This study was designed to identify probiotic characteristics and test the cellulolytic ability of Bacillus megaterium and Bacillus mycoides bacteria for probiotic microbe candidates in fish and shrimp feed. The identification of the cellulolytic and amylolytic abilities of these bacteria was obtained by non-experimental method and descriptive analysis. Results indicated that the maximum growth of B. megaterium was observed after six hours at 35.62 x 1010 (CFU), while B. mycoides was after 30 hours at 42.6 x 1010 (CFU). Macroscopic observation showed that the colony of B. megaterium was concave and smooth, while B. mycoides was flat, relatively rough, with silken threads around the colony. Both bacteria had a milky white color, bacillus shape, Gram positive, and sporous. The activity of cellulose and amylase enzymes in B. megaterium were 3,974 units/ml and 1,831 units/ml respectively. The activity of cellulose and amylase enzymes in B. mycoides were 3,506 units/ml and 3,730 units/ml respectively. This study concludes that both bacteria could be used in fish feed.
Keywords: Characterization, Bacillus megaterium, Bacillus mycoides, probiotic microbes, feed.