జర్నల్ ఆఫ్ మైక్రోబియల్ & బయోకెమికల్ టెక్నాలజీ

నైరూప్య

Studies on Bioactive Actinomycetes in a Niche Biotope, Nambul River in Manipur, India

Debananda S. Ningthoujam, Suchitra Sanasam and Salam Nimaichand

As part of our ongoing studies on actinomycete diversity in Manipur, an underexplored zone falling in the Indo- Burma biodiversity hotspot, this paper reports bioactivity screening and characterization of bioactive actinomycetes from Nambul River. Bioprospecting studies on actinobacteria have been largely focused on terrestrial and, more recently, on marine ecosystems but freshwater habitats have been largely neglected and studies on freshwater actinomycetes are very scanty in India. Hence we investigated the actinomycete diversity in one of the freshwater rivers of Manipur, Nambul River in Manipur, India. A total of 156 actinomycetes were isolated from three samples of Nambul River. Based on the results of primary screening, 23 isolates were selected for secondary screening. Nine strains showed significant antibacterial or broad spectrum antimicrobial (antibacterial and antifungal) activities in the secondary screening. Phylogenetic analyses indicated that a majority of them were Streptomyces species though some rare actinobacteria were also recovered. Seven strains were identified as Streptomyces spp. while one strain each was identified as Nocardia sp. and Micromonospora sp. Three strains showed promising antifungal activities against human and plant pathogens. This study highlights the potential for discovering bioactive actinomycetes in underexplored niche biotopes such as river sediments.