International Journal of Engineering, Science and Mathematics Vol. 7 Special Issue 4(1), April 2018, ISSN: 2320-0294 Impact Factor: 6.765 Journal Homepage: http://www.ijmra.us, Email: editorijmie@gmail.com Double-Blind Peer Reviewed Refereed Open Access International Journal - Included in the International Serial Directories Indexed & Listed at: Ulrich's Periodicals Directory ©, U.S.A., Open J-Gage as well as in Cabell’s Directories of Publishing Opportunities, U.S.A 84 International Journal of Engineering, Science and Mathematics http://www.ijmra.us, Email: editorijmie@gmail.com Characterize heavy metal tolerant rhizospheric sewage bacteria isolated from Tolly nullah (with special emphasis on strain Microbacterium radiodurans K12016) Chitrita Chatterjee  Rabindranath Bhattacharyya  Shampa Sarkar (Biswas)  Abstract Because of rapid industrialization and urbanization, heavy metals are deposited in the environment in frightening quantity. Literature survey manifested, that the heavy metal contaminated soil born microbes can be a potent mode of environmental heavy metal degradation. In the present study, to reveal microbial heavy metal tolerant activity rhizosperic microbes were isolated from sewage sludge of circular canal (Tolly Nullah) and characterize. Microbial heavy metal resistance pattern was checked against four heavy metal salts (Cr2O3, CrO3, CdCl2 and CoCl2) individually and in consortium. Plant growth promoting rhizobacterial (PGPR) traits of isolated microbes were evaluated. One interesting isolated strain (Microbacterium radiodurans strain K12016), identified by 16s rDNA, shown total tolerance against 100 mM Cr2O3 (Cr 3+ ) and also mentionable Cobalt and hexavalent Chromium (Cr 6+ ) tolerance, but didn’t produce a significant amount of plant growth promoting IAA whereas the most of the rest isolates produced adequate amount of IAA. 16s rDNA of that particular isolate was analyzed and phylogenic tree was constructed using the neighbor-joining method to ensure its taxonomic position. Furthermore experimentation and gene study should require to determining heavy metal resistance mechanism of Microbacterium radiodurans K12016. Keywords: Heavy Metal tolerance; Biochemical analysis; Antibiotic resistance; Indole Acetic Acid (IAA); 16s rDNA. Copyright © 2018 International Journals of Multidisciplinary Research Academy. All rights reserved. Author correspondence: Chitrita Chatterjee, PhD Student, Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata, West Bengal, India Email: chitrita87@gmail.com; chitrita.rs@presiuniv.ac.in 1. Introduction As a result of different unrestricted anthropogenic activities, different concerning heavy metals like Chromium (Cr), Lead (Pb), Cadmium (Cd), Cobalt (Co), Nickel (Ni), Iron (Fe) are alarmingly increased in the environment, particularly the areas where waste materials from different industrial sectors, tannery, household, medical sectors are coming from. The presence of trace amount of heavy metal in soil, water and even in the atmosphere is a huge threat for different living organisms including human being [17]. Some  PhD Student, Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata, West Bengal, India  Associate Professor (Retired), Presidency University, Department of Life Sciences (Microbiology Laboratory), 86/1 College Street, Kolkata, West Bengal, India  Assistant Professor, Presidency University, Department of Life Sciences, 86/1 College Street, Kolkata, West Bengal, India