Response of VFAs and microbial interspecific interaction to primary sludge fermentation temperature

It's not clear how fermentation affects the succession and interspecific interaction of functional microorganism in primary sludge anaerobic fermentation system. So as to explore the decisive role of temperature on microorganisms to reveal the mechanism, four fermentation experiments groups (25, 35, 45, and 55 degrees C) were designed. Results indicated the promotion in proportion of acetic and iso-valeric acid with temperature increasing. High-throughput sequencing reflected that the dominant microbial groups in all samples were Proteobacteria, Firmicutes, Bacteroidetes, Synergetes, Spirochaetae, and then key microbial interspecific interaction changed significantly due to the adjustment of microbial temperature. In addition, amino acid metabolism was the lowest at 35 degrees C, but carbohydrate metabolism was the highest. The metabolic abundances of amino acids at different temperatures were the highest, but the differences among kind of amino acids were significant. This study could reveal the effect of temperature on VFAs production in terms of microbial interspecific interaction and lay a theoretical foundation for sludge fermentation.

Automated summary

This study found that temperature plays a crucial role in the succession and interspecific interaction of microorganisms in primary sludge anaerobic fermentation system, affecting the production of volatile fatty acids (VFAs). Higher temperatures promote the production of acetic and iso-valeric acid, and there are metabolic differences among microorganisms at different temperatures.