Bacterial diversity of a floating vegetation (Phumdi) of Loktak Lake and its extracellular enzymes and bacterial antagonistic property.

Abstract

134 bacterial strains were isolated from phumdis of Loktak Lake. Through 16S rRNA sequencing, Bacillus sp. (23, 17.1%), Staphylococcus sp. (14, 10.4%), Pseudomonas sp. (11, 8.2%) and Acinetobacter sp. (8, 5.9%) were identified as the predominant bacterial taxa of Loktak Lake. B. pumulis (12, 8.9%), S. arlettae (4, 2.9%), P. knackmussii (6, 4.4%) are the leading species of Bacillus, Staphylococcus and Pseudomonas, respectively. Similarly, A. seifertii (2, 1.4%) and A. calcoaceticus (2, 1.4%) are the common species of Acinetobacter. 75 (55.9%) bacterial strains showed the ability to hydrolyze one or more extracellular enzymes tested. Among the extracellular enzymes produced by the bacterial isolates, the presence of elastase activity cannot be underestimated, since the enzyme is involved in the process of bacterial lung infection. Phosphate solubilizing activity could be seen in 11.1% of the bacterial isolates. 27 (20.1%) of the strains shown to have antagonistic activity against one or more tested pathogens. An isolate, MRC 52 showed antagonistic activity against eleven different pathogens including carbapenem resistant E. coli which was further subjected to extraction and identification of the biomolecule exerting the antimicrobial property. Based on GC-MS analysis, the bioactive compound was identified as phenyl ethyl alcohol.