Clostridium spp. is anaerobic and hence, in this case, all aerobic endospore-bearing Gram-positive antagonists enter into Bacillus spp. Certain Clostridium spp. (eg. C. tertium) are aerotolerant, which can be confused with Bacillus spp. But C. tertium is catalase-negative, in contrast to the Bacillus spp. which is catalase-positive. According to the identification flow chart of Bergey's Manual [20], the Bacillus spp., which had higher cell diameter (≥1 μm) and could hydrolyze starch and gave a positive response on the Voges–Proskauer test, were either B. subtilis, B. polymyxa, B. licheniformis, B. alvei or B. coagulans. Among these, only B. subtilis, B. licheniformis and B. coagulans could utilize citrate. Among the seven isolates, isolate C3 could not utilize citrate, which indicated its possibility of being either B. polymyxa or B. alvei. Since C3 was mannitol-fermenting, it was identified as B. polymyxa or P. polymyxa. The other six isolates were able to grow in 6.5% NaCl at 55 °C, which was a characteristic property of B. subtilis; further species confirmation was carried out using chromogenic medium and 16S rRNA encoding gene sequences.