Pigment-producing Bacteria Research Articles

Isolation and Molecular Characterization of Pigment Producing Bacteria from Soil of Different Locality of Assam

Pigment is the most attractive attribute and integral part of human life. The source of the pigment used for different applications is chemically synthesised. However, pigment produced from natural sources (such as plants and microorganisms) can also be applied as a coloring agent. In addition to being colorants, many natural pigments are also fascinating bioactive substances with possible health benefits. Agrochemicals, food, medicine, pharmacology, cosmetics, and numerous other industries use these compounds. In this study, a total of 7 pigmented colonies were isolated from the soil samples of different areas of Assam. Out of 7 pigmented colonies, 3 colonies showed orange color and 4 colonies showed yellow color. Based on the similarity of growth pattern and high intensity of pigmentation one colony from each pigment was picked for further studies. The isolated orange and yellow pigments were denoted as S1 and S2, respectively. With the help of Bergey’s Manual of Determinative Bacteriology the isolated pigmented strains were preliminary identified based on their morphological, microscopic, and biochemical characteristics and after that 16S rRNA gene sequencing helped to identify the bacteria at the species level and the strains were identified as (S1) Micrococcus aloeverae ON377368 and (S2) Exiguobacterium aestuarii ON377409. The identified strains Micrococcus aloeverae and Exiguobacterium aestuarii showed a high pigment production rate at specific optimized conditions such as at temperature 37°C, pH 6, and NaCl concentrations at 1.5-2% and strains also showed a good characteristic growth pattern at a specific time interval. Therefore, the present study may be a helpful step towards the large-scale manufacture of pigments and the extraction, purification, and characterization of the pigment extracted from these strains will lead to provide a potent eco-friendly natural dye in the industrial sector.

Identification of pigmented extremophilic bacteria from mangrove soil with antibiofilm activity on food pathogens

Mangrove ecosystems and associated microorganisms are always a source of curiosity for researchers. Pigment producing bacteria were isolated from the mangrove soil in Kadamakkudi, Cochin, Kerala. The bacteria were biochemically identified and by 16 S rRNA gene sequence. The pigments extracted had been tested for antibiofilm activity against food pathogens Pseudomonas aeruginosa (NCIM 2863), Klebsiella pneumoniae (NCIM 5215), and Escherichia coli (NCIM 2343). Antibiofilm activity was further confirmed by fluorescent and scanning electron microscopy. Six yellow-orange pigmented bacteria (KDR2, KDR3, KDR7, KDR8, KDR14 and KDS1) were isolated. KDR2 was identified as Cellulosimicrobium funkei, KDR7 and KDS1 as Cytobacillus depressus, KDR8 as Bacillus aquimaris, and KDR3 and KDR14 as Halobacillus sp. All of these organisms are known to be extremophiles. The UV-Visible absorption spectrum of all the pigments ranged from 400 nm to 550 nm with different absorbance maxima. All the pigments showed antibiofilm activity against the food pathogens tested.

The potency of yellow pigment extract from the marine bacterium Pseudomonas oryzihabitans SAB E-3 as an antioxidant agent

Abstract. Putri DA, Astuti RI, Wahyudi AT. 2024. The potency of yellow pigment extract from the marine bacterium Pseudomonas oryzihabitans SAB E-3 as an antioxidant agent. Biodiversitas 25: 2565-2575. Metabolic processes in cells can produce byproducts in the form of Reactive Oxygen Species (ROS). Excessive amounts of ROS are one of the causes of oxidative stress. Antioxidants are known to act as free radical-scavenging compounds. Pigment-producing bacteria associated with sponges have been widely reported to have antioxidant compounds. In this study, the marine bacterium Pseudomonas oryzihabitans SAB E-3 produced intracellular yellow pigments with potential antioxidant activity. Therefore, this study aimed to assess the in vitro antioxidant and mitochondrial activity at the cellular level and identify chemical compounds. The intracellular pigments produced by P. oryzihabitans SAB E-3 were extracted using methanol, acetone, chloroform, and ethyl acetate. The methanol pigment extract contained the highest number of phenolic and flavonoid compounds, which may have contributed to its antioxidant activity. Furthermore, the active fraction obtained from the bioautographic TLC and harvested using preparative TLC had stronger antioxidant activity against DPPH radicals (75.71 µg/mL) than the crude pigment extract. However, the ABTS radical-reducing activity was lower (226.59 µg/mL) than the crude pigment extract. The maximum wavelength of the pigment extract was 453 nm, indicating the presence of carotenoids. In addition, the lowest concentration of the crude pigment extract (50 µg/mL) and selected active fractions (18.75 µg/mL) increased yeast Schizosaccharomyces pombe ARC039 tolerance to oxidative stress and induced mitochondrial activity. Active fraction one extract analyzed using LC-MS/MS contained piceatannol, resveratrol, isorhapontigenin, isoliquiritigenin, liquiritin, and 2-Omethylisohemigossylic acid lactone, which may contribute to its antioxidant activity. Therefore, the yellow pigment extract and the active fraction produced by P. oryzihabitans SAB E-3 are potential candidates for natural antioxidant sources.

Evaluation of the antimicrobial activity of some bacteria-derived bio-active pigments

There is a growing interest and concern for both the safety of the human population and the protection of the environment which has spurred renewed interest in the search for alternative chemicals from microbial origins which are biodegradable and environmentally friendly. Production of stable bio-products has been reported to be strain-dependent. The aim of this study was to evaluate the antimicrobial activity of pigments extracted from some pigmented native bacteria on some tomato spoilage pathogenic bacteria and fungi. In total, four pigment-producing bacteria spp. were isolated from samples including underneath tomato roots, soils from vegetation sites, wastewater from potato processing sites, tree liters, and tree bark using the enrichment culture and pour plating technique. The isolates were morphologically and biochemically identified as Serratia sp., Salinococcus sp., Exiguobacterium sp., and Xanthomonas sp. The crude bacteria pigments were tested for bio-activity (antimicrobial activity) against some tomato-derived spoilage bacteria (Xanthomonas sp. and Clavibacter sp.) and fungi pathogens (Alternaria alternata and Phytophthora infections) respectively. Among the isolates, pigments of Serratia sp had inhibition zones of 34.5mm and 32.1mm against Xanthomonas sp. and Clavibacter sp. bacteria and 27.8mm and 29.7mm against Alternaria alternata and Phytophthora infectans respectively. While Salinococcus sp. had 30.5mm and 34.2mm against the bacteria species and 27.9mm and 29.3mm against the fungi respectively. These are promising results. Therefore, further purification of the pigment should lead to discovering potent antimicrobial bio-active ingredients for drug development in the pharmaceutical industry.

Microbes on the "peachy spots" of ancient Kaihua paper: microbial community and functional analysis.

Kaihua paper is a type of precious hand-made paper in China that has been used throughout Chinese history. Due to its extraordinary whiteness and fine texture, it was adopted by the imperial palace in the reign of Emperor Kang Xi and Yong Zheng of the Qing Dynasty of China in the 17th and 18th century. It is stained by a special type of yellowish-brown spot after years of storage, which is called a "peachy spot." The formation of such spots remains unclear, although complicated physicochemical processes or microbial activities might be involved. We performed nondestructive sampling and high-throughput sequencing on peachy spot surfaces, unstained areas, and air samples in the stack room to analysis the the bacterial and fungal communities, and performed prediction of functional genes of the bacterial communities. The results showed that peachy spot formation was mainly related to bacterial communities rather than fungal communities. Significantly more potential acid- producing, acidophilic or cellulase-producing bacteria, such as, Streptococcus, Staphylococcus, and Lysinibacillus, and pigment-producing bacteria, such as Methylobacterium and Rubrobacter, were identified in the peachy spot samples. Prediction of the functional genes of the bacterial community also suggested the production of acidic substance pigments. These findings provide new insights into the pigment formation mechanism in ancient paper and open an opportunity to develop new strategies to preserve the ancient paper documents.

Isolation and Screening of Pigment Producing Bacteria from Soil and Study of Antimicrobial Activity of Pigments

Pigments are colored compounds that play important roles in various biological systems, such as photosynthesis, vision, and signalling. Pigment-producing bacteria are a diverse group of microorganisms that can produce a wide range of pigments with different colors and properties. The present study is aimed to isolate the pigment-producing bacteria from the soil with the antibacterial activity of pigments. Soil samples were collected from nearby Karad city. All eight different pigmented colonies were isolated that produced the pigments like Yellow, Red, Golden Yellow, and Orange and they were designated as YP-I, YP-II, YP-II, GYP-I, GYP-II, RP-I, RP-II, and OP. The isolated organisms were characterized with the help of Bergey’s Manual of Determinative Bacteriology. The pigments were extracted with a solvent like chloroform and the antibacterial activity of the extract was tested against E. coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The extracted pigments had an inhibitory effect on both Gram-positive and Gramnegative bacteria. The pigments of isolates designated as YP-III, GYP-I, GY-II, and RP-II showed the highest antibacterial activity against E. coli.

Study on the Mechanism of the Pink Tooth Phenomenon Using Bovine Teeth: A Pilot Study.

The pink teeth phenomenon has occasionally been observed in forensic autopsies. This study aimed to establish an experimental pink tooth model and an objective color tone evaluation method in order to clarify changes in the color tone of teeth and the relationship with hemoglobin monoxide and its decomposition products and with red pigment-producing bacteria, under various external environmental factors. It was confirmed that the color tone evaluation with ΔE and the L*C*h color space was useful. The results of various examinations using this model showed that color development was suppressed under aerobic conditions, faded early under light, became bright red under a low temperature and showed a tendency to be reddish at 3 days under high humidity and in the presence of soft tissue. The biochemical analysis revealed a significant increase in carboxyhemoglobin at 7 days and a tendency toward increasing the total heme pigment and bilirubin levels over time. The bacteriological analysis revealed that red pigment-producing bacteria increased over time but that the color faded after 7 days. These results suggest that putrefaction greatly affects the pink teeth phenomenon, whereas red pigment-producing bacteria have little effect on the occurrence of pink teeth. However, further studies are needed to clarify bacteriological involvement.

Isolation and Characterization of Pigment Producing Bacteria from Solid Food Waste Samples

Due to increasing advertence of hazards of chemical colours, biocolours produced by pigment producing microorganisms can be helpful option to be used commercially. In the current study it was attempted to isolate pigment producing bacteria from solid food waste samples which are rich in microflora. Three isolates designated as IS-1, IS-2 and IS-3 were obtained which were later tentatively identified as Staphylococcus roseus (red pigment), Staphylococcus saprophyticus (pink pigment) and Micrococcus luteus (lemon yellow pigment), respectively on the basis of morphological and biochemical characteristics. Each pigment was further extracted and its antimicrobial activity was checked against Staphylococcus aureus, Candida albicans, Klebsiella pneumoniae and Pseudomonas aeruginosa. The pigment produced by Staphylococcus roseus showed antimicrobial activity against Staphylococcus aureus and Candida albicans. Hence, this red pigment has potential to be used in food industry and also in skin creams. Further work on this pigment for its feasibility in above use is in process.

Selective Isolation of Bioactive-Pigmented Bacteria from Saline Agricultural Soil and Assessment of Their Antimicrobial Potential against Plant Pathogens

The high incidence of disease and pests and their resistance to chemical control agents pose serious threats to both the agriculture sector and the environment. The present study assessed the antagonistic potential of bioactive pigment-producing bacteria isolated from the saline agricultural fields of Gujrat, Pakistan, against plant pathogenic fungi and bacteria. The seeded agar overlay method was used to selectively isolate bioactive pigment-producing colonies. Isolates were identified as Nonomurae salmonae, Streptomyces chromofuscus, and Actinocorallia libanotica using 16S rRNA gene sequence analysis. All the isolates and their crude pigment extracts were screened to assess antifungal activity against five fungal phytopathogens, namely Fusarium oxysporum (F. oxysporum), Fusarium solani (F. solani), Aspergillus flavus (A. flavus), Aspergillus niger (A. niger), and Alternaria alternata (A. alternata), as well as two bacterial phytopathogens, namely Psuedomonas syringae (P. syringae) and Xanthomonas axonopodis (X. axonopodis). Of these, Streptomyces chromofuscus was found to be active against most of the fungal and bacterial phytopathogens tested, followed by Nonomurae salmonae. Actinocorallia libanotica showed little to no activity against the tested microbes. Nonomurae salmonae and Actinocorallia libanotica are rare actinomycetes and the current study is the first to assess their antimicrobial activity against plant pathogens, specifically, plant pathogenic bacteria, i.e., P. syringae and X. axonopodis. The isolation of these species suggests that the chances of the isolation of rare species of microbes, which can serve as promising new sources of bioactive compounds, can be increased by using enhanced techniques for isolation. The results of this preliminary study assessing the antagonistic effect of bioactive pigment-producing bacterial isolates against plant pathogens are encouraging, and suggest a detailed research on the modes of action, optimum working conditions, and active components involved in an antagonism of these bioactive pigment-producing bacteria.

Antibacterial Activity and Potential Of Natural Textile Dyes From Sea Water Bacteria

This research aims to determine the potential of bacterial isolates from Marina beach seawater to be used as natural textile dyes and to test their antibacterial ability. The media used for culturing bacteria is a zobel synthesis medium with a mixture of seawater. The results of the isolation and extraction of color pigments obtained a red color with a characteristic wavelength of 535 nm and has a variety of chemical content results. Pigment immersion trials using 3 types of fabric, namely cotton, primisima and dobby fabric. The results of immersion with ethanolic solvent obtained optimum results for 12 hours and with the addition of mordant (Fe.H2O4S.7H2O), the color of the fabric is strong enough to withstand washing with detergent and sunlight. From the results of the study, data showed that the dyed primisima fabric gave a reduction or inhibition of the growth of E. coli bacteria by 9% while the inhibition of S. aureus bacteria was 116%. The pigment has the potential to be used as a dye for batik cloth with the provisions of optimizing to find the right reinforcement or mordant. This study has implications for the discovery of red pigment-producing bacteria from the isolation of seawater at Marina Semarang beach.

Isolation and Identification of Pigment Producing Bacteria From the Ratargul Swamp Forest Soil

Pigments are one of the most significant secondary metabolites produced by microorganisms. The aim of the present study was to isolate and identify pigmentproducing bacteria from the Ratargul Swamp Forest (RSF) soil, which is the one and only fresh water swamp forest of Bangladesh. Soil samples were randomly collected from 10 different quadrates (10 m x 10 m) of RSF. The pH values of the soil samples were found to be strongly acidic and ranged between 4.71 and 5.48. Bacterial load of the samples ranged from 1.33×105 to 1.93×108 cfu/g, 6.05×106 to 9.07×107 cfu/g and from 1.16×107 to 1.61×108 cfu/g on nutrient agar (NA), peptone yeast-extract glucose (PYG) agar and Luria-Bertani (LB) agar media, respectively. Interestingly, both the highest and lowest bacterial counts were observed on NA, which was 1.93×108 cfu/g and 1.33×105 cfu/g, respectively. The isolates were found to produce various pigments like yellow, red, dark orange and sweet pink during their colony developments. A total of 71 bacterial isolates were obtained of which 11 were subjected to further study. All the selected bacteria were found to be rod shaped. Out of the 11 isolates, 9 were Gram-positive and 2 were Gramnegative. Provisionally identified potential pigment producing eight bacterial isolates were identified by using molecular marker. Seven of them were matched with their conventional identification up to generic level but conventionally identified Erwinia stewartii was found to be as Aeromonas sobria. Among the 11 isolates, 8 could produce three different types of pigments namely red, yellow and dark orange during in vitro pigment production. The isolated pigment producing bacteria could be used for better biotechnological application. Dhaka Univ. J. Biol. Sci. 31(1): 1-8, 2022 (January)

Screening, Characterization, and Isolation of Pigments from Bacteria in Mesophotic Depths of the Benham Bank Seamount, Philippine Rise Region

The exploration for pigment-producing bacteria and structurally novel pigment continues to increase, and the marine environment has recently become an attractive research site for these investigations because of its rich yet untapped biodiversity. In this study, 16S rRNA gene sequencing and HPLC (high-performance liquid chromatography) profiling of the microbial pigments produced by marine heterotrophic bacteria were described. Seven phenotypically distinct isolates of marine pigmented heterotrophic bacteria (MPHB) were isolated from near-bottom waters and coral reef sediments at mesophotic depths of the Benham Bank Seamount – namely, isolates BR14, BR61, BR63, BR100, BR101, BR144, and BR146. Four promising isolates were subjected to 16S rRNA gene sequencing and revealed that strains BR61 and BR100 were related to members of the genus Cytobacillus, whereas isolates BR144 and BR146 clustered with Meridianimaribacter flavus and Pseudoalteromonas rubra, respectively. Growth of the seven isolates on three media – natural sea water (NSW) Reasoner’s 2A (R2A), marine agar (MA), and tryptic soy agar – revealed variable pigment production and growth yield. MA appeared to be a superior substrate, resulting in darker pigmentation and higher biomass yield. Through a liquid-liquid partitioning approach, isolates BR14 and BR100 produced pigments that were acetone-soluble, whereas isolates BR101, BR144, and BR146 are hexane soluble. Moreover, the BR146 red pigment was proposed to be a mixture of putative prodiginine analogs. The putative prodiginines produced by isolate BR146 can stain fabrics, supporting a proof-of-concept that marine bacteria can be utilized as fabric colorants. The data presented here provided new insights into the utilization of local Philippine marine microbial resources for natural marine pigments with industrial applications.

Isolation, Optimization and Application of Pigment Producing Bacteria from Soil

Color is the most crucial aspect of any item since it improves its attractiveness and acceptability. Different dyes are available in the market which makes their way to different industries. Synthetic colors are more reliable and less expensive than natural colors, but due to health hazards, few remain prohibited. In dye, food, pharmaceutical, cosmetic industries, widely use innocuous pigments from microbes. The work focuses on isolating the pigment-producing bacteria from soil and investigate several parameters that influence pigment synthesis. Bio colorant derived from A1 and A2 were applied on cotton fabric with pigment extracted by the solvent method. Different temperature, pH, incubation, and static and shaking conditions were investigated in this study. Biochemical and Molecular analysis identified both isolates A1 and A2 as Pseudomonas aeruginosa and SalinococcusI roseus. This work demonstrated pigment production was good under neutral pH and at shaking conditions. Both isolates showed different incubation times for pigment synthesis. Only Pseudomonas aeruginosa exhibited antibacterial action against the test pathogens E.coli and Staphylococcus aureus.

Kinetika Pertumbuhan dan Analisis Fourier Transform Infra Red (FTIR) Spectroscopy Bakteri Penghasil Pigmen Serratia marcescens dan Rhodococcus sp.

Serratia marcescens and Rhodococcus sp. are two pigment-producing bacteria that have the potential to be used in industry. Pigment production is closely related to bacterial growth. This study examined the growth and specific growth rate (umaks) as well as functional group analysis using FTIR from the bacteria S. marcescens and Rhodococcus sp. isolated from the Gedong Songo hot spring, Bandungan Semarang. The results showed that the maximum growth of S. marcescens and Rhodococcus sp. of 0.044 g/L and 0.0038 g/L were achieved at the same hour, namely 48 hours of incubation time. The specific growth rate (umax) of S. marcescens was 0.11(1/hour) and Rhodococcus sp. of 0.15 (1/hour). FTIR analysis of these two bacteria showed absorption at N-H, C-H, O-H and C=O, so that the pigment compounds belonged to the alkaloid group.

Evaluation of antioxidant potential of pigments extracted from Bacillus spp. and Halomonas spp. isolated from mangrove rhizosphere.

The present study aimed to isolate different pigment-producing bacteria from the mangrove rhizosphere habitat and to extract their pigments for evaluating their antioxidant and sun-protective properties. Three pigment-producing bacterial cultures were isolated from soil samples and were identified by morphological analysis and 16S rDNA sequencing. The pigments were isolated by the solvent extraction method and named as MZ (Pink), Orange, and Yellow. They were characterized by Fourier Transform Infrared (FTIR) and UV-Vis spectroscopy. The sun protection factor (SPF) values of these pigments were then determined using the Mansur equation. The total polyphenol content was estimated by the Folin-Ciocâlteu method, and the antioxidant activity of the pigments was determined using DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric reducing antioxidant power), and ABTS (2,2-azinobis-3-ethyl-enzothiazoline-6-sulfonic acid) assays. The in vitro antioxidant potential of the pigments in the presence of oxidative stress (H2O2) was confirmed in the mouse macrophage cell line RAW264.7 by using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The pigment-producing bacterial isolates were identified as Bacillus infantis (MZ), Halomonas spp. (Orange), and Bacillus spp. (Yellow). The pigments were found to be carotenoid in nature, and the SPF values were in the range of 3.99 to 5.22. All three pigments had high polyphenol content (22 to 48 μg tannic acid equivalent) and showed significant antioxidant properties in both chemical and cell line-based studies. The results of this study indicate that these pigments have the potential to be used as an antioxidant agent and can be further developed as a pharmaceutical compound.

Purification and optimization of pink pigment produced by newly isolated bacterial strain Enterobacter sp. PWN1

Pigment-producing bacteria were isolated from kitchen wastewaters of the National Institute of Technology, Rourkela. A pink non-virulent bacterial strain PWN1 was selected based on the India Ink Broth and Coomassie Brilliant Blue (R-250) dye assay. According to morphological and biochemical characterization, the strain PWN1was a Gram-negative, rod-shaped, motile, non-coliform bacterium and could utilize only glucose and adonitol as sole carbon source. The pigment was found to be a growth-associated product, and the pigment production was accelerated after 40 h of bacterial culture. Further, 16S rRNA gene-based molecular identification showed its similarity with Enterobacter sp. The pigments were extracted by the solvent extraction method using chloroform and ethanol (3:1). The extracted pigments were then purified through thin-layer chromatography and column chromatography. To maximize pigment production, the culture condition was optimized for maximum biomass production using statistical software Design Expert v13. A quadratic model was structured describing the process efficiently and it suggested a moderate temperature, pH, and a high inoculum concentration which generated biomass of 3.81 ± 0.02 g/L. At optimized condition, 1 L of cell culture produced 3.77 g of biomass which produced a crude pigment of 0.234 g after solvent extraction and 0.131 g after column chromatography, implying a yield of 6.2% for crude pigment and 3.47% for purified pigment from biomass. The yield of the obtained pigment was high enough to draw interest for industrial production, although the application of the pigment is considerable for further study.

Characterization of Yellow Pigmented Bacteria Associated with Gracilaria sp.

Research on the kinship analysis of endophytic bacterial isolated from Gracillaria sp has been carried out. The presence of bacteria associated with Gracilaria sp. has enabled the use of these bacteria as a source of new bioactive compounds, such as biopigments. The research aims to isolated bacteria from Gracilaria sp., screened their symbiont bacteria that could potentially produce pigments. Sampling Gracilaria sp. conducted in the waters of the Island of Karimunjawa, Jepara. Furthermore, bacterial isolation was carried out, screening for pigment-producing bacteria and 16S rRNA sequence analysis. Research result showed that the symbiont bacteria isolate TK 373 produced consistent pigments after several regenerations, in several types of growth media incubated at room temperature. The results of 16S rDNA identification showed that the TK 373 isolate had the closest relationship with Pseudoalteromonas sp. with 98.72 % homology.

Bioactive Pigments from Isolated Bacteria and Its Antibacterial, Antioxidant and Sun Protective Application Useful for Cosmetic Products.

Bacterial pigments are the unique and sustainable source of bioactive colour compounds used in cosmetics, food, textiles, printing and pharmaceutical products. Here, we report the pigment-producing isolates and their biological activities that could be benefited for different industries including cosmeceuticals. In this study, a total of 19 pigment-producing bacteria were isolated and purified from collected soil and water samples. The colour production ability of purified bacteria was observed up to 5 transfers. Of the 19 isolates, two isolates lost colour production ability in subsequent transfers. Crude pigments extracted from the remaining 17 isolates showed sunscreen activity in the range of 0.4-8.34. However, only 6 of them showed significant antibacterial and antioxidant activities. In the media optimization experiment, these 6 bacteria showed optimum growth in neutral to alkaline pH, while optimum temperatures for growth were different for different bacteria. One isolate produces the promising pigment, out of all six potential pigments. It is stable up to 5 transfers, having antioxidant and antibacterial activity with Sun protective activity; the strain was identified using 16srRNA gene sequencing and obtained accession number as MK770403 (probable strain is Staphylococcus xylosus) from National Center for Biotechnology Information (NCBI) database. The results of this study suggested that these bioactive pigments can further be developed and used as antibacterial, antioxidant and sun-protective ingredients in cosmeceuticals.

EVALUATION OF CYTOTOXIC ACTIVITY OF ETHYL ACETATE EXTRACT OF PIGMENT FROM PSEUDOMONAS AERUGINOSA

Objective: Bacterial pigments have promising applications in food, cosmetics, textile, and therapeutics. Pigments from microbial origin are stable, safer, cost effective, easy production, and extraction and thus preferred over other natural sources. Under this backdrop, isolation and characterization of pigment-producing bacteria and analysis of bioactivity of the pigment were the aim of the study. From the literature studies, the pigment production was found to be influenced by various physical factors which directed the study toward optimization of physical parameters for pigment production.
 Methods: Isolation of pigment-producing bacteria from water sample, cultural, and microscopic identification was done as per the standard protocol. Extraction of pigment by solvent extraction was carried out and its antibacterial and cytotoxic activity was assayed.
 Results: Molecular characterization of the bacteria resembled the query sequence of the isolate to 99% with Pseudomonas aeruginosa strain. Extraction of pigment by solvent extraction method resulted in crude pigment extract with antibacterial activity against Gram-negative bacteria (17 mm zone of inhibition) at 100 μg/ml concentration. Pigment showed dose-dependent inhibition on proliferation of HeLa cells at the concentration of 345.83 μg/mL.
 Conclusion: From the above results, it was evident that the pigment extracted from the bacterial isolate Pseudomonas aeruginosa strain JBT18N was therapeutically potential.

Isolation and molecular identification of carotenoid-producing bacteria

Abstract. The production of pigments from bacteria is significant due to the low cost, high yield and ease of extract compared with other sources. Carotenoids are one of the most important pigments with antioxidant properties which are the precursor of vitamin A synthesis and have antibody overproduction ability, anti-tumor activity and inhibitory effect on the cardiovascular disease. The present study aimed to isolate and identify carotenoid-producing bacteria by highperformance liquid chromatography (HPLC) analysis of their carotenoid pigments. Twenty soil samples were collected from different regions of Tehran. After serial dilution each sample was cultured on BHI agar medium and incubated at 37°C. The pigment-producing bacteria were selected for further identification and their pigments were extracted bymethanol. The screening was carried out at two levels: i) selection of the strains by visual color inspection, ii) analysis of the pigment extracts by UV-VIS spectroscopy and HPLC. The isolates were identified by phenotypic methods and their 16S rDNA gene was amplified by PCR method and sequenced. Staphylococcus epidermidis, Micrococcus aloeverae, Citricoccus alkalitolerans, Rhodococcus zopfii, Arthrobacter agilis, Dietzia natronolimnaea and Rhodococcus ruber were identified as carotenoid-producing strains. The highest rate of absorption was observed using UV-VIS analysis in Staphylococcus epidermidis and Dietzia natronolimnaea. The comparison of HPLC analysis with the standard β-carotene curve showed that the carotenoids were beta-carotene. Micro-organisms are a potential source in the production of pigments. In this study we introduced two genera of bacteria (Staphylococcus epidermidis and Dietzia natronolimnaea) with carotenoid-producing ability.