Straw- and slurry-associated prokaryotic communities differ during co-fermentation of straw and swine manure

Abstract

Anaerobic co-fermentation of straw and manure is widely used for waste treatment and biogas production. However, the differences between the straw-and slurry-associated prokaryotic communities, their dynamic changes throughout the co-fermentation process, and their correlations with bioreactor performance are not fully understood. To address these questions, we investigated the prokaryotic community compositions and the dynamics of prokaryotes attached to the straw and in the slurry during co-fermentation of wheat straw and swine manure using pyrosequencing technique. The results showed that straw-and slurry-associated prokaryotes were different in their structure and function. Strawassociated prokaryotic communities were overrepresented by the phyla Spirochaetes and Fibrobacteres, while Synergistetes and Euryarchaeota were more abundant in the slurry. The straw-associated candidate class TG3, genera Fibrobacter, Bacteroides, Acetivibrio, Clostridium III, Papillibacter, Treponema, Sedimentibacter, and Lutispora may specialize in substrate hydrolysis. Propionate was the most abundant volatile fatty acid in the slurry, and it was probably degraded through syntrophic oxidation by the genera Pelotomaculum, Methanoculleus, and Methanosaeta. The protein-fermenting bacteria Aminobacterium and Cloacibacillus were much abundant in the slurry, indicating that proteins are important substrates in the co-fermentation. This study provided a better understanding of the anaerobic co-fermentation process that is driven by spatially differentiated microbiota.

Bacterial communities and metabolic activity of faecal cultures from equol producer and non-producer menopausal women under treatment with soy isoflavones

“…DNA samples obtained from the primary and secondary cultures were subjected to PCR amplification of the variable region V4-V5 of the 16S rRNA gene using the universal prokaryotic primers 515F and 909R [22]; these were designed to include Illumina adapters. Double indexed amplicons were generated by the protocol of Caporaso et al [23] with minor modifications.…”

Anaerobic microbial community response to methanogenic inhibitors 2‐bromoethanesulfonate and propynoic acid

“…Populations identified as indicators of inhibited conditions include cellulose degraders and bacteria commonly found in rumen and plant matter digesters, including Cellulosilyticum (Li et al. ), Clostridium III and IV (Collins et al. ), Prevotella (Williams et al.…”

“…An unclassified member of the order Fusobacteriales was also more active in control samples compared to all other conditions. Populations identified as indicators of inhibited conditions include cellulose degraders and bacteria commonly found in rumen and plant matter digesters, including Cellulosilyticum (Li et al 2014), Clostridium III and IV (Collins et al 1994), Prevotella (Williams et al 2013), and Succinivibrio (Yue et al 2013). Future studies employing methanogenic inhibitors should recognize the potential for these populations to exhibit increased activity and for the activity of some syntrophic bacteria to decrease.…”

Temperature affects microbial abundance, activity and interactions in anaerobic digestion

“…The injection port, column oven, and detector were operated at 100°C, 70°C, and 150°C, respectively. The carrier gas was Argon with a flow rate of 30 mL min À1 (Li et al, 2014a). Total solid, volatile solid and COD were measured as previously described (APHA, 1981).…”