonstrating superior inhibitory stability compared to most non-blue light-based combinations.

[0107] Green / Yellow Group (Comparative Example 20) The antibacterial effect is moderate to weak, characterized by the latest onset of action, significant rebound in the later stages, and poor inhibitory stability. From 2 to 12 hours, the colony count was very close to the control group (increasing from 60 to 180), showing almost no antibacterial effect, with the bacteria completing a large-scale proliferation. From 12 to 18 hours, the colony count decreased to 100, and antibacterial effect became apparent. From 18 to 24 hours, the colony count rebounded significantly to 120, showing a significant upward trend. The difference in colony count between the 24-hour group and the control group was 135,000, indicating that the bacteria easily adapted to the microenvironment of this light combination, with significant proliferation in the later stages. This group exhibited the worst inhibitory stability among non-blue light-based combinations.

[0108] III. Conclusion Experiments were conducted to analyze the inhibitory effects of different dual-color visible light combinations (blue / red, blue / pink, blue / yellow, blue / green, red / pink, red / yellow, red / green, pink / yellow, pink / green, green / yellow) on Candida albicans at different durations (gradual changes from 2 to 24 hours). The results clarified that the blue-based combinations (blue / red, blue / pink, blue / green, blue / yellow) exhibited significant antibacterial activity under short-term irradiation (2-6 hours), demonstrating early onset, sustained inhibition, and no colony resurgence. In contrast, non-blue-based combinations mostly showed delayed onset, later fluctuations, and even colony resurgence, further confirming... This invention demonstrates the core role of blue light in dual-color light antibacterial treatment, showcasing the inhibitory effects of monochromatic light and dual-color light combinations on Candida albicans. It then selects preferred light-based antibacterial schemes such as 10W blue light, 26.5W blue light, blue / green, blue / red, and blue / pink light. These schemes are free from secondary pollution and radiation pollution risks, and are low-cost and easy to operate, making them highly valuable for widespread application. They are particularly suitable for inhibiting the growth of Candida albicans in existing pigeon farming environments, helping to improve the pigeon farming environment and reduce the workload of pigeon keepers.

[0109] The above examples are merely illustrative of the technical content of the present invention to facilitate easier understanding by the reader, but do not imply that the implementation of the present invention is limited to these examples. Any technical extensions or re-creations made based on the present invention are protected by the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A method for inhibiting Candida albicans, characterized in that, The method includes the step of irradiating Candida albicans with visible light during its growth process, wherein the visible light includes blue light, the peak wavelength of the blue light is 440 nm to 465 nm, and the power of the blue light is 22 W to 28 W.

2. The method for inhibiting Candida albicans as described in claim 1, characterized in that, The peak wavelength of the blue light is 450.7 nm to 455.8 nm.

3. The method for inhibiting Candida albicans as described in claim 2, characterized in that, The power of the blue light is 26.5W.

4. The method for inhibiting Candida albicans as described in claim 3, characterized in that, The exposure time of visible light to Candida albicans is not less than 2 hours.

5. The method for inhibiting Candida albicans as described in claim 4, characterized in that, The visible light includes first visible light and second visible light, wherein the first visible light includes blue light, and the second visible light is one of red light, yellow light, green light, and pink light.

6. The method for inhibiting Candida albicans as described in claim 5, characterized in that, The second visible light is powder light.

7. A method for inhibiting Candida albicans as described in claims 1-6, characterized in that, Candida albicans was irradiated with blue light in a well-ventilated breeding space that could block out external light.

8. The method for inhibiting Candida albicans as described in claim 7, characterized in that, The breeding space is provided with a reflective surface for reflecting the visible light, and the reflective surface is arranged to surround the irradiation range of the visible light.

9. An application of monochromatic visible light to inhibit Candida albicans, characterized in that, The visible light mentioned is blue light.

10. An application of using dual-color visible light to inhibit Candida albicans, characterized in that, The visible light includes first visible light and second visible light, wherein the first visible light is blue light and the second visible light is one of red light, yellow light, green light and pink light.

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