A Study on L-Asparaginase of Nocardia levis MK-VL_113

An enzyme-based drug, L-asparaginase, was produced by Nocardia levis MK-VL_113 isolated from laterite soils of Guntur region. Cultural parameters affecting the production of L-asparaginase by the strain were optimized. Maximal yields of L-asparaginase were recorded from 3-day-old culture grown in modified asparagine-glycerol salts broth with initial pH 7.0 at temperature 30°C. Glycerol (2%) and yeast extract (1.5%) served as good carbon and nitrogen sources for L-asparaginase production, respectively. Cell-disrupting agents like EDTA slightly enhanced the productivity of L-asparaginase. Ours is the first paper on the production of L-asparaginase by N. levis

PURIFICATION AND CHARACTERIZATION OF L-ASPARAGINASE BY PSEUDONOCARDIA ENDOPHYTICA VUK-10 ISOLATED FROM NIZAMPATNAM MANGROVE ECOSYSTEM

Objective: L-asparaginase has been a promising therapeutic agent in the treatment of acute lymphoblastic leukaemia. In the present study a rare actino bacterial strain Pseudonocardia endophytica VUK-10 isolated from Nizampatnam mangrove ecosystem was explored for the production of L-asparaginase.Methods: The extracellular L-asparaginase enzyme was purified to homogeneity from the P. endophytica VUK-10 strain. The crude culture filtrate was subjected to different purification steps including ammonium sulphate fractionation followed by separation on Sephadex G-100 gel filtration and CM-Sephadex C-50 ion exchange chromatography to obtain a pure enzyme preparation.Results: The enzyme was purified 96 fold and showed a final specific activity of 702.04 IU/mg with a 61% yield. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme revealed its nature as single peptide chain with molecular weight of 120 kDa. This is the first report on production and purification of L-asparaginase from P. endophytica of mangrove origin.Conclusion: The extracellular L-asparaginase of the P. endophytica may be effectively used as potential chemotherapeutic agent.Keywords: Mangrove ecosystem, Pseudonocardia endophytica, L-asparaginase, Purification, SDS-PAG

ISOLATION AND CHARACTERIZATION OF BIOACTIVE STREPTOMYCES FROM MANGROVE ECOSYSTEM OF MACHILIPATNAM, KRISHNA DISTRICT, ANDHRA PRADESH

ABSTRACTObjective: The aim of the present study was to isolate, identify, and analyze the taxonomic characteristics of the potent actinobacterial strains VJSY-2and VJSY-3 isolated from mangrove soils of Gilakaladindi, Machilipatnam, Krishna District of Andhra Pradesh.Methods: Soil samples pretreated with calcium carbonate were used for isolation of potent actinobacterial strains. Identification of the strains wascarried out by studying the cultural, morphological, biochemical, and physiological characteristics. The phylogenetic study of the strains was carriedout by employing 16S r DNA sequence-based analysis. Phylogenetic tree was constructed using the molecular evolutionary genetic analysis softwareversion 6.Results: Based on the polyphasic taxonomic studies, the potent strains belong to Streptomyces genus. The bioactive metabolites produced by the strainswere active against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, and Bacillus megaterium), Gram-negative bacteria (Xanthomonascampestris, Pseudomonas aeruginosa, and Escherichia coli), and fungi (Aspergillus niger, Fusarium solani, Fusarium oxysporum, and Candida albicans).Conclusion: The results of the experiment showed that the crude ethyl acetate extract of the strains VJSY-2 and VJSY-3 showed significant antimicrobialpotential; hence, they can be used for isolation of compounds with pharmaceutical importance.Keywords: Mangrove Actinobacteria, Streptomyces, Bioactive metabolites

STUDIES ON OPTIMIZATION OF L-ASPARAGINASE PRODUCTION BY ARTHROBACTER KERGUELENSIS VL-RK_09 ISOLATED FROM MANGO ORCHARDS

Objectives: To optimize the cultural parameters for improved production of L-asparaginase by Arthrobacter kerguelensis VL-RK_09 isolated from Mango orchards of Vissannapet, Krishna District, A. P., India.Methods: The strain A. kerguelensis was screened for L-asparaginase production on modified asparagine dextrose salts agar medium. L-asparaginase assay was performed as described by Peterson and Ciegler (1969) with slight modifications. Cell free broth (0.2 ml) was placed with 0.8 ml of 0.05M Tris-HCl and 1 ml of 0.04M L-asparagine and incubated for 15 min at 37oC and liberated ammonia was determined spectrophotometrically at 500 nm by nesslerization. Attempts were made to optimize cultural parameters affecting the production of L-asparaginase by the strain.Results: Maximal yield of L-asparaginase was recorded after 3days of incubation in asparagine dextrose salts broth with initial pH 7.0 and temperature 30 °C. Biosynthesis of L-asparaginase by the strain was improved (from initial 4.28 IU to 6.5 IU) when cultured in modified asparagine dextrose salts broth (initial pH 7.0) supplemented with 1.5% yeast extract and 2% xylose maintained at 30 ° C for 72 h. This is the first report on the production and optimization of L-asparaginase by A. kerguelensis.Conclusion: In the present study, the optimal cultural and nutritional conditions for the production of L-asparaginase by A. kerguelensis VL-RK_09 were recorded. This is the first report on the production and optimization of L-asparaginase by A. kerguelensis and further studies on purification and characterization of the enzyme is in progress.Â

STREPTOMYCES CELLULOSAE VJDS-1, A PROMISING SOURCE FOR POTENTIAL BIOACTIVE COMPOUNDS

Objectives: The aim of the present study was to isolate, identify and analyze the phylogenetic characteristics of the potent actinobacterial strain VJDS-1 with antagonistic activities isolated from Mangrove ecosystems of Nizampatnam, Guntur Dist, A.P., India.Methods: Soil samples collected were pre treated with calcium carbonate and used for isolation of potent actinobacterial strain designated as VJDS-1. Identification of the strain was carried out by studying the micro morphological, cultural, biochemical and physiological methods. The Phylogenetic study of the strain was carried out by employing 16S rDNA sequence based analysis. Phylogenetic tree was constructed using the MEGA (Molecular Evolutionary Genetic Analysis) software version 6.Results: The potent actinobacterial strain was identified as Streptomyces cellulosae VJDS-1 and the bioactive metabolites produced by the strain inhibited Gram positive bacteria (Staphylococcus aureus, Bacillus megaterium), Gram negative bacteria (Xanthomonas campestris, Proteus vulgaris, Pseudomonas aeruginosa and Escherichia coli) and fungi (Aspergillus niger, Botrytis cinerea, Fusarium solani F. oxysporum and Candida albicans).Conclusion: The results of the experiment showed that the crude ethyl acetate extract of Streptomyces cellulosae VJDS-1 showed significant antimicrobial potential hence it can be used for isolation of compounds with pharmaceutical importance.Â

SACCHAROMONOSPORA OCEANI VJDS‑3, A POTENT ACTINOBACTERIAL STRAIN FROM MANGROVE ECOSYSTEM

Objective: The aim of the present study was to isolate, identify, and analyze the phylogenetic characteristics of a rare actinobacterial strain VJDS‑3with antagonistic activities isolated from Mangrove ecosystems of Nizampatnam, Guntur District, Andhra Pradesh, India.Methods: Soil samples collected were pre‑treated with calcium carbonate and used for isolation of potent actinobacterial strain designated as VJDS‑3.Identification of the strain was carried out by studying the micro‑morphological, cultural, biochemical, and physiological methods. The phylogeneticstudy of the strain was carried out by employing 16S rDNA sequence‑based analysis. The phylogenetic tree was constructed using the MolecularEvolutionary Genetic Analysis software version 6.Results: The potent actinobacterial strain was identified as Saccharomonospora oceani VJDS‑3, and the bioactive metabolites produced by the straininhibited Gram‑positive bacteria (Bacillus megaterium, Bacillus subtilis), Gram‑negative bacteria (Xanthomonas campestris, Pseudomonas aeruginosa,Proteus vulgaris, and Escherichia coli), and fungi (Aspergillus niger, Botrytis cinerea, Fusarium solani, Fusarium Oxysporum, and Candida albicans).Conclusion: The results of the experiment showed that the crude ethyl acetate extract of S. oceani VJDS‑3 showed significant antimicrobial potential,and hence it can be used for isolation of compounds with pharmaceutical importance.Keywords: Mangrove ecosystems, Phylogenetic study, Saccharomonospora oceani VJDS‑3, Bioactive compounds

EXPLORATION OF POTENT ACTINOBACTERIUM NOCARDIOPSIS HALOTOLERANS VJPR-2 ISOLATED FROM MANGROVE HABITATS

ABSTRACTObjectives: This study was aimed at isolation and identification of potent bioactive metabolite producing actinobacterial strain VJPR-2 isolated fromthe mangrove ecosystem of Nizampatnam, Andhra Pradesh, India.Methods: Soil sediments collected were subjected to pre-treatment with CaCO, and actinobacterial strains were isolated using selective media. Thescreening of the isolated strains was carried out and the potent bioactive metabolite producing strain was designated as VJPR-2. An identification ofthe strain was carried out by employing polyphasic approach including morphological, cultural, physiological, biochemical, and phylogenetic analysisof 16S rRNA gene sequence. Antimicrobial potency of the isolate was tested against bacterial and fungal pathogens.3Results: The strain VJPR-2 was identified as Nocardiopsis halotolerans by morphological, cultural, physiological, and biochemical studies along with16S rRNA gene sequence analysis. The rRNA sequence was deposited in the NCBI GenBank with the accession number KP313613. The strain exhibitedantimicrobial activities against Gram-positive as well as Gram-negative bacteria and fungi.Conclusion: Actinobacterium strain N. halotolerans VJPR-2 having good antimicrobial potential was identified from the 16 strains isolated from thesediment samples of Nizampatnam mangrove ecosystem using CaCObased approach. The present study reveals the isolation, identification andbiological evaluation of the bioactive metabolites produced by strain VJPR-2.3 Keywords: Mangrove ecosystem, Nocardiopsis halotolerans VJPR-2, Polyphasic approach, Bioactive metabolites

ANTIMICROBIAL POTENTIAL OF STREPTOMYCES CHEONANENSIS VUK-A FROM MANGROVE ORIGIN

Objectives: The aim of the present study was to isolate, characterize and evaluate the activity of compounds produced by Streptomyces cheonanensis VUK-A.Methods: Chemical examination of the secondary metabolites of the strain Streptomyces cheonanensis VUK-A has led to the segregation of one bioactive compound (1) and a partially purified fraction (2). The strain was isolated from the sediment samples of mangrove ecosystem of Coringa, south coastal Andhra Pradesh, India. The chemical structure of the active compound 1 was established on the basis of spectroscopic analysis including 1H NMR, 13C NMR spectroscopy, FTIR and EIMS. The partially purified sub-fraction (2) subjected to Gas Chromatography-Mass spectroscopy. The antimicrobial activity of the bioactive compounds produced by the strain was expressed in terms of minimum inhibitory concentration.Results: The compound 1 was isolated from the fermentation broth was characterized as benzoic acid (1) based on spectroscopic analysis. The partially purified sub-fraction (2) subjected to Gas Chromatography-Mass spectroscopy contained nine analogues: 1-tetradecene, tetradecane, 1-hexadecene, hexadecane, 5-octadecene, octadecane, 5-eicosene, 1-nonadecene and cyclo tetracosane. The compounds recorded moderate to significant antimicrobial activity against medicinally and agriculturally important bacteria and fungi. This is the first report of six partially purified compounds 1-tetradecene, tetradecane, hexadecane, octadecane, 5-eicosene and cyclo tetracosane from the genus Streptomyces.Conclusion: The results of the present study showed that the metabolites of Streptomyces cheonanensis VUK-A exhibited antibacterial and antifungal activities. The study also supports that Coringa, a promising mangrove ecosystem remained to be explored for new bioactive compounds.Keywords: Streptomyces cheonanensis, Mangrove Ecosystem, Natural Products, Antimicrobial activity

OPTIMIZATION, ISOLATION AND CHARACTERIZATION OF BIOACTIVE COMPOUNDS FROM STREPTOMYCES LAVENDULOCOLOR VHB-9

Objectives: Optimization, isolation, and characterization of bioactive compounds from Streptomyces lavendulocolor VHB-9 isolated from granite mines of Mudigonda village of Khammam district of Telangana state.Methods: The potent strain was identified as S. lavendulocolor VHB-9 by polyphasic taxonomy. The influence of culture conditions on growth and bioactive compounds production was investigated. Purification of bioactive compounds was done using column chromatography. The structures of the compounds were elucidated on the basis of spectroscopic analysis including Fourier transform infrared, electron spray ionization mass spectrophotometry,1H nuclear magnetic resonance (NMR), and13C NMR. The antimicrobial activity of the compounds produced by the strain was tested against both Gram-positive and Gram-negative bacteria and fungi in terms of minimum inhibitory concentration.Results: Isolation and identification of two compounds, namely (2R, 3R)-2, 3-Butanediol (B1A), and nonadecanoic acid (B1B). Fraction B4 was isolated partially purified fraction and identified by the gas chromatography-mass spectrometry analysis. B1B compound exhibited the highest activity against Bacillus megaterium, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Candida albicans when compared to B1A and B4 compounds

A BIOACTIVE METABOLITE PRODUCTION BY NOCARDIOPSIS SYNNEMATAFORMANSVLS-10 OF MANGROVE ORIGIN: Isolation, Screening and optimization of Nocardiopsis synnemataformansVLS-10

Antibiotic resistance of pathogens has become a serious problem all over the world. Therefore, focusing for novel antibiotics is an important endeavor which is very much needed. Around 50 morphologically different actinobacteria isolated from mangrove habitats of Krishna district, Andhra Pradesh, India were screened for antimicrobial activity. Among the 50 isolates, one strain designated as VLS-10 was efficient to produce potential secondary metabolites. It was identified as Nocardiopsis synnemataformans based on polyphasic taxonomy. The present work is mainly aimed to study process optimization parameters to get high yield of bioactive compounds. ISP-2 medium supplemented with sodium chloride @ 9% maintained at pH 7.0 supported maximum yield of secondary metabolites by the strain when incubated at 35oC for nine days. Secondary metabolites possessed broad-spectrum activity against human pathogenic bacteria and fungi. Hence, strain N. synnemataformansVLS-10 becomes a significant source for antimicrobial compounds