Red Pigment Production Research Articles

Improving natural red pigment production by Streptomyces phaeolivaceus strain GH27 for functionalization of textiles with in silico ADME prediction

The red pigment was recovered from the S. phaeolivaceus GH27 isolate, which was molecularly identified using 16S rRNA gene sequencing and submitted to GenBank as OQ145635.1. The ideal growth conditions included 1% (w/v) starch, diammonium citrate, dibasic sodium phosphate, 5% (v/v) inoculum, pH 8, a rotation speed of 150 rpm, a temperature of 37 °C, and an incubation period of 9 days. Using ethanol as a solvent, the red pigment was effectively recovered. Data indicates that pigment content remained steady at 40 and 50 °C. Heating the pigment extract to 60, 70, 80, 90, and 100 °C for one hour results in pigment retention of 98%, 96.5%, 95.5%, 94.6%, and 92.6% of its pigment density, respectively. Studies indicate that the pigment extracts exhibited optimal stability at alkaline pH levels. The findings demonstrate that the red pigment extract has a peak absorbance range of 280–340 nm, with a λmax of 300 nm. GC/MS analysis revealed that the primary components of the pigment extract were linolenic acid methyl ester and oleic acid methyl ester, constituting 26.41% and 25.25%, respectively. Fabrics dyed with extracted red pigment exhibit excellent fastness when using the comprehensive green method. In comparison to conventional and nanotechnological attributes, printed samples exhibit significant color strength without environmental repercussions. The treatment of cotton, wool, and polyester samples suppressed pathogen growth to differing extents. Polyester had the most important inhibitory effects on Staphylococcus aureus (50.03%) and Bacillus cereus (39.49%). The ADME physicochemical properties of the predominant medication were assessed, together with its bioavailability. The radar plot demonstrated ideal parameters for size, polarity, lipophilicity, solubility, and saturation, excluding flexibility. It exhibited intermediate synthetic accessibility, exceptional permeability and absorption, elevated gastrointestinal absorption, and blood–brain barrier penetration; nonetheless, it did not adhere to the medicinal chemistry rule of three.Graphical

Evaluation of Monascus purpureus fermentation in dairy sludge-based medium for enhanced production of vibrant red pigment with minimal citrinin content.

This study aimed to explore the production of red pigment from Monascus purpureus in waste culture medium and its potential health benefits. Subsequently, the M. purpureus cultivated in a medium containing dairy sludge as waste, the extracted pigment was purified, and subjected to various analyses, including liquid chromatography mass spectrometry (LCMS) and nuclear magnetic resonance (NMR) to verify its purity, high-pressure liquid chromatography (HPLC) to measure the citrinin levels, microbial, and antioxidant activity. Finally, fermentation was conducted in a batch system using a fermenter. M. purpureus was grown in a medium composed of dairy sludge, monosodium glutamate, and glucose, resulting in a biomass yield of 26.15 g/L. After extraction and purification, the sample yielded 4.85 g of dry color. Analysis confirmed the purity of the pigment by LCMS and NMR and revealed low citrinin levels by HPLC. In the fermenter, the sample obtained from enriched culture conditions displayed the highest concentration of monascorubramine, maximum specific growth rate of 0.029/1/h, a cell yield (Yx/s) of 0.29 g/g, and a production efficiency of 65% for M. purpureus. The produced pigment sample showed potential for use in the food industry due to its low citrinin content and high concentration of red pigment.

Production and Extraction of Red Bioactive Pigment from Streptomyces griseorubiginosus and Formulation of Bio-Lip Balm

Production and Extraction of Red Bioactive Pigment from Streptomyces griseorubiginosus and Formulation of Bio-Lip Balm

Correlation of oxygen consumption with growth and red pigment production of Monascus purpureus in solid state fermentation of rice

Since aeration has a crucial role in mass and heat transfer during solid-state fermentation (SSF), the aim of the present work was to find out how it related to biomass and red pigment production of Monascus purpureus TISTR3615 during SSF. The fungal consumption of oxygen, one of the air's constituents important for fungal metabolism, was used to explain the relationship between the aeration rate, the fungal growth, and the red pigment production during the SSF of rice. Findings showed that at increased aeration rates, the fungus absorbed more oxygen, which boosted fungal growth but decreased red pigment production. Conversely, red pigment production increased when the fungus' oxygen consumption decreased. Regression equations with an acceptable R2 were used to explain the relationship between M. purpureus' red pigment production and its oxygen consumption and aeration rate. The ideal oxygen concentration for increasing M. purpureus' capacity to produce red pigment was 0.0685 mmol/day/g of dry biomass, which produced red pigment at around 2,897 AU500nm/g of dry biomass. However, the optimal oxygen consumption of the fungus for overall red pigment production (including growth impact) was 1.390 mmol/day/g of dry biomass, which produced red pigment at around 2,787 AU500nm/g of dry fermented rice. The results of the present work could potentially be utilised in developing M. purpureus' red pigment production approach.

Morphology, Development, and Pigment Production of Talaromyces marneffei are Diversely Modulated Under Physiologically Relevant Growth Conditions.

Talaromyces marneffei is an opportunistic pathogenic fungus that mainly affects HIV-positive individuals endemic to Southeast Asia and China. Increasing efforts have been made in the pathogenic mechanism and host interactions understanding of this pathogen in the last two decades; however, there are still no conclusions on how T. marneffei was transmitted from the donor bamboo rats to humans. A perception that the failure of fungus isolation from soil was attributed to the low salt tolerance of T. marneffei. Therefore, the effect of environmental fluctuations in fungal growth and development is fundamental for the characterization of its origin and fungal biology understanding. Herein, we characterized high osmolarity, pH, metal ions, nutrients, and oxidative stress have versatile effects on T. marneffei hyphal or yeast growth, conidia generation, and pigment production. Among these, high pH, low glucose amounts, and the inorganic nitrogen ammonium tartrate stimulated the red pigment production, whereas high osmolarity, high pH, and the inorganic nitrogen sodium nitrate could significantly accelerate the conidia generation. Specifically, zinc starvation repressed conidia generation and prevented the wrinkled yeast colony formation, indicating the function of zinc regulators in pathogenicity regulation. Since conidia are recognized as the infectious propagules, the effects characterization of different environmental factors in T. marneffei morphology in this work will not only expand the growth and pathogenic biology understanding of the fungus but also provide more clues for the T. marneffei infection transmission origin investigation.

Expanding the Toolbox for Genetic Manipulation in Pseudogymnoascus: RNAi-Mediated Silencing and CRISPR/Cas9-Mediated Disruption of a Polyketide Synthase Gene Involved in Red Pigment Production in P. verrucosus.

Fungi belonging to the genus Pseudogymnoascus have garnered increasing attention in recent years. One of the members of the genus, P. destructans, has been identified as the causal agent of a severe bat disease. Simultaneously, the knowledge of Pseudogymnoascus species has expanded, in parallel with the increased availability of genome sequences. Moreover, Pseudogymnoascus exhibits great potential as a producer of specialized metabolites, displaying a diverse array of biological activities. Despite these significant advancements, the genetic landscape of Pseudogymnoascus remains largely unexplored due to the scarcity of suitable molecular tools for genetic manipulation. In this study, we successfully implemented RNAi-mediated gene silencing and CRISPR/Cas9-mediated disruption in Pseudogymnoascus, using an Antarctic strain of Pseudogymnoascus verrucosus as a model. Both methods were applied to target azpA, a gene involved in red pigment biosynthesis. Silencing of the azpA gene to levels of 90% or higher eliminated red pigment production, resulting in transformants exhibiting a white phenotype. On the other hand, the CRISPR/Cas9 system led to a high percentage (73%) of transformants with a one-nucleotide insertion, thereby inactivating azpA and abolishing red pigment production, resulting in a white phenotype. The successful application of RNAi-mediated gene silencing and CRISPR/Cas9-mediated disruption represents a significant advancement in Pseudogymnoascus research, opening avenues for comprehensive functional genetic investigations within this underexplored fungal genus.

Tamyb10-D1 restores red grain color and increases grain dormancy via suppressing expression of TaLTP2.128, non-specific lipid transfer protein in wheat

Grain dormancy of wheat is closely associated with grain color: red-grained lines show higher dormancy than white-grained lines. The production of red pigments is regulated by R-1, Tamyb10 gene. However, the relation between grain color and dormancy remains unknown. For this study, we generated transgenic lines which were introduced a DNA fragment containing Tamyb10-D1 gene and its a 2 kb promoter including the 5′ untranslated region into white-grained wheat. Transgenic lines showed red-grained and higher dormant traits. Contents of plant hormones and gene expression of embryos at 30 days after pollination were examined in a wild type and a transgenic line. No differences were observed in the contents of plant hormones, but several genes are differentially expressed between these lines. One differentially expressed gene, TaLTP2.128, is a member of non-specific lipid transfer proteins. It was expressed higher in white grains than in red grains. A putative amino acid sequence showed similarity to that of OsHyPRP5, which is identified as QTL controlling low-temperature germinability in rice. Expression of TaLTP2.128 was increased by grain imbibition. The increasing levels were higher not only in other white-grained lines, but also in non-dormant red-grained lines. TaLTP2.128 was expressed at a quite early stage of germination. These study findings indicate that Tamyb10 regulates dormancy release by the modification of TaLTP2.128 acting as trigger of germination.

Precursor-directed production of water-soluble red Monascus pigments with high thermal stability via azaphilic addition reaction-based semi-synthesis

Red Monascus pigments (MPs) are a large group of polyketides from the fungus Monascus which have been widely used as food colorants. In this study, a variety of red MPs congeners were prepared to explore promising water-soluble candidates for application in liquid food formulations. The results showed that by combining the two-stage, low-pH fermentation strategy with a downstream purification step of fractional crystallization, precursors of red MPs, namely monascorubrin and rubropunctatin, were obtained with a purity of 91.9%. Then, via the azaphilic addition reaction, 18 types of red MPs congeners carrying different amino acid moieties (MPs-aa) were semi-synthesized. Compared to rubropunctamine and monascorubramine, the water solubility, pH and thermal stability of MPs-aa were improved greatly. MPs-His, MPs-Phe, MPs-Tyr and MPs-Trp were identified to be the most resistant to pasteurization. These findings provide water-soluble red MPs candidates with high thermal stability and an attractive approach for their large scale production.

Production of biopigment by Monascus ruber AUMC 245 under submerged fermentation and its application as colorants of some food products

The goal of the current investigation was to examine the production of red biopigment by Monascus ruber AUMC 245 during submerged fermentation and assess its safety as a bio-colorant in the food sector due to due to only sensory evaluation in food products. The various factors used for the production of red pigments, citrinin, and biomass yield were follows: 20 ℃–40 ℃ of temperature, 4.5–8.5 of pH, carbon and nitrogen sources. The optimum conditions were 30 ℃, pH 6.5, rice, peptone and incubation time for 10 days. The produced biopegment was without mycotoxin (citrinin). So, it is suitable for application in food industry. Kids jelly cola, ice sherbets and luncheon meat were prepared using the red pigments as natural colorant. The tested foods colored by nature biopigment appeared sensory results (90%) as acceptable consuming evaluation. It was not far from the applied industrial chemical one, but it is advantages by safe conditions. In conclusion, we can state that the obtained red pigments are safe to use in food products instead of chemical one.

Valorization of rice husk by hydrothermal processing to obtain valuable bioproducts: Xylooligosaccharides and Monascus biopigment

Rice husk is a readily available residue which can be used for producing bioproducts in a biorefinery context. In this study, the hemicellulose fraction was hydrolyzed in a hydrothermal process to produce xylooligosaccharides (XOS), whereas the cellulosic hydrolysate was used for red pigment production by Monascus ruber Tieghem IOC 2225. The highest XOS (X2-X4) production (24 g per 1 kg of rice husk) was achieved at 180 °C for 68 min in a non-stirred Parr reactor (50 mL). Subsequently, using a stirred parr reactor (1 L) at 180 °C for 60 min, 40 g of XOS (42% of xylobiose, 35% of xylobiose, 13% of xylotriose, 7% of xylotetraose, and 3% of xylopentaose) per 1 kg of rice husk were obtained. The XOS was then purified by using ultrafiltration (UF) with two diafiltration membranes at 6.5 pH, recovering approximately 92% of total XOS. Further purification was conducted with nanofiltration (NF) at 3.8 pH, recovering approximately 86.4% of XOS in the retentate. This process yielded XOS with a purity of 77%. Additionally, the enzymatic process yielded 132 g/kg of sugar, and the hydrolysate was used to produce 2.1 UA490nm of red pigment by fungi after 7 days.

Enhancement of Monacolin K Production by Intergeneric Hybridization between Monascus purpureus (Arg-) and Monascus ruber (Thi-, Met-) Auxotrophs

This study aims to reconcile industrially suitable strains of higher red pigment producing Monascus purpureus MPA5 and higher Monacolin K producing Monascus ruber MRA7, were tried to fuse for development of increased efficacy of targeted secondary metabolites production. The optimum concentration of protoplast mixture was standardized, before the fusion experiment. The effective fusion was observed with the solution of 30 % PEG 6000, CaCl2.2H2O (0.01 M) and glycine (0.05 M). Colonies of the fusants were segregated using complete medium. The fusants were irradiated under UV- light in LD50 dose. On the basis of non-segregation of colony appearance after repeated subculturing in complete medium, 8 colonies were selected. Finally, one of the stable fusant MF11 grew more rapidly than one of the parental strain M. purpureus MPA5, but not as fast as M. ruber MRA7, were selected and grown on low grade rice as solid substrate for production of metabolites. Production of red pigments, alpha-amylase and acid protease were at intermediate stage between two parental strains but enhancement of Monacolin K was observed. High performance liquid chromatography (HPLC) analysis was revealed that Monacolin K content was increased as much as two and half times than the parents. No fluorescent yellow band was detected in TLC plate, indicating of citrinin negativity of the fusant MF11. It is the first report of enhanced Monacolin K production by a stable fusant of Monascus sp.

Prodigiosin pigment from Serratia marcescens MBM‐17 from facial acne as antimicrobial agent

AbstractA 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.

47 Investigating links between pigmentation genes and opioid effectiveness in horses

The pleiotropic effects of the melanocortin system show promise in overcoming limitations associated with large variations in opioid analgesic effectiveness observed in equine practice. Of particular interest is the melanocortin-1-receptor gene (MC1R), which influences melanin type through its epistatic interaction with the agouti signaling protein gene (ASIP), dictating the production of black or red pigment. MC1R has previously been associated with opioid effectiveness in other species; however, evidence of similar relationships in horses is lacking. As such, this study investigated if associations between opioid response and pigmentation genes were also observable in horses. Nociceptive response data were opportunistically collected during the performance of spinal fluid centesis (SFC), noting the pain response of individual horses after sedation. A target dosage range of 0.01–0.02 mg/kg body weight intravenously was used in the administration of the opioid hydromorphone, the primary drug of interest in this study. Genomic regions responsible for the bay (ASIP) and chestnut (MC1R) coat colors were extracted from genome sequence data, and opioid analgesic effectiveness was scored (1–3) based on pain response for each horse (n = 48). Haplotype and SNP association analyseswere performed using the SNPassoc (testing multiple models) and haplo.stats packages and generalized linear models within the statistical software R. Age, breed, sex, and dosage rates were recorded as covariates. Breeds with less than 2 horses were excluded from analyses. Six single-nucleotide polymorphisms (SNPs) within ASIP and one within MC1R were identified as significantly (P < 0.05) associated with opioid analgesic effectiveness during SFC. Haplotype analysis of the significant ASIP SNPs revealed that the most common ASIP haplotype was associated with lower opioid analgesic effectiveness, both in isolation and when looked at in conjunction with MC1R. The recessive MC1Re/e mutation resulting in the production of red pigment only was also significantly associated with decreased opioid analgesic effectiveness. The current study provides promising evidence for important links between pigmentation genes and opioid effectiveness in horses. However, given the complexity of opioid metabolism and the opportunistic nature of the current study, additional investigations are needed if precision medicine approaches are to become a reality in equine veterinary medicine.

Mannitol-Based Media and Static pH Are Efficient Conditions for Red Pigment Production from Monascus purpureus ATCC 36928 in Submerged Culture

Fungi of the Monascus species are used in Asia for the production of fermented foods, mainly due to the ability of these fungi to produce secondary metabolites such as pigments. Due to the growing discussion about the use of synthetic dyes and the fact that their ingestion is associated with harm to human health, studies have sought to replace these dyes using natural pigments, and new alternatives for the production of these natural pigments have been presented. In this context, Monascus pigments are a viable alternative for application in the food industry. This study aimed to evaluate different main carbon sources and pH conditions in the red pigment production of Monascus sp. We found that mannitol, when used as the only carbon source, stimulated the production of extracellular red pigment, reaching a concentration of 8.36 AU in 48 h, while glucose and sucrose reached concentrations of 1.08 and 1.34 AU, respectively. Cultivation in a bioreactor using mannitol showed great potential for optimizing pigment production and obtaining a high concentration of extracellular pigment in a short time, reaching a concentration of 25 AU in 60 h of cultivation. The change in pH altered the production of extracellular red pigment in a culture medium containing mannitol as a carbon source, demonstrating less potential than the use of static pH during cultivation in a bioreactor. Mannitol proved to be an efficient carbon source for M. pupureus under static pH conditions for both flask and benchtop bioreactor cultivation.

A reduction in temperature induces bioactive red pigment production in a psychrotolerant Penicillium sp. GEU_37 isolated from Himalayan soil

Filamentous fungi are being globally explored for the production of industrially important bioactive compounds including pigments. In the present study, a cold and pH tolerant fungus strain Penicillium sp (GEU_37), isolated from the soil of Indian Himalaya, is characterized for the production of natural pigments as influenced by varying temperature conditions. The fungal strain produces a higher sporulation, exudation, and red diffusible pigment in Potato Dextrose (PD) at 15 °C as compared to 25 °C. In PD broth, a yellow pigment was observed at 25 °C. While measuring the effect of temperature and pH on red pigment production by GEU_37, 15 °C and pH 5, respectively, were observed to be the optimum conditions. Similarly, the effect of exogenous carbon and nitrogen sources and mineral salts on pigment production by GEU_37 was assessed in PD broth. However, no significant enhancement in pigmentation was observed. Chloroform extracted pigment was separated using thin layer chromatography (TLC) and column chromatography. The two separated fractions i.e., fractions I and II with Rf values 0.82 and 0.73, exhibited maximum light absorption, λmax, at 360 nm and 510 nm, respectively. Characterization of pigments using GC–MS showed the presence of the compounds such as phenol, 2,4-bis (1,1-dimethylethyl) and eicosene from fraction I and derivatives of coumarine, friedooleanan, and stigmasterole in fraction II. However, LC-MS analysis detected the presence of derivatives of compound carotenoids from fraction II as well as derivative of chromenone and hydroxyquinoline as major compounds from both the fractions along with other numerous important bioactive compounds. The production of such bioactive pigments under low temperature conditions suggest their strategic role in ecological resilience by the fungal strain and may have biotechnological applications.

Scale-Up of Pigment Production by the Marine-Derived Filamentous Fungus, Talaromyces albobiverticillius 30548, from Shake Flask to Stirred Bioreactor

Talaromyces albobiverticillius 30548, a marine-derived fungus, produces Monascus-like azaphilone red/orange pigments which have the potential for various industrial applications. The objective of this study was to scale up pigment production in a 2 L bioreactor with a working volume of 1.3 L media and to compare its biomass growth and pigment production against small volume (500 mL) shake flasks with 200 mL working volume. Additionally, fungal morphology, pigment intensity, fermentation length and duration of pigment production were also compared. Experiments were carried out at laboratory scale in 200 mL shake flasks without controlling pH and oxygen. In parallel, fermentation was performed in a 2 L bioreactor as an initial scale-up to investigate the influence of dissolved oxygen, agitation speed and controlled pH on pigment production and biomass growth of T. albobiverticillius 30548. The highest orange and red pigment production in bioreactor at 24 °C was noticed after 160 h of fermentation (70% pO2) with 25.95 AU 470 nm for orange pigments and 22.79 AU 500 nm for red pigments, at pH set point 5.0. Meanwhile, the fermentation using 200 mL shake flasks effectively produced orange pigments with 22.39 AU 470 nm and red pigments with 14.84 AU 500 nm at 192 h under the same experimental conditions (24 °C, pH 5.0, 150 rpm). Regarding fungal morphology, growth of fungus in the bioreactor was in the form of pellets, whereas in the shake flasks it grew in the form of filaments. From the observed differences in shake flasks and closed bioreactor, it is known that the bioprocess was significantly influenced by dissolved oxygen saturation and agitation speed in scale-up. Thus, oxygen transfer appears to be the rate-limiting factor, which highly influences overall growth and production of pigments in Talaromyces albobiverticillius 30548 liquid culture.

Technological organization and initial production stages of a maritime slate tradition: insights from the first investigated Stone Age slate source in Arctic Europe (the Djupvik slate formation, Norway)

ABSTRACT While ground slate technology is a trademark of maritime hunter-gatherers across the circumpolar region, we lack robust understanding of 1) the organization of slate tool production and 2) its initial production stages – maintained by the absence of formally investigated slate sourcing sites and the loss of diagnostic production features inherent to grinding techniques. This paper contributes along both dimensions, presenting the first investigated prehistoric slate raw material source in Arctic Europe (Djupvik, Norway). Technological analyses of the assemblage rich in initial production stages are related to the material properties of the geological slate formation, supplemented by experimental research. The paper discusses the role of slate technological organization within the broader context of mid-Holocene adaptations in Arctic Norway. The results from Djupvik help establish the production stages and techniques distinct to slate tool technologies and demonstrate organizational principles diverging from cryptocrystalline lithic resources of the contemporary lithic technocomplex. Finally, potential secondary (non-tool) uses of Djupvik materials are discussed, referencing the intriguing possibility of ochre and red pigment production both at Djupvik and a nearby site, suggesting a relation to rock art paintings.

Painting personhood: Red pigment practices in southern Peru

In the Chincha Valley of southern Peru,pigmented human remains and grave goods were found in over 100 large and accessible mortuary structures associated with the Late Intermediate Period (1000 – 1400 CE), the Late Horizon (1400 – 1532 CE), and the Colonial Period (1532 – 1825 CE). We characterize 38 red pigment samples, reveal their potential sources and how they were processed and applied to human remains, and determine the demographic profiles of pigmented individuals. Results suggest that cinnabar- (HgS) and hematite (Fe2O3)-based pigments, likely from local and nonlocal sources, were mixed in water and applied to skeletonized and disarticulated individuals of different age and sex categories. We interpret red pigment application to human remains as partof a prolonged process of social dying that transitioned the ontological status of the dead and contributed to the development of social difference and group identity.Multidisciplinary research designs are ideal for studying red pigment practices, which are activities concerning the production and use of red pigment that range from procurement to the treatment of the dead. Here, we advance a methodology integrating archaeometric, archaeological, and bioarchaeological analyses with anthropological theories of personhood and social dying to investigate red pigment practices.

Maximization of red pigment production from Streptomyces sp. LS1 structure elucidation and application as antimicrobial/antifouling against human pathogens and marine microbes

BackgroundNatural dyes are present in living organisms such as animals and plants and microorganisms such as fungi, bacteria, algae, and yeast. Pigments are fast and easy growth by using cheap components and do not effect by environmental conditions because they required some physical factors like heat, light, and pH and also they have many biotechnological applications such as medical and industrial needs. The natural pigments can act as antimicrobial agents and are used in drug manufacturing. Also, it can be used in the food industry as natural colorants instead of the synthetic colorants due to their safety on human health and low toxicity when emitted into the environment. ResultsA pigmented actinomycetes LS1 strain isolated from El Mahmoudia canal (sediment soil) located in Egypt was microscopically examined and identified as Streptomyces sp. by molecular approach. Extraction, purification, and characterization of produced red pigment metabolite like carotenoids related were established based on spectroscopic studies and comparing the data from the literature. Factors (nutritional and physical) influencing red pigmentation by this isolate were investigated through One Variable At Time (OVAT), and then, the optimal levels of the significant key variables were recorded. Also, the productivity yield reached 30 mg of dried purified pigment/gram dry weight. The biological activity of the red product was tested against Gram-positive and Gram-negative marine bacterial pathogens; the recorded antimicrobial activity is more prominent against (P. aeruginosa ATCC 9027, K. pneumoniae ATCC 13883, S. aureus ATCC 6538, B. subtilis ATCC 6633 and E. coli ATCC 10418) at nearly 0.07 mg mL−1 concentration. Also, the tested red pigment showed a positive antifouling activity (AF) against marine microbes; the activity increased by increasing the pigment concentrations from 1 to 3 mg mL−1. ConclusionThe present work focused on the optimization of culture conditions for the production of red pigment by Streptomyces sp. LS1; then, the antibacterial activity and antifouling activity of the produced pigments were tested.

Production of pigments by Monascus ruber CCT0302 in culture media containing maltose as substrate

The aim of this study was to show how maltose production residues can be used to obtain natural pigments by Monascus ruber CCT 3802 in solid and submerged cultures. The microbial growth and the colour and heat stability characteristics of the pigments produced in both solid and submerged media, with different maltose syrup concentrations, were determined. The results showed that the addition of maltose provided significant increases in the velocity of microbial growth and production of red pigments. The highest radial growth velocity of Monascus ruber (0.1053 mm h−1) was obtained when cultivated in a medium containing 5 g L−1 of maltose syrup, corresponding to a 71.7% increase in growth as compared to the growth velocity in the control medium. Using submerged fermentation, the culture medium containing 10 g L−1 of maltose syrup provided the greatest concentrations of red pigments (14.54 AU510nm g−1 dry biomass) with an intense dark red colour, showing that Monascus ruber CCT 3802 had the capacity to assimilate the substrate and produce pigments. The red pigments produced in the cultures showed good heat stability with activation energies of 13.735 Kcal mol−1.