Optimised production of blue pigments by streptomyces using potato waste as a base substrate

Abstract

The present invention relates to a method for the optimised and sustainable production of pigments produced by microbial agents from potato waste. In particular, the invention relates to an optimised and sustainable method for fermentation in liquid state for the improved production of blue pigments produced by Streptomyces actinobacteria cultured in potato waste, and to the use of same.

Description

[0001] OPTIMIZED PRODUCTION OF BLUE PIGMENTS BY STREPTOMYCES USING POTATO WASTE AS A BASAL SUBSTRATE DESCRIPTIVE MEMORANDUM FIELD OF THE INVENTION

[0002] The present invention relates to the biotechnology industry. In particular, the present invention relates to an optimized production process for pigments produced by microbial agents.

[0003] In particular, the present invention relates to an optimized method for the production of pigments produced by microbial agents from potato waste. Specifically, the invention relates to an optimized and sustainable liquid-state fermentation method for the improved production of blue pigments produced by the Streptomyces bacteria cultivated on potato waste. This proposed method allows for the optimization of blue pigment production, either with respect to the same base material without an optimized method or to what is reported in the prior art; and its use.

[0004] BACKGROUND OF THE INVENTION

[0005] Currently, there is widespread use of inexpensive synthetic pigments, which has led to health problems for people and negative environmental impacts. This has resulted in the banning of many artificial colorants and a resurgence in demand for natural pigments, as these exhibit better biodegradability and, in general, greater environmental compatibility.

[0006] INDUSTRIAL DYES

[0007] In various industrial sectors, synthetic dyes derived from petroleum-based precursors (a non-renewable resource) are used, with only nine synthetic color additives permitted by the FDA. The limited number of permitted synthetic dyes is due to strict restrictions imposed following reports of risks to human health and behavior (Olas et al., 2021). According to Denish et al. (2021), blue dyes are very rare in nature, being actually red and purple. The two commercially available artificial blue dyes are Blue #1 and Blue #2, which produce cyan (Amax = 630 nm) and indigo (Amax = 608 nm) tones, respectively.

[0008] BLUE MICROBIAL DYES: SOURCES, TYPES, STABILITY AND PURIFICATION PROCESSES.

[0009] The stability of natural blue pigments, coupled with production yield and cost, are the main barriers to entering the dye market. Dye production by bacteria has comparative advantages over fungi and microalgae. Bacteria exhibit rapid growth compared to fungi and can produce pigments extracellularly, avoiding cell rupture and the consequent release of impurities (intracellular), as occurs with microalgae, which also require photobioreactors, increasing energy costs. Examples of blue dyes of microbial origin include:

[0010] Phycocyanin: Food-grade phycocyanin is produced from the cyanobacterium Spirulina platensis, cultivated in a seawater-based medium and purified by ammonium sulfate precipitation. In terms of stability, the optimum pH range is 5.0 to 6.0. However, its stability in solution is highly temperature-dependent, remaining stable at temperatures up to 45 °C for short periods. Constant exposure to light at 100 pmol rrr 2 s -1 During 36 h the concentration of phycocyanin also decreases to 78.4% (Wu et al., 2016).

[0011] Indigoidin: can be obtained from bacteria of the genera Erwinia, Streptomyces, and Photorhabdus, among others (Santos and Bicas, 2021). The low production yield of this pigment from microbial strains has led to the study of genetic recombination, which has allowed yields of ~2 g L⁻¹ to be obtained. 1in cultures in shake flasks and ~26 g L' 1 in fed-batch cultures (Banerjee et al., 2020). Reported extraction and purification methods indicate the use of dimethyl sulfoxide (DMSO), as it is insoluble in most aqueous solutions and organic solvents.

[0012] Actinorrhodin: the actinobacterium Streptomyces coelicolores is the most reported producing species, with yields of ~3 g L' 1 Zhang et al. (2006) indicated that it is possible to obtain the dye by dissolving it in alkaline water and a number of commonly used organic solvents. The color of the aqueous solution of the pigment varies with the pH value, it is stable to light, heat, and commonly used food additives, and is non-toxic with an LD50 > 15,000 mq / kq. 1(acute toxicity test) (Zhang et al., 2006). The characteristics of the dye make it potentially useful in the food processing industry as an additive and a safe ingredient for cosmetics. However, despite the studies carried out to date, there is no commercially available method for use such as the one proposed here.

[0013] Other sources: Bacteria such as Collimonas CT have been reported to produce violacein through the acquisition of a gene for this pigment, and glaucotalin is produced by Rheinheimera sp. (Chatragadda and Dufossé, 2021). Over the last few decades, several dyes have been isolated from little-explored marine sources, such as purpurone from a marine sponge and ammosamide A from Streptomyces CNR-698, which provide purple and blue pigments but are toxic for use as food additives (Newsome et al., 2013). An interesting study was reported by Venil et al. (2015) on the production of violet pigments by Chromobacterium violaceum and their applications in the food industry, which reported the use of spray drying. OPTIMIZATION OF PRODUCTION PROCESSES.

[0014] To improve yields, it is necessary to optimize production processes, which also results in less process variability, more accurate confirmation of the output response to nominal and target requirements, and a reduction in development time and process costs (Elibol, 2004). The synthesis of microbial dyes can be improved by selecting a suitable fermentation process and optimizing parameters such as temperature, agitation, pH, and substrate, among others. pH has a particular influence not only on the production rate of some dyes but also on the profile of the resulting dyes (De Oliveira et al., 2019). Supplementation with different carbon and nitrogen sources and salinity adjustment are also factors that influence dye production.However, it has been determined that phosphate and glutamate (a nitrogen source) can negatively control actinorhodin formation, while starch has been shown to be favorable for its production, even in excess (Doull and Vining, 1990). Therefore, starch-rich waste products represent an interesting alternative for the efficient and sustainable production of actinorhodin. It is estimated that optimizing the culture medium can lead to a 32% increase in actinorhodin compared to a non-optimized medium, reaching 195 mg L⁻¹. 1 of actinorrhodin (Elibol, 2004). However, the optimized process reported by Elibol (2004) becomes unfeasible when considering the pigment yield in relation to the cost associated with the culture medium under optimized conditions (339 g L 1 of sucrose, 1 g L 1 of glucose, 1.95 g / L 1 of yeast extract and 2.72 g L' 1 of peptone).

[0015] SUSTAINABLE PRODUCTION OF DYES

[0016] The components of the culture medium are one of the main factors influencing the production cost of microbial dyes, estimated to account for between 38% and 73% of the total production cost (Panesar et al., 2015). An alternative is the use of agro-industrial waste as a substrate in fermentation processes and the production of microbial products (reports in Table 1), which represents a reduction in the adverse environmental impact associated with the industrial production of dyes.

[0017]

[0018] While the genus Streptomyces has already been studied for its production of the blue pigment actinorhodine, to date there are no scientific reports indicating that Streptomyces spp. can produce the pigment using waste as a growth medium. This presents an advantage for the development of a novel, sustainable product for the industry. The Food and Agriculture Organization of the United Nations (FAO) has reported that 250 million tons of agro-industrial waste are generated globally each year, requiring a sustainable strategy to reduce its environmental impact. Using this waste as raw material positively affects environmental and socioeconomic aspects, generating not only additional income for farmers but also profitable, high-value-added bioproducts (Ghaffar, 2020).In Chile, agricultural waste requires valorization strategies to reduce the carbon footprint associated with its production and final disposal, as well as its integration into circular economy models. One such waste is discarded potatoes, which have a high starch content and therefore high potential for formulating culture media for microorganisms. It is estimated that 30% of total potato production is unsuitable for consumption or seed and is either discarded or used at very low cost for animal feed (Torres et al., 2020). Based on this percentage and information provided by ODEPA regarding potato production for the 2020 / 2021 agricultural year, it is estimated that the amount of potatoes unsuitable for consumption nationwide is 298,352 tons, and in the La Araucanía region, 74,413 tons.

[0019] PRODUCTION COST STUDY

[0020] The cost of traditional culture media can vary considerably depending on the nutrient composition and the quantity required for pigment production. In the case of blue pigment production from the actinorhodin group, it has been reported that the medium composition can significantly influence yield and that the cost of the medium is a factor to consider when optimizing the production process. There are wide differences in the reported costs of culture media for the production of actinorhodin group pigments (Table 2).

[0021] Table 2. Estimated cost of culture media reported for the fermentation process of Streptomyces spp. for the production of blue pigments of the actinorhodin group.

[0022]

[0023] *Does not include energy and equipment costs for dehydration.

[0024] For the calculations of the cost of the culture media reported, the prices reported for each reagent (for microbiology or for analysis as appropriate) by the Merck KGaA website were used as a reference (Table 3).

[0025]

[0026] Table 3. Reagent values ​​used as a reference for estimating the cost of culture media reported for the fermentation process

[0027]

[0028]

[0029]

[0030] In the case of discarded potatoes, the average weighted monthly price of potatoes in Chilean wholesale markets in March 2024, as reported by the Potato Bulletin (ODEPA, 2024), was CLP $9,600 per 25 kg green weight sack (USD $9.94 at the exchange rate on March 1, 2024 - CLP $966 per dollar). Discarded potatoes are a waste product, which are incinerated to prevent the spread of disease or, in the best-case scenario, sold for animal feed at an approximate cost of USD $1 per 25 kg sack. Therefore, if we consider assigning a value to them as a byproduct of the potato production and processing industry, at 25% of the value of potatoes for consumption, we can estimate a cost of USD $2.49 per 25 kg green weight sack. Given that green potatoes contain approximately 80% moisture, it is possible to obtain 5 kg of potato powder from a 25 kg sack of green potatoes.As mentioned above, 16 g L are required for the preparation of culture media based on discarded potatoes. 1 of discarded potato powder, so the cost of 1 L of culture medium based on the substrate would be estimated at USD$0.008.

[0031] STATE OF THE ART

[0032] In this regard, the state of the art has yielded various solutions that partially resolve the technical problem posed.

[0033] Regarding disclosures about using potato waste in culture media, publications by the inventors of the present invention (Schalchli H, et al; Bioconversion of potato solid waste into antifungals and biopigments using Streptomyces spp.; Heidi Schalchli et al; From waste to resource. Microbial dyes from discarded potatoes; Heidi Schalchli et al; Microbial bio-products: green and sustainable production) mention the use of discarded potatoes as the sole nutrient source in culture media to generate biopigments produced by Streptomyces spp. bacteria. It is also mentioned that this agricultural waste is an important energy source due to its high carbohydrate and protein content, which certain microorganisms, such as actinides or bacteria, can utilize to obtain bioproducts like microbial pigments and dyes.Also in the state of the art are publications such as those by Sharmila et al. (Sharmila et al.; Sequential statistical optimization of red pigment production by Monascus purpureus (MTCC 369) using potato powder), which disclose an optimization of red pigment production by Monascus purpureus and the use of potato powder as a low-cost carbon source for culture media. Additionally, it is necessary to mention that in the state of the art there are different studies and publications related to the production of different pigments in both fungi (Talaromyces albobiverticillius, Monascus) and other bacteria such as Chryseobacterium artocarpi (Aruldass et al.; Utilization of agro-industrial waste for the production of yellowish-orange pigment from Chryseobacterium artocarpi CECT 8497) through the use of agro-industrial waste.Specifically, the publication by Aruldass et al. indicates that pigment production is costly, so the researchers in this study developed an optimized production method for an orange-yellow pigment from Chryseobacterium artocarpi CECT 8497 in a pineapple waste culture medium. In their study, they concluded that the most significant variables affecting the production of this pigment are, in addition to pineapple waste, L-tryptophan and potassium phosphate (KH2PO4).

[0034] On the other hand, a characteristic mentioned in the state of the art is that certain mineral salts, such as MgSC, K2HPO4, and KH2PO4, positively influence pigment production. For example, in Sajjad et al. (Pigment production by cold-adapted bacteria and fungi: colorful tale of cryosphere with wide range applications), in addition to citing studies using potato dextrose medium, they also cite authors who conclude that mineral salts such as MgSC and KH2PO4 can enhance pigment production in organisms like Penicillium. There are also publications such as that of Venkatachalam et al. (OVAT Analysis and Response Surface Methodology Based on Nutrient Sources for Optimization of Pigment Production in the Marine-Derived Fungus Talaromyces albobiverticillius 30548 Submerged Fermentation), where, for the optimization of culture medium components for the production of orange and red pigments using T.albobiverticillius 30548, it was found that the use of compounds such as KH2PO4 and MgSC -7H2O were important factors for the production of pigments, along with other components such as yeast extract.

[0035] However, in the state of the art, although methods for obtaining pigments through microorganisms are mentioned, where these means can use carbon sources such as potato, pineapple, among others, and potassium and calcium salts for the cultures, a method has not been found that, through the determination of specific optimal parameters such as temperature, agitation, addition of salts, light and time conditions, among others, achieves an improvement in terms of the amount of product (pigment) obtained, that is, a yield above what is expected.

[0036] Thus, the problem of the state of the art associated with the production of blue pigments such as actinorrhodin by Streptomyces spp. are the low production yields and the need to use traditional culture media that increase production costs.

[0037] The technical problem that this technology solves is the need for a method to produce blue pigments of natural origin, optimizing the quantity generated by combining variables such as pH, temperature, agitation (rpm), light conditions, and potassium salts, among others. This aims to reduce process costs and time, enabling its application in various industrial sectors, including food, textile, pharmaceutical, and cosmetic industries. This would prevent health problems, reduce production costs, and offer an environmentally friendly alternative by utilizing natural waste such as discarded potatoes.

[0038] SOLUTION TO THE TECHNICAL PROBLEM

[0039] To solve this technical problem, the inventors propose an optimized, improved, and sustainable fermentation method that allows for more efficient production of blue pigments compared to what has been reported for Streptomyces spp. This method is based on the use of discarded potatoes as a substrate, which, being considered a waste product, is readily available worldwide, does not compete with human food sources, and is rich in nutrients. In this improved and optimized fermentation method, the actinobacterium Streptomyces lydicus (S. lydicus) strain PM7 is cultivated on a carbon source such as potato substrate to obtain blue pigment. The process is optimized by improving parameters such as temperature, agitation, pH, incubation time and conditions, and KH₂PO₄ salt concentration, among others. This PM7 strain of S.The lydicus used in the method of the present invention is deposited in the Chilean Collection of Microbial Genetic Resources (CChRGM) under deposit number RGM 3663, and in accordance with the requirements established by the Budapest Treaty.

[0040] BRIEF DESCRIPTION OF THE INVENTION

[0041] In one aspect, the present invention relates to a homogeneous, optimized, improved, and sustainable fermentation process that allows for the more efficient production of blue pigments compared to other reported methods for Streptomyces spp. This method is based on the use of discarded potatoes as a substrate, which, being considered a waste product, is readily available worldwide, does not compete with human food sources, and is rich in nutrients. This improved fermentation method employs the actinobacterium Streptomyces lydicus (S. lydicus) PM7—deposited with the CChRGM under deposit number RGM 3663—for the production of the blue pigment.

[0042] In another aspect, the present invention relates to an optimized and sustainable fermentation method for the efficient production of blue pigments produced by the actin or bacterium Streptomyces lydicus strain PM7, deposited in the CChRGM under deposit number RGM 3663, cultivated on potato waste. This improved method allows for progress in the production of blue pigments, as it yields at least five times the amount of blue pigment as a product compared to a non-optimized method, that is, a non-optimized method that uses the same base material without considering the operational variables of the method proposed herein.The method proposed in the present invention (improved) allows for progress in the production of blue pigments, since with said proposed method blue pigment is obtained through the use of variables and reagents that do not affect or inhibit the production of said pigment.

[0043] For the present invention, in which the method employs potato waste for the production of pigments by the actinobacterium Streptomyces lydicus strain PM7, the term “potato waste” refers to both discarded potatoes and any type of potato and its derivatives, whether whole potatoes or parts thereof with or without peel, potato peels, or a combination thereof, whether fresh or dehydrated, whole, chopped, ground, grated, or in any similar state. This potato waste is transformed into potato substrate, or potato as a substrate, for the culture medium used in the present invention.

[0044] Furthermore, contrary to current reports with other blue pigment-producing bacteria such as S. coelicolor, the blue pigment production process by the species S. lydicus does not require the addition of processed commercial nutrients such as glucose or soluble starch, only KH2PO4.

[0045] The method consists of, firstly, preparing the discarded potato medium as a culture medium for subsequent use in the optimized fermentation method for obtaining blue pigment. Simultaneously, an inoculum of the actinobacterium S. lydicus is prepared and incubated in International Streptomyces Project 2 (ISP2) medium for at least three days under specific conditions of darkness, temperature, pH, agitation, and culture time.

[0046] Having overcome this step and completed the necessary time, the inventors managed to determine the production of blue pigment under optimized conditions, where the inoculum of S. lydicus is added to the previously prepared discarded potato culture medium, and this bacteria is incubated under determined parameters of salts, pH, temperature, light and agitation.

[0047] Finally, the blue pigment obtained is extracted and separated through centrifugation, freeze-drying and fractionation processes.

[0048] To arrive at this improved production process, researchers conducted trials using the Plackett-Burman experimental design and Response Surface Method (RSM) tests to determine which variables had a significant effect on pigment production using discarded potato medium. The characteristics that correlated with the improvement of this fermentation process were: temperature, stirring speed, pH, and the addition of specific salts. [DESCRIPTION OF THE FIGURES]

[0049] Figure 1 shows a Pareto chart illustrating the influence of each factor on the production of the blue pigment: A (residue concentration); B (inoculum size); D (pH); E (temperature); F (stirring speed); G (working volume (ml / 250 ml flask); J (starch); K (KH2PO4); L (yeast extract). It can be observed that the parameters corresponding to residue concentration, temperature, pH, stirring speed, and KH2PO4 had the most positive effects on the production of the blue pigment.

[0050] Figure 2 shows the production of blue pigments by Streptomyces lydicus PM7 at different concentrations of discarded potatoes under optimized cultivation conditions. It can be observed that the concentration significantly influences the amount of pigment produced: the highest pigment production was approximately 3,300 mg L⁻¹. 1, using concentrations of 16 and 32 g L' 1 Furthermore, the production of blue pigments begins on the third day at the concentrations tested. On the other hand, the lowest production of blue pigment is obtained at a concentration of 4 g L⁻¹. 1 of discarded potatoes, with an approximate production of 790 mg L' 1 .

[0051] Figure 3 shows a residual diagram comparing the actual and projected production of blue pigments from S. lydicus using DCC. In this regard, the R value 2 The value of 0.9839 indicates a high correlation between experimental and predicted values, suggesting good reproducibility of the model for pigment production. Furthermore, the p-value is less than 0.0001, and the p-value for lack of fit is 0.2584. The predicted value of R 2The value of 0.9067 is a good fit to describe the response trends. Likewise, the standard deviation, mean, and predicted residual sum (PRESS) values ​​are 198, 3.216, and 2.74E+6, respectively. Figure 4 shows a calibration curve for estimating blue pigment production.

[0052] Figure 5 corresponds to a representative scheme of the optimized and sustainable production method of blue pigments of the polyketide type of the actinorhodine group produced by Streptomyces sp. proposed in the present invention.

[0053] DETAILED DESCRIPTION OF THE INVENTION

[0054] The present invention describes an optimized and sustainable method for producing blue polyketide pigments of the actinorhodine group, produced by Streptomyces sp. from potato waste. Specifically, the blue pigment-producing bacterium for the method of the present invention is the actin or bacterium S. lydicus strain PM7, deposited with the CChRGM under deposit number RGM 3663. This production process comprises the following steps:

[0055] STAGE 0. PREPARATION OF DISCARDED POTATOES AS A CULTURE MEDIUM FOR FERMENTATION. In the first part, whole discarded potatoes are used according to the protocol published by the inventors in 2017. The potatoes are cut into small pieces (1x1 cm), dried at 70°C for 24 hours and ground to obtain a fine powder.

[0056] STEP 1. INOCULUM PREPARATION. For the collection of spores of the actin or bacterium S. lydicus, colonies of the strain obtained from test tubes with agar slants stored under refrigeration at 4 °C are cultured on Petri dishes with ISP2 agar culture medium (pH 7.0 ± 1) and incubated in the dark at 28 °C ± 5 °C for 6 ± 2 days. Spores are collected from the surface of the plate using 0.9% ± 0.2% saline solution and placed in a Neubauer chamber to obtain a pre-inoculum. Subsequently, 100 mL of ISP2 culture medium (pH 7.0 ± 1) are placed in 250 mL Erlenmeyer flasks and inoculated with the spore suspension at a concentration of at least 10 3 spores m L 1 These flasks containing the culture medium inoculated with spores are incubated in an orbital shaker under dark conditions at 28°C ±5°C and 100 rpm ± 100 rpm, for at least two days.

[0057] STAGE 2. PIGMENT PRODUCTION UNDER OPTIMIZED CONDITIONS. 250 mL Erlenmeyer flasks are used with 50 mL (working volume) of discarded potato culture medium at a concentration of 16 g L 1 , supplemented with 0.15 ± 0.1 g L' 1 of KH2PO4 and initial pH adjustment to 9.0 ± 3.0. The culture medium is inoculated with the S. lydicus inoculum at a concentration of 8% v / v ± 3% v / v (inoculum size), which is incubated on an orbital shaker in darkness at 30°C ±5°C and 180 rpm ± 100 rpm for at least 8 days.

[0058] STAGE 3. EXTRACTION AND SEPARATION OF BLUE PIGMENTS. Once the incubation period is complete, the biomass is separated from the culture medium by centrifugation at 9,000 RCF for 10 min at 4°C and filtered using 0.22 µm syringe filters to obtain a cell-free supernatant. The cell-free supernatant is lyophilized and fractionated on a chromatographic column (10 x 2.5 cm) with 5 g of LiChroprep RP-18 (15-25 µm). Fifty milliliters of solvents of increasing polarity (EtOH, EtOH / H₂O 1:1, H₂O) are used as the mobile phase, with the majority fraction being recovered from the EtOH / H₂O 1:1 solution. This fraction is concentrated to dryness to obtain a semi-purified extract of blue pigments from the actinorhodin group. First, the ethanol is removed in a rotary evaporator, and then the mixture is freeze-dried to remove water and obtain a freeze-dried powder. The resulting freeze-dried powder is completely soluble in alkaline water.

[0059] To arrive at this improved blue pigment production process, researchers conducted optimization tests, including Plackett-Burman tests and Response Surface Method (RSM) tests, to determine which variables had a significant effect on pigment production using discarded potato as a medium. The characteristics that correlated with the improvement of this fermentation process were: temperature, stirring speed, pH, and the addition of KH₂PO₄.

[0060] With the aim of achieving the optimal operational variables, the inventors carried out two sequential optimization models: Plackett-Burman design and a response surface test using a central composite design.

[0061] In the present invention, where potato waste is used for the production of pigments by the actin or bacterium Streptomyces lydicus strain PM7, the term "potato waste" refers to both discarded potatoes and any type of potato and its derivatives, whether whole potatoes or parts thereof with or without peel, potato peels, or a combination thereof, whether fresh or dehydrated, whole, chopped, ground, grated, or in any similar state. This potato waste is transformed into potato substrate, or potatoes as a substrate, for the culture medium used in the present invention. The examples and test results presented below validate the fact that the present optimized method yields a greater quantity of blue pigments as a product compared to a non-optimized method, both of which use potato waste as a substrate.Furthermore, they validate the obtaining of high quantities of blue pigment under this optimized method without the use of reagents such as glucose with respect to what has been reported in the state of the art (Elibol, 2004), since the production of pigments by S. lydicus PM7 is inhibited in the presence of components such as glucose and soluble starch, since it increases the bacterial biomass but no pigmentation of the culture medium is observed.

[0062] Thus, the present invention and its advantages will be better understood from the following examples, which are for illustrative purposes only. The examples are not intended to, and should not be interpreted as, limiting the scope of the present invention in any way. APPLICATION EXAMPLES

[0063] EXAMPLES OF PREFERRED REALIZATIONS

[0064] The following are examples of applications of this patent application. These examples are provided for illustrative purposes only to provide a better understanding of the invention, but should in no way be considered as limiting the scope of the protection sought. Furthermore, specifications of different technical features described in the examples may be combined with each other, or with other technical features previously described, without limiting the scope of the protection sought.

[0065] EXAMPLE 1

[0066] PREPARATION OF DISCARDED POTATO MEDIUM AND S. LYDICUS INOCULUM Preparation of discarded potato medium as a culture medium for fermentation.

[0067] Discarded potatoes unsuitable for human consumption are used according to a protocol published by the inventors in 2017. The potatoes are cut into small pieces (1x1 cm), dried at 70°C for 24 hours and ground into a fine powder.

[0068] Preparation of S. lydicus inoculum.

[0069] For the collection of spores of the actin or bacterium S. lydicus strain PM7, deposited in the CChRGM under deposit number RGM 3663, colonies of this strain obtained from test tubes with agar slants stored under refrigeration at 4 °C are cultured on Petri dishes with ISP2 agar culture medium (pH 7.0) and incubated in the dark at 28 °C for 6 days. Spores are collected from the surface of the plate using 0.9% saline solution and placed in a Neubauer chamber to obtain a pre-inoculum. Subsequently, 100 mL of ISP2 culture medium (pH 7.0) are placed in 250 mL Erlenmeyer flasks and inoculated with the spore suspension at a concentration of 10 4 spores mL' 1 These flasks containing the culture medium inoculated with spores are incubated in an orbital shaker under dark conditions at 28°C and 120 rpm, for 3 days.

[0070] EXAMPLE 2

[0071] PRODUCTION OF BLUE PIGMENTS BY S. LYDICUS PM7 UNDER NON-OPTIMIZED CONDITIONS (ASTUDILLO ET AL., 2024).

[0072] Different concentrations of discarded potato (powder) were evaluated for the production of blue pigments by S. lydicus PM7 under standard culture conditions (28°C, 120 rpm, no added supplements, 4% v / v inoculum, 100 mL working volume, 10 days incubation). The inoculum consisted of S. lydicus spores (10 4 mL' 1 ) cultivated in 250 mL Erlenmeyer flasks with 100 mL of ISP2 medium (pH 7.0) for 3 days at 28°C and 120 rpm. The results indicated the highest production of blue pigments when using 16 g L' 1 of discarded potato residue (powder) with a maximum of 870 ± 30 mg L' 1 No significant differences were obtained in the production of blue pigments when using 4, 8 and 32 g L' 1 of discarded potatoes.

[0073] EXAMPLE S MEASUREMENT OF BLUE PIGMENTS

[0074] Starting with a culture of S. lydicus PM7 using potato waste as the basal substrate under liquid fermentation conditions (not yet optimized), pigment extraction and separation were performed. After the incubation period, the biomass was separated from the culture liquid by centrifugation at 9,000 RCF for 10 min at 4°C and filtered through 0.22 µm syringe filters to obtain a cell-free supernatant. The cell-free supernatant was lyophilized and fractionated using a chromatographic column (10 x 2.5 cm) with 5 g of LiChroprep RP-18 (15–25 µm). Fifty milliliters of solvents of increasing polarity (EtOH, EtOH / F 1:1, H₂O) were used as the mobile phase, with the majority of the fraction being recovered from the EtOH / F 1:1 solution. This fraction was concentrated to dryness in order to obtain a semi-purified extract of blue pigments from the actinorhodin group.The extract of the semi-purified fraction (F3) was solubilized in distilled water at different concentrations (10 to 300 ppm) to obtain a calibration curve. This curve (concentration of the semi-purified fraction vs. absorbance) was used to estimate pigment production in the optimization tests.

[0075] Using the first-order equation, which represents the absorbance obtained in relation to the different concentrations of semi-purified blue pigment obtained. Y = 0.0024x + 0.0032

[0076] where Y is the absorbance and X corresponds to the concentration of the semi-purified blue pigment (mg ■ L -1 ).

[0077] EXAMPLE 4

[0078] EVALUATION OF THE SUPPLEMENTATION OF THE CULTURE MEDIUM OF DISCARDED POTATOES

[0079] Different sources of carbon, nitrogen, and micronutrients commonly used in the production of microbial compounds were evaluated separately, including K2HPO4 (0.1 g L' 1 ), KH2PO4 (0.1 g L -1 ), CaCO3(0.15 g L' 1 ), MgSO4■ 7 H2O (0.5 g L' 1 ), glucose (10 g L 1 ) and soluble starch (4 g L' 1 ). Before autoclaving, 250 mL Erlenmeyer flasks with 100 mL of discarded potato culture medium at a concentration of 16 g ■ L' 1 The media were supplemented with the different components at concentrations defined in the literature separately, with pH adjusted to 7.0. The media were inoculated with a fresh culture of the actin or bacterium S. lydicus strain PM7 at 4% v / v obtained from a spore culture (10 4 spores mL' 1) in ISP2 medium maintained at 28°C and 120 rpm for 3 days. The cultures were maintained at 28°C and 120 rpm for 10 days. Three replicates were considered for each treatment, with the control (-) treatment being the media without inoculum and the control (+) treatment being the culture medium without inoculum supplementation.

[0080] The pigments were extracted from the supernatant obtained by centrifugation at 9,000 RCF for 10 min at 4°C and filtered to 0.22 pm to obtain a cell-free supernatant (Bystrykh et al., 1996; Yi et al., 2015).

[0081] The results showed that, when using phosphate sources, the production of blue pigments showed a significant increase compared to the control in both cases, reaching production values ​​of approximately 2.337 mg L' 1 In contrast, when using CaCO3 and MgSO4, a decrease in production was observed compared to the control (approximately 672 mg L'1 ), obtaining concentrations of 300 mg L' 1 and 450 mg L' 1 These results suggest that the phosphate source contributes positively to the production of blue pigments, while CaCO3 and MgSO4 appear to limit this production. Furthermore, contrary to reports on microbial pigment production by Streptomyces spp., pigment production by S. lydicus PM7 was completely inhibited by supplementation with glucose and soluble starch, increasing bacterial biomass but with no observed pigmentation of the culture medium.

[0082] Thus, the above indicates that pigment production by the microorganism under study requires culture conditions that differ from those reported for other microorganisms of the same genus. Therefore, it was necessary to adapt the culture conditions considering the metabolism of S. lydicus PM7, beginning with the identification of influencing factors to identify positive and negative effectors.

[0083] EXAMPLE S OPTIMIZATION OF BLUE PIGMENT PRODUCTION

[0084] To optimize the production of blue pigments, two sequential optimization models were performed: Plackett-Burman design and a response surface test using a central composite design.

[0085] Plackett-Burman design - identification of influencing variables.

[0086] The 11 selected variables included the concentration of discarded potato, inoculum size, incubation time, pH, temperature, stirring speed, working volume in 250 mL flasks, antifoam, starch addition, KH₂PO₄ addition, and yeast extract addition. The variables were analyzed at low (-1) and high (+1) levels (Table 4). Variables with a significant effect on blue pigment production were selected. Table 4. Levels of the selected independent variables for blue pigment production using the Plackett-Burman design.

[0087] Table 4. Levels of the independent variables selected for the production of blue pigments using the PB design

[0088] .. Variable Levels Variables Low High 0

[0089] (-1) (+1)

[0090] A Residue concentration (g L -1 ) 4 32 B Inoculum size (%vv 1) 4 8 C Incubation time (days) 6 10 D pH 6 8 E Temperature (°C) 20 30 F Stirring speed (rpm) 50 150 G Working volume (mL) 250 mL flask -1 ) 50 100 H Antifoaming Agent (%vv -1 ) 0 1 J Starch (g L -1 ) 0 4 K KH2PO4(g L -1 ) 0 0.1 L Yeast extract (g L -1 0.4 Based on the results obtained in the best run of the experimental design (No. 6), an inoculum concentration of 4% v / v was defined to test the effect of the discarded potato concentration for the preparation of the culture medium, considering that in the assay to determine the influencing variables, the discarded potato concentration was not significant. The experiment was carried out in 250 mL Erlenmeyer flasks with 50 mL of culture medium with different concentrations of discarded potato (4, 8, 16, and 32 g L⁻¹). 1 ), with the addition of KH2PO4 at a concentration of 0.1 g L 1with pH 8. The selected incubation conditions were 30 °C at 150 rpm for 10 days. Each test was performed in triplicate.

[0091] The results of the Plackett-Burman design assay to determine the influencing factors are presented in Table 5. The results showed a wide variability in the production of blue pigments (44 to 3,615 mg L -1 ), which reflects the importance of optimizing the environment. The maximum production of blue pigments (3,615 mg L -1 ) was obtained in run 6. The lowest production of blue pigments (44 mg L -1The result was obtained in run 3. The results indicated that the variables corresponding to the incubation period (C) and the addition of antifoam (H) are not significant variables, as their contribution is low (0.07% and 0.04%, respectively). Therefore, the model was adjusted for the significance test. The Pareto chart shows the variables that have the most importance in the production of blue pigments in the Plackett-Burman experimental design (Figure 1). Table 5. Plackett-Burman design of eleven independent variables used in the production of blue pigments. A (Residue concentration); B (Inoculum size); C (Incubation time); D (pH); E (Temperature); F (Stirring speed); G (Working volume (mL in a 250 mU flask) 1 ); H (Antifoaming agent); J (Starch); K (KH2PO4); L (Yeast extract).

[0092] Coded values ​​of independent factors Blue pigment (mg-L) 1) Corrida Residual A B C D E F G H J K L a V c a t l u o a r ,l pr V e a v l .i o s r f to 1 -1 1 -1 1 1 -1 1 1 1 -1 -1 73 66 7 2 -1 -1 -1 1 -1 1 1 -1 1 1 1 530 480 50 3 1 1 1 -1 -1 -1 1 -1 1 1 -1 44 51 -7 4 -1 1 1 -1 1 1 1 -1 -1 -1 1 91 98 -7 5 1 -1 1 1 -1 1 1 1 -1 -1 -1 2.105 2.155 -50 6 1 1 -1 1 1 1 -1 -1 -1 1 -1 3.615 3.565 50 7 1 -1 -1 -1 1 -1 1 1 -1 1 1 66 59 7 8 -1 -1 1 -1 1 1 -1 1 1 1 -1 1.734 1.784 -50 9 1 1 -1 -1 -1 1 -1 1 1 -1 1 117 110 7 10 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 54 4 50 11 1 -1 1 1 1 -1 -1 -1 1 -1 1 77 84 -7 12 -1 1 1 1 -1 -1 -1 1 -1 1 1 60 110 -50 Nivel g / L %v / v días pH °C rpm mL %v / v g / L g / L g / L

[0093] -1 4 4 6 6 20 50 50 0 0 0 0

[0094] 1 32 8 10 8 30 150 10 1 4 0,1 4

[0095] The Analysis of Variance (ANOVA) for the Plackett-Burman design was significant (Table 6). The p-value < 0.05 (0.0047) indicates that the terms are significant. The coefficients of determination (R²) 2 = 0.9990) and the adjusted coefficients of determination 5 (Adj. R 2 = 0.9943) are very high, so it can be concluded that the model is significant. Table 6. Statistical analysis of the Plackett-Burman design.

[0096] Table 6. Statistical analysis of the Plackett-Burman design.

[0097] Variable Coefficient Effect c . . %

[0098] F-value p contribution r -value Intercept 713.83 213.23 0.0047* A-Residue concentration 290.17 580 6.87 131.88 0.0075* B-Inoculum size -47.17 -94 o, 18 3.48 0.2027 D-pH 362.83 726 10.73 206.2 0.0048* E-Temperature 228.83 458 4.26 82.02 0.0120* F-Stirring speed 651.5 1303 34.61 664.82 0.0015* G-Working volume in 250 flask n ni 9n * mL -229

[0099]

[0100] 4.28 82.14 U ' U U

[0101] J-Starch -284.67 -569 6.60 126.93 0.0078* K-KH2PO4 294.33 589 7.07 135.69 0.0073* L-Yeast extract .557 -1114 25.30 485.95 0.0021* Average 713.83 R2 0.999

[0102] Std. Dev. 87.53 R 2 Adjusted 0.9943

[0103] CV % 12.26 R2 predicted 0.9625

[0104] 552E+05 P

[0105] PRESS 0,0 U0 ad re

[0106] e c

[0107] c ' s i° n

[0108] 44.5667

[0109] * Significant values, "F: Fisher functions, PRESS is the predicted residual sum of squares. CV% is the coefficient of variation%"

[0110] The first-order polynomial equation representing the production of blue pigments in relation to the independent factors, omitting non-significant factors, is:

[0111] And (Production of blue pigments) = 714 + 290A - 47B + 363D + 229E + 652F - 229G ■ 285J + 294K - 557L

[0112] Where, Y is the answer and A, B, D, E, F, G, J, K, L correspond to the concentration of the potato residue, the inoculum size, the pH, the temperature, the stirring speed, the working volume in 250 mL flasks, the addition of starch, the addition of KH2PO4 and the addition of yeast extract, respectively.

[0113] Based on the optimization performed on the Plackett-Burman design, the production of blue pigments was evaluated at different concentrations of discarded potato culture medium. The data indicate that concentration significantly influences the amount of pigment produced. The highest pigment production was approximately 3,400 mg L⁻¹. 1 , using concentrations of 16 and 32 g L 1 Furthermore, the production of blue pigments begins on the third day at the concentrations tested. The lowest production of blue pigment is obtained at a concentration of 4 g L⁻¹. 1 of discarded potatoes, with a production of 792 ± 71 mg L' 1 (Figure 5).

[0114] Response surface methodology (RSM) Based on the variables that showed a significant effect on the production of blue pigments using discarded potato medium and considering that the selected discarded potato concentration was 16 g L 1A central composite design was implemented. Variables with a positive influence were selected, including temperature, stirring speed, pH, and KH2PO4 addition. These variables were tested at three levels (-1, 0, +1) (RSM Matrix Table). Predictive values ​​were obtained using RSM (Table 7).

[0115] Table 1. Selected variables and low and high levels in DCC

[0116] Code Variables Unit Low (-1) Medium (0) High (+1)

[0117] X1 Temperature °C 28 32 36

[0118] X2 Stirring speed rpm 120 150 180

[0119] X3pH 7 8 9

[0120] X4KH2PO4 g L 1 0.10 0.15 0.20

[0121] Based on previous trials, a central composite design was implemented using the four selected variables that positively affected blue pigment production, as determined by the Plackett-Burman design. These variables were evaluated at the highest levels used due to their positive impact on blue pigment production. Table 8 shows the variables: temperature (X1), stirring speed (X2), pH (X3), and KH₂PO₄ concentration (X4); the levels used (-1, 0, +1) for each factor; the design matrix; and the experimental and predicted values. Maximum production was observed in runs 9 and 27, with 5,345 and 5,247 mg L⁻¹, respectively. 1 of blue pigments respectively. While the minimum production is observed in run 22 with 1,160 mg L 1 The results were analyzed using analysis of variance (ANOVA) to establish a quadratic response surface model (Table 9).

[0122] Table 8. Central composite design of independent variables for blue pigment production.

[0123] Variables Blue pigment (mg L' 1 )

[0124] Run _ Residue

[0125] Xi X2 X3 X4 Actual Predicted

[0126] 1 1 -1 1 -1 4,070 3,996 74

[0127] 2 0 0 -1 0 3.635 3.655 -20

[0128] 3 -1 1 -1 -1 4,759 4,602 157

[0129] 4 1 -1 1 1 4.151 4.298 -147

[0130] 5 1 -1 -1 1 2,740 2,779 -39

[0131] 6 1 -1 -1 -1 2.812 2.691 121

[0132] 7 0 0 0 -1 2.693 2.778 -85

[0133] 8 1 1 1 -1 2,880 3,028 -148

[0134] 9 -1 1 1 -1 5.345 5.275 70

[0135] 10 0 0 1 0 4.611 4.751 -140

[0136] 11 0 -1 0 0 2.455 2.633 -178

[0137] 12 0 0 0 0 2.849 2.662 187

[0138] 13 1 1 1 1 3,630 3,420 210

[0139] 14 -1 -1 1 -1 3.556 3.480 76

[0140] 15 0 0 0 1 2.788 2.863 -75

[0141] 16 -1 -1 -1 -1 2,400 2,580 -180

[0142] 17 0 0 0 0 2.923 2.662 261

[0143] 18 -1 -1 -1 1 2.516 2.359 15719 0 1 0 0 3.222 3.204 18 20 1 1 -1 1 2.060 2.127 -67

[0144] 21 1 1 -1 -1 1.864 1.949 -85

[0145] 22 1 0 0 0 1,160 1,080 80

[0146] 23 0 0 0 0 2.693 2.662 31

[0147] 24 -1 0 0 0 1.753 1.993 -240

[0148] 25 -1 -1 1 1 3.588 3.473 115

[0149] 26 -1 1 -1 1 4.427 4.471 -44

[0150] 27 -1 1 1 1 5.247 5.358 -111

[0151] X1: Temperature x2: Agitation (rpm) X3: pH X4: KH2PO4 (g L 1 )

[0152] 28 120 7 0.10

[0153] 32 150 8 0.15

[0154] 36 180 9 0.20

[0155] Table 9. Analysis of variance of the CCD results used for optimization in the production of blue pigments.

[0156] Var . ab e Suma d ,e df Cuadrado _ F.va ue n-va ue cuadrados medio 1 P VA,UC Model 2.89E+07 14 2.06E+06 52.25 < 0.0001* 0.0001* 0.0001* X3 1.64E+05 1 1 ,64E+05 4.16 0.0641 8055.06 1 8055.06 0.2039 0.6597 X3X4 45903.06 1 45903.06 1.16 0.3023 X1 2 3.26E+06 1 3.26E+06 82.42 < 0.0001* 2 1.69E+05 1 1.69E+05 4.29 0.0607 X3 2 6.11 E+06 1 6.11 E+06 154.57 < 0.0001* 2 64705.78 1 64705.78 1.64 0.2248 Residual 4.74E+05 12 39512.65

[0157] Falta de ajuste 4,47E+05 10 44658.12 3.24 0.2588 Pure error 27570.67 2 13785.33

[0158] Cor Total 2.94E+07 26

[0159] R 2 = 0.9839; Adj. R 2 = 0.9650; Pred. R 2 = 0.9067; Accuracy appropriate = 28.8785;

[0160] * Statistically significant (P < 0.05)

[0161] A regression analysis and a second-order polynomial equation were obtained to describe the relationship between the response and the independent variables studied:

[0162] Y (Production of blue pigments) = 2662 — 457 X1 + 286 X2 + 548 X3 + 43 X4 — 691 X1X2 + 101 X1X3 + 77 X1X4 - 57 X2X3 + 22X2X4 + 54 X3X4 - 1 .125 X1 2 + 257 X2 2 + 1.541 X3 2 + 159 X4 2 where, Y represents the blue pigments produced and Xi, X2, X3 and X4 correspond to the temperature (X1), the stirring speed (X2), the pH (X3) and the concentration of KH2PO4 (X4), respectively.

[0163] The model used is statistically significant, as indicated by the model's F-value (52.25). The significant variables in the model are Xi, X2, X3, X1, X2, X1 2 and X3 2 The F-value for Lack of Fit of 3.24 suggests that it is not significant compared to pure error.

[0164] The R value 2 The value of 0.9839 indicates a high correlation between experimental and predicted values, suggesting good reproducibility of the model for pigment production. Furthermore, the p-value is less than 0.0001, and the p-value for lack of fit is 0.2588. The predicted value of R 2 The value of 0.9039 is a good fit to describe the response trends. Likewise, the predicted standard deviation, mean, and sum of residuals (PRESS) values ​​are 198, 3215, and 2.74E+6, respectively.

[0165] To validate the predicted model, the point prediction function of the software employed was used, as described in Example 6 of the invention. The optimized levels of the effective variables were a temperature of 30°C, a stirring speed of 180 rpm, an initial pH of 9.0, and the addition of K₂HPO₄ at a concentration of 0.15 g L⁻¹. 1 EXAMPLE 6

[0166] MEASUREMENT OF BLUE PIGMENTS UNDER OPTIMIZED CONDITIONS

[0167] To validate the improved blue pigment production method proposed by the inventors, an experiment was carried out using the optimized culture conditions: 50 mL of discarded potato culture medium (16 g L' 1 ) in 250 mL Erlenmeyer flasks, starting with an 8% inoculum (vv 1 ), temperature of 30°C, stirring speed of 180 rpm, initial pH of 9.0 and KH2PO4 at 0.15 g L' 1 for 8 days in darkness.

[0168] As a result of the optimized method, it was observed that the maximum production of blue pigments by S. lydicus was 5,000 ± 37 mg L 1 This value represents a 91% relationship between the experimental values ​​and those predicted according to the response surface methodology (RSM).

[0169] This result demonstrates that the optimized method proposed in the present invention allows obtaining a higher concentration of blue pigments as a product compared to a non-optimized method, by using discarded potatoes as a substrate; because, as mentioned in example 1 above, the production of blue pigments using 16 g L' 1 The waste potato residue allows generating a maximum concentration of 870 ± 30 mg L' as a product 1 after 10 days of incubation.EXAMPLE 7

[0170] OBTAINING BLUE PIGMENT VERSUS STATE OF THE ART

[0171] The production of blue pigment using the optimized discarded potato culture medium was compared with the optimized culture medium reported by Elibol (2004). In this study, only the composition of the medium was compared because the author does not explicitly indicate the culture conditions, such as temperature, agitation, pH, and incubation time, in his publication.

[0172] Treatment 1: Optimized discarded potato culture medium containing 16 g L' 1 of dehydrated discarded potato and 0.15 g L 1 of K2HPO4.

[0173] Treatment 2: Optimized culture medium (Elibol, 2004) containing 339 g L' 1 of sucrose, 1 g L' 1 of glucose, 1.95 g L' 1 of yeast extract and 2.72 g L 1 of peptone. Negative control: culture media described in treatment 1 and 2 without inoculum.

[0174] Inoculation and incubation: 500 pL of a spore suspension prepared according to Elibol (2004) were used to inoculate 100 mL of culture medium in 500 mL Erlenmeyer flasks sealed with hydrophobic cotton plugs covered with gauze. Since Elibol (2004) does not specify the pH of the culture medium, in this study it was adjusted to the optimum pH for S. lydicus (pH 9.0) to eliminate differences due to the initial pH of the medium. Given that Elibol (2004) does not specify the culture conditions, the flasks were placed in an incubator with shaking at 30°C and 180 rpm for 8 days. At the end of the incubation period (8 days), the concentration of blue pigments was measured by spectrophotometry, the concentration of reducing sugars was measured, and the final pH was determined.

[0175] The results indicated that pigment production began on the third day of incubation in the case of the discarded potato culture medium, reaching approximately 590 mg L' 1In the case of the culture medium optimized by Elibol (2004), the production of blue pigment began on the fifth day of culture, reaching 98 mg L' 1 These results suggest a delay in the onset of blue pigment production due to the presence of glucose, a rapidly metabolized microbial carbon source, which could be inhibiting the secondary metabolism of S. lydicus PM7 during the first few days of incubation. At the end of the study (8 days of incubation), no significant differences were observed between the optimized discarded potato medium and the optimized traditional medium reported by Elibol (2004), reaching a blue pigment concentration of 5,965 ± 476 mg L⁻¹ 1 and 6,068 ± 331 mg L' 1 respectively. This experiment shows that, compared to the state of the art, this optimized method allows obtaining high quantities of blue pigment without the use of reagents such as glucose, as reported by Elibol (2004).

Claims

1. CLAIMS 1. A method for optimizing the production of blue pigments of bacterial origin in a safe / sustainable manner based on potato substrate, CHARACTERIZED in that it comprises: a) Prepare the bacterial inoculum, where this step comprises: i) Cultivate a bacterium, which is an actinobacteha, in an ISP2 agar culture medium (pH 7.0 ± 1), incubate in darkness at 28 °C ± 5°C for 6 days ± 2 and collect the spores with a 0.9% ± 0.2% saline solution to prepare a pre-inoculum; i) Inoculate ISP2 culture medium with the spore suspension at a concentration of at least 10 3 spores mL' 1 . iii) Incubate the culture medium inoculated with spores under dark conditions, at 28°C ±5°C and 100 rpm ± 100 rpm, for at least 2 days. b) Producing the pigment under optimized conditions, where this stage comprises: i) Use a culture medium based on potato substrate, where said potato substrate corresponds to potato waste, fresh or dehydrated, at a concentration of 16 g L' 1 ± 10 g L' 1 , supplemented with 0.15 g L' 1 ± 0.1 g L' 1 of KH2PO4 and initial pH adjustment to 9.0 ± 3.0; i) Inoculate the culture medium with the actinobacteha inoculum at a concentration between 8% v / v ± 3% v / v (inoculum size) and incubate in darkness at 30°C ±5°C and 180 rpm ± 100 rpm for at least 8 days. c) Extracting and separating the blue pigments, where this step comprises: i) Separate the biomass from the culture liquid by centrifugation at 9,000 RCF for 10 min at 4°C and filter with 0.22 pm syringe filters to obtain a cell-free supernatant; i) Lyophilize and fractionate the cell-free supernatant in a reversed-phase chromatographic column; and where the mobile phase corresponds to solvents of increasing polarity (EtOH, EtOH / F 1 :1 , H2O), recovering the majority fraction corresponding to EtOH / F 1 :

1. iii) Remove the ethanol in an evaporator and freeze-dry or spray-dry to remove water to obtain a semi-purified extract of blue pigments from the actinorhodin group.

2. The method according to claim 1, CHARACTERIZED in that the actinobacteria culture corresponds to Streptomyces spp, more particularly to Streptomyces lydicus (S. lydicus) which is deposited in the Chilean Collection of Microbial Genetic Resources (CChRGM) under deposit number RGM 3663, and in accordance with the requirements established by the Budapest Treaty 3. A pigment-producing actinobacteha, CHARACTERIZED in that said actinobacterium corresponds to Streptomyces lydicus (S. lydicus) which is deposited in the Chilean Collection of Microbial Genetic Resources (CChRGM) under deposit number RGM 3663 and in accordance with the requirements established by the Budapest Treaty.

4. Use of Actinobacteha according to claim 3, CHARACTERIZED in that it serves to produce blue pigment from potato waste.

5. The use of claim 4, CHARACTERIZED in that the potato waste corresponds to any type or variety of potato, preferably, discarded potatoes, potato waste and its derivatives, potato peels, whole potatoes (with and / or without peel) and / or combinations thereof.

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