Basis Of 16S rDNA Sequences Research Articles

PRODUCTION OF CELLULASE FROM NATURAL BACTERIAL ISOLATES FROM SOIL SAMPLE OF DISTRICT JAUNPUR, U.P., INDIA

The present study aims at isolating, screening, characterizing and optimizing cellulolytic bacteria isolated from soil samples. Different soil samples were collected from different locations of district Jaunpur, Uttar Pradesh, India. The morphological, biochemical and molecular characterization of the isolates were carried out for their identification. A total number of 23 isolates were screened at preliminary level for cellulolytic activity out of which three potent cellulase producers were selected for further study. On the basis of 16S rDNA sequencing these three isolates were identified as Bacillus velezensis PS-14, Bacillus velezensis PS-09 and Bacillus paramycoides PS-05. The optimal conditions for cellulase enzyme production was also determined and maximum activity was obtained at pH 7 and 40 0 C temperature, while 2% inoculum level and 48 hr incubation period were found to be optimum for cellulase production by all the strains. Glucose and Carboxymethyl cellulose was proved to be the best carbon sources, while ammonium choride and peptone was observed to be the most favourable nitrogen source for all three bacterial isolates.

Deciphering the Potential of Sulphur-Oxidizing Bacteria for Sulphate Production Correlating with pH Change.

Sulphur, available in the form of sulphate, is one of the essential nutrients that is required by plants. Bacteria capable of oxidizing reduced forms of sulphur to sulphate play an important role in sulphur nutrition for plants. The present study was conducted to isolate, screen, and characterize sulphur-oxidizing bacteria from different soil samples collected from mustard rhizosphere and fly ash mixed soil. A total of 33 sulphur-oxidizing bacterial isolates (HMSOB1-33) were retrieved from soil and further screened for sulphur-oxidizing ability. Maximum solubilization index (3.76), pH reduction (3.93), and sulphate production (173.61µg/ml) were observed for the isolate HMSOB2 which on the basis of 16S rDNA sequencing was identified as Pantoea dispersa with sequence similarity 98.22%. Four other selected bacterial isolates were identified as Bacillus megaterium, Bacillus tropicus, Bacillus velezensis, and Bacillus cereus. Sulphate solubilization index (SSI) correlated positively (r = 0.91) with sulphate production; however, pH showed negative correlation (r = - 0.82) with SSI as well as sulphate production after 120h of incubation. These promising bacterial isolates could be further explored as bioinoculant after assessing plant growth traits.

In Vitro and In Planta Antagonistic Effect of Endophytic Bacteria on Blight Causing Xanthomonas axonopodis pv. punicae: A Destructive Pathogen of Pomegranate

Pomegranate bacterial blight caused by Xanthomonas axonopodis pv. punicae (Xap) is a highly destructive disease. In the absence of host resistance to the disease, we aimed to evaluate the biocontrol potential of endophytic bacteria against Xap. Thus, in this study, we isolated endophytes from pomegranate plants, identified them on the basis of 16S rDNA sequencing, tested them against Xap, and estimated the endophyte-mediated host defense response. The population of isolated endophytes ranged from 3 × 106 to 8 × 107 CFU/g tissue. Furthermore, 26 isolates were evaluated for their biocontrol activity against Xap, and all the tested isolates significantly reduced the in vitro growth of Xap (15.65% ± 1.25% to 56.35% ± 2.66%) as compared to control. These isolates could reduce fuscan, an uncharacterized factor of Xap involved in its aggressiveness. Lower blight incidence (11.6%) and severity (6.1%) were recorded in plants sprayed with endophytes 8 days ahead of Xap spray (Set-III) as compared to control plants which were not exposed to endophytes (77.33 and 50%, respectively%) during in vivo evaluation. Moreover, significantly high phenolic and chlorophyll contents were estimated in endophyte-treated plants as compared to control. The promising isolates mostly belonged to the genera Bacillus, Burkholderia, and Lysinibacillus, and they were deposited to the National Agriculturally Important Microbial Culture Collection, India.

Decolourization and Detoxification of Azo Dye, Malachite Green by Pseudomonas monteilii Strain RZT1, a Bacterium Isolated from Textile Wastewater

Discharge of textile industrial effluent without proper treatment has become a severe hazard for the animal health and environment worldwide. Therefore, this study was designed to isolate azo dye-degrading bacteria from textile wastewater and evaluate their ability to biodegrade reactive dyes into non-toxic products. The potent bacterial strain which was isolated from textile wastewater was identified as Pseudomonas monteilii strain RZT1 on the basis of 16S rDNA sequence. The isolated bacterial strain exhibited good decolorization ability with yeast extract supplementation as cosubstrate in static conditions for Malachite Green dye. The optimal condition for the decolorization of Malachite Green dye by P. monteilii strain RZT1 were at pH 7.0 and 28°C. Decolorization rates of Malachite Green dye by P. monteilii strain RZT1 were varied with initial dye concentration as follow: 84.8%, 75.4%, 63.4% and 45.5% decolorization for 100ppm, 200ppm, 300ppm and 400ppm initial dye concentration respectively. We investigated the effects of dyes used in the textile industry on the seed germination of Five crops - Rice (Oryza sativa), Wheat (Triticum aestivum L.), Khesari (Lathyrus sativus), Mustard (Brassica nigra) and Bitter Melon (Momordica charantia). It was found that textile dye Malachite Green had negative effect on seed germination and seedling growth in test cultures. The harmful effects of dye on seed germination and early seedling growth parameters were augmented with increase of dye concentration. Interestingly, treatment of the Malachite Green dye with isolated bacteria reduced the adverse effects of that dye on seed germination and seedling growth. Thus, it indicated the potentiality of P. monteilii strain RZT1 for bioremediation of textile effluents into a non-toxic form for plants.

Molecular Characterization of Gram Negative Isolated from Walnut (Juglans regia L.) Rhizosphere

In this study, 10 Gram negative bacteria isolated from the rhizosphere soil of walnut (Juglans regia) orchard in the Kırşehir (Central Anatolia of Turkey) were identified at species level by classical and molecular methods. It was determined that 99% of phylogenetic similarities with bacterial isolates were closely related to the isolated Gram negative bacterial isolates. Ten isolates were morpho-biochemically and molecularly characterized and on the basis of 16S rDNA sequencing were identified as 3 Enterobacter cloacae, 3 Enterobacter ludwigii, 2 Escherichia coli, 1 Enterobacter hormaechei and 1 Plesiomonas shigelloides. Gram negative bacteria showed enzymes activities. Except for P. shigelloides and E. coli, other Gram negative bacteria showed lipase, protease, cellulase, amylase, gelatinase and pectinase activities at 4 °C and 28 °C. As a result, the current research suggests that strains isolated from walnut rhizosphere soil can be used as bio-fertilizing and bio-control agents.

Impact of Algicidal Bacillus mycoides on Diatom Ulnaria acus from Lake Baikal

Algae–bacteria interactions play an important role in water ecosystems. In this work, the BS2-15 algicidal strain was isolated from the bottom sediments of Lake Baikal and identified as Bacillus mycoides on the basis of 16S rDNA sequencing, its described ultrastructure, and biochemical properties. B. mycoides BS2-15 was demonstrated to have a strong algicidal effect against a freshwater diatom culture of Ulnaria acus, inhibiting its growth and increasing frustules fragility. By analyzing the impact of bacterial filtrate onto the cells of U. acus, we demonstrated that perhaps an algicidal compound is produced by bacteria independently in the presence of diatoms in a medium. Using methods of TUNEL and confocal microscopy, we revealed that the bacterial algicidal effect on the diatom cells results in DNA fragmentation, nucleus destruction, and neutral lipid accumulation. This phenomenon highlights the complexity of algae–bacteria interactions and their potential role in regulating water ecosystem microbial populations.

Phytobeneficial and salt stress mitigating efficacy of IAA producing salt tolerant strains in Gossypium hirsutum

Salinity is one of the major agricultural concern that significantly limits the crop productivity. The plant growth promoting rhizobacteria (PGPR) may contribute in sustainable crop production under salt stress. The current study was designed to isolate the Indole Acetic Acid (IAA) producing salt tolerant PGPR to promote the growth of cotton (Gossypium hirsutum, FH-142) and induce its salt stress tolerance. Ten Salt Tolerant (ST) bacterial strains were screened for their PGP trait in vitro and evaluated for their beneficial effect on cotton plants growth by plant–microbe interaction assay in lab and under natural condition. GC–MS analysis of the metabolites of the selected bacterial strains confirmed the presence of indolic compounds like indole, indole-3-butyramide, benzylmalonic acid and 4-methyl-2-pyrrolidinone. The bacterial isolates ST4, ST5, ST6, ST15, ST16, ST17, ST18, ST20, ST22 and ST25 were identified as Bacillus sp., B. sonorensis, B. cereus, B. subtilis, Brevibacillus sp. B. safensis, B. paramycoides, Bacillus sp., B. cereus and B. tequilensis respectively on the basis of 16S rDNA sequencing. Bacteria inoculated plants had a significant (P < 0.05) increase in percentage germination up to (31%), root length (17%) and shoot length (34%) in lab while in wire house pot experiments, maximum enhancement in root length (31%) and shoot length (29%) was observed. ST bacterial strains inoculation improved the chlorophyll content index (34%), relative water content (36%), leaf area (33%), absorption of K+ (28%) and decreased the uptake of Na+ (58%) from soil in plants under salt stress over control in pot experiment. These ST PGPR have the potential to act as plant defense agents by enhancing plant growth, productivity, and tolerance in saline environment.

UV-B irradiation enhances the production of unique mycosporine-like amino acids and carotenoids in the subaerial cyanobacterium Pseudanabaena sp. CCNU1

ABSTRACT The harmful effects of ultraviolet (UV) radiation have increased the demand for new sources of UV photoprotectants to develop cosmetic and skin care products. In this study, a filamentous cyanobacterial strain was isolated from the topsoil collected in an arid and exposed region in Chetimari, Niger. On the basis of 16S rDNA sequences, the isolated strain was identified as Pseudanabaena sp. CCNU1. UV-B treatment of Pseudanabaena sp. CCNU1 significantly enhanced the production of active photoprotectants, including UV-absorbing mycosporine-like amino acids (MAAs) and carotenoids. UV-B irradiation mainly induced the production of one MAA, identified as palythine-serine. The palythine-serine content was as high as 16 mg g−1 dry weight after a 4-day UV-B treatment. Eight carotenoids were detected in the methanol extracts of UV-B-treated Pseudanabaena sp. CCNU1: β-carotene, echinenone, canthaxanthin, zeaxanthin, synechoxanthin, and three myxoxanthophyll derivatives. With the exception of β-carotene and echinenone, these carotenoids were positively correlated with the UV-B treatment duration. Thus, Pseudanabaena sp. CCNU1 was identified as a unique organism that produces a considerable abundance of palythine-serine as well as carotenoids to protect against UV-B radiation. Pseudanabaena sp. CCNU1 may be useful as a producer of UV photoprotectants, although the genetic basis of the relevant biosynthetic pathways remains to be precisely characterized in the future.

Screening of an Alkaline CMCase-Producing Strain and the Optimization of its Fermentation Condition.

Alkaline Carboxymethyl Cellulase (CMCase) is an attractive enzyme for the textile, laundry, pulp, and paper industries; however, commercial preparations with sufficient activity at alkaline conditions are scarce. High CMCase-producing bacterial isolate, SX9-4, was screened out from soil bacteria, which was identified as Flavobacterium sp. on the basis of 16S rDNA sequencing. The optimum pH and temperature for CMCase reaction were 8.0 and 55°C, respectively. Alkaline CMCase was stable over wide pH (3.0-10.6) and temperature (25-55°C) ranges. Enzyme activity was significantly inhibited by the bivalent cations Mn2+ and Cu2+, and was activated by Fe2+. To improve the alkaline CMCase production of SX9-4, fermentation parameters were selected through onefactor- at-a-time and further carried out by response surface methodologies based on a central composite design. High CMCase production (57.18 U/mL) was achieved under the optimal conditions: 10.53 g/L carboxymethylcellulose sodium, 7.74 g/L glucose, 13.71 g/L peptone, and 5.27 g/L ammonium oxalate.

Isolation of Cadmium and Lead Tolerant Plant Growth Promoting Rhizobacteria: Lysinibacillus varians and Pseudomonas putida from Indian Agricultural Soil

ABSTRACTCadmium and lead tolerant plant growth promoting rhizobacteria can be an eco-friendly option for reclamation of metal-contaminated soil and mitigation of heavy metal stress for phytostimulation to develop sustainable agriculture. Novel heavy metal tolerant PGPR strain isolation is prerequisite in practical scale. The present study was to isolate, characterize and identify cadmium and lead tolerant PGPR strains. Some potent multi heavy metal tolerant PGPRs were isolated from rhizospheric soil contaminated with industrial, sewage or agrochemical waste and two most promising strains were identified as Lysinibacillus varians strain KUBM17 and Pseudomonas putida strain KUBM18 on the basis of 16S rDNA sequencing. These two strains were exhibiting a high degree of Cd and Pb tolerant ability with bioaccumulatory properties to remove Cd and Pb from the medium which was evidenced by AAS study. Furthermore, L. varians strain KUBM17 and P. putida strain KUBM18 showed very promising PGP traits such as ammonia production, IAA production (20–22 µg/ml), Nitrogen fixation, phosphate solubilization (55–515 ppm) and siderophore production (14–40 nmole) capability together with biocontrol properties with survival ability under different agro-climatic conditions. These PGPR isolates improved the early radish plant growth under cadmium and lead stress condition. So, KUBM 17 and KUBM 18 might be concerned as PGPR-biofertilizer in heavy metal-contaminated agricultural soil.

Endogenous Bacterial Contamination of Plant Tissue Culture Materials: Identification and Control Strategy

The endogenous bacterial contamination of plant tissue culture materials and their possible control was studied. Nine bacterial isolates were isolated from the contaminated tissue culture materials viz. potato and tea. On the basis of morphology and biochemical characters of nine isolates, seven were identified as Gram positive belonging to Bacillus alcalophilus, B. circulans, B. infantis, B. lentus, B. schlegelii, B. pumilus and B. subtilis. Remaining two were Gram negative and identified as Enterobacter cloacae sub. sp. dissolvens and Pantoea agglomerans. Molecular analysis was conducted on the basis of 16S rDNA sequence to confirm three isolates. Culture and sensitivity test was carried out to screen out the antibiotic sensitivity where streptomycin (S-10), polymyxin (PB-300) and gentamicin (CN-120) antibiotics were found to be effective against all bacterial isolates. The culture and sensitivity test reflected the feasibility to control or eliminate the contaminant bacteria during in vitro culture of plant which is very much required in the commercial tissue culture production.Plant Tissue Cult. &amp; Biotech. 28(1): 99-108, 2018 (June)

Removal enactment of organo-phosphorous pesticide using bacteria isolated from domestic sewage

Three bacteria (MS I, II and III) i.e., Pseudomonas aeruginosa (KY781886), Enterobactor ludwigii (KX881423) and Enterobacter cloacae (KX881513) isolated from domestic sewage were identified on the basis of 16S rDNA sequencing and are capable to growth in the presence of organo-phosphorous pesticide (chlorpyrifos). The mega plasmid size >23 kb was found in MS I and III. Biosurfactants of the significant amount were produced by three isolates. The ability of the isolates to degrade pesticide over 3 days in the presence of pesticides containing chlorpyrifos as the active component was estimated. Results of UV–visible, FTIR spectroscopy and GC–MS studies confirmed the removal of chlorpyrifos rather than degradation. Pesticide uptake results showed chlorpyrifos in intracellular components and bound to the cell surface in its native state. Removal of pesticide from soil was also recorded by these bacteria. Microbial treated pesticide did not have any effect on Vigna radita seedlings and goat erythrocytes.

Molecular characterization of rhizobacteria isolated from walnut (Juglans regia) rhizosphere in Western Himalayas and assessment of their plant growth promoting activities

Dar GH, Sofi S, Padder SA, Aisha Kabli A. 2018. Molecular characterization of rhizobacteria isolated from walnut (Juglans regia) rhizosphere in Western Himalayas and assessment of their plant growth promoting activities. Biodiversitas 19: 712-719. The present study was aimed to isolate and characterize effective bacteria from the rhizosphere of walnut (Juglans regia) grown in North Western Himalayas and assess their growth promoting potential so that they may, in future, be exploited as biofertilizers. Based on preliminary screening of 98 bacterial isolates obtained from four walnut growing districts of Kashmir valley during survey in 2015, 12 isolates were characterized morpho-biochemically and molecularly basis. On the basis of 16S rDNA sequencing they were identified as Bacillus licheniformis WI 90, B. tequilensis WI 62, B. cereus WI 36, B. subtilis strains WI 63 and WI 65, Micrococcus luteus strains WI 12, WI 41 and WI 80; M. yunnanensis strains WI 60 and WI 30 and Micrococcus sp. strains WI 11 and WI 91. The assessment of these rhizobacteria for plant growth promoting attributes revealed that B. licheniformis WI 90 possessed higher phosphorus solubilization activity (312 mg/L), followed by Micrococcus sp. WI 91 (267 mg/L) while high siderophore was produced by M. luteus WI 12 (27.2% siderophore units), followed by B. licheniformis WI 90. B. cereus strains WI 36. High IAA contents (30 µg/mL) was yielded by WI 41, followed by M. yunnanensis WI 60 (28 µg IAA/mL) while higher and statistically at par gibberellic acid was produced by B. licheniformis WI 90, Micrococcus sp. WI 91 and M. luteus WI 80. Higher chitinase enzyme activity was observed in B. subtilis WI 63 (30.5 units/mL), followed by B. tequilensis WI 62 (25.3 units/mL) and B. subtilis WI 65 (25.1 units/mL). The study revealed high plant growth promoting potential in these rhizobacteria.

In vitro bioefficacy of rhizobacteria, isolated from walnut (Juglans regia L.) rhizosphere in North-Western Himalayas, against five fungal phytopathogens

The present study was aimed to assess the bioefficacy of rhizobacteria isolated from walnut (Juglans regia) grown in North Western Himalayas against five fungal phytopathogens so that they may, in future, be exploited as biocontrol agents against fruit crop diseases. Ninety eight rhizobacterial isolates were isolated from walnut rhizosphere in major walnut growing areas of Kashmir. The siderophore & HCN production and chitinase activity were detected in 53, 82 and 35 isolates, respectively. In vitro assessment of rhizobacteria for biocontrol efficacy against 5 fungal pathogens viz., Dematophora necatrix, Alternaria solani, Pythium aphanidermatum, Fusarium oxysporum and Phytophthora capsici revealed that most of the rhizobacterial isolates exhibiting growth inhibition of various fungal pathogens belonged to the genus Bacillus. In present study, 23, 20, 19, 21 and 20 isolates were found antagonistic to D. necatrix, A. solani, F. oxysporum, P. aphanidermatum and P. capsici, respectively, with maximum inhibition in each respective case by isolate WI 90 (66%), WI 63 (55.6%), WI 62 (43.8%), WI 63 (45.5%) and WI 65 (49%). Twelve most effective isolates were morpho-biochemically and molecularly characterized and on the basis of 16S rDNA sequencing were identified as Bacillus licheniformis (isolates WI 90, Bacillus subtilis (isolates WI 63 and WI 65), Bacillus tequilensis (isolate WI 62), Bacillus cereus (isolate WI 36), Micrococcus luteus (isolates WI 12, WI 41 and WI 80), Micrococcus yunnanensis (isolates WI 30 and WI 60) and Micrococcus sp. (isolates WI 11 and WI 91).

Characterization of Leptospira species isolated from soil collected in Japan.

Leptospira were isolated from soil obtained from Hokkaido, the northernmost island, to Okinawa, the southernmost island, of Japan using sulfamethoxazole, trimethoprim, amphotericin B, fosfomycin, and 5- fluorouracil. Fifty of 132 soil samples (37.9%) were culture-positive. On the basis of 16S-rDNA sequences, 12 of the isolated Leptospira were classified into a pathogenic species clade that is closely associated with L. alstonii and L. kmetyi. Nine isolates were classified as intermediate species and were found to be similar to L. licerasiae. Twenty-seven isolates were classified as non-pathogenic species, of which 23 were found to be related to L. wolbachii. Non-pathogenic Leptospira are commonly distributed in environmental soil.

Nanochitosan supports growth of Zea mays and also maintains soil health following growth.

The present study evaluated the effect of nanochitosan in combination with plant growth promoting rhizobacteria (PGPR), PS2 and PS10 on maize growth. The PGPR were earlier recognized as Bacillus spp. on the basis of 16S rDNA sequencing. The observation revealed enhanced plant health parameters like seed germination (from 60 to 96.97%), plant height (1.5-fold increase), and leaf area (twofold). Variabilityin different physicochemical parameters (pH, oxidizable organic carbon, available phosphorous, available potassium, ammoniacal nitrogen and nitrate nitrogen) was observed. Activities ofsoil health indicator enzymes (dehydrogenase, fluorescein diacetate hydrolysis and alkaline phosphatase) were also enhanced 2to3 fold. Plant metabolites with respect to different treatments were also analyzed using gas chromatography-mass spectroscopy (GC-MS) and the result revealed an increase in the amounts of alcohols, acid ester and aldehyde compounds. Increase in organic acids indicates increased stress tolerance mechanism operating in maize plant after treatment of nanochitosan.

Isolation and Characterization of Acinetobacter lwoffii from the Intestine of Grass Carp (Ctenopharyngodon idella)

Acinetobacter lwoffii infections are largely concentrated in mammals; very few reports are available for such infections in fish. In this study, a Gram-negative rod bacillus was isolated from the intestine of grass carp (Ctenopharyngodon idella), and designed as strain CY1. The isolated strain was then identified as A. lwoffii according to morphological, physiological, and biochemical properties, and 16S rDNA sequencing. The phylogenetic tree constructed on the basis of 16S rDNA sequences indicated that strain CY1 is most closely related to A. lwoffii, and has 98.08% similarity with type strain ATCC17925. Experimental infection assays were conducted, and a cumulative mortality rate of 75% was observed in grass carp. Antimicrobial susceptibility test showed that the isolated strain CY1 was highly susceptible to most antimicrobial agents tested, including aminoglycosides, β-lactams, and quinolones. To our knowledge, this is the first report on pathogenic A. lwoffii in grass carp.

Isolation and Characterization of Acinetobacter lwoffii from the Intestine of Grass Carp (Ctenopharyngodon idella)

Acinetobacter lwoffii infections are largely concentrated in mammals; very few reports are available for such infections in fish. In this study, a Gram-negative rod bacillus was isolated from the intestine of grass carp (Ctenopharyngodon idella), and designed as strain CY1. The isolated strain was then identified as A. lwoffii according to morphological, physiological, and biochemical properties, and 16S rDNA sequencing. The phylogenetic tree constructed on the basis of 16S rDNA sequences indicated that strain CY1 is most closely related to A. lwoffii, and has 98.08% similarity with type strain ATCC17925. Experimental infection assays were conducted, and a cumulative mortality rate of 75% was observed in grass carp. Antimicrobial susceptibility test showed that the isolated strain CY1 was highly susceptible to most antimicrobial agents tested, including aminoglycosides, β-lactams, and quinolones. To our knowledge, this is the first report on pathogenic A. lwoffii in grass carp.

Initial microbial degradation of polycyclic aromatic hydrocarbons

The group of polycyclic aromatic hydrocarbons (PAHs) are very hazardous environmental pollutants because of their mutagenic, carcinogenic and toxic effects on living systems. The aim of this study was to examine and compare the ability and efficiency of selected bacterial isolates obtained from oil-contaminated areas to biodegrade PAHs. The potential of the bacteria to biodegrade various aromatic hydrocarbons was assessed using the 2,6-dichlorophenol-indophenol assay. Further biodegradation of PAHs was monitored by gravimetric and gas-chromatographic analysis. Among the eight bacterial isolates, identified on the basis of 16S rDNA sequences, two isolates, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, had the ability to grow on and utilize almost all examined hydrocarbons. Those isolates were further examined for biodegradation of phenanthrene and pyrene, as single substrates, and as a mixture, in vitro for ten days. After three days, both isolates degraded a significant amount phenanthrene, which has a simpler chemical structure than pyrene. Planomicrobium sp.RNP01 commenced biodegradation of pyrene in the PAH mixture only after it had almost completly degraded phenanthrene. The isolated and characterized bacteria, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, have shown high bioremediation potential and are likely candidates to be used for degradation of highly toxic PAHs in contaminated areas.

Degradation of Reactive Black 5 dye by a newly isolated bacterium Pseudomonas entomophila BS1.

The textile and dye industries are considered as one of the major sources of environmental pollution. The present study was conducted to investigate the degradation of the azo dye Reactive Black 5 (RB 5) using a bacterium isolated from soil samples collected around a textile industry. The bacterial strain BS1 capable of degrading RB 5 was isolated and identified as Pseudomonas entomophila on the basis of 16S rDNA sequencing. The effects of different parameters on the degradation of RB 5 were studied to find out the optimal conditions required for maximum degradation, which was 93% after 120 h of incubation. Static conditions with pH in the range of 5-9 and a temperature of 37 °C were found to be optimum for degrading RB 5. Enzyme assays demonstrated that P. entomophila possessed azoreductase, which played an important role in degradation. The enzyme was dependent on flavin mononucleotide and NADH for its activity. Furthermore, a possible degradation pathway of the dye was proposed through gas chromatography - mass spectrometry analysis, which revealed that the metabolic products were naphthalene-1,2-diamine and 4-(methylsulfonyl) aniline. Thus the ability of this indigenous bacterial isolate for simultaneous decolorization and degradation of the azo dye signifies its potential application for treatment of industrial wastewaters containing azo dyes.