ABSTRACT
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.
Subject(s)
Arthrobacter/isolation & purification , Arthrobacter/metabolism , Mangifera/microbiology , Anti-Infective Agents/metabolism , Anti-Infective Agents/pharmacology , Salts/metabolism , Temperature , Carbon/metabolism , Microbial Sensitivity Tests , Metabolome , Metabolomics/methods , Hydrogen-Ion Concentration , Anti-Infective Agents/isolation & purification , Anti-Infective Agents/chemistry , Minerals/metabolism , Nitrogen/metabolismABSTRACT
El reino Fungi está representado por innumerable cantidad de organismos entre los cuales se encuentran hongos patógenos que deterioran los principales componentes estructurales de la madera, como celulosa, hemicelulosa y lignina. El objetivo de nuestro trabajo fue caracterizar la actividad antifúngica y la producción de diversas aminas de Arthrobacter agilis UMCV2 con acción antagónica sobre hongos xilófagos. Para ello, se aislaron 4 organismos fúngicos (designados en conjunto UMTM) a partir de madera en descomposición en un bosque de pino encino de la comunidad de Cuanajo, Michoacán, México. Dos de ellos presentaron una clara actividad enzimática de celulasas, xilanasas y enzimas accesorias óxido-reductoras, y fueron identificados como pertenecientes a 2 géneros agresivos para la madera: Hypocrea (aislado UMTM3) y Fusarium (aislado UMTM13). In vitro, las aminas evaluadas mostraron tener efecto inhibitorio sobre el crecimiento de los UMTM y la dimetilhexadecilamina; uno de estos compuestos mostró un fuerte potencial para ser utilizado como tratamiento preventivo contra el ataque de hongos destructores de madera.
The kingdom Fungi is represented by a large number of organisms, including pathogens that deteriorate the main structural components of wood, such as cellulose, hemicellulose and lignin. The aim of our work was to characterize the antifungal activity in Arthrobacter agilis UMCV2 and diverse amines against wood-decaying fungi. Four fungal organisms (designated as UMTM) were isolated from decaying wood samples obtained from a forest in Cuanajo-Michoacán, México. Two of them showed a clear enzymatic activity of cellulases, xylanases and oxido-reducing enzymes and were identified as Hypocrea (UMTM3 isolate) and Fusarium (UMTM13 isolate). In vitro, the amines showed inhibitory effect against UMTM growth and one of the amines, dimethylhexadecylamine (DMA16), exhibited strong potential as wood preventive treatment, against the attack of decaying fungi.
Subject(s)
Arthrobacter/isolation & purification , Wood/microbiology , Hypocrea/drug effects , Fusarium/drug effects , Amines/therapeutic use , Arthrobacter/metabolism , Hypocrea/isolation & purification , Fusarium/isolation & purificationABSTRACT
Microbiological analysis of overburden samples collected from chromite mining areas of Orissa, India revealed that they are rich in microbial density as well as diversity and dominated by Gramnegative (58%) bacteria. The phenotypically distinguishable bacterial isolates (130) showed wide degree of tolerance to chromium (2-8 mM) when tested in peptone yeast extract glucose agar medium. Isolates (92) tolerating 2 mM chromium exhibited different degrees of Cr+6 reducing activity in chemically defined Vogel Bonner (VB) broth and complex KSC medium. Three potent isolates, two belonging to Arthrobacter spp. and one to Pseudomonas sp. were able to reduce more than 50 and 80% of 2 mM chromium in defined and complex media respectively. Along with Cr+6 (MIC 8.6-17.8 mM), the isolates showed tolerance to Ni+2, Fe+3, Cu+2 and Co+2 but were extremely sensitive to Hg+2 followed by Cd+2, Mn+2 and Zn+2. In addition, they were resistant to antibiotics like penicillin, methicillin, ampicillin, neomycin and polymyxin B. During growth under shake-flask conditions, Arthrobacter SUK 1201 and SUK 1205 showed 100% reduction of 2 mM Cr+6 in KSC medium with simultaneous formation of insoluble precipitates of chromium salts. Both the isolates were also equally capable of completely reducing the Cr+6 present in mine seepage when grown in mine seepage supplemented with VB concentrate