Antimicrobial profile of Arthrobacter kerguelensis VL-RK_09 isolated from Mango orchards

Abstract

An actinobacterial strain VL-RK_09 having potential antimicrobial activities was isolated from a mango orchard in Krishna District, Andhra Pradesh (India) and was identified as Arthrobacter kerguelensis. The strain A. kerguelensis VL-RK_09 exhibited a broad spectrum of in vitro antimicrobial activity against bacteria and fungi. Production of bioactive metabolites by the strain was the highest in modified yeast extract malt extract dextrose broth, as compared to other media tested. Lactose (1%) and peptone (0.5%) were found to be the most suitable carbon and nitrogen sources, respectively, for the optimum production of the bioactive metabolites. The maximum production of the bioactive metabolites was detected in the culture medium with an initial pH of 7, in which the strain was incubated for five days at 30 °C under shaking conditions. Screening of secondary metabolites obtained from the culture broth led to the isolation of a compound active against a wide variety of Gram-positive and negative bacteria and fungi. The structure of the first active fraction was elucidated using Fourier transform infrared spectroscopy, electrospray ionization mass spectrometry, 1H and 13C nuclear magnetic resonance spectroscopy. The compound was identified as S,S-dipropyl carbonodithioate. This study is the first report of the occurrence of this compound in the genus Arthrobacter.

Optimization, Isolation and Characterization of Bioactive Compounds From Streptomyces Lavendulocolor VHB-9

“…1). A previous report demonstrated high antimicrobial activity of crude extracts of a 4-dayold culture of Arthrobacter kerguelensis VL-RK_09 [18]. The metabolites collected from 4-day-old culture of Streptomyces griseus exhibited good antifungal activity [19].…”

“…The antimicrobial activity of bioactive metabolites against Staphylococcus aureus (MTCC 3160), Lactobacillus casei, Bacillus megaterium (NCIM 2187), Proteus vulgaris (ATCC 6380), Pseudomonas aeruginosa (ATCC 9027), Escherichia coli (ATCC 9027), Aspergillus niger, Fusarium solani, Fusarium oxysporum, and Candida albicans (MTCC 183) was determined by agar well diffusion assay, and inhibition zones against test microbes were determined [8].…”

“…The optimum pH for antibiotic production by several actinomycetes was reported to be 7 for Streptomyces hygroscopicus D1.5 [28], Streptomyces torulosus KH-4 [29], Streptomyces sp. VITSVK 9 [30], Streptomyces cellulosae VJDS-1 [31], Rhodococcus erythropolis VLK-12 [32], and A. kerguelensis VL-RK_09 [18].…”

Isolation and Characterization of Bioactive Streptomyces From Mangrove Ecosystem of Machilipatnam, Krishna District, Andhra Pradesh

“…Samples were collected from 20 cm depth and brought to the laboratory in sterilized containers and air dried at room temperature. The airdried soil sample was pretreated with calcium carbonate (10:1w/w) and incubated at 37°C for four days [7].…”

“…Actinobacterial colonies [9] were picked out, purified, and 259 preserved on yeast extract malt extract dextrose (YMD) agar slants at 4°C [10]. The actinobacterial strains were then screened for their potential to generate bioactive compounds [11]. Among the 25 different actinobacterial strains tested for antimicrobial activity, two predominant actinobacterial strains -VJSY-2 and VJSY-3 found to be potent as they exhibited high antimicrobial activity.…”