Zhang Nan, Peng Huijuan, Li Yong, Yang Wenxiu, Zou Yuneng, Duan Huiguo
Neijiang Normal University, College of Life Sciences, Neijiang, China; Department of Education, Key Laboratory of Regional Characteristic Agricultural Resources, Neijiang, China.
Neijiang Normal University, College of Life Sciences, Neijiang, China.
Braz J Microbiol. 2018 Oct-Dec;49(4):770-776. doi: 10.1016/j.bjm.2018.04.008. Epub 2018 May 21.
Anaerobic digestion is important for the management of livestock manure with high ammonia level. Although ammonia effects on anaerobic digestion have been comprehensively studied, the molecular mechanism underlying ammonia inhibition still remains elusive. In this study, based on metatranscriptomic analysis, the transcriptional profile of microbial community in anaerobic digestion under low (1500mgL) and high NH (5000mgL) concentrations, respectively, were revealed. The results showed that high NH concentrations significantly inhibited methane production but facilitated the accumulations of volatile fatty acids. The expression of methanogenic pathway was significantly inhibited by high NH concentration but most of the other pathways were not significantly affected. Furthermore, the expressions of methanogenic genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase were significantly inhibited by high NH concentration. The inhibition of the co-expressions of the genes which encode acetyl-CoA decarbonylase was observed. Some genes involved in the pathways of aminoacyl-tRNA biosynthesis and ribosome were highly expressed under high NH concentration. Consequently, the ammonia inhibition on anaerobic digestion mainly focused on methanogenic process by suppressing the expressions of genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase. This study improved the accuracy and depth of understanding ammonia inhibition on anaerobic digestion.
厌氧消化对于处理高氨水平的家畜粪便很重要。尽管已经对氨对厌氧消化的影响进行了全面研究，但氨抑制作用背后的分子机制仍然难以捉摸。在本研究中，基于宏转录组分析，分别揭示了低（1500mg/L）和高NH₃（5000mg/L）浓度下厌氧消化过程中微生物群落的转录谱。结果表明，高NH₃浓度显著抑制甲烷产生，但促进了挥发性脂肪酸的积累。高NH₃浓度显著抑制了产甲烷途径的表达，但大多数其他途径没有受到显著影响。此外，编码乙酰辅酶A脱羧酶和甲基辅酶M还原酶的产甲烷基因的表达受到高NH₃浓度的显著抑制。观察到编码乙酰辅酶A脱羧酶的基因共表达受到抑制。一些参与氨酰基-tRNA生物合成和核糖体途径的基因在高NH₃浓度下高度表达。因此，氨对厌氧消化的抑制主要通过抑制编码乙酰辅酶A脱羧酶和甲基辅酶M还原酶的基因表达而集中在产甲烷过程上。本研究提高了对氨抑制厌氧消化的理解的准确性和深度。
