Isolation and screening of marine associated bacteria from Tamil Nadu, Southeast coast of India for potential antibacterial activity

Abstract

The bacteria associated with living surfaces are rich sources of bioactive metabolites. In the present study, 182 heterotrophic epibacterial colonies, isolated from seaweeds (44%), ascidians (30.2%), barnacles (10.4%) and molluscan egg mass (15.4%), were subjected to high throughput screening by cross streaking method against six human pathogenic bacteria, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Vibrio cholerae, Proteus mirabilis and Klebsiella pneumoniae. The 137 epibacterial isolates, which showed activity against at least one human bacterial pathogen in cross streaking method, were further cultured and the ethyl acetate extract of the culture broth (100 μg/disc) was assayed for antibacterial activity through disc diffusion method. The four epibacterial colonies, BR1, EM13, EM14 and PC4, isolated from the barnacle Balanus amphitrite, seaweed Enteromorpha compressa, and ascidian Polyclinum constellatum showed broad spectral antibacterial activity.

Antimicrobial Potential of Epiphytic Bacteria Associated With Seaweeds of Little Andaman, India

“…The secondary metabolites produced by these bacteria are highly recognized for their importance in the field of biomedical applications ( Armstrong et al, 2001 ; Kelecom, 2002 ; Burgess et al, 2003 ). Antimicrobial activity of the epiphytic bacterial communities from seaweeds have been reported ( Kanagasabhapathy et al, 2006 , 2008 ; Vijayalakshmi et al, 2008 ; Ravisankar et al, 2013 ; Horta et al, 2014 ; Martin et al, 2014 ; Karthick et al, 2015a ), similarly anti-diatom activity have also been observed by Kumar et al (2011) . In the Andaman Islands, luxuriant growth of all the three groups of seaweeds are available throughout the year.…”

Screening for Antibacterial Activity of Marine Bacteria from Seaweeds

“…The prepared discs were placed on the inoculated plates and the plates were incubated at 37 o C for 24 hours. After incubation, the zone of inhibition was measured from border of the disc to the edge of the clear zone (Vijayalakshmi et al, 2008).…”