Consortia of Specific Bacteria in Callyspongia subarmigera (Ridley, 1884) and their Exocellular Activity against Clinical and Fish Pathogens

Abstract

The antimicrobial potency of cultivable associated bacteria in Callyspongia subarmigera was determined. C. subarmigera, the predominant sponge along the South east coast of India at 10 to 15 m (Lat 8° 4′ 41″, Long 77° 32′ 28″ E) of the Indian Ocean was collected off ‘by catch’. The temperature and pH for maximum retrieval of colonies were standardized at 30 °C and 8.5. The retrievable associates from the sponge were isolated for a period of 1 year and their antibacterial activity studied against 16 test pathogens. Among the 56 isolates, six isolates with broad antibacterial spectrum were optimized at different cultural conditions and biochemically characterized. Two Lactobacillus isolates in MRS agar and an extreme salt tolerant isolates in Halophilic agar were noticed during the isolations. The isolates survived the pH range of 4.0–13, while S. rubidae CSP and B. amyloliquefaciens CSG propagated at temp range of 20°- 45 °C. The cell free filtrates of Serratia rubidaea CSP and Bacillus amyloliquefaciens CSG showed profound antibacterial activity even during prolonged incubation timewhile the antifungal activity noticedwas considerably low. Consortia of specific cultivable bacteria in Callyspongia diffusa were isolated. The two potent strains were characterized to the species level. Further studies are required to sort out the antibacterial principle in the sponge associated bacteria.