The phylogenetic and physiological characteristics of mesophilic and thermophilic bacteria isolated from a field-scale sewage sludge composter were determined by 16S rDNA and phenotype analyses. Of the 34 mesophilic isolates, 5 (15%), 16 (47%), and 3 (9%) displayed amylase, protease, and lipase activities, respectively. Among these isolates, the following species were identified based on their 16S rRNA gene sequences: Aneurinibacillus aneurinilyticus, Bacillus fortis, Bacillus subtilis, Brachybacterium paraconglomeratum, Brevibacterium otitidis, Dietzia maris, Pseudomonas xiamenensis, Staphylococcus lentus, Thermobifida fusca, Ureibacillus thermosphaericus, and Vagococcus lutrae. However, 15 isolates could not be identified as known taxa, thus indicating new bacterial taxa. Of these new taxa, it is likely that NoID A plays an important role in organic matter decomposition during composting based on its physiological characteristics. Sapporo sewage sludge compost contains a microbial ecosystem with novel bacterial biodiversity, comprising a high percentage of previously unrecognized species. This study improves our knowledge of the unique bacteria in sewage sludge compost, providing a future resource for bacterial genetic information and bacterial species of agricultural benefit.

Megasphaera micronuciformis is an anaerobic microbe isolated from humans. However, since the microbe is strictly anaerobic, its cultivation requires complicated facilities, making detection costly. For rapid, inexpensive detection and identification of M. micronuciformis in the clinical setting, a new technique is necessary. This study aimed to develop a species-specific PCR primer set for the detection of M. micronuciformis. A ribosomal DNA-specific PCR primer Mm2F was designed for M. micronuciformis. Analytical specificity data showed that the PCR primer set Mm2F/Mega-X produced amplicons from M. micronuciformis but not from the other species tested, including 4 Megasphaera species and representative related species. Of the 52 oral samples from Japanese subjects evaluated in our study, 71% were positive for M. micronuciformis, suggesting the likelihood that M. micronuciformis is widely distributed in the oral cavity of the Japanese population.