Isolation of photosynthetic bacteria and potentiality as an aquaculture feed

An indigenous strain of the phototrophic bacteria, isolated from the Kingfisher mangrove area (UMSPSB1) and seabass tank in UMS Hatchery (UMSPSB2) was mass cultured under anaerobic light conditions. The bacterial cell mass was analyzed for carotenoids (mgg⁻¹ dry cell), bacteriochlorophyll and dry cell weight (mgg⁻¹). UMSPSB1 strain shows higher dry cell weight of 24.3 mgI⁻¹ and carotenoid of 22.73 mgg⁻¹ dry cell contents compare to the bacterial strain UMSPSB2,3.7 mgl⁻¹ dry cell weight and carotenoid 16.36 mgg⁻¹ dry cell weight. The strain UMSPSB1 was tested for toxicity and acceptability as an aquaculture feed additives. Feeding trial on brine shrimp (Artemia) larvae showed that the mix feed (UMSPSB1+ Spirulina) gives the highest growth in length 3500μm of the Artemia compare to Spirulina solely 1200μm in length and UMSPSBI solely fed 876μm in Artemia. Other than this, brine shrimp fed by UMSPSB1+Spirulina gives the highest survival rate of 88% which is comparable with bacteria free mixed diet and Spirulina. The UMSPSB1 strain was also fed to the Asian sea bass (Lates calcarifer) larvae to observe the growth and survival in the sea bass larvae. Larvae of Asian seabass fed by bacteria as a solely diet was died on the second day of the experiment and the larvae reared solely by green water (Nanno chloropsis) were died on the third day of the experiment. The larvae fed by UMSPSB1 enriched Artemia showed the highest growth of 8.9mm and survival rate of 75% rate after 10 days of experiment