Biochemical and molecular characterization of hemolytic Bacillus licheniformis strains isolated from shrimp and clam aquacultures

A polyphasic approach was used to discriminate among the significantly hemolytic and closely related Bacillus licheniformis strains, NE-1, NE-2 and NE-3. Utilization of the API 20E kit revealed that B. licheniformis NE-1 is unique in its ability to utilize sorbitol as a sole carbon source, whereas B. licheniformis NE-2 is an exceptional in L-arabinose utilization. The phylogenetic analysis using the 16S rDNA 5'end revealed a strong relatedness to B. licheniformis strains found in the GenBank with a similarity percentage ranging from 97 to 99. Moreover, the partial sequences was successfully differentiated among the novel strains. The plasmid pattern is almost the same for the strains and plasmid curing using acridine orange showed no effect on the hemolytic activity of them.