Lin Qiang, De Vrieze Jo, Fang Xiaoyu, Li Lingjuan, Li Xiangzhen
Key Laboratory of Environmental and Applied Microbiology, CAS; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, Ghent 9000, Belgium.
Water Res. 2022 Nov 1;226:119307. doi: 10.1016/j.watres.2022.119307. Epub 2022 Oct 27.
Microbial life strategy, reflected by rRNA operon (rrn) copy number, determines microbial ecological roles. However, the relationship between microbial life strategy and the energy and nutrient flux in anaerobic digestion (AD) remains elusive. This study investigated microbial rrn copy number and expression ratio using amplicon sequencing of 16S rRNA gene and 16S rRNA, and monitored CH daily production to approximate the status of energy and nutrient flux in semi-continuous AD. A significantly positive correlation between the mean rrn copy number of microbial communities in digestate and CH daily production was detected in the control treatment fed swine manure. The reduced feedstock complexity, by replacing parts of swine manure with fructose or apple waste, weakened the correlation. When feedstock complexity was increased again, the correlation was strengthened again. Similar results were detected in mean rrn expression ratio of microbial communities. The responses of mean rrn copy number and expression ratio of communities to feedstock addition differed between the reduced feedstock complexity and the control treatment, as well as between in digestate and in straw. Our findings reveal a novel relationship between microbial community life strategy and the energy and nutrient flux, and the roles of feedstock characteristics therein in AD.
由rRNA操纵子（rrn）拷贝数反映的微生物生命策略决定了微生物的生态作用。然而，微生物生命策略与厌氧消化（AD）中能量和养分通量之间的关系仍不明确。本研究通过对16S rRNA基因和16S rRNA进行扩增子测序，研究了微生物rrn拷贝数和表达比率，并监测了甲烷（CH）的日产量，以估算半连续厌氧消化中能量和养分通量的状态。在以猪粪为原料的对照处理中，检测到消化液中微生物群落的平均rrn拷贝数与甲烷日产量之间存在显著正相关。通过用果糖或苹果废料替代部分猪粪来降低原料复杂性，削弱了这种相关性。当原料复杂性再次增加时，相关性又得到加强。在微生物群落的平均rrn表达比率中也检测到了类似结果。群落平均rrn拷贝数和表达比率对原料添加的响应在降低原料复杂性处理和对照处理之间存在差异，在消化液和秸秆中也存在差异。我们的研究结果揭示了微生物群落生命策略与能量和养分通量之间的新关系，以及原料特性在厌氧消化中的作用。
