Microbial Pigments Research Articles

Prodigiosin Demonstrates Promising Antiviral Activity Against Dengue Virus and Zika Virus in In‐silico Study

ABSTRACTDengue (DENV) and Zika virus (ZIKV), transmitted by Aedes mosquitoes, pose significant public health challenges. Effective treatments for these viruses remain elusive, highlighting the urgent need for new efficient antiviral therapies. This study explores prodigiosin, a microbial tripyrrole pigment, as an antiviral agent against both DENV and ZIKV employing advanced analytical approaches which integrate molecular docking, CASTp 3.0 validation and molecular dynamics (MD) simulations providing insights into molecular interactions at an atomic level. Prodigiosin exhibited favourable drug‐likeness properties, meeting Lipinski's rule of five and demonstrating optimal physicochemical and pharmacokinetic characteristics according to Ghose's, Veber's, Egan's and Muegge's filters, essential for oral bioavailability. Absorption, Distribution, Metabolism, Excretion, and Toxicity profiling indicated high intestinal absorption, minimal risk for drug‐drug interactions and a low toxicity profile, with no AMES toxicity, hepatotoxicity, or skin sensitization. Molecular docking revealed prodigiosin's strong binding affinities to NS5 methyltransferases of both DENV (−7.6 kcal/mol) and ZIKV (−7.7 kcal/mol) viruses, suggesting potential disruption of viral replication. Notably, prodigiosin's binding affinities were comparable to ribavirin‐5'‐triphosphate and chloroquine, known inhibitors of DENV and ZIKV, respectively. MD simulations confirmed stable and specific interactions with prodigiosin with low root‐mean‐square deviation values. Additional analyses, including root‐mean‐square fluctuation, radius of gyration and solvent‐accessible surface area, indicated compact and stable complexes. These multi‐parametric in‐silico analytical strategies provide a novel perspective of prodigiosin as an antiviral agent, demonstrating its drug interactions at the molecular level. These promising results suggest that prodigiosin could serve as a broad‐spectrum antiviral agent against both DENV and ZIKV, warranting further experimental validation for therapeutic development against flaviviral infections.

Microbial Pigment Isolation, Culturing, and Extraction to Use as Textile Dyes

The textile industry is one of the largest worldwide polluters of clean water due to the heavy use of synthetic dyes. These chemicals negatively affect the environment, especially aquatic life due to their toxic and mutagenic properties. Synthetic dyes cause harm to human health such as skin allergies and respiratory sensitization. Several advantages such as ease of extraction, availability, high yields and no seasonal variation make microbial pigments the most ideal source of natural pigments. This study was done to isolate colour pigment producing bacteria and fungi from soil collected from organic farms from various locations in Sri Lanka. Out of 7 soil samples, 3 yielded pigment producing bacteria and fungi. In total, 9 pigment producing bacteria and 3 pigment producing fungi were isolated. Gause’s synthetic agar yielded the most pigmented isolates. Isolates were inoculated in broths and pigment production was observed. Extracellular pigments produced by 5 of the bacterial isolates were extracted by a water-based method. The antibacterial activity of the pigments in their crude and concentrated forms was tested using the well diffusion method against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P. Inhibition zone against S. aureus was observed for both crude (12.33±0.58mm) and concentrated pigments (9.67±0.58mm) extracted from purple pigment producing bacterial isolate (BPU). This pigment has the potential to be used in antibacterial textile preparation. Extracted pigments were used to dye scoured cotton fabric with the use of 3% alum as mordant. Pigment from BPU isolate resulted in better coloured fabric.

Unveiling the Intricacies of Microbial Pigments as Sustainable Alternatives to Synthetic Colorants: Recent Trends and Advancements

Bio-pigments are the colored primary and secondary metabolites released by microbes under stress conditions and are crucial for adaptation. Bio-pigments are being widely accepted for industrial utilization due to their natural form, organic source, and biodegradability. Also, the ease of cultivation, scalability and cost-effectiveness in terms of pigment extraction is bringing bio-pigments into the limelight. Chemical dyes are carcinogenic and pose a serious threat to human lives, which is another issue that environmentalists must address. However, bacterial pigments are safe to employ; therefore, the food, pharmaceutical, textile, and cosmetics sectors may all benefit from their applications. The therapeutic nature of bacterial pigments is revealed because of their antimicrobial, anticancer, cytotoxic, and remarkable antioxidant properties. Bio-pigments also have multifaceted properties and thus can be an attractive source for the next generation to live a sustainable life. The present review discusses the importance of bacterial pigments over synthetic dyes and their therapeutic and industrial potential. Extensive literature has been reviewed on the biomedical application of bacterial pigments, and further opportunities and future challenges have been discussed.

Improved yield of UV and heat-stable Monascus yellow pigment by statistical optimization of solid-state fermentation conditions and extraction process

Monascus species are well-known for their ability to produce biocolorants. A high-performing strain, M. purpureus F2–19, was recently developed by genome shuffling. Here, the entire bioprocess, starting from solid-state fermentation conditions to the extraction method, was statistically optimized to improve yellow pigment yield by the strain. Among culture conditions, monosodium glutamate concentration (used as nitrogen source), moisture content, and incubation period significantly influenced pigment production using less expensive broken rice as a substrate. Post-optimization, a yield of 1548.4 ± 14.6 AU/g was achieved, representing a 9.7-fold increase over the primary condition. The statistical model developed using central composite design of response surface methodology (CCD-RSM) is highly significant, with a P value of <0.0001. Similarly, a significant model (P < 0.0001) for extraction improved pigment yield further by 1.16-fold (actual output: 1796.4 ± 13.4 AU/g). The pigment remained highly stable with a preservation rate of ~90 % after 2.5 h exposure to a high temperature of 100 °C or UV light (254 nm). Even autoclaving at 121 °C for 15 min preserved 96.9 % of the pigment. These values are higher than reported for other commercial microbial yellow pigments, riboflavin, β-carotene, or lutein, thus highlighting its potential as a natural food colorant. Liquid chromatography-mass spectrometry (LC-MS) of the pigment identified nine distinct yellow compounds, with monascin being the most abundant. Thus, the optimized bioprocess would facilitate economical large-scale production of the yellow pigment; but its implementation still requires efficient selection of bioreactors and optimizations of scaling-up, especially the heat and mass transfer parameters.

Valorization of agricultural by-product for cleaner and sustainable production of microbial pigments and cellulolytic enzymes in a zero-waste approach

This work presents a zero-waste concept for the valorization of banana peel into Monascus value-added metabolites, such as pigments and cellulolytic enzymes, and for evaluation of the feasibility of treated peel as a promising source for animal feedstuff. M. purpureus YRU01 exhibited satisfactory pigment and cellulolytic enzyme production in solid-state fermentation. Particularly, repeated solid-state fermentation of non-sterile peel with 90% substrate replacement was effective in offering high recovery of pigments, xylanase, and cellulase (7.19-, 31.19-, and 92.62-fold higher than those of solid-state fermentation, respectively). The LC/MS profile of fermented peel provided important evidence of fungal metabolites (>100 metabolites) for understanding and evaluating the fermentation. Moreover, citrinin-related mycotoxin fragments were not found. The treated peel had high carbohydrate, neutral detergent fiber, and acid detergent fiber contents, but low protein content, indicating its potential to be used as a roughage in animal feed.

Extraction of Bacterial Pigments and Evaluation of its Antioxidant Activity

Carotenoid are pigment that exist in a wide variety of plant and microorganism they are characterized by red, yellow or orange coloration .These important pigment play significant role in animal and human health .In contrast to plant production, the advantages of microbial fermentation of carotenoids were lower media cost, fast growth rate of microorganism and the ease of culture control . When the microbial cells are used to produce the color the term refers to ‘microbial pigments’. Different types of pigments extracted from different microbes. In this study, soil and water samples were collected from different areas of MGM University, Chh. Sambhajinagar .Different pigmented colonies were observed on nutrient agar plate .Out of these, the orange and yellow colonies were selected and sub-cultured further to obtain their pure cultures. These samples were inoculated onto nutrient agar plates, and after an incubation period of 24 hours, different colonies were observed on the plates. Out of these, the orange and yellow isolated were selected and sub-cultured further to obtain their pure cultures. After production of the pigment in liquid medium, it was further processed for the extraction of these pigments. Further, antioxidant assay by radical scavenging activity of DPPH was carried out, which revealed that the pigment had an radical scavenging activity of 60% as compared to that of the standard ascorbic acid, which showed radical scavenging activity of 33 %. Thus, the current study can be a useful step for large-scale production of pigments, their purification and application in cosmetic industries

Novel nanoconjugates of metal oxides and natural red pigment from the endophyte Monascus ruber using solid-state fermentation

BackgroundAntimicrobial resistance has emerged as a major global health threat, necessitating the urgent development of new antimicrobials through innovative methods to combat the rising prevalence of resistant microbes. With this view, we developed three novel nanoconjugates using microbial natural pigment for effective application against certain pathogenic microbes.ResultsA natural red pigment (RP) extracted from the endophyte Monascus ruber and gamma rays were applied to synthesize RP-ZnO, RP-CuO, and RP-MgO nanoconjugates. The synthesized nanoconjugates were characterized by different techniques to study their properties. The antimicrobial potential of these nanoconjugates was evaluated. Moreover, the antibiofilm, protein leakage, growth curve, and UV light irradiation effect of the synthesized nanoconjugates were also studied. Our results confirmed the nano-size, shape, and stability of the prepared conjugates. RP-ZnO, RP-CuO, and RP-MgO nanoconjugates showed broad antimicrobial potential against the tested bacterial and fungal pathogens. Furthermore, the RP-ZnO nanoconjugate possessed the highest activity, followed by the RP-CuO against the tested microbes. The highest % inhibition of biofilm formation by the RP-ZnO nanoconjugate. Membrane leakage of E. coli and S. aureus by RP-ZnO nanoconjugate was more effective than RP-MgO and RP-CuO nanoconjugates. Finally, UV light irradiation intensified the antibiotic action of the three nanoconjugates and RP-ZnO potential was greater than that of the RP-MgO, and RP-CuO nanoconjugates.ConclusionThese findings pave the way for exploiting the synthesized nanoconjugates as potential materials in biomedical applications, promoting natural, green, and eco-friendly approaches.

Exploring of Bacterial Pigments from Thamirabarani River Alluvial Soil: Harnessing their Versatility in Dye and Paint Manufacturing

Color is a fundamental aspect of human life, playing a vital role in culture and industry. The paints and coatings industry, a significant sector within global manufacturing, has seen increased scrutiny due to its environmental and health impacts. Conventional paints contain harmful chemicals like volatile organic compounds (VOCs) and solvents, which pose risks to both workers and the environment. Recent shifts towards natural and bio-based pigments, particularly those derived from microorganisms, offer a promising alternative. Microbial pigments, such as those produced by chromogenic bacteria, provide eco-friendly, non-toxic colorants with additional benefits like antioxidant and antimicrobial properties. This review highlights the potential of bacterial pigments in various applications, particularly in the textile industry as natural dyes, and discusses their role in reducing the environmental footprint of synthetic pigments. The study also emphasizes the importance of further research into improving the production and stability of these bio- pigments for broader commercial use in industries such as food, cosmetics, and pharmaceuticals.

Development of innovative dye sensitized solar cells (DSSCs) based on co-sensitization of natural microbial pigments

In the last years, the growing attention towards environmental sustainability and circular economy has led to a renewed interest in the use of eco-friendly and recyclable materials in various sectors.Developing innovative dye sensitized solar cells (DSSCs) based on microbial pigments, is very important to meet the demands of sustainable devices. Microbial extracts obtained from Talaromyces atroroseus GH2, Arthrobacter bussei CP30 and Paracoccus bogoriensis BOG6 cultivations, and characterized by HPLC-DAD-ESI-MS analyses, have been used in this work for this purpose. The extracted pigments were tested to evaluate their suitability as photosensitizers through co-sensitization method. UV–vis measurements were carried out to determine the absorbance intensity, while Photoelectrochemical and Electrochemical Impedance Spectroscopy (EIS) analyses were applied to evaluate the devices' photovoltaic parameters and impedance characteristics. The best device, obtained by the co-sensitization of the dyes produced by Talaromyces atroroseus GH2/Paracoccus bogoriensis BOG6, exhibited a Jsc of 1.59 mA/cm2, Voc of 0.35 V, FF of 0.62, and a PCE of 0.34 %. This study highlights the potential of microbial-derived pigments in the development of DSSCs.

Transforming microbial pigment into therapeutic revelation: extraction and characterization of pyocyanin from Pseudomonas aeruginosa and its therapeutic potential as an antibacterial and anticancer agent

BackgroundThe objectives of the current study were to extract pyocyanin from Pseudomonas aeruginosa clinical isolates, characterize its chemical nature, and assess its biological activity against different bacteria and cancer cells. Due to its diverse bioactive properties, pyocyanin, being one of the virulence factors of P. aeruginosa, holds a promising, safe, and available therapeutic potential.Methods30 clinical P. aeruginosa isolates were collected from different sources of infections and identified by routine methods, the VITEK 2 compact system, and 16 S rRNA. The phenazine-modifying genes (phzM, phzS) were identified using polymerase chain reaction (PCR). Pyocyanin chemical characterization included UV-Vis spectrophotometry, Fourier Transform Infra-Red spectroscopy (FTIR), Gas Chromatography-Mass Spectrometry (GC-MS), and Liquid Chromatography-Mass Spectrometry (LC-MS). The biological activity of pyocyanin was explored by determining the MIC values against different clinical bacterial strains and assessing its anticancer activity against A549, MDA-MB-231, and Caco-2 cancer cell lines using cytotoxicity, wound healing and colony forming assays.ResultsAll identified isolates harboured at least one of the phzM or phzS genes. The co-presence of both genes was demonstrated in 13 isolates. The UV-VIS absorbance peaks were maxima at 215, 265, 385, and 520 nm. FTIR could identify the characteristic pyocyanin functional groups, whereas both GC-MS and LC-MS elucidated the chemical formula C11H18N2O2, with a molecular weight 210. The quadri-technical analytical approaches confirmed the chemical nature of the extracted pyocyanin. The extract showed broad-spectrum antibacterial activity, with the greatest activity against Bacillus, Staphylococcus, and Streptococcus species (MICs 31.25–125 µg/mL), followed by E. coli isolates (MICs 250–1000 µg/mL). Regarding the anticancer activity, the pyocyanin extract showed IC50 values against A549, MDA-MB-231, and Caco-2 cancer cell lines of 130, 105, and 187.9 µg/mL, respectively. Furthermore, pyocyanin has markedly suppressed colony formation and migratory abilities in these cells.ConclusionsThe extracted pyocyanin has demonstrated to be a potentially effective candidate against various bacterial infections and cancers. Hence, the current findings could contribute to producing this natural compound easily through an affordable method. Nonetheless, future studies are required to investigate pyocyanin’s effects in vivo and analyse the results of combining it with other traditional antibiotics or anticancer drugs.

OPTIMIZING PIGMENT PRODUCTION FROM PENICILLIUM SP. FOR SUSTAINABLE SILK DYEING

This study explores the use of microbial pigments from Penicillium sp. as a sustainable alternative to synthetic dyes in textile dyeing, focusing on optimizing pigment production and assessing color fastness on silk. Static Potato Dextrose Broth (PDB) at 28°C produced the highest concentration of red pigment after 27 days of incubation, with an optical density (O.D) of 1.010 at λmax = 530 nm. In contrast, 15°C resulted in slower pigment production (O.D = 0.860), and 37°C showed negligible growth. Adjusting the PDB pH to 5 increased pigment yield, aligning with previous studies showing Penicillium sp. thrive in acidic conditions. The final broth pH decreased to 4.0 due to organic acid production by the fungus.Silk samples dyed with these pigments were evaluated for color strength and fastness. The colorimetric values indicated moderate color intensity (K/S = 4.25) with a bright, pastel-like appearance (L* = 81.23), and a warm reddish-yellow hue (a* = 9.23, b* = 6.48). Fastness tests showed excellent performance for dry rub (rating 5), good results for wet rub (rating 4), and favorable wash fastness (rating 4 for staining and color change). However, light fastness was lower, suggesting potential fading under prolonged exposure.Overall, the study identifies Penicillium sp. as a promising source of natural dyes for silk, with optimized fermentation conditions (PDB, 28°C, pH 5, 27 days) leading to high pigment yield and strong fastness performance, offering a sustainable alternative to synthetic dyes in textiles.

Development of dye-sensitized solar cells using pigment extracts produced by Talaromyces atroroseus GH2

The identification of more efficient, clean, secure, and competitive energy supply is necessary to align with the needs of sustainable devices. For this reason, a study for developing innovative dye-sensitized solar cells (DSSCs) based on microbial pigments is reported starting from Talaromyces atroroseus GH2. The fungus was cultivated by fermentation and the extracellular pigment extract was characterized by HPLC-DAD-ESI-MS analyses. The most abundant compound among the 22 azaphilone-type pigments identified was represented by PP-O. The device’s behavior was investigated in relation to electrolyte and pH for verifying the stability on time and the photovoltaic performance. Devices obtained were characterized by UV–vis measurements to verify the absorbance intensity and transmittance percentage. Moreover, photovoltaic parameters through photo-electrochemical measurements (I–V curves) and impedance characteristics by Electrochemical Impedance Spectroscopy (EIS) were determined. The best microbial device showed a short-circuit current density (Jsc) of 0.69 mA/cm2, an open-circuit photo-voltage (Voc) of 0.27 V and a Fill Factor (FF) of 0.60. Furthermore, the power conversion efficiency (PCE) of the device was 0.11%. Thus, the present study demonstrated the potential of microbial origin pigments for developing DSSCs.Graphical abstract

BRIEF REVIEW ON MICROBIAL PIGMENTS AND THEIR PROSPECTS

The large number of microorganisms present in nature, as well as their ease of cultivation, contributes to the advantage in the extraction and manufacture of natural colours or pigments. Microbial pigments are classified as secondary metabolites and are mostly formed owing to poor metabolism during stressful situations. These microbial pigments are safe for human use, have increased biodegradability, and are more environmentally friendly, making them suitable for a variety of applications in the pharmaceutical, textile, cosmetic and food sectors. The therapeutic character of bacterial pigments is demonstrated by their antibacterial, anticancer, cytotoxic and outstanding antioxidant activities. Identifying novel microbiological sources and improving process parameters are two areas of focus for affordable pigment production. This also suggests that future generations will rely on microbial pigments rather than manmade colorants for a sustainable lifestyle. This article has attempted to take a brief idea on microbial pigments and their prospects in different sectors.

Acute toxicity and anti-enterotoxigenic activity of pigment extracted from Micrococcus roseus.

Microbial pigments are considered as one of the main sources of natural types, and the attention to them is increasing in the food and pharmaceutical industries. This study aimed to investigate the effects of pigments extracted from Micrococcus roseus (PEM) on the gene expression of a and b staphylococcal enterotoxins (sea and seb) and their acute toxicity. Real-time PCR was used to study the anti-enterotoxigenic activity of PEM against Staphylococcus aureus at sub-inhibitory concentrations. In addition, the acute toxicity of PEM was evaluated on albino mice through alkaline phosphatase (ALP), aspartate aminotransferas (AST), and alanine aminotransferase (ALT) of liver and its histopathological changes. Based on the results, the expression of sea and seb was decreased in the presence of PEM at sub-inhibitory concentrations. The 2-∆∆CT was measured 0.02 and 0.01 for the expression of sea and seb of S. aureus grown in the MHB containing 16mg/ml PEM. The results showed that the expression of seb is more sensitive to PEM compared to the expression of sea. After treatment of mice with PEM for two weeks, the condition of mice was normal, and the results of liver enzymatic activities and histopathological changes showed insignificant difference compared to the control sample.

Biosynthetic mechanism of the yellow pigments in the marine bacterium Pseudoalteromonas sp. strain T1lg65.

The Pseudoalteromonas genus marine bacteria have attracted increasing interest because of their abilities to produce bioactive metabolites. The pigmented Pseudoalteromonas group encodes more secondary metabolite biosynthetic gene clusters (BGCs) than the non-pigmented group. Here, we report a yellow pigmented bacterium Pseudoalteromonas sp. strain T1lg65, which was isolated from a mangrove forest sediment. We showed that the yellow pigments of T1lg65 belong to the group of lipopeptide alterochromides. Further genetic analyses of the alterochromide BGC revealed that the yellow pigments are biosynthesized by aryl-polyene synthases and nonribosomal peptide synthases. Within the gene cluster, altA encodes a tyrosine ammonia acid lyase, which catalyzes synthesis of the precursor 4-hydroxycinnamic acid (4-HCA) from tyrosine in the alterochromide biosynthetic pathway. In addition, altN, encoding a putative flavin-dependent halogenase, was proven to be responsible for the bromination of alterochromides based on gene deletion, molecular docking, and site mutagenesis analyses. In summary, the biosynthetic pathway, precursor synthesis, and bromination mechanism of the lipopeptide alterochromides were studied in-depth. Our results expand the knowledge on biosynthesis of Pseudoalteromonas pigments and could promote the development of active pigments in the future.IMPORTANCEThe marine bacteria Pseudoalteromonas spp. are important biological resources because they are producers of bioactive natural products, including antibiotics, pigments, enzymes, and antimicrobial peptides. One group of the microbial pigments, alterochromides, holds a great value for their novel lipopeptide structures and antimicrobial activities. Previous studies were limited to the structural characterization of alterochromides and genome mining for the alterochromide biosynthesis. This work focused on the biosynthetic mechanism for alterochromide production, especially revealing functions of two key genes within the gene cluster for the alterochromide biosynthesis. On the one hand, our study provides a target for metabolic engineering of the alterochromide biosynthesis; on the other hand, the 4-HCA synthase AltA and brominase AltN show potential in the biocatalyst industry.

Screening for pigment production and characterization of pigment profile and photostability in cold-adapted Antarctic bacteria using FT-Raman spectroscopy

Microbial pigments can replace synthetic organic pigments which often produced in unsustainable way and can be toxic. Therefore, search for new pigment producing microorganisms is of high interest for industry. In this study, a screening and characterization of pigment profile and photostability in seventy-four newly isolated Antarctic bacteria using Fourier-transform (FT) Raman spectroscopy and HPLC-MS was performed. Screening of the bacterial biomass by FT-Raman identified thirty-seven bacterial strains from the genera Agrococcus, Arthrobacter, Brachybacterium, Cryobacterium, Leifsonia, Micrococcus, Paeniglutamicibacter, Rhodococcus, Salinibacterium and Flavobacterium as having relatively high pigment content. The impact of growth temperature on the pigment production in the studied Antarctic bacteria was species - specific, while blue light exposure triggered pigment production in majority of the studied bacteria. HPLC-MS analysis of a biomass of a set of ten pigmented Antarctic bacteria identified eighteen different carotenoids and precursors. FT-Raman spectroscopy showed to be suitable for both, semi-qualitative library-independent identification of pigment producing bacteria and determination of pigment profile using spectral library of reference pigment standards. This study provides valuable insights into the pigment production capabilities of Antarctic bacteria and highlighting the potential of FT-Raman spectroscopy for characterizing microbial pigments.

Mikrobiyal Pigmentlerin Gıdalarda Renklendirici Olarak Kullanılması

Günümüzde tüketicilerin sentetik gıda boyaları ile ilgili olumsuz düşüncelerinin yaygınlaşması doğal kaynaklardan elde edilen renklendiricilere olan talebi artırmıştır. Doğal kaynaklı renklendiriciler bitki, hayvan ve mikroorganizmalardan elde edilmektedir ve biyorenklendirici olarak ifade edilmektedir. Bunlardan mikroorganizmalardan elde edilen pigmentler, sağlık üzerine yararlı etkileri ve üretimdeki çeşitli avantajları sebebiyle tercih edilmektedir. Çeşitli mikroorganizmalar (Monascus, Flavobacterium, Bacillus, Paracoccus, Streptomyces, Penicillium, Rhodotarula, Brevibacterium vb. mikroorganizmaların çeşitli türleri) pigment üretme yeteneğine sahiptir; β-karoten, arpink red, riboflavin, monascus pigmenti, prodigiosin ve likopen başlıca üretilen pigmentlerdir. Mikrobiyal pigmentlerin, kolay ekstrakte edilebilmeleri, üretim maliyetlerinin düşük olması, hammadde sorunu olmaması, çevre dostu olmaları gibi çeşitli avantajları mevcuttur. Bununla birlikte bazı mikrobiyal pigmentlerin suda çözünmemesi, farklı pH koşulları altında renk değişiklikleri göstermeleri, tat değişikliğine yol açmaları, daha sınırlı renk yelpazelerinin olması gibi dezavantajları da vardır. Bu derleme mikroorganizmaların gıdalarda kullanılan renk pigmentleri ile ilgili temel bilgileri sunmaktadır.

Insights into the synthesis, engineering, and functions of microbial pigments in Deinococcus bacteria.

The ability of Deinococcus bacteria to survive in harsh environments, such as high radiation, extreme temperature, and dryness, is mainly attributed to the generation of unique pigments, especially carotenoids. Although the limited number of natural pigments produced by these bacteria restricts their industrial potential, metabolic engineering and synthetic biology can significantly increase pigment yield and expand their application prospects. In this study, we review the properties, biosynthetic pathways, and functions of key enzymes and genes related to these pigments and explore strategies for improving pigment production through gene editing and optimization of culture conditions. Additionally, studies have highlighted the unique role of these pigments in antioxidant activity and radiation resistance, particularly emphasizing the critical functions of deinoxanthin in D. radiodurans. In the future, Deinococcus bacterial pigments will have broad application prospects in the food industry, drug production, and space exploration, where they can serve as radiation indicators and natural antioxidants to protect astronauts' health during long-term space flights.

Synergetic construction of color and multifunction for sustainable lyocell fabric by microbial nano pigment

As a kind of low-carbon, environmentally friendly and high-quality regenerated cellulose fiber derived from nature plant, the promotion and application of lyocell fiber is attracting much attention. In this paper, for the first time, microbial pigment was applied for color and multifunction construction of lyocell fabric. The size change of the pigment nano-particles during the color construction process was explored to verify the dyeing mechanism of nano-suspension system, and the optimal dyeing condition was obtained. In order to improve the dyeing effect and functionality of fabric, 1,2,3,4-butanetetracarboxylic acid (BTCA) was used to realize the anionic modification of lyocell fabric with high strength retention rate. Under optimal color construction condition, the color depth of the modified fabric was 298.5% higher than that of the unmodified one, and the dyed fabric possessed excellent dyeing uniformity and permeability. Moreover, the crosslinking reaction between BTCA and cellulose macromolecules, as well as the pigment deposition inside the fibers were helpful to the fibrillation prevention function of lyocell fibers. Dyed fabrics inherited the antibacterial and ultraviolet absorption properties of prodigiosins. The bacteriostatic rate against Staphylococcus aureus was above than 98.5%, and the UV protection performance was obviously improved. This technology successfully realized the color and multi-functional construction of the lyocell fabric in one step by natural pigment from microorganism.

Influence of Agro wastes on Enhanced Carotenoid Production – An Untapped Resource from Tropical Wetland Actinobacterial Cell Factory for Multifunctional Prospectives

The environmental toxicity problems caused by synthetic dyes, have incited the need for expedition of natural pigments or biochromes. Henceforth, microbial pigments can dwell as a promising alternative for synthetic colorants. In the current study, an extracellular yellow carotenoid was isolated from tropical mangrove wetland sediment. An actinomycete isolate, producing a characteristic extracellular yellow carotenoid, was attributed to be Streptomyces coelicolor strain SPR7 by 16SrDNA sequencing. The influence of agro wastes on Carotenoid production was scrutinized. The purified pigment was characterized by UV-Vis spectroscopy, FTIR and GC-MS; bioprospected for distinct applications such as antimicrobial activity, antioxidant activity and textile applications post to silica gel G60 chromatography. The obtained results leaded the yellow carotenoid to accept as natural dye and displayed a prospective antibacterial coupled antioxidant activity along with textile dying attributes. Ultimately, the present study could be a progressive streamline for sophisticated research and scopes in the distinct industrial arena scale.