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Bacterial pigments stand out as exceptional natural bioactive compounds with versatile functionalities. The pigments represent molecules from distinct chemical categories including terpenes, terpenoids, carotenoids, pyridine, pyrrole, indole, and phenazines, which are synthesized by diverse groups of bacteria. Their spectrum of physiological activities encompasses bioactive potentials that often confer fitness advantages to facilitate the survival of bacteria amid challenging environmental conditions. A large proportion of such pigments are produced by bacterial pathogens mostly as secondary metabolites. Their multifaceted properties augment potential applications in biomedical, food, pharmaceutical, textile, paint industries, bioremediation, and in biosensor development. Apart from possessing a less detrimental impact on health with environmentally beneficial attributes, tractable and scalable production strategies render bacterial pigments a sustainable option for novel biotechnological exploration for untapped discoveries. The review offers a comprehensive account of physiological role of pigments from bacterial pathogens, production strategies, and potential applications in various biomedical and biotechnological fields. Alongside, the prospect of combining bacterial pigment research with cutting-edge approaches like nanotechnology has been discussed to highlight future endeavours. [ABSTRACT FROM AUTHOR]

In response to escalating concerns about environmental pollution from conventional plastic packaging, there is a growing interest in ecological and sustainable materials for food packaging. Consequently, biopolymer-based electrospun materials, particularly polysaccharides such as chitosan (CH), starch, and cellulose, have emerged as promising alternatives to synthetic ones due to their remarkable barrier properties and mechanical strength. Moreover, following the trend of employing polysaccharides as ecological and sustainable solutions for packaging materials, natural colorants have also been recognized as safer alternatives to synthetic dyes, addressing concerns about potential adverse effects on human health and the environment. These natural colorants add color to food packaging and enhance food freshness, possibly extending shelf life and promoting consumers' perception of food quality and safety. Therefore, this review summarizes recent advancements in fabricating and characterizing electrospun materials based on polysaccharides and natural colorants for sustainable food packaging. It explores various electrospinning techniques and highlights the incorporation of natural colorants, including bacterial pigments, for active and intelligent packaging applications. Moreover, it emphasizes the increasing role of the biobased industry in developing sustainable packaging materials with bioactive coloration. Lastly, the review addresses challenges, opportunities, and future research directions. [ABSTRACT FROM AUTHOR]

Obtaining natural pigments from microorganisms is an alternative with high potential for biotechnological application. The use of agro-industrial wastes as substrate for cultivations enables a reduction of the production cost and may add value to potentially polluting byproducts. In this work, the extraction of pigments produced by the bacterium Chryseobacterium sp. strain kr6 was evaluated, employing feather meal as the sole carbon source for bacterial growth. The maximum production of the yellow pigments was observed for cultivation at 30 °C, during 48 h, with 5 g/L feather meal. The pigment extraction from the bacterial biomass was performed with the aid of physical methods and the testing of different organic solvents. The conditions that provided better extraction were using ultrasound with acetone as the solvent, reaching a yield of 180 μg/g biomass after optimization. The pigment was partially characterized via UV-visible, FTIR and mass spectroscopy and CIELAB color parameters, suggesting the presence of molecules belonging to the flexirubin group (aryl polyenes). The antioxidant capacity of the pigment was confirmed via the scavenging of DPPH radical and thiobarbituric acid reactive substances (TBARS) methodologies. Moreover, the pigment extract showed antimicrobial activity against Staphylococcus aureus and Enterococcus faecalis. [ABSTRACT FROM AUTHOR]

A pigment is a naturally occurring colored substance that is created by plants, animals, and microbes. Pigments are utilized in a variety of industries, including food coloring, pharmaceuticals, fabric dying, cosmetics, ink plastics, coloring paints, and so on. The Natural pigments /Bio pigments are very expensive because mass production is difficult. There are more pigments in nature, but only a small number are available in large enough amounts to be useful for industry. This study is attempted to isolate a bacterial red pigmented organism from facial acne was identified as Serratia marcescens MBM‐17 according to Bergey's manual of determinative bacteriology and molecular characterization and production of red pigment was optimized at various growth factors, maximum pigment production was at pH 4, 72 h and 37 ± 2°C, that is, 15.56 g/ L. The partial purified pigment was characterized by UV–Vis, and maximum absorbance was at 533.5 nm. SEM analysis shows that the surface morphology and FTIR spectroscopy revealed the presence of prodigiosin. Prodigiosin has antibacterial efficacy against gram positive bacterial strains, Staphylococcus aureus, Bacillus sp, and gram negative bacterial strains. Klebsiella sp, Pseudomonas sp, Salmonella sp, antifungal potency against Aspergillus niger, Aspergillus flavus, Penicillium sp, Rhizopus sp, and Mucor sp, and checked the fabric dying effects of pigments. Prodigiosin used as fabric dye is applied on clothes, which shows good color tone. This study is highlighting the production of a natural pigment/drug, Prodigiosin with antimicrobial activity may be used for the manufacture of dyed dress materials and masks having antimicrobial action for public especially health workers in this pandemic situation. [ABSTRACT FROM AUTHOR]

Bacterial pigments represent a diverse group of secondary metabolites, which confer fitness advantages to the producers while residing in communities. The bioactive potential of such metabolites, including antimicrobial, anticancer, and immunomodulation, are being explored. Reckoning that a majority of such pigments are produced in response to quorum sensing (QS) mediated expression of biosynthetic gene clusters and, in turn, influence cell–cell communication, systemic profiling of the pigments for possible impact on QS appears crucial. A systemic screening of bacterial pigments for QS-inhibition combined with exploration of antibiofilm and antimicrobial action against Acinetobacter baumannii might offer viable alternatives to combat the priority pathogen. Major bacterial pigments are classified (clustered) based on their physicochemical properties, and representatives of the clusters are screened for QS inhibition. The screen highlighted prodigiosin as a potent quorum quencher, although its production from Serratia marcescens appeared to be QS-independent. In silico analysis indicated potential interactions between AbaI and AbaR, two major QS regulators in A. baumannii, and prodigiosin, which impaired biofilm formation, a major QS-dependent process in the bacteria. Prodigiosin augmented antibiotic action of ciprofloxacin against A. baumannii biofilms. Cell viability analysis revealed prodigiosin to be modestly cytotoxic against HEK293, a non-cancer human cell line. While developing dual-species biofilm, prodigiosin producer S. marcescens significantly impaired the fitness of A. baumannii. Enhanced susceptibility of A. baumannii toward colistin was also noted while growing in co-culture with S. marcescens. Antibiotic resistant isolates demonstrated varied responsiveness against prodigiosin, with two resistant strains demonstrating possible collateral sensitivity. Collectively, the results underpin the prospect of a prodigiosin-based therapeutic strategy in combating A. baumannii infection. [ABSTRACT FROM AUTHOR]

Introduction: Staphylococcus capitis naturally colonizes the human skin but as an opportunistic pathogen, it can also cause biofilm-associated infections and bloodstream infections in newborns. Previously, we found that two strains from the subspecies S. capitis subsp. capitis produce yellow carotenoids despite the initial species description, reporting this subspecies as non-pigmented. In Staphylococcus aureus, the golden pigment staphyloxanthin is an important virulence factor, protecting cells against reactive oxygen species and modulating membrane fluidity. Methods: In this study, we used two pigmented (DSM 111179 and DSM 113836) and two non-pigmented S. capitis subsp. capitis strains (DSM 20326T and DSM 31028) to identify the pigment, determine conditions under which pigment-production occurs and investigate whether pigmented strains show increased resistance to ROS and temperature stress. Results: We found that the non-pigmented strains remained colorless regardless of the type of medium, whereas intensity of pigmentation in the two pigmented strains increased under low nutrient conditions and with longer incubation times. We were able to detect and identify staphyloxanthin and its derivates in the two pigmented strains but found that methanol cell extracts from all four strains showed ROS scavenging activity regardless of staphyloxanthin production. Increased survival to cold temperatures (-20°C) was detected in the two pigmented strains only after long-term storage compared to the non-pigmented strains. Conclusion: The identification of staphyloxanthin in S. capitis is of clinical relevance and could be used, in the same way as in S. aureus, as a possible target for anti-virulence drug design. [ABSTRACT FROM AUTHOR]

The textile industry stands as a prominent contributor to global environmental pollution, primarily attributable to its extensive reliance on synthetic dyes, hazardous components, and solvents throughout the textile dyeing and treatment processes. Consequently, the pursuit of sustainable textile solutions becomes imperative, aimed at replacing these environmentally unfriendly constituents with biobased and bioactive pigments, antibacterial agents, and, notably, natural solvents. Achieving this goal is a formidable yet indispensable challenge. In this study, the dyeing ability of the crude gel prodigiosin, produced by non-pathogenic bacteria Serratia plymuthica, was investigated on various multifiber fabrics at different conditions (temperature and pH) and by using salts and alternative mordants (the conventional Ferrous Sulphate (FeSO4) and a new bio-mordant, L-Cysteine (L-Cys)). Additionally, a novel gel-based Choline chloride (ChCl)/Lactic acid (LA) (1:2) deep eutectic solvent (DES) dyeing medium was studied to replace the organic solvents. Nylon fabrics dyed with 3.0% over the weight of the fiber (owf) L-Cys at pH = 8.3 had improved color fastness to washing, while the gel-based ChCl/LA (1:2) DES dyebath provided a better color fastness to light. Moreover, nylon fabrics under these conditions exhibited remarkable antimicrobial activity against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). In conclusion, the utilization of the crude gel-based prodigiosin pigment demonstrates a distinct advantage in dyeing textile materials, aligning with the growing consumer demand for more eco-friendly and sustainable products. Additionally, the application of the natural reducing agent L-Cys, previously untested as a bio-mordant, in conjunction with the use of gel-based DES as a dyeing medium, has showcased improved colorimetric and antibacterial properties when applied to nylon that is dyed with the crude gel prodigiosin pigment. [ABSTRACT FROM AUTHOR]

Abstract A subject of great interest is the bioprospecting of microorganisms and their bioactive byproducts, such as pigments. Microbial pigments have various benefits, including being safe to use due to their natural makeup, having therapeutic effects, and being produced all year round, regardless of the weather or location. Pseudomonas aeruginosa produces phenazine pigments that are crucial for interactions between Pseudomonas species and other living things. Pyocyanin pigment, which is synthesized by 90–95% of P. aeruginosa, has potent antibacterial, antioxidant, and anticancer properties. Herein, we will concentrate on the production and extraction of pyocyanin pigment and its biological use in different areas of biotechnology, engineering, and biology.

The use of synthetic dyes has been found to have negative environmental impacts, leading to a growing demand for natural alternatives. This study explores the potential of bacterial pigments, derived from microorganisms, as a sustainable alternative for textile dyeing. The first chapter examines the ecological impact of synthetic dyes and the potential of natural dyes, including bacterial pigments, as a sustainable alternative. Biodegradability and life-cycle-assessment are discussed in this chapter since they are important factors to evaluate the environmental impact of any substance. The second chapter discusses the potential for bacterial pigments to functionalize textile materials with new therapeutic properties, including antifungal and anti-inflammatory effects. Additionally, some bacterial pigments can be used as semiconductors for electronics. The third chapter outlines the challenges of using natural pigments in textile production and suggests techniques to improve colourfastness. The chapter also highlights the successful uses of pigments such as anthraquinone, carotenoid, violacein, melanin, and prodiginine in textile colouring. Finally, the future perspectives section identifies potential areas for further research and development in the field of bacterial pigments, which could revolutionize the textile industry towards a more eco-friendly and innovative approach to textile production.

Dye sensitized solar cells have proven its potential as affordable, green method of turning solar energy into electrical energy. This article presents an extensive comparative study on dye sensitized solar cells with two types of transport layers made of ZnO nanorods and TiO2 mesoporous film, wherein bacterial pigment extracted from microorganism Serratia nematodiphila strain B2 is employed as a sensitizer. For performance enhancement via the plasmonic effect, Ag nanoparticles have been deposited onto conducting glass and used as counter electrode (CE). The efficiency and fill factor (averaged over 3 readings) are found to be approximately 2% and 43%, respectively, with TiO2 mesoporous film and 0.4% and 25%, respectively, with ZnO nanorod in the designed DSSCs. Experiments have been conducted with TiO2 film for ten weeks to evaluate the stability of the pigment. The findings suggest that bacterial pigments may possibly replace dyes, creating a new category of solar cells known as biopigment-sensitized solar cells. [ABSTRACT FROM AUTHOR]

A subject of great interest is the bioprospecting of microorganisms and their bioactive byproducts, such as pigments. Microbial pigments have various benefits, including being safe to use due to their natural makeup, having therapeutic effects, and being produced all year round, regardless of the weather or location. Pseudomonas aeruginosa produces phenazine pigments that are crucial for interactions between Pseudomonas species and other living things. Pyocyanin pigment, which is synthesized by 90–95% of P. aeruginosa, has potent antibacterial, antioxidant, and anticancer properties. Herein, we will concentrate on the production and extraction of pyocyanin pigment and its biological use in different areas of biotechnology, engineering, and biology. [ABSTRACT FROM AUTHOR]

Bacterial pigments are the wonder molecules of nature that have attracted the attention of industries in recent years. To date, various synthetic pigments have been in use in food, cosmetics, and textile industries that have not only shown a notoriously toxic nature but also posed threat to the ecosystem. Moreover, nutraceuticals, fisheries, and animal husbandry were highly dependent on plant sources for products that aid in disease prevention and improve stock health. In this context, the use of bacterial pigments as new-generation colorants, food fortifiers, and supplements can hold great prospects as low-cost, healthy, and eco-friendly alternatives. The majority of studies on these compounds were restricted to antimicrobial, antioxidant, and anticancer potentials to date. Each of these can be highly beneficial for the development of new-generation drugs, but their other potential niche in various industries that pose health and environmental risks needs to be explored. Recent advances in novel strategies of metabolic engineering, advancements in optimization tools for the fermentation process, and the design of appropriate delivery systems will greatly expand the market of bacterial pigments in industries. This review summarizes the current technologies for enhancing production, recovery, stability, and appreciable use of bacterial pigments in industries apart from therapeutics with proper financial aspects. The toxicity perspectives have been focused to emphasize that these wonder molecules are the need of the hour and their future prospects have been highlighted. Extensive literature has been studied to include the challenges of bacterial pigments from environmental and health risk perspectives. [Display omitted] • Role of pigments and need of bio-pigment for health and environmental safety. • Bacterial pigments as an alternative to commercial toxic dyes. • A good source of stock color enhancer in fisheries and animal husbandry. • Current upstream and downstream strategies to enhance its production and stability. • Industrial market and environmental risk aspects of bacterial pigments. [ABSTRACT FROM AUTHOR]

IntroductionStaphylococcus capitis naturally colonizes the human skin but as an opportunistic pathogen, it can also cause biofilm-associated infections and bloodstream infections in newborns. Previously, we found that two strains from the subspecies S. capitis subsp. capitis produce yellow carotenoids despite the initial species description, reporting this subspecies as non-pigmented. In Staphylococcus aureus, the golden pigment staphyloxanthin is an important virulence factor, protecting cells against reactive oxygen species and modulating membrane fluidity.MethodsIn this study, we used two pigmented (DSM 111179 and DSM 113836) and two non-pigmented S. capitis subsp. capitis strains (DSM 20326T and DSM 31028) to identify the pigment, determine conditions under which pigment-production occurs and investigate whether pigmented strains show increased resistance to ROS and temperature stress.ResultsWe found that the non-pigmented strains remained colorless regardless of the type of medium, whereas intensity of pigmentation in the two pigmented strains increased under low nutrient conditions and with longer incubation times. We were able to detect and identify staphyloxanthin and its derivates in the two pigmented strains but found that methanol cell extracts from all four strains showed ROS scavenging activity regardless of staphyloxanthin production. Increased survival to cold temperatures (−20°C) was detected in the two pigmented strains only after long-term storage compared to the non-pigmented strains.ConclusionThe identification of staphyloxanthin in S. capitis is of clinical relevance and could be used, in the same way as in S. aureus, as a possible target for anti-virulence drug design.

Exploring untapped microbial potentials in previously uncharted environments has become crucial in discovering novel secondary metabolites and enzymes for biotechnological applications. Among prokaryotes, actinomycetes are well recognized for producing a vast range of secondary metabolites and extracellular enzymes. In the present study, we have used surface sediments from ‘Kadolkele’ mangrove ecosystem located in the Negombo lagoon area, Sri Lanka, to isolate actinomycetes with bioactive potentials. A total of six actinomycetes were isolated on modified-starch casein agar and characterized. The isolates were evaluated for their antibacterial activity against four selected bacterial strains and to produce extracellular enzymes: cellulase, amylase, protease, and lipase. Three out of the six isolates exhibited antibacterial activity against Staphylococcus aureus, Escherichia coli, and Bacillus cereus, but not against Listeria monocytogenes. Five strains could produce extracellular cellulase, while all six isolates exhibited amylase activity. Only three of the six isolates were positive for protease and lipase assays separately. Ac-1, Ac-2, and Ac-9, identified as Streptomyces spp. with the 16S rRNA gene sequencing, were used for pigment extraction using four different solvents. Acetone-extracted crude pigments of Ac-1

In the past two decades, a growing body of research regarding the utilization of natural bacterial pigments or dyes for textile dyeing has emerged. Bacterial pigments are bacterial secondary metabolites that usually have bright colors and some special properties (e.g., antimicrobial, antioxidative, UV protective etc.). In addition to their high production yield, these special properties led scientists to research and develop methods for utilizing bacterial pigments in textile dyeing. This study presents the current state this field of research, with a focus on the dyeing potential of bacterial pigments for different types of textile material. The potential future directions of research in this area are also highlighted. In addition to the durable dyeing of textiles, bacterial pigments with special properties, such as antimicrobial activity, can add multifunctionality to dyed materials, thus increasing the value of the final product. This emerging field of research will also have a great impact on sustainability and the environment, contributing to the decreased usage of synthetic dyes in the textile industry.

The textile industry stands as a prominent contributor to global environmental pollution, primarily attributable to its extensive reliance on synthetic dyes, hazardous components, and solvents throughout the textile dyeing and treatment processes. Consequently, the pursuit of sustainable textile solutions becomes imperative, aimed at replacing these environmentally unfriendly constituents with biobased and bioactive pigments, antibacterial agents, and, notably, natural solvents. Achieving this goal is a formidable yet indispensable challenge. In this study, the dyeing ability of the crude gel prodigiosin, produced by non-pathogenic bacteria Serratia plymuthica, was investigated on various multifiber fabrics at different conditions (temperature and pH) and by using salts and alternative mordants (the conventional Ferrous Sulphate (FeSO4) and a new bio-mordant, L-Cysteine (L-Cys)). Additionally, a novel gel-based Choline chloride (ChCl)/Lactic acid (LA) (1:2) deep eutectic solvent (DES) dyeing medium was studied to replace the organic solvents. Nylon fabrics dyed with 3.0% over the weight of the fiber (owf) L-Cys at pH = 8.3 had improved color fastness to washing, while the gel-based ChCl/LA (1:2) DES dyebath provided a better color fastness to light. Moreover, nylon fabrics under these conditions exhibited remarkable antimicrobial activity against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). In conclusion, the utilization of the crude gel-based prodigiosin pigment demonstrates a distinct advantage in dyeing textile materials, aligning with the growing consumer demand for more eco-friendly and sustainable products. Additionally, the application of the natural reducing agent L-Cys, previously untested as a bio-mordant, in conjunction with the use of gel-based DES as a dyeing medium, has showcased improved colorimetric and antibacterial properties when applied to nylon that is dyed with the crude gel prodigiosin pigment.

In this study, needleless electrospinning technology was used to obtain flexirubin (F)‐loaded polyvinyl alcohol (PVA)_kefiran (KF)/polycaprolactone (PCL) electrospun nanofibers. The SEM images of PVA_KF_ F and PCL_F nanofibers displayed beadless morphology with average diameters of 211.90 ± 96.08 and 1610.71 ± 996.68 nm, respectively. FTIR‐ATR analysis revealed increased intensity at specific wavelengths, after pigment incorporation. The high porosity exhibited by each layer and the mechanical properties of the double‐layered nanofibrous material remained unaffected after flexirubin‐type pigment incorporation. In addition, PVA_KF_F/PCL_F nanofibers showed antioxidant activity of 41.03 ± 0.29%, evaluated by the scavenging of the ABTS radical as well as the ability to reduce enzymatic browning of apple slices. Thus, we believe that the fabricated PVA_KF_F/PCL_F double‐layered material can be considered for application in active food packaging systems. [ABSTRACT FROM AUTHOR]

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Pigments find widespread application in the fields of food, medicine, textiles, and cosmetics. At present, synthetic colorants dominate the global pigment market. However, the environmental and health hazards associated with synthetic colorants have spurred extensive research on eco-friendly and safe alternatives. Natural pigments are particularly intriguing for meeting consumer demands and sustainable development, as they not only exhibit various vibrant color shades without discernible toxic side effects but also offer additional healthful features such as antibacterial, antioxidant, anticancer, and antiviral properties compared with their synthetic counterparts. Among natural sources, bacterial strains share distinct advantages for large-scale pigment production because of their intrinsic robustness of cellular metabolic systems. This review comprehensively outlines the bacterial sources, extraction and purification methods, structural characteristics, biological activities, and potential applications of typical pigments, including but not limited to violacein, indigoidine, melanin, carotenoids, prodigiosin, and rhodopsin. Additionally, it underscores the primary obstacles to the development and production of bacterial pigments for commercial applications, discussing feasible strategies for overcoming production bottlenecks. This work also provides valuable insights for the scientific and rational advancement of bacterial pigment development.

Nowadays, worldwide challenges such as global warming, pollution, unsustainable consumption patterns, and scarcity of natural resources are key drivers toward future-oriented bioeconomy strategies, which rely on renewable biobased resources, such as bacterial pigments and bacterial cellulose (BC), for materials production. Therefore, the purpose of this study was to functionalize bacterial cellulose with violacein, flexirubin-type pigment, and prodigiosin and test their suitability as pH indicators, due to the pigments' sensitivity to pH alterations. The screening of the most suitable conditions to obtain the BC-pigment indicators was achieved using a full factorial design, for a more sustainable functionalization process. Then, the pH response of functionalized BC to buffer solutions was assessed, with color changes at acidic pH (BC-violacein indicator) and at alkaline pH (BC-violacein, BC-prodigiosin, and BC-flexirubin-type pigment indicators). Moreover, the indicators also revealed sensitivity to acid and base vapors. Furthermore, leaching evaluation of the produced indicators showed higher suitability for aqueous foods. Additionally, color stability of the functionalized BC indicators was carried out, after light exposure and storage at 4 °C, to evaluate the indicators' capacity to maintain color/sensitivity. Thus, BC membranes functionalized with bacterial pigments have the potential to be further developed and used as pH indicators. [ABSTRACT FROM AUTHOR]

Among 46 local bacterial isolates capable synthetized pigments, 26% produced extracellular of blue green and fluorescent whereas 74% produced intra-cellular pigments of red, brown, yellow, orange, and rose. Seven isolates were selected as a potential candidate for the synthesis of pigments. They were Pseudomonas fluoresces, P. aeruginosa, Serratia marcescens, Azotobacter chroococcum, Micrococcus kristinae, M. luteus, and M. roseus after their morphological and biochemical studies. They capable to produce fluorescent, blue green, red, brown, orange, yellow, and rose with maximum absorbance at 400, 520, 530, 320, 440, 460, and 470 nm, with an optical density of 0.62, 1.42,1.35, 1.11, 0.45, 0.98, and 0.40, respectively. Antibacterial activity of pigments was studied against 7 bacterial pathogenic strains namely P. aeruginosa ATCC27853, Escherichia coli 0157h7 ATCC25922, Klebsiella pneumonia ATCC00607, Salmonella typhimurium ATCC25566, Listeria monocytogenes ATCC19115, Staphylococcus aureus ATCC29737, and Bacillus cereus ATCC33018. The last tested strain behaved high significant (p≤ 0.05) sensitivity for blue green, fluorescent, brown, and rose pigments while, L. monocytogenes ATCC19115 was more susceptible for red, and yellow pigments and S. aureus ATCC29737 had more inhibited by orange pigment. These bacterial pigments seemed to have antioxidant activity which inhibited the formation of diphenyl-2-picrylhydrazyl radicals with percentage ranged from 40 % to 80 %. It could therefore be stated that the bacterial pigments tested had a broad impact on foodborne pathogens and had an antioxidant effect

This work was to quantify the superficial growth and the pigmentation of filamentous fungi colonies by effect of an extremely low frequency oscillating magnetic field (OMF-ELF) depending on nutritional status of these microorganisms in two culture media. OMF-ELF of 2 mT by 60 Hz/200 V during 2 h (optimization of an experimental design) was applied at two filamentous fungi strains isolated from indoor environments: Aspergillus niger (hyaline mycelium seen under the optic microscope) and Cladosporium cladosporioides (pigmented mycelium), this latter strain was used as a negative control. The strains were inoculated in Petri dishes with Malt Extract Agar (MEA) and Czapek Dox Agar (CDA), incubated at 30°C and photographs were taken every 4 hours for 10 days. The area (superficial growth) and color intensity (pigmentation) of these colonies were evaluated by digital images processing (DIP) using MatLab®. The stimulating effect of OMF-ELF on the cellular metabolism of both fungal strains was demonstrated, with an increase of the superficial growth and a greater variation in pigmentation (indicative of sporulation by conidiogenesis) in CDA until reaching values of spores similar to when there are enough nutrients (MEA). The predictive mathematical model obtained by optimization of the experimental design to predict the growth of Aspergillus niger colony was validated with the algorithm implemented for the DIP. It was concluded that the OMF-ELF stimulated the metabolism of the studied fungal strains independently of the nutrients in the culture media and that the DIP is a precise technique to quantify the macroscopic phenomena that occur due to magnetobiological effects at the cellular level. [ABSTRACT FROM AUTHOR]

Pigments from natural sources, such as bacterial pigments, have gained increased attention in recent years due to their biodegradability, non-toxicity, and noncarcinogenicity. The intention to replace synthetic and oil-derived compounds is not restricted to synthetic dyes; other applications include the replacement of oilderived polymers for more environmentally friendly options, such as biopolymers. In this work, the functionalization of a bacterial cellulose (BC) biopolymer with bacterial pigments was explored using a full factorial design methodology to evaluate the best functionalization conditions to produce colored BC. From the factors and interactions evaluated, it was possible to conclude that the variable duration of the functionalization procedure could be reduced to a low level without significantly affecting the functionalization of the BC samples with bacterial pigments. Moreover, BC is a product with high industrial applicability, versatility, and sustainability. Hence, the multifunctional colored BC can be applied in the packaging, paper, and textile industries, among others. [ABSTRACT FROM AUTHOR]

The aim of this work was to reuse a fish processing waste, shrimp head powder (SHP), for the production of prodigiosin (PG) via microbial technology and to assess its potential bioactivities. PG was produced in a 12 L-bioreactor system, and the highest PG productivity of 6310 mg L-1 was achieved when Serratia marcescens CC17 was used for fermentation in a novel designed medium (6.75 L) containing 1.5% C/N source (SHP/casein = 9/1), 0.02% K2SO4, ans 0.025% Ca3(PO4)2, with initial pH 7.0, and fermentation was performed at 28 °C for 8 h. The purified PG showed moderate antioxidants, efficient anti-NO (anti-nitric oxide), and acetylcholinesterase (AChE) inhibitory activities. In a docking study, PG showed better binding energy scores (-12.3 kcal/mol) and more interactions (6 linkages) with several prominent amino acids in the biding sites on AChE that were superior to those of Berberine chloride (-10.8 kcal/mol and one linkage). Notably, this is the first investigation using shrimp heads for the mass bioproduction of PG with high productivity, and Ca3(PO4)2 salt was also newly found to significantly enhance PG production by S. marcescens. This study also provided available data on the anti-NO and anti-AChE effects of PG, especially from the docking simulation PG towards AChE that was described for the first time in this study. The above results suggest that SHP is a good material for the cost-effective bioproduction of PG, which is a potential candidate for anti-NO and anti-Alzheimer drugs. [ABSTRACT FROM AUTHOR]

Background and Objectives: Serratia is a gram-negative bacterium. The pigmentation property of Serratia Marcescens is used as a marker of dust particles in the environment and in the hospital. Today biopigments are also widely used in the manufacture and production of pharmaceutical products. Prodigiosin is a promising drug due to its reported properties of antifungal immunosuppressive and antiproliferative activities. In the present study, cloning of pig gene- isolated from Serratia Marcescens in Ecoli XL1blue was performed. Subjects and Methods 60 Samples were taken from clinical sources of patients hospitalized with urinary tract infections in Saveh Hospitals. Serratia Marcescens were identified and isolated by different tests. The pig gene was cloned by T-A cloning using PTG-19 vector into the Escherichia coli XL1blue as host. Expression of cloned gene in recombinant colonies was evaluated by Real time PCR. The phylogenetic tree was plotted using clustalX and Mega5 software Results Screening of samples identified 12 isolates of Serratia Marcescens from then 4 isolates had pig gene. Expression of Pig gene in Escherichia coli XL1blue was confirmed by Real-Tima PCR. As a result of phylogenetic studies, some close relatives of serratia have been identified as candidates for further studies Conclusion Serratia Marcescens can be considered as a rich source of pigments with many applications and can be used as indigenous strains to produce Prodigiosin. [ABSTRACT FROM AUTHOR]

Among 46 local bacterial isolates capable synthetized pigments, 26% produced extracellular of blue green and fluorescent whereas 74% produced intra-cellular pigments of red, brown, yellow, orange, and rose. Seven isolates were selected as a potential candidate for the synthesis of pigments. They were Pseudomonas fluoresces, P. aeruginosa, Serratia marcescens, Azotobacter chroococcum, Micrococcus kristinae, M. luteus, and M. roseus after their morphological and biochemical studies. They capable to produce fluorescent, blue green, red, brown, orange, yellow, and rose with maximum absorbance at 400, 520, 530, 320, 440, 460, and 470 nm, with an optical density of 0.62, 1.42,1.35, 1.11, 0.45, 0.98, and 0.40, respectively. Antibacterial activity of pigments was studied against 7 bacterial pathogenic strains namely P. aeruginosa ATCC27853, Escherichia coli 0157h7 ATCC25922, Klebsiella pneumoniae ATCC00607, Salmonella typhimurium ATCC25566, Listeria monocytogenes ATCC19115, Staphylococcus aureus ATCC29737, and Bacillus cereus ATCC33018. The last tested strain behaved high significant (p≤ 0.05) sensitivity for blue green, fluorescent, brown, and rose pigments while, L. monocytogenes ATCC19115 was more susceptible for red, and yellow pigments and S. aureus ATCC29737 had more inhibited by orange pigment. These bacterial pigments seemed to have antioxidant activity which inhibited the formation of diphenyl-2-picrylhydrazyl radicals with percentage ranged from 40 % to 80 %. It could therefore be stated that the bacterial pigments tested had a broad impact on foodborne pathogens and had an antioxidant effect. [ABSTRACT FROM AUTHOR]

Abstract Background and Aim:With respect to the increasing of antibiotic resistance in pathogenic bacteria, identification of new antimicrobial compounds is necessary. Bacterial pigments as bioactive products are one of the agents for identifying new antimicrobial agents. Microorganisms have been considered for the production of new microbial products such as pigments. Methods: In the present research, a total of 37 pigmented bacterial strains were obtained from soil samples of different regions of Fars province, Iran. These strains contained a wide variety of pigmentation including: red, yellow and green. Strains with different pigmentation were selected for further studies. Pigments were extracted by methanol-water or methanol for secreted and non-secreted pigments, respectively. In order to evaluate the antibacterial activity of pigments, disc diffusion and macrodilution assay were used on MDR Klesiella isolated from clinical samples. Finally, microorganism with anti-bacterial pigment was identified by molecular method. Results: Based on the morphology of isolated pigment colonies in different environments and carrying out biochemical tests, the presence of bacteria such as, Pseudomonas aeroginosa, Serratia marcescens, Enterobacter sakazakii, Flavobacter mizutaii, Micrococcus luteus and Staphylococcus aureus were identified. The total frequency of Klebsiella isolates was 8.5%. Of the 17 isolated isolates, 12 isolates were completely resistant to all antibiotics, and six isolates were sensitive to the imipenem antibiotic. All of Klebsiella isolates were multi drug resistance. A Red pigment from Serratia marcessence was the most potent and showed inhibitory effects on MDR Klebsiella. Conclusion: Isolated microorganisms from environmental resources contained a very diverse collection of pigments, where different pigment structures with different antimicrobial properties can be searched. The present study indicated that bacterial pigments can be effective against MDR Klebsiella isolates.

When two coherent green beams offset from each other by a small angle are coupled in bacteriorhodopsin film, the diffraction intensity rises from zero to a maximum, and then decreases along with the writing time. Based on the change of the diffraction intensity with the writing time, we proposed and demonstrated a time-dependent all-optical exclusive not or (XNOR) operation and a time-dependent all-optical logical inverter (NOT) operation. Based on the relation between the self-diffraction intensity and the polarization states of the input beams, the time-dependent all-optical XNOR logic gate was achieved, and based on the relation between the polarization states of the diffraction beams and that of the recording beams, the time-dependent all-optical NOT logic gate was obtained. [ABSTRACT FROM AUTHOR]

Prodigiosin, a pigment produced by Serratia marcescensinhibits the growth of different microorganisms and the proliferation of some human cancer cell lines. Prodigiosin is usually produced by fermentations of substrates such as starch and proteins, andpig-ment yield depends on the concentration of the carbon source, stirring speed of cultures, temperature and time of incubation,nitro-gen sources, and pH of medium. In the present study, pigment production was assessed using two types of casein as substrate; pigment yield was greater when casein precipitated with vinegar was used as substrate than when high purity casein was. The maxi-mum prodigiosin production was achieved with 10 g/L casein at pH 8.0. Additionally, supplementation of culture media with glu-cose was found to considerably decrease prodigiosin production and growth inhibition of Staphylococcus aureus, which is directly related to pigment yield. Production in stirred-tank bioreactor at 0.75 vvm aeration was higher than that at 0.5 and 1.0 vvm. Sub-strate type, concentration and pH affected pigment production in Erlenmeyer flasks, whereas aeration rate influenced pigment pro-duction in a stirred-tank bioreactor.

The Prodiginins (PGs) natural pigments are secondary metabolites produced by a broad spectrum of gram-negative and gram-positive bacteria, notably by species within the Serratia and Streptomyces genera. These compounds exhibit diverse and potent biological activities, including anticancer, immunosuppressive, antimicrobial, antimalarial, and antiviral effects. Structurally, PGs share a common tripyrrolic core but possess variable side chains and undergo cyclization, resulting in structural diversity. Studies have investigated their antiproliferative effects on various cancer cell lines, with some PGs advancing to clinical trials for cancer treatment. This review aims to illuminate the molecular mechanisms underlying PG-induced apoptosis in cancer cells and explore the structure-activity relationships pertinent to their anticancer properties. Such insights may serve as a foundation for further research in anticancer drug development, potentially leading to the creation of novel, targeted therapies based on PGs or their derivatives., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Microorganisms are considered one of the most promising niches for prospecting, production, and application of bioactive compounds of biotechnological interest. Among them, bacteria offer certain distinctive advantages due to their short life cycle, their low sensitivity to seasonal and climatic changes, their easy scaling as well as their ability to produce pigments of various colors and shades. Natural pigments have attracted the attention of industry due to an increasing interest in the generation of new products harmless to humans and nature. This is because pigments of artificial origin used in industry can have various deleterious effects. On this basis, bacterial pigments promise to be an attractive niche of new biotechnological applications, from functional food production to the generation of new drugs and biomedical therapies. This review endeavors to establish the beneficial properties of several relevant pigments of bacterial origin and their relation to applications in the biomedical area.

Pigments are light-absorbing substances that are abundant in nature, serving roles in coloration, camouflage, mate/pollinator attraction and photosynthesis among higher life forms. Among microbial organisms, pigments can also be found in a wide range of phyla. While some of these pigments function in photosynthesis, namely among algae and some bacteria, the great majority of microbial pigments play entirely different roles. The exploratory study presented here will stimulate students to think about the cost and benefit of a heritable trait (pigment production) of microscopic organisms and its effects on survival in a competitive and hostile environment. Exploring and understanding the roles these pigments play allows for a number of cross-disciplinary learning opportunities that combine physics, chemistry, biology and even art, and can be set up as an inquiry-based learning module suitable for small-group and active learning experiences. [ABSTRACT FROM AUTHOR]

The synthetic dyes were highly used from 19th century onwards which is a reason for declining of natural dyes. In textile industry synthetic pigments are highly used which is harmful to our environments but the natural color are safe. The source for natural colors is plants, animals and microorganisms. In microbes, the bacteria produce a more number of pigments which is used as natural colorants and they used for dyeing a cloth in textile industry. These types of natural dyes are known as green dyes or biocolors which have more applications on other industries like food, pharmaceuticals and cosmetics. This review summarizes the importance of natural pigments from bacteria which can be used to dyeing the fabrics in textile industry with the help of mordant. [ABSTRACT FROM AUTHOR]

Pigments synthesised by Chryseobacterium sp. kr6 growing on feather waste were extracted and characterised. The pigment extract was characterised by KOH test, UV–vis, CIELAB colour system, HPLC-DAD-MS, FTIR and its antioxidant capacity was evaluated. A positive bathochromic shift was observed when kr6 colonies or pigment extracts were subjected to alkaline solution (20% KOH) and a λmax at 450 nm was detected for acetone extracts, although no typical fine structure of carotenoids was detected in the electomagnetic spectra. The HPLC profile of the extracted pigment showed that the compound has three different peaks with λmax near 450 nm. The FTIR analysis shows some principal functional groups from a flexirubin-like molecule. The pigmented compound also presents antioxidant activity evaluated by the scavenging of the ABTS radical. [ABSTRACT FROM AUTHOR]

Prodigiosin and undecylprodigiosin are tripyrrolic red pigmented antibiotics produced by certain bacteria. Many strains of Serratia and certain other Gammaproteobacteria produce prodigiosin and undecylprodigiosin is produced by certain strains of Streptomyces. This is a multistage process which involves the synthesis of a bipyrrolic compound from L-proline and its subsequent condensation with a mono pyrrole synthesized from 2-octenal in the case of prodigiosin and malonyl-CoA in the case of undecylprodigiosin respectively. We have carried out sequence analysis of the genes involved in the pathway and identified the distribution of the prodigiosin producing genes amongst the various bacteria which have been fully sequenced. The presence of the operon was clearly seen in certain clustered branches suggesting inheritance from a common ancestor. This was further confirmed by the absence of traits observed in horizontally acquired genes like, GC content variation, codon bias or the presence of mobile elements. Multiple sequence alignment of the promoter of the prodigiosin operon in seven fully sequenced Serratia marcescens strains showed excellent homology. Putative regulatory elements in this region were identified by sequence analysis studies and many of them have been found to influence pigment production. The undecylprodigiosin gene cluster on the other hand, shows homology to other gene clusters involved in the production of other pyrrole-containing antibiotics of the genus Streptomyces. This coupled with the presence of ORFs with three different promoters could indicate lateral gene transfer. Hence the evolution of undecylprodigiosin operon could be an example of convergent evolution. [ABSTRACT FROM AUTHOR]

Highlights • Antarctic bacterial strain So13.3 produces a pigment with DSSC sensitizer activity. • Pigment from Antarctic bacteria can produce energy and is a type of melanin. • Pigment-producing microorganisms from Antarctic can be a source for DSSC use. Abstract The study of bacterial pigment for their application in DSSC is an in-development area of solar energy. However, studies on bacterial pigments for application in solar cells are scarce. We evaluated the use of a pigment obtained from the Antarctic So13.3 bacterial strain as a sensitizer in DSSC. Based on the sequence of the 16S gene, the So13.3 strain was identified as Streptomyces fildesensis. The bacterial pigment was characterized by UV–Vis and Fourier-Transform Infrared Spectroscopy (FTIR). Results indicate that the pigment has very similar characteristics to melanin. DSSC showed the best performance at a concentration of 6500 (μg/mL), obtaining a voltage of 493 [mV], a current density of 0.091 [mA/cm2], 0.026% efficiency and a 0.579 Filling Factor (FF). Considering that there are few studies on bacterial pigments applied in DSSC, we demonstrate the importance of focusing research on pigment-producing microorganism isolation and evaluating their potential use in DSSC. [ABSTRACT FROM AUTHOR]

Summary: The disposal of reject brine, a highly concentrated waste by‐product generated by various industrial processes, represents a major economic and environmental challenge. The common practice in dealing with the large amounts of brine generated is to dispose of it in a pond and allow it to evaporate. The rate of evaporation is therefore a key factor in the effectiveness of the management of these ponds. The addition of various dyes has previously been used as a method to increase the evaporation rate. In this study, a biological approach, using pigmented halophilic bacteria (as opposed to chemical dyes), was assessed. Two bacteria, an Arthrobacter sp. and a Planococcus sp. were selected due to their ability to increase the evaporation of synthetic brine. When using industrial brine, supplementation of the brine with an iron source was required to maintain the pigment production. Under these conditions, the Planococcus sp. CP5‐4 produced a carotenoid‐like pigment, which resulted in a 20% increase in the evaporation rate of the brine. Thus, the pigment production capability of halophilic bacteria could potentially be exploited as an effective step in the management of industrial reject brines, analogous to the crystallizer ponds used to mine salt from sea water. The pigment production capability of halophilic bacteria could potentially be exploited as an effective step in the management of industrial reject brines The pigment produced by CP5‐4was sufficient to increase brine evaporation rates in a controlled system. [ABSTRACT FROM AUTHOR]

Abstract Anoxygenic photosynthetic bacteria thrive under diverse habitats utilising an extended range of inorganic/organic compounds under different growth modes. Although they display incredible metabolic flexibility, their responses and adaptations to changing carbon regimes is largely unexplored. In the present study, we employed iTRAQ-based global proteomic profiling and physiological studies to uncover the adaptive strategies of a phototrophic bacterium, Rubrivivax benzoatilyticus JA2 to glucose. Strain JA2 displayed altered growth rates, reduced cell size and progressive loss of pigmentation when grown on glucose compared to malate under photoheterotrophic condition. A ten-fold increase in the saturated to unsaturated fatty acid ratio of glucose-grown cells indicates a possible membrane adaptation. Proteomic profiling revealed extensive metabolic remodelling in the glucose-grown cells wherein signal-transduction, selective-transcription, DNA-repair, transport and protein quality control processes were up-regulated to cope with the changing milieu. Proteins involved in DNA replication, translation, electron-transport, photosynthetic machinery were down-regulated possibly to conserve the energy. Glycolysis/gluconeogenesis, TCA cycle and pigment biosynthesis were also down-regulated. The cell has activated alternative energy metabolic pathways viz., fatty acid β-oxidation, glyoxylate, acetate-switch and Entner-Doudoroff pathways. Overall, the present study deciphered the molecular/metabolic events associated with glucose-grown cells of strain JA2 and also unraveled how a carbon source modulates the metabolic phenotypes. Significance Anoxygenic photosynthetic bacteria (APB) exhibit incredible metabolic flexibility leading to diverse phenotypes. They thrive under diverse habitat using an array of inorganic/organic compounds as carbon sources, yet their metabolic adaptation to varying carbon regime is mostly unexplored. Present study uncovered the proteomic insights of the cellular responses of strain JA2 to changing carbon sources viz. malate and glucose under photoheterotrophic conditions. Our study suggests that carbon source can also determine the metabolic fate of the cells and reshape the energy dynamics of APB. Here, for the first time study highlighted the plausible carbon source (glucose) mediated regulation of photosynthesis in APB. The study sheds light on the plausible cellular events and adaptive metabolic strategies employed by strain JA2 in presence of non-preferred carbon source. It also revealed new insights into the metabolic plasticity of APB to the changing milieu. Graphical abstract Unlabelled Image Highlights • Strain JA2, a metabolically versatile bacterium utilizes an array of compounds for growth. • Strain JA2 grown on a non-preferred carbon source led to a phenotypic shift. • Alternate energy metabolic pathways are adopted by the cells during stressed state. • Energy dynamics is a likely contributor of metabolic remodelling in strain JA2. • Organism displayed stringent response via rewiring its biological processes. [ABSTRACT FROM AUTHOR]

DNA-binding motif of bacterioopsin activator (Bat) protein is a Helix-Turn-Helix motif, which binds to bop promoter and induces bacterioopsin (Bop) expression under light and low oxygen tension. Bacterioopsin is linked to retinal to produce bacteriorhodopsin (BR), which in turn supplies energy source in Halobacterium salinarum. In this study, effect of Bat HTH motif-promoter DNA interaction on bacterioopsin (Bop) expression was investigated using in silico and experimental approaches. Molecular docking showed that the most stable DNA-protein complex was generated by Q661R/Q665R mutant. Based on the in silico analysis, HTH motif was mutated using site-directed mutagenesis and Hbt. salinarum recombinant strains were developed by introduction of mutant bat genes. Double positively charged amino acid substitutions (Q661R/Q665R) in second helix of HTH motif increased whereas deletion of this region decreased BR production. However, other single substitutions (Q665R and Q661H) did not change BR production. These findings represent key role of HTH motif stability for DNA binding and regulation of bacterioopsin (Bop) expression and bacteriorhodopsin (BR) production independent of environmental condition. [ABSTRACT FROM AUTHOR]

Pyocyanin was the first natural phenazine described. The molecule is synthesized by about 95% of the strains of Pseudomonas aeruginosa. From discovery up to now, pyocyanin has been characterised by a very rich and avant-garde history, which includes its use in antimicrobial therapy, even before the discovery of penicillin opened the era of antibiotic therapy, as well as its use in electric current generation. Exhibiting an exuberant blue colour and being easy to obtain, this pigment is the subject of the present review, aiming to narrate its history as well as to unveil its mechanisms and suggest new horizons for applications in different areas of engineering, biology and biotechnology.

Survey data and wet lab reports presented in this paper were collected from Western coastlines of India from Goan beaches. Oil polluted areas were captured on camera as evidence for oil and tar pollution. Several microorganisms showing diverse characteristics such as pigment producers, salt tolerant and hydrocarbon resistance were isolated and cultured in the laboratory. The dataset presented in this paper supports “A case study on effects of oil spills and tar-ball pollution on beaches of Goa (India)” (Rekadwad and Khobragade, 2015) [1] and “Microbial diversity of oil spills and tar resistant bacteria isolated from beaches of Goa (India)” (Rekadwad and Khobragade, 2016) [2].

The genus Streptomyces is the best-known source of therapeutic secondary metabolites, especially antibiotics with pharmaceutical applications. Here, we performed a comparative study based on the time-resolved metabolic disparity in S. coelicolor A3(2) subjected to fermentative cultivation in two different types of media (R2YE and RSM3) in order to investigate secondary metabolite production pathways. The relative abundance of secondary metabolites, such as prodiginines, indoles, germicidins, and selected diketopiperazines, was increased in S. coelicolor A3(2) cultivated in R2YE medium compared to that in RSM3 medium, variably at the late-log and stationary phases of fermentative growth. Correlation analysis indicated that “antibiotic prodiginines” contributed maximally to the absorption maxima (A530) of culture supernatants, indicating their optimal production at 96 hours in R2YE medium. A higher abundance of -proline (48–72 hours) followed by prodiginines (96 hours) was evident, substantiating the intertwined links between precursor and activated prodiginines pathway. Similarly, the higher abundance of indoles was concurrent with tryptophan levels in the shikimate pathway, whereas diketopiperazines were synchronously abundant along with the levels of phenylalanine, leucine, and proline. Additionally, acetyl-CoA induced the acetate pathway, resulting in the production of germicidins. Thus, our results demonstrate that S. coelicolor A3(2) produces specific secondary metabolites by enhancing the dedicated metabolic pathway responsible for their production. In conclusion, our results from this study provide insight into the metabolic pathways of S. coelicolor A3(2), and can be applied to further optimize the production of prodiginines. [ABSTRACT FROM AUTHOR]

Abstract As a kind of natural dye, microbial pigments are attracting more and more attention for their application in textile dyeing. In this study, prodigiosins suspension produced by fermentation of Serratia marcescens was utilized as a novel kind of cleaner dye liquor for silk fabric dyeing. The average particle size of pigment particles was 217.1 nm and the prodigiosins concentration was determined to be 69.38 mg/L. Effects of technical parameters including dyeing temperature, dyeing time and dye liquor pH on dyeing effect and antibacterial capability of dyed fabrics were explored. The results indicated that when the dyeing temperature was 80 °C with a holding time of 30 min, dyed silk under dye bath pH 2.1 possessed high color strength, good color fastness and outstanding bacteriostatic rate of above 93.0% against Staphylococcus aureus. In addition, in vitro cytocompatibility test indicated that dyed silk fabric had no potential cytotoxicity to L929 cells. This study provided an innovative clean approach of dyeing silk with prodigiosins and endowed the fabric with antibacterial activity, simultaneously. Graphical abstract Image Highlights • Prodigiosins suspension produced by liquid fermentation is utilized as a kind of cleaner natural dye for silk fabric dyeing. • Influences of dyeing temperature, time and dye bath pH on dyeing effect are investigated. • Dyed silk fabric possesses excellent antimicrobial activity against S. aureus and good cytocompatibility with L929 cells. [ABSTRACT FROM AUTHOR]

Twenty years ago an Arctic cryptophyte was isolated from Baffin Bay and given strain number CCMP2045. Here, it was described using morphology, water‐ and non‐water soluble pigments and nuclear‐encoded SSU rDNA. The influence of temperature, salinity, and light intensity on growth rates was also examined. Microscopy revealed typical cryptophyte features but the chloroplast color was either green or red depending on the light intensity provided. Phycoerythrin (Cr‐PE 566) was only produced when cells were grown under low‐light conditions (5 μmol photons · m−2 · s−1). Non‐water‐soluble pigments included chlorophyll a, c2 and five major carotenoids. Cells measured 8.2 × 5.1 μm and a tail‐like appendage gave them a comma‐shape. The nucleus was located posteriorly and a horseshoe‐shaped chloroplast contained a single pyrenoid. Ejectosomes of two sizes and a nucleomorph anterior to the pyrenoid were discerned in TEM. SEM revealed a slightly elevated vestibular plate in the vestibulum. The inner periplast component consisted of slightly overlapping hexagonal plates arranged in 16–20 oblique rows. Antapical plates were smaller and their shape less profound. Temperature and salinity studies revealed CCMP2045 as stenothermal and euryhaline and growth was saturated between 5 and 20 μmol photons · m−2 · s−1. The phylogeny based on SSU rDNA showed that CCMP2045 formed a distinct clade with CCMP2293 and Falcomonas sp. isolated from Spain. Combining pheno‐ and genotypic data, the Arctic cryptophyte could not be placed in an existing family and genus and therefore Baffinellaceae fam. nov. and Baffinella frigidus gen. et sp. nov. were proposed. [ABSTRACT FROM AUTHOR]

Abstract Cyanobacteria are the oxygenic photosynthesis performing prokaryotes and show a connecting link between plastids of eukaryotic autotrophs and prokaryotes. A variety of pigments, like chlorophyll, carotenoids and phycobiliproteins which exhibit different colors are present in cyanobacteria. Increasing consciousness about the harmful effects of synthetic or chemical dyes encouraged people to give more preference towards the usage of natural products, such as plant or microbial-derived colors in food and cosmetics. That is why cyanobacteria are exploited as a source of natural colors and have high commercial value in many industries. This review mainly focuses on different cyanobacterial pigments, their applications and modern biotechnological approaches such as genetic engineering, systems biology to enhance the production of biopigments for their potential use in pharmaceuticals, food, research, and cosmetics industries. Graphical abstract Image 1 Highlights • Coloration provides product attractiveness; so many coloring agents are used in textile, food and cosmetic industries. • Pigments are light absorbing compounds and cyanobacteria are rich source of variety of pigments. • Carotenoids have commercial value because of their brilliant colors, antioxidant property and health promoting factors. • Phycobiliprotein production is directly affected by the environmental factors and the quality of the light. • Cyanobacterial structural similarity with plastids elucidates their potential for genetic and metabolic engineering. [ABSTRACT FROM AUTHOR]