Carotenoid pigments of Kocuria flava PUTS1_3 isolated from sediments of Puttalam lagoon mangrove ecosystem, Sri Lanka exhibit bioactive properties

Microorganisms, inhabiting various ecological niches, exhibit a capacity to produce a diverse array of pigments with different shades. These colorful microbial pigments may also potentially possess beneficial bioactivities. This dual functionality together with the ease of mass production and downstream processing has shifted the global attention towards the use of microbially-derived pigments as bioactive colorants in different industries. Therefore, the present study was conducted with the aim of characterizing the pigments from Kocuria flava and identifying their potential biotechnological applications. The bacterium, PUTS1_3, was isolated using the surface sediment samples from the Puttalam mangrove ecosystem, Sri Lanka and it was identified as Kocuria flava using 16S rRNA gene sequencing. The yellow, intracellular pigment of PUTS1_3 was obtained by treating the cell pellet with methanol. Characterization of the pigment extract using UV-visible spectroscopy, TLC, and HPLC confirmed the presence of three carotenoid compounds, including β-carotene. The pigment extract also demonstrated antibacterial activity, against Gram positive bacteria tested. Antioxidant properties were observed with an IC50 value of 181.95 ± 4.57 µg/ml in the DPPH free radical scavenging assay. Although its sun protection factor was comparatively low (SPF 7.69 ± 0.01), the pigment showed promising results as a textile dye demonstrating good color performance and stability in washing and pH stability tests. Moreover, fabrics dyed with the pigment extract displayed antibacterial activity against Staphylococcus aureus (ATCC 25923). These findings suggest the potential use of the yellow pigments of K. flava PUTS1_3 for various biotechnological applications.

Synthesis, characterization and application of microbial pigments in foods as natural colors

Colorants have played a crucial role in various applications, particularly in food processing, with natural sources such as mineral ores, plants, insects, and animals being commonly used. However, the nineteenth century saw the development of synthetic dyes, which replaced these natural colorants. In recent years, there has been a growing demand for natural products, driving an increased interest in natural colorants. Microbial pigments have emerged as promising sources of natural pigments due to their numerous health benefits. They can be produced in large quantities rapidly and from more affordable substrates, making them economically attractive. This review focuses on the current advancements in the low-cost synthesis of microbial pigments, exploring their biological activities and commercial applications. Microbial pigments offer a sustainable and economically viable alternative to natural and synthetic colorants, meeting the growing demand for natural products. These pigments are relatively nontoxic and exhibit significant health benefits, making them suitable for a wide range of applications. As interest in natural products continues to rise, microbial pigments hold great potential in shaping the future of colorant production across various sectors.

Azaphilone pigments from the marine-derived Penicillium sclerotium UJNMF 0503 and their neuroprotective potential against H2O2-induced cell apoptosis through modulating PI3K/Akt pathway

Azaphilones represent a particular group of fascinating pigments from fungal source, with easier industrialization and lower cost than the traditional plant-derived pigments, and they also display a wide range of pharmacological activities. Herein, 28 azaphilone analogs, including 12 new ones, were obtained from the fermentation culture of a marine fungus Penicillium sclerotium UJNMF 0503. Their structures were elucidated by MS, NMR and ECD analyses, together with NMR and ECD calculations and biogenetic considerations. Among them, compounds 1 and 2 feature an unusual natural benzo[d][1,3]dioxepine ring embedded with an orthoformate unit, while 3 and 4 represent the first azaphilone examples incorporating a novel rearranged 5/6 bicyclic core and a tetrahydropyran ring on the side chain, respectively. Our bioassays revealed that half of the isolates exhibited neuroprotective potential against H2O2-induced injury on RSC96 cells, while compound 13 displayed the best rescuing capacity toward the cell viability by blocking cellular apoptosis, which was likely achieved by upregulating the PI3K/Akt signaling pathway.

Physicochemical characterization and phase II metabolic profiling of echinochrome A, a bioactive constituent from sea urchin, and its physiologically based pharmacokinetic modeling in rats and humans

Echinochrome A, a natural naphthoquinone pigment found in sea urchins, is increasingly being investigated for its nutritional and therapeutic value associated with antioxidant, anticancer, antiviral, antidiabetic, and cardioprotective activities. Although several studies have demonstrated the biological effects and therapeutic potential of echinochrome A, little is known regarding its biopharmaceutical behaviors. Here, we aimed to investigate the physicochemical properties and metabolic profiles of echinochrome A and establish a physiologically-based pharmacokinetic (PBPK) model as a useful tool to support its clinical applications. We found that the lipophilicity, color variability, ultraviolet/visible spectrometry, and stability of echinochrome A were markedly affected by pH conditions. Moreover, metabolic and pharmacokinetic profiling studies demonstrated that echinochrome A is eliminated primarily by hepatic metabolism and that four possible metabolites, i.e., two glucuronidated and two methylated conjugates, are formed in rat and human liver preparations. A whole-body PBPK model incorporating the newly identified hepatic phase II metabolic process was constructed and optimized with respect to chemical-specific parameters. Furthermore, model simulations suggested that echinochrome A could exhibit linear disposition profiles without systemic and local tissue accumulation in clinical settings. Our proposed PBPK model of echinochrome A could be a valuable tool for predicting drug interactions in previously unexplored scenarios and for optimizing dosage regimens and drug formulations.

Genetic and Environmental Factors Influencing the Production of Select Fungal Colorants: Challenges and Opportunities in Industrial Applications

Natural colorants, mostly of plant and fungal origins, offer advantages over chemically synthetic colorants in terms of alleviating environmental pollution and promoting human health. The market value of natural colorants has been increasing significantly across the globe. Due to the ease of artificially culturing most fungi in the laboratory and in industrial settings, fungi have emerged as the organisms of choice for producing many natural colorants. Indeed, there is a wide variety of colorful fungi and a diversity in the structure and bioactivity of fungal colorants. Such broad diversities have spurred significant research efforts in fungi to search for natural alternatives to synthetic colorants. Here, we review recent research on the genetic and environmental factors influencing the production of three major types of natural fungal colorants: carotenoids, melanins, and polyketide-derived colorants. We highlight how molecular genetic studies and environmental condition manipulations are helping to overcome some of the challenges associated with value-added and large-scale productions of these colorants. We finish by discussing potential future trends, including synthetic biology approaches, in the commercial production of fungal colorants.

Pigments of aminophenoxazinones and viridomycins produced by termite-associated Streptomyces tanashiensis BYF-112

Termite-associated Streptomyces tanashiensis BYF-112 was found as a potential source for yellow and green pigments, which were stable under the tested temperature, light and metal ions. Eight metabolites (1-8), including four new natural yellow pigments aminophenoxazinones (1-4), and two rarely iron dependent green pigments viridomycin A and F (9-10) were isolated from BYF-112 cultured in YMS and YMS treated with FeSO₄, respectively. The metabolites 2-4 displayed a significant safety performance on the normal liver cell line L-02, while the metabolite 1 showed weak cytotoxicity against the L-02 and several cancer cells. Especially, in the filter paper disc tests, the compound 1 possessed strong antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) with the zone of inhibition (ZOI) of 15.3 mm, which was equal to that of referenced levofloxacin (ZOI = 15.2 mm). And the metabolite 1 also showed moderate antibacterial activities against Micrococcus teragenus and S. aureus, with the ZOI values of 15.3 and 17.2 mm. In addition, by the minimum inhibitory concentration (MIC) assay, the compound 1 displayed potential antibacterial activities against M. teragenus, S. aureus and MRSA, with the MIC values of 12.5, 12.5, and 25.0 μg/ml, respectively. The present results indicate that BYF-112 may be a promising source for safe and bioactive pigments, which can be used for further development and industrial applications.

Microbiome and metagenomic analysis of Lake Hillier Australia reveals pigment-rich polyextremophiles and wide-ranging metabolic adaptations

Lake Hillier is a hypersaline lake known for its distinctive bright pink color. The cause of this phenomenon in other hypersaline sites has been attributed to halophiles, Dunaliella, and Salinibacter, however, a systematic analysis of the microbial communities, their functional features, and the prevalence of pigment-producing-metabolisms has not been previously studied. Through metagenomic sequencing and culture-based approaches, our results evidence that Lake Hillier is composed of a diverse set of microorganisms including archaea, bacteria, algae, and viruses. Our data indicate that the microbiome in Lake Hillier is composed of multiple pigment-producer microbes, including Dunaliella, Salinibacter, Halobacillus, Psychroflexus, Halorubrum, many of which are cataloged as polyextremophiles. Additionally, we estimated the diversity of metabolic pathways in the lake and determined that many of these are related to pigment production. We reconstructed complete or partial genomes for 21 discrete bacteria (N = 14) and archaea (N = 7), only 2 of which could be taxonomically annotated to previously observed species. Our findings provide the first metagenomic study to decipher the source of the pink color of Australia's Lake Hillier. The study of this pink hypersaline environment is evidence of a microbial consortium of pigment producers, a repertoire of polyextremophiles, a core microbiome and potentially novel species.

Biocolorants in food: Sources, extraction, applications and future prospects

Color of a food is one of the major factors influencing its acceptance by consumers. At presently synthetic dyes are the most commonly used food colorant in food industry by providing more esthetically appearance and as a means to quality control. However, the growing concern about health and environmental due to associated toxicity with synthetic food colorants has accelerated the global efforts to replace them with safer and healthy food colorants obtained from natural resources (plants, microorganisms, and animals). Further, many of these biocolorants not only provide myriad of colors to the food but also exert biological properties, thus they can be used as nutraceuticals in foods and beverages. In order to understand the importance of nature-derived pigments as food colorants, this review provides a thorough discussion on the natural origin of food colorants. Following this, different extraction methods for isolating biocolorants from plants and microbes were also discussed. Many of these biocolorants not only provide color, but also have many health promoting properties, for this reason their physicochemical and biological properties were also reviewed. Finally, current trends on the use of biocolorants in foods, and the challenges faced by the biocolorants in their effective utilization by food industry and possible solutions to these challenges were discussed.

Nature's palette: An emerging frontier for coloring dairy products

Consumers all across the world are looking for the most delectable and appealing foods, while also demanding products that are safer, more nutritious, and healthier. Substitution of synthetic colorants with natural colorants has piqued consumer and market interest in recent years. Due to increasing demand, extensive research has been conducted to find natural and safe food additives, such as natural pigments, that may have health benefits. Natural colorants are made up of a variety of pigments, many of which have significant biological potential. Because of the promising health advantages, natural colorants are gaining immense interest in the dairy industry. This review goes over the use of various natural colorants in dairy products which can provide desirable color as well as positive health impacts. The purpose of this review is to provide an in-depth look into the field of food (natural or synthetic) colorants applied in dairy products as well as their potential health benefits, safety, general trends, and future prospects  in food science and technology. In this paper, we listed a plethora of applications of natural colorants in various milk-based products.

Lignocellulosic substrates as starting materials for the production of bioactive biopigments

The search for sustainable processes is constantly increasing in the last years, so reusing, recycling and adding value to residues and by-products from agroindustry is a consolidated area of research. Particularly in the field of fermentation technology, the lignocellulosic substrates have been used to produce a diversity of chemicals, fuels and food additives. These residues or by-products are rich sources of carbon, which may be used to yield fermentescible sugars upon hydrolysis, but are usually inaccessible to enzyme and microbial attack. Therefore, pre-treatments (e.g. hydrolysis, steam explosion, biological pretreatment or others) are required prior to microbial action. Biopigments are added-value compounds that can be produced biotechnologically, including fermentation processes employing lignocellulosic substrates. These molecules are important not only for their coloring properties, but also for their biological activities. Therefore, this paper discusses the most recent and relevant processes for biopigment production using lignocellulosic substrates (solid-state fermentation) or their hydrolysates.

Colorful Treasure From Agro-Industrial Wastes: A Sustainable Chassis for Microbial Pigment Production

Colors with their attractive appeal have been an integral part of human lives and the easy cascade of chemical catalysis enables fast, bulk production of these synthetic colorants with low costs. However, the resulting hazardous impacts on the environment and human health has stimulated an interest in natural pigments as a safe and ecologically clean alternative. Amidst sources of natural producers, the microbes with their diversity, ease of all-season production and peculiar bioactivities are attractive entities for industrial production of these marketable natural colorants. Further, in line with circular bioeconomy and environmentally clean technologies, the use of agro-industrial wastes as feedstocks for carrying out the microbial transformations paves way for sustainable and cost-effective production of these valuable secondary metabolites with simultaneous waste management. The present review aims to comprehensively cover the current green workflow of microbial colorant production by encompassing the potency of waste feedstocks and fermentation technologies. The commercially important pigments viz. astaxanthin, prodigiosin, canthaxanthin, lycopene, and β-carotene produced by native and engineered bacterial, fungal, or yeast strains have been elaborately discussed with their versatile applications in food, pharmaceuticals, textiles, cosmetics, etc. The limitations and their economic viability to meet the future market demands have been envisaged. The most recent advances in various molecular approaches to develop engineered microbiological systems for enhanced pigment production have been included to provide new perspectives to this burgeoning field of research.

Evaluation Study on Extraction of Anthocyanins from Red Cabbage Using High Pressure CO2 + H2O: A Fuzzy Logic Model and Metabolomic Analysis

In this work, a fuzzy logic model was developed to elucidate the extraction performance of high-pressure CO2 + H2O compared with traditional H2O extraction and aqueous ethanol extraction. The high-pressure CO2 + H2O group acquired the highest comprehensive score considering yield, quality and stability. Both targeted and untargeted metabolomics results proved that the polarity of water was slightly modified; in particular, with the evidence from the untargeted metabolomics data, a higher proportion of water-insoluble compounds (2-methylindole, 3-formylindole, guanine, tyrosine and tryptophan) obtained by high-pressure CO2 + H2O extraction compared with traditional H2O extraction has been reported for the first time. Finally, the “3I” extraction mechanism of high-pressure CO2 + H2O is proposed, which offers an improvement in the solid–liquid mass transfer efficiency of phytochemicals, improving the polarity of solution and the isolation of O2.

Bacterial Carotenoids: Extraction, Characterization, and Applications

Natural carotenoids are secondary metabolites that exhibit antioxidant, anti-inflammatory, and anti-cancer properties. These types of compounds are highly demanded by pharmaceutical, cosmetic, nutraceutical, and food industries, leading to the search for new natural sources of carotenoids. In recent years, the production of carotenoids from bacteria has become of great interest for industrial applications. In addition to carotenoids with C40-skeletons, some bacteria have the ability to synthesize characteristic carotenoids with C30-skeletons. In this regard, a great variety of methodologies for the extraction and identification of bacterial carotenoids has been reported and this is the first review that condenses most of this information. To understand the diversity of carotenoids from bacteria, we present their biosynthetic origin in order to focus on the methodologies employed in their extraction and characterization. Special emphasis has been made on high-performance liquid chromatography-mass spectrometry (HPLC-MS) for the analysis and identification of bacterial carotenoids. We end up this review showing their potential commercial use. This review is proposed as a guide for the identification of these metabolites, which are frequently reported in new bacteria strains.

Melanin: Production from Cheese Bacteria, Chemical Characterization, and Biological Activities

Pigments are compounds of importance to several industries, for instance, the food industry, where they can be used as additives, color intensifiers, and antioxidants. As the current trend around the world is shifting to the use of eco-friendly commodities, demand for natural dyes is increasing. Melanins are pigments that are produced by several microorganisms. Pseudomonas putida ESACB 191, isolated from goat cheese rind, was described as a brown pigment producer. This strain produces a brown pigment via the synthetic Müeller-Hinton Broth. This brown compound was extracted, purified, analyzed by FTIR and mass spectrometry, and identified as eumelanin. The maximum productivity was 1.57 mg/L/h. The bioactivity of eumelanin was evaluated as the capacity for scavenging free radicals (antioxidant activity), EC₅₀ 74.0 ± 0.2 μg/mL, and as an acetylcholinesterase inhibitor, with IC₅₀ 575 ± 4 μg/mL. This bacterial eumelanin did not show cytotoxicity towards A375, HeLa Kyoto, HepG2, or Caco2 cell lines. The effect of melanin on cholesterol absorption and drug interaction was evaluated in order to understand the interaction of melanin present in the cheese rind when ingested by consumers. However, it had no effect either on cholesterol absorption through an intestinal simulated barrier formed by the Caco2 cell line or with the drug ezetimibe.

Microbial pigments as an alternative to synthetic dyes and food additives: a brief review of recent studies

Synthetic coloring agents have been broadly utilized in several industries such as food, pharmaceuticals, cosmetic and textile. Recent surveys on the potential of teratogenicity and carcinogenicity of synthetic dyes have expressed concerns regarding their use in foods. Worldwide, food industries have need for safe, natural and new colorings to add variety to foods and make them appealing to consumers. Natural colorings not only expand the marketability of the food product, but also add further healthful features such as antibacterial, antioxidant, anticancer and antiviral properties. Novel microbial strains should be explored to meet the increasing global search of natural pigments and suitable techniques must be developed for the marketable production of new pigments, using microbial cultures, viz., fungi, and bacteria. To address the issue of the natural coloring agents, this review presents the recent trends in several studies of microbial pigments, their biological properties and industrial applications.