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Summary: Nowadays, much of what we know regarding the isolated cellulolytic bacteria comes from the conventional plate separation techniques. However, the culturability of many bacterial species is controlled by resuscitation‐promoting factors (Rpfs) due to entering a viable but non‐culturable (VBNC) state. Therefore, in this study, Rpf from Micrococcus luteus was added in the culture medium to evaluate its role in bacterial isolation and enhanced effects on cellulose‐degrading capability of bacterial community in the compost. It was found that Proteobacteria and Actinobacteria were two main phyla in the compost sample. The introduction of Rpf could isolate some unique bacterial species. The cellulase activity of enrichment cultures with and without Rpf treatment revealed that Rpf treatment significantly enhanced cellulase activity. Ten isolates unique in Rpf addition displayed carboxymethyl‐cellulase (CMCase) activity, while six isolates possessed filter paper cellulase (FPCase) activity. This study provides new insights into broader cellulose degraders, which could be utilized for enhancing cellulosic waste treatment. [ABSTRACT FROM AUTHOR]

Considering wide utilization and high methane fluxes from anaerobic biological stabilization ponds ( ABSPs), understanding the methanogenesis in ABSPs is of fundamental importance. Here we investigated the variation and impact factors of methanogenesis in seven ABSPs that spanned from the north to the south of China. Results showed that methanogen abundance (7.7 × 109-8.7 × 1010 copies g−1 dry sediment) and methanogenic activities (2.2-21.2 μmol CH4 g−1 dry sediment h−1) were considerable for all sediments. Statistical analysis demonstrated that compared with other factors (ammonium, pH, COD and TOC), mean annual temperature ( MAT) showed the lowest P value and thus was the most important influencing factor for the methanogenic process. Besides, with the increasing MAT, methanogenic activity was enhanced mainly due to the shift of the dominant methanogenic pathway from acetoclastic (49.8-70.7%) in low MAT areas to hydrogenotrophic (42.0-54.6%) in high MAT areas. This shift of methanogenic pathway was also paralleled with changes in composition of bacterial communities. These results suggested that future global warming may reshape the composition of methanogen communities and lead to an increasing methane emission from ABSPs. Therefore, further research is urgently needed to globally estimate methane emissions from ABSPs and re-examine the role of ABSPs in wastewater treatment. [ABSTRACT FROM AUTHOR]

Methane can be used as an alternative carbon source in biological denitrification because it is nontoxic, widely available and relatively inexpensive. A microbial consortium involved in methane oxidation coupled to denitrification (MOD) was enriched with nitrite and nitrate as electron acceptors under micro-aerobic conditions. The 16S rRNA gene combined with pmoA phylogeny of methanotrophs and nirK phylogeny of denitrifiers were analysed to reveal the dominant microbial populations and functional microorganisms. Real-time quantitative polymerase chain reaction results showed high numbers of methanotrophs and denitrifiers in the enriched consortium. The 16S rRNA gene clone library revealed that Methylococcaceae and Methylophilaceae were the dominant populations in the MOD ecosystem. Phylogenetic analyses of pmoA gene clone libraries indicated that all methanotrophs belonged to Methylococcaceae, a type I methanotroph employing the ribulose monophosphate pathway for methane oxidation. Methylotrophic denitrifiers of the Methylophilaceae that can utilize organic intermediates (i.e. formaldehyde, citrate and acetate) released from the methanotrophs played a vital role in aerobic denitrification. This study is the first report to confirm micro-aerobic denitrification and to make phylogenetic and functional assignments for some members of the microbial assemblages involved in MOD., (© 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.)