Fermentation method and application of lignocellulose-based bacterial cellulose mask

Abstract

The invention belongs to the technical field of beauty products, and discloses a fermentation method and application of a lignocellulose-based bacterial cellulose mask. The fermentation method of the lignocellulose-based bacterial cellulose mask provided by the invention comprises the following steps: S1, inoculating an activated bacterial cellulose-producing strain into a fermentation culture medium with the inoculation amount being greater than or equal to 1.0 * 10 < 6 > CFU / mL, uniformly mixing, putting into a mask mold, and statically culturing for 48-72 hours at the temperature of 25-37 DEG C; s2, soaking the culture obtained in the step 1 in a 0.1-1 mol / L NaOH solution until the culture is white, and then soaking the culture in distilled water until the culture is neutral, so as to obtain the lignocellulose-based bacterial cellulose mask; the volume ratio of the lignocellulose hydrolysate in the fermentation culture medium is greater than or equal to 30%. According to the fermentation method provided by the invention, the mask with a finished product appearance can be directly obtained, the preparation period is remarkably shortened, and the production cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of beauty products and discloses a fermentation method and application of a lignocellulose-based bacterial cellulose facial mask. Background Art

[0002] Bacterial cellulose (BC) is produced by bacteria growing in a liquid sugar matrix. Bacterial cellulose is a natural high molecular polymer formed by glucose connected by β-1,4 glycosidic bonds. It has high chemical purity and does not contain impurities such as hemicellulose and lignin in plant fibers. In addition, bacterial cellulose has the advantages of biodegradability, high water retention, good biocompatibility, water permeability, high elastic modulus and tensile strength. Therefore, bacterial cellulose is an ideal facial mask material.

[0003] In the prior art, bacterial cellulose is prepared by fermentation, mostly using glucose and sucrose as carbon sources, which has the problems of high cost and long fermentation time. At the same time, the performance of the prepared bacterial cellulose-based facial mask needs to be improved. Summary of the invention

[0004] In view of these defects, the present invention provides a fermentation method and application of a lignocellulose-based bacterial cellulose mask. The method is simple to operate, low in cost, and short in time, and is suitable for large-scale production of bacterial cellulose masks. The bacterial cellulose film obtained by fermentation using this method has better water retention and mechanical properties, can load skin care active ingredients, and can improve the mask experience and efficacy.

[0005] To achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for preparing a lignocellulose-based bacterial cellulose facial mask, comprising the following steps: S1: Inoculate the activated bacterial cellulose-producing strain into the fermentation medium with an inoculation volume of ≥1×10 6 CFU / mL, mix well and place in a mask mold, temperature 25-37℃, static culture for 48-72 h; S2: Soak the culture obtained in step 1 in a 0.1-1 mol / L NaOH solution until it turns white, and then soak it in distilled water until it turns neutral to obtain a lignocellulose-based bacterial cellulose mask.

[0006] The volume proportion of lignocellulose hydrolysate in the fermentation medium is ≥30%.

[0007] The lignocellulose hydrolyzate described in the present invention is a liquid obtained by subjecting the lignocellulose raw material to the steps of pretreatment, enzymatic cellulose hydrolysis, solid-liquid separation and the like.

[0008] The present invention uses lignocellulose hydrolyzate as a carbon source to produce a lignocellulose-based bacterial cellulose facial mask, and directly obtains a facial mask with a finished product appearance through fermentation without cutting. The preparation method is simple in process, suitable for industrial production, can reduce production costs, and improve product cost performance. The obtained lignocellulose-based bacterial cellulose facial mask has excellent moisturizing properties and repair functions, can keep the skin moist for a long time, and slow down skin aging. Its good fit and flexibility make it an ideal skin care substrate, which can be used to load various skin care active substances.

[0009] The bacterial cellulose producing strains used in the present invention include, but are not limited to, strains of the genus xylogluconicacetobacter and the genus gluconoacetobacter.

[0010] Preferably, the bacterial cellulose producing strain in step 1 is Gluconobacter xylinacetoacetate ( Komagataeibacter xylinus ), inoculation amount ≥1.0×10 7 CFU / mL.

[0011] Gluconobacter xylinacetobacter is a Gram-negative bacterium with good safety to the human body. It is one of the main strains for bacterial cellulose (BC) production and has a high BC synthesis ability. The BC synthesized by it has excellent mechanical properties and structural characteristics.

[0012] More preferably, in step 1, the pH value of the fermentation medium is 5.5-6.0, and the temperature is 28-30°C.

[0013] Preferably, the components of the fermentation medium in step 1 further include yeast powder, peptone and disodium hydrogen phosphate dodecahydrate.

[0014] More preferably, the fermentation medium consists of the following ingredients: 7.5 g / L yeast powder, 10 g / L peptone, 10 g / L disodium hydrogen phosphate dodecahydrate, 33.3%-50% by volume of lignocellulose hydrolyzate, and a pH value of 6.0.

[0015] Preferably, the bacterial cellulose-producing strain is activated before step 1, and the activation is performed 1-3 times; the seed culture medium for activation consists of the following ingredients: 25 g / L glucose, 7.5 g / L yeast powder, 10 g / L peptone, and 10 g / L disodium hydrogen phosphate dodecahydrate.

[0016] Preferably, step 2 further includes the steps of removing residual bacteria, sterilizing, and regulating moisture content.

[0017] Preferably, step 2 further includes the step of adding skin care active substances.

[0018] The skin care active substances include, but are not limited to, antioxidant, moisturizing, and whitening skin care active substances.

[0019] More preferably, the skin care active ingredient is Centella asiatica extract; the adding method is: placing the lignocellulose-based bacterial cellulose facial mask in a Centella asiatica extract solution for immersion treatment to obtain a finished lignocellulose-based bacterial cellulose facial mask.

[0020] Centella asiatica is a perennial herb with excellent effects on the skin, such as anti-inflammatory, antioxidant, and improving skin barrier hydration. Studies have shown that an in vivo test formula containing 5% Centella asiatica extract has a good effect in improving skin moisture by enhancing skin barrier hydration and reducing transepidermal water loss.

[0021] In a second aspect, the present invention also provides a lignocellulose-based bacterial cellulose facial mask prepared according to the above method.

[0022] The cellulose-based bacterial cellulose mask prepared by fermenting cellulose hydrolysate with xylindoleacetobacter has a crystallinity of 80.3%, which is a typical type I cellulose. Compared with traditional bacterial cellulose masks, it is more comfortable and fits better, and has better moisture permeability, liquid absorption, water retention and mechanical properties.

[0023] In a third aspect, the present invention also provides the use of the above-mentioned lignocellulose-based bacterial cellulose facial mask in the preparation of a patch-type facial mask.

[0024] Lignocellulose-based bacterial cellulose membranes are ideal for patch-type facial masks due to their three-dimensional nano-network structure, high water holding capacity (60-700 times the dry weight of water) and breathability. The prepared facial masks can be used for daily skin care, such as hydration and anti-wrinkle, as well as medical beauty and postoperative repair, such as burn care and wound repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A lignocellulose-based bacterial cellulose facial mask was prepared according to Example 1 of the present invention; Figure 2 Scanning electron microscope (SEM) photos of the BC mask in the verification example of the present invention (A is LH-BC mask; B is HS-BC mask); Figure 3 Fourier transform infrared spectrum of BC facial mask in the verification example of the present invention; Figure 4 XRD test diagram of the sample of BC mask in the verification example of the present invention; Figure 5 The elongation at break of the BC mask in the verification example of the present invention; Figure 6 The elastic modulus of the BC mask in the verification example of the present invention; Figure 7 The tensile strength of the BC mask in the verification example of the present invention; Figure 8 Transparency test of BC mask in the verification example of the present invention; Fig. 9 The bending performance and stiffness test of the BC mask in the verification example of the present invention; Fig.10 Water vapor transmission rate test of BC mask in the verification example of the present invention; Fig.11 Liquid absorption performance test of BC facial mask in the verification example of the present invention; Fig.12 The water retention performance test of the BC mask in the verification example of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The test materials used in the present invention are all common commercial products and can be purchased in the market.

[0029] The strains used in the embodiments of the present invention are: Komagataeibacter xylinus CGMCC No. 27300 was deposited in the General Microbiology Center of China Culture Collection Administration on May 9, 2023. The strain deposit number is CGMCCNO.27300, and the deposit address is No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing.

[0030] The culture medium used in the embodiments of the present invention is: Seed culture medium: 25 g / L glucose, 7.5 g / L yeast powder, 10 g / L peptone, 10 g / L disodium hydrogen phosphate dodecahydrate, sterilized at 115°C for 30 min.

[0031] The preparation method of the lignocellulose hydrolyzate used in the embodiments of the present invention is as follows: Corncob residue was used as substrate and cellulase was used for enzymatic hydrolysis at a cellulase dosage of 20 FPU / g. The obtained lignocellulose hydrolysate contained 18.8 g / L of total sugar, including 11.6 g / L of glucose and 7.2 g / L of xylose.

[0032] Centella asiatica extract was purchased from Shaanxi Tianen Biotechnology Co., Ltd.

[0033] The determination method involved in the embodiments of the present invention is: Moisturizing rate test method: stick a medical transparent tape on a glass slide and weigh it, put a 5% Centella asiatica extract-loaded lignocellulose-based bacterial cellulose mask on the tape, leave it at room temperature for 15 minutes, then remove the mask, weigh it at 5, 10, 15, 20, 30, and 60 minutes, and calculate the moisturizing rate at each time. The moisturizing rate calculation formula is as follows: Moisture retention rate (%) = [(M 1 -M 0 ) / (MM 0 )]×100%; M 0 is the mass of the glass slide (skin simulation device) with medical transparent tape, g; M is the mass of the skin simulation device after the mask is removed 15 min after applying the mask, g; M 1 The mass of the device after removing the mask for 5, 10, 15, 20, 30, and 60 min, g.

[0034] Antioxidant test method: Soak the lignocellulose-based bacterial cellulose mask loaded with 5% Centella asiatica extract in PBS solution for 30 min to prepare the sample solution, dilute 1.5 mg DPPH with 95% ethanol in a 50 mL volumetric flask, take 2 mL of the sample solution and DPPH solution respectively, mix them, take 2 mL of the sample solution and 95% ethanol solution respectively, take 2 mL of the 95% ethanol solution and DPPH solution respectively, mix them, and then stand in the dark for 30 min, and use a UV-visible spectrophotometer to measure the absorbance at 517 nm. The formula is as follows: DPPH removal rate (%) = [1-(As-Ar) / Ao] × 100; As: absorbance of the mixed solution of sample solution and DPPH solution; Ar: absorbance of the mixed solution of sample solution and 95% ethanol; Ao: absorbance of the mixed solution of DPPH solution and 95% ethanol.

[0035] Example 1 This embodiment provides a fermentation method of a lignocellulose-based bacterial cellulose facial mask and a lignocellulose-based bacterial cellulose facial mask, which specifically consist of the following steps.

[0036] (1) Activation of bacterial strains: 100 μL of Glucose Acetobacter xylinum was pipetted from the glycerol tube into 10 mL of seed culture medium and cultured at 30°C for 1 day to obtain the primary seed solution. 1 mL of the primary seed solution was pipetted from the test tube and inoculated into a conical flask containing 30 mL of seed culture medium and cultured at 30°C for 1 day to obtain the secondary seed solution.

[0037] (2) Fermentation culture: The secondary seed liquid was inoculated into the fermentation medium. The bacterial concentration in the fermentation medium was 3×10 7 CFU / mL, mixed and poured into the mask mold, cultured in a constant temperature incubator at 30°C for 48 h, and after fermentation, the mask was purified by soaking in 1 mol / LNaOH solution to white, and then washed with distilled water to neutral to obtain a lignocellulose-based bacterial cellulose mask, such as Figure 1 The fermentation medium used was prepared as follows: 50 mL of lignocellulose hydrolysate was taken, the pH was adjusted to 5.5, and then sterilized at 115°C for 30 min; 0.75 g of yeast powder, 1 g of peptone, and 1 g of disodium hydrogen phosphate dodecahydrate were dissolved in distilled water and the volume was adjusted to 50 mL, the pH was adjusted to 5.5, and after sterilization at 115°C for 30 min, the mixture was mixed with the lignocellulose hydrolysate at a ratio of 1:1 to obtain the fermentation medium.

[0038] Comparative Example 1 This comparative example provides a bacterial cellulose facial mask. The fermentation method is basically the same as that in Example 1, except that the fermentation medium used is HS medium, and its components are: 25 g / L glucose, 7.5 g / L yeast powder, 1 g / L peptone, and 1 g / L disodium hydrogen phosphate dodecahydrate.

[0039] Verification example: Characterization and performance testing of lignocellulose-based bacterial cellulose facial mask The structures and properties of the lignocellulose-based bacterial cellulose mask (LH-BC mask) obtained in Comparative Example 1 and the bacterial cellulose mask (HS-BC mask) obtained in Comparative Example 1 were measured.

[0040] 1. Scanning electron microscopy (SEM) analysis The LH-BC mask and HS-BC mask were scanned by scanning electron microscope (SEM). The LH-BC mask and HS-BC mask were dried in an oven at 105°C to constant weight (water content close to 0), and 0.3 cm × 0.3 cm samples were cut and pasted on conductive adhesive, placed in a vacuum coating machine and sprayed with gold for 1 min, and then tested at a voltage of 5 kV; Figure 2 shown.

[0041] Depend on Figure 2It can be seen that the LH-BC mask has a higher porosity than the HS-BC mask. Larger pores can hold more water, allowing the mask to absorb more essence, and release water more slowly during use, extending the moisturizing time of the mask, allowing the skin to fully absorb nutrients and maintain a hydrated state. The base material of the BC mask with a large porosity is usually more flexible, can better fit the facial contour, adapt to different face shapes and facial curves, make the mask in close contact with the skin, promote the absorption of essence, and also avoid the problem of the mask falling off easily during use.

[0042] 2. Fourier transform infrared spectroscopy (FTIR) analysis The infrared spectroscopic analysis of LH-BC mask and HS-BC mask was performed using the KBr tablet method, with a scanning range of 400-4000cm -1 , resolution 4 cm -1 The infrared spectrum of BC mask is as follows: Figure 3 shown.

[0043] Depend on Figure 3 It can be seen that both HS-BC and LH-BC show the typical peaks of cellulose materials at 3341 cm -1 The characteristic absorption peak at 2894 cm is the stretching vibration of -OH; -1 The absorption peak near 1056 cm is caused by the stretching vibration of the CH bond; -1 is the stretching peak of the COC bond; 890 cm -1 The nearby absorption peak is the characteristic peak of β-1,4-glycosidic bond, which indicates that the LH-BC mask prepared in this study is pure cellulose.

[0044] 3. X-ray diffraction (XRD) analysis X-ray diffraction (XRD) analysis was performed on the LH-BC mask and HS-BC mask. After the LH-BC mask and HS-BC mask were fully dried, an appropriate amount of ground powder was placed on a sample plate, with a Cu target, 40 kV high voltage, and a tube current of 40 mA. The crystallinity (CI) was calculated using Jade 6.5 software according to the following formula: CI(%)=( I 002 - I am ) / I 002 ; Where: I am is the diffraction peak intensity at 2θ=18°; I 002 is the highest intensity of lattice diffraction.

[0045] like Figure 4As shown in the figure, LH-BC and HS-BC have the same diffraction peaks at 2θ values ​​of 14.8° and 16.7°, corresponding to (100), (010), and (110) Iα crystal planes, respectively, confirming that the crystal structure of the bacterial cellulose membrane produced is type I cellulose, and indicating that the crystal structure of the BC mask produced by fermentation of lignocellulose hydrolysate is consistent with that of the BC mask produced by fermentation of HS medium and the commercially available BC mask. Among them, the crystal peaks at 2θ=14.8° and 2θ=22.6° are its characteristic diffraction peaks; the peak at 2θ=16.7° is the non-crystallization peak of the amorphous region. The crystallinity of LH-BC is 80.3%, and that of HS-BC is 73.4%, which indicates that they both have a high degree of crystallinity, which can ensure that they have a certain strength and stability. The higher degree of crystallinity will make it less likely to deform or break, and can better maintain its original size and shape when the environment such as temperature and humidity changes, and have better stability. When used as a mask base material, it is not easy to over-expand or shrink due to absorption of moisture or external factors, and can always maintain the appropriate size and shape to better fit the skin.

[0046] 4. Mechanical properties analysis Referring to GB / T 1040.3-2006, a universal tensile machine was used to measure the mechanical properties of LH-BC mask and HS-BC mask, and the tensile strength (σt), elongation at break (e) and elastic modulus (E) were calculated to characterize the mechanical properties of LH-BC mask and HS-BC mask. Figure 5-7 shown.

[0047] The tensile strength of LH-BC mask and HS-BC mask were 112.66±10.10 Mpa and 110.65±13.40 Mpa, respectively, and the elastic modulus was 4.14±0.62 Gpa and 3.96±0.59 Gpa, respectively; the elongation at break was 2.40±0.43 (%) and 2.20±0.23 (%), respectively. The tensile strength and elastic modulus of LH-BC mask were slightly higher than those of HS-BC mask. This is because LH-BC mask has higher crystallinity and is not easily deformed or displaced when pulled. Therefore, LH-BC mask has better tensile resistance than HS-BC mask.

[0048] 5. Transparency Analysis The transparency of LH-BC mask and HS-BC mask when applied on the human face was evaluated by UV-visible near-infrared spectrophotometer (integrating sphere). Figure 8 The purpose of measuring transparency is to compare the transparent feeling of the mask on the face when using the mask. The results show that the bacterial cellulose mask produced by fermentation of wood cellulose hydrolysate has better transparency.

[0049] Bending performance and stiffness The bending performance and stiffness of LH-BC mask and HS-BC mask were evaluated by stiffness instrument. The results are as follows Fig. 9 The purpose of measuring the bending performance and stiffness is to compare the comfort and fit of the mask on the face when using the mask. The results show that the bacterial cellulose mask produced by fermentation of lignocellulose hydrolysate has a higher bending stiffness, can better carry the essence and maintain a certain shape and strength, and will not be excessively deformed or drooped due to the weight of the essence.

[0050] 7. Water vapor transmission rate test Cut the LH-BC mask and HS-BC mask into pieces of about 10 cm each. 2 The water vapor transmission rate of the circular membrane was tested according to GB 1037-1988. Each sample was tested 3 times. The water vapor transmission rate ( W ) is calculated using the following formula: W = (24 × ∆m) / (A × t); Where: W is the water vapor transmission rate, g / (m 2 ·24 h); t is the interval between two times after the mass increment stabilizes, h; ∆m is the mass increment within t time, g; A is the water vapor permeability area of ​​the sample, m 2 .

[0051] The results are as follows Fig.10 As shown. Moisture permeability refers to the diffusion of water vapor from the side with higher humidity to the side with lower humidity when there is a humidity difference on both sides of the material. The moisture permeability of the mask is generally evaluated by the amount of water vapor permeation. From the results, it can be seen that the moisture permeability of the LH-BC mask is better than that of the HS-BC mask, which helps to maintain the oxygen supply on the skin surface, enables skin cells to metabolize better, promotes waste discharge and nutrient absorption, and thus maintains the health of the skin.

[0052] 8. Liquid absorption performance The LH-BC mask and HS-BC mask were cut into samples of about 100 mm × 100 mm in size, and their liquid absorption performance was tested according to GB / T24218.6-2010. Each sample was tested 3 times, soaked for 8 hours, and the liquid absorption rate was measured every half an hour from the beginning of soaking. The liquid absorption rate (LAC) was calculated using the following formula: LAC(%)=(m2-m1) / (m1)×100; Where: m1 is the mass of the sample before immersion, g; m2 is the mass of the sample after absorbing liquid, g.

[0053] The results are as follows Fig.11The liquid absorption rate is used to characterize the liquid absorption performance of the mask substrate. The results show that the liquid absorption performance of the LH-BC mask is better than that of the HS-BC mask, which indicates that LH-BC can carry more essence while evaporating less, achieving a longer care time and better skin care effect.

[0054] 9. Water retention performance LH-BC mask and HS-BC mask were cut into samples of about 5 cm × 5 cm to test their water retention performance. The cut masks were soaked in deionized water for 30 min to fully absorb water, taken out and gently squeezed until they were saturated and dripping, and placed in a constant temperature and humidity incubator at 25°C and 40% relative humidity. The moisture content was calculated after weighing at different times. The moisture content (w) was calculated using the following formula: W(%)=(m n -m 1 ) / (m 2 -m 1 )×100; Where: m 1 is the mass before immersion, g; m 2 is the mass before being placed in the incubator, g; m n is the mass of the mask at time n.

[0055] The results are as follows Fig.12 The water content is used to characterize the water retention performance of the mask substrate. The results show that within 20 minutes, the water retention performance of the LH-BC mask is better than that of the HS-BC mask, and the water loss rate is slower. When applied to the skin, it can form a moisturizing film to reduce the evaporation of water on the skin surface. At 30 minutes, the water content of both is greater than 80%, and the mask is generally used for 20-30 minutes, which proves its good water retention potential.

[0056] Example 2 This embodiment provides a fermentation method for a lignocellulose-based bacterial cellulose facial mask, which specifically consists of the following steps.

[0057] (1) Activation of bacterial strains: 100 μL of Glucose Acetobacter xylinum was pipetted from the glycerol tube into 10 mL of seed culture medium and cultured at 30°C for 1 day to obtain the primary seed solution. 1 mL of the primary seed solution was pipetted from the test tube and inoculated into a conical flask containing 30 mL of seed culture medium and cultured at 30°C for 1 day to obtain the secondary seed solution.

[0058] (2) Fermentation culture: The secondary seed liquid was inoculated into the fermentation medium. The bacterial concentration in the fermentation medium was 3×10 7CFU / mL, mix well and pour into the mask mold, and culture in a constant temperature incubator at 30℃ for 48 h; after the fermentation is completed, the mask is taken out of the mold and then placed in 0.1 mol / L NaOH solution and placed in a 100℃ water bath for 15 min to remove the residual culture medium and residual bacteria, and then washed with distilled water until neutral to obtain a lignocellulose-based bacterial cellulose mask.

[0059] Preparation of the fermentation medium used: take 50 mL of lignocellulose hydrolysate, adjust the pH to 5.5, and then sterilize at 115°C for 30 min; take 0.75 g of yeast powder, 1 g of peptone and 1 g of disodium hydrogen phosphate dodecahydrate, dissolve them in distilled water and make up to 50 mL, adjust the pH to 5.5, sterilize at 115°C for 30 min, and mix with the lignocellulose hydrolysate in a 1:1 ratio to obtain the fermentation medium.

[0060] (3) After the lignocellulose-based bacterial cellulose facial mask is sterilized by ultraviolet radiation, it is pressed to a moisture content of 50% by a pressing method to obtain a lignocellulose-based bacterial cellulose facial mask with a moisture content of 50% for use.

[0061] (4) Dissolve 10 g of Centella asiatica extract in distilled water and make up to 200 mL. Filter the solution through a 0.22 μm water filter membrane using a syringe.

[0062] (5) The sterilized 5% Centella asiatica extract solution was added to a lignocellulose-based bacterial cellulose mask with a water content of 50%, and the mixture was incubated in an oscillating incubator at 30°C for 12 h to obtain a lignocellulose-based bacterial cellulose mask loaded with 5% Centella asiatica extract.

[0063] After testing, the moisturizing rate of the obtained lignocellulose-based bacterial cellulose mask containing 5% Centella asiatica extract was 63%, and the DPPH free radical scavenging rate was 17%.

[0064] Example 3 This embodiment provides a fermentation method for a lignocellulose-based bacterial cellulose facial mask, which specifically consists of the following steps.

[0065] (1) Activation of bacterial strains: 100 μL of Glucose Acetobacter xylinum was pipetted from the glycerol tube into 10 mL of seed culture medium and cultured at 30°C for 1 day to obtain the primary seed solution. 1 mL of the primary seed solution was pipetted from the test tube and inoculated into a conical flask containing 30 mL of seed culture medium and cultured at 30°C for 1 day to obtain the secondary seed solution.

[0066] (2) Fermentation culture: The secondary seed liquid was inoculated into the fermentation medium. The bacterial concentration in the fermentation medium was 1.6×10 7CFU / mL, mix well and pour into the mask mold, culture in a constant temperature incubator at 28℃ for 72 h, and immerse the mask in 1 mol / LNaOH solution to purify it to white after fermentation, and then wash it with distilled water until it is neutral to obtain a lignocellulose-based bacterial cellulose mask. The fermentation medium used was prepared as follows: 40 mL of lignocellulose hydrolysate was taken, the pH was adjusted to 6, and then sterilized at 115℃ for 30 min; 0.9 g of yeast powder, 1.2 g of peptone and 1.2 g of sodium hydrogen phosphate dodecahydrate were dissolved in distilled water and fixed to 80 mL, the pH was adjusted to 6, and after sterilization at 115℃ for 30 min, it was mixed with lignocellulose hydrolysate at a ratio of 2:1 to obtain a fermentation medium.

[0067] (3) After the lignocellulose-based bacterial cellulose facial mask is sterilized by ultraviolet radiation, it is pressed to a moisture content of 50% by a pressing method to obtain a lignocellulose-based bacterial cellulose facial mask with a moisture content of 50% for use.

[0068] (4) Dissolve 10 g of Centella asiatica extract in distilled water and make up to 200 mL. Filter the solution through a 0.22 μm water filter membrane using a syringe.

[0069] (5) The sterilized 5% Centella asiatica extract solution was added to a lignocellulose-based bacterial cellulose mask with a water content of 50%, and the mixture was incubated in an oscillating incubator at 30°C for 12 h to obtain a lignocellulose-based bacterial cellulose mask loaded with 5% Centella asiatica extract.

[0070] After testing, the moisturizing rate of the obtained lignocellulose-based bacterial cellulose mask containing 5% Centella asiatica extract was 63%, and the DPPH free radical scavenging rate was 17%.

[0071] In summary, the method provided by the present invention utilizes lignocellulose hydrolyzate to replace the traditional carbon source for strain fermentation to produce lignocellulose-based bacterial cellulose facial mask, which can directly obtain a facial mask with a finished product appearance, significantly reducing the production cost and shortening the preparation cycle. The prepared facial mask has high crystallinity and belongs to typical type I cellulose, with excellent moisture permeability, liquid absorption, water retention and mechanical properties, and improves the comfort of use.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fermentation method for a lignocellulose-based bacterial cellulose facial mask, characterized in that: The following steps are involved: S1: Inoculate the activated bacterial cellulose-producing strain into the fermentation medium with an inoculation volume of ≥1.0×10 6 CFU / mL, mix well and place in a mask mold, temperature 25-37℃, static culture for 48-72 h; S2: Soak the culture obtained in step 1 in a 0.1-1 mol / L NaOH solution until it turns white, and then soak it in distilled water until it turns neutral to obtain a lignocellulose-based bacterial cellulose mask; The volume proportion of lignocellulose hydrolysate in the fermentation medium is ≥30%.

2. The fermentation method according to claim 1, characterized in that The bacterial cellulose producing strain in step 1 is Gluconobacter xylinacetoacetate ( Komagataeibacter xylinus ), inoculation amount ≥1.0×10 7 CFU / mL.

3. The fermentation method according to claim 2, characterized in that In step 1, the pH value of the fermentation medium is 5.5-6.0, and the temperature is 28-30°C.

4. The fermentation method according to claim 1 or 3, characterized in that The components of the fermentation medium in step 1 also include yeast powder, peptone and disodium hydrogen phosphate dodecahydrate.

5. The fermentation method according to claim 4, characterized in that The fermentation medium is composed of the following ingredients: 7.5 g / L yeast powder, 10 g / L peptone, 10 g / L disodium hydrogen phosphate dodecahydrate, 33.3%-50% by volume of lignocellulose hydrolyzate, and a pH value of 6.

0.

6. The fermentation method according to claim 1, characterized in that Before step 1, the bacterial cellulose-producing strain is activated for 1-3 times; the activation seed culture medium is composed of the following ingredients: 25 g / L glucose, 7.5 g / L yeast powder, 10 g / L peptone, and 10 g / L disodium hydrogen phosphate dodecahydrate.

7. The fermentation method according to claim 1, characterized in that The step 2 further includes the steps of removing residual bacteria, sterilizing, and regulating the moisture content; and / or The step 2 further includes a step of adding skin care active substances.

8. The fermentation method according to claim 7, characterized in that The skin care active ingredient is Centella asiatica extract; the adding method is: placing the lignocellulose-based bacterial cellulose facial mask in a Centella asiatica extract solution for immersion treatment to obtain a finished lignocellulose-based bacterial cellulose facial mask.

9. A lignocellulose-based bacterial cellulose facial mask prepared according to the method of any one of claims 1 to 8.

10. Use of the lignocellulose-based bacterial cellulose facial mask according to claim 9 in the preparation of a patch-type facial mask.

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