The functional property of Bacillus for shrimp feeds

In shrimp cultures, feed represents the most expensive production cost. The quantity and quality of diets are primary factors influencing shrimp growth, nitrogen loading of the culture system and disease proliferation. For these reasons there is an interest in developing 'environmentally friendly' feeds for optimal growth. In this study, Bacillus strains were isolated from marine environments. The isolates were qualitatively assayed for proteases, carbohydrolases and lipases using selective media. The selected strains (9b, 31 and 33) were molecularly identified as Bacillus subtilis, B. megaterium and B. megaterium, respectively. Subsequently the strains were grown in an inexpensive culture medium (soybean mineral medium (MMS)). The information generated from the present investigation may contribute towards better feed formulations for shrimp at low cost, including bacterial strains as probiotics. (c) 2005 Elsevier Ltd. All rights reserved.