Change of Dominant Microbial Community in Composting of Rice Bran by Adding Charcoal

Tom Miles

Change of Dominant Microbial Community in Composting of Rice Bran by Adding Charcoal
Shuji Yoshizawa, Satoko Tanaka, ACER, December 2006

When composting rice bran, charcoal of Moso bamboo was added and the effect of the charcoal in breeding microbial community was examined by DNA analysis using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method. This was to estimate the dominant microorganisms in composting. Fig. 1 shows the result of the DGGE analysis. A-J were selected as major bands in order to identify the dominant microorganism originated DNA base sequence. Then DNA was extracted from band A and cloned. The two types of obtained and cloned base sequences were blasted for analogy retrieval and the existence of bacteria that are estimated to be Paenibacillus and Alcaligenes were confirmed. It is known that Paenibacillus are facultative anaerobic bacteria and Alcaligenes are aerobic bacteria, and that both Paenibacillus and Alcaligenes exist in cow dung. It is considered that these exist in rice bran compost because seed bacteria were originated from cow manure. From another experiment it was confirmed that base sequences of bands K and L are Bacillus circulans and Bacillus cereus respectively.