Remodulation of central carbon metabolic pathway in response to arsenite exposure in Rhodococcus sp. strain NAU-1.
Bottom Line: Assays confirmed the presence of membrane bound arsenite oxidase and cytoplasmic arsenate reductase in NAU-1.Specific activities of antioxidant enzymes (catalase, ascorbate peroxidase, superoxide dismutase and glutathione S-transferase) increased in dose-dependent manner with arsenite, whereas glutathione reductase activity decreased with increase in As(III) concentration.Enzyme assays revealed the increase in direct oxidative and glyoxylate pathway in Rhodococcus NAU-1 in the presence of As(III).
Affiliation: Department of Biotechnology, ASPEE College of Horticulture and Forestry, Navsari Agricultural University, Navsari, Gujarat 396456, India.Show MeSH
Mentions: Twenty isolates of arsenite‐resistant bacteria were isolated from organic farm of Navsari Agricultural University (NAU), Gujarat, India. Out of these 20 isolates, one isolate (NAU‐1) showed hyper‐tolerance to both AsIII (Arsenite, 23 mM) and AsV (Arsenate, 180 mM). Microscopic observation of the isolate (NAU‐1) was found to be Gram‐positive, non‐motile and coccobacilli. Analysis of the partial 16S rRNA sequence of NAU‐1 showed 99% identity to 16S rRNA genes of Rhodococcus sp. (Accession No. HQ659188). Growth kinetics of Rhodococcus sp. NAU‐1 showed increased lag phase of growth and achieved stationary phase at 21 h in the presence of AsIII‐amended M9 minimal media containing 100 mM glucose as carbon source (Fig. 1). Rhodococcus sp. strain NAU‐1 could also grow in the presence of other heavy metals (data not shown) like CuSO4 (1.5 mM), CoCl2 (2 mM), CdCl2 (1 mM), NiCl2 (1 mM) and HgCl2 (0.1 mM).
Affiliation: Department of Biotechnology, ASPEE College of Horticulture and Forestry, Navsari Agricultural University, Navsari, Gujarat 396456, India.