Isolation and characterization of heavy metals and non-metallic pollutant-tolerant microorganism from wastewater of Tollygunge Canal (Kolkata) West Bengal, India

The present study is aimed at isolating a heavy metal and non-metallic pollutants tolerant microorganism from wastewater samples which has the highest capability to remove toxicants from contaminated water bodies. From the wastewater samples of Tolly Canal, 35 bacterial, 10 yeast and 5 filamentous fungal strains were isolated and tested for their toxicant tolerance capacities. The obtained isolates were subjected to gradually increasing concentration of toxic metal salts Pb(CH 3 COO) 2 .3H 2 O, NiSO 4 .6H 2 O, CuSO 4 .5H 2 O, CdCl 2 .H 2 O, NaF, NaAsO 2 . All the isolated strains reached the minimal inhibitory concentration much earlier than a yeast strain named as JIC. The strain was proved to be the most toxicant tolerant and also showed efficient toxicant removal capacity by employing 10 ppm of each of the pollutants. It showed removal capacities of Cd (II) (43.60%), Pb (II) (38.20%), Cu (II) (22.60%), As (III) (31.20%), F − (27.60%) and Ni (II) (24.80%). The isolated strain has been undergone some biochemical and phylogenetic analyses for identification and subsequently found to be a strain of Candida tropicalis . The Internal Transcribed Spacer (ITS) 1–4 RNA gene sequence obtained was deposited to National Center for Biotechnology Information (NCBI) and finally the accession number has been obtained as Candida tropicalis isolate JIC MZ798901.