A systematic approach re-analyzing the effects of temperature disturbance on the microbial community of mesophilic anaerobic digestion

Grace Tzun-Wen Shaw,Cheng-Yu Chen,Chieh-Yin Weng,Daryi Wang,Francis Cheng-Hsuan Weng

doi:10.1038/s41598-019-42987-0

Grace Tzun-Wen Shaw, Cheng-Yu Chen + Show 3 more

Open Access

https://doi.org/10.1038/s41598-019-42987-0

Copy DOI

Abstract

Microbial communities are key drivers of ecosystem processes, but their behavior in disturbed environments is difficult to measure. How microbial community composition and function respond disturbances is a common challenge in biomedical, environmental, agricultural, and bioenergy research. A novel way to solve this problem is to use a systems-level perspective and describe microbial communities as networks. Based on a mesophilic anaerobic digestion system of swine manure as a tool, we propose a simple framework to investigate changes in microbial communities via compositions, metabolic pathways, genomic properties and interspecies relationships in response to a long-term temperature disturbance. After temperature disturbance, microbial communities tend towards a competitive interaction network with higher GC content and larger genome size. Based on microbial interaction networks, communities responded to the disturbance by showing a transition from acetotrophic (Methanotrichaceae and Methanosarcinaceae) to methylotrophic methanogens (Methanomassiliicoccaceae and Methanobacteriaceae) and a fluctuation in rare biosphere taxa. To conclude, this study may be important for exploring the dynamic relationships between disturbance and microbial communities as a whole, as well as for providing researchers with a better understanding of how changes in microbial communities relate to ecological processes.

Highlights

Environmental disturbances are important factors in shaping the structure of plant, animal or microbial populations
The present study shows that the COD and total solids (TS) removal efficiency, ORP, and methane content improved after a long-term temperature disturbance, which suggests that the temperature disturbance may be a feasible strategy in shaping the profile of microbial community compositions for anaerobic digesters
Functional and network analyses, we found the complete digestion via hydrolysis process led to more complex materials being transformed into hydrogen, organic acids and methane; this was conducted by a series of reactions performed by dozens of interacting microbial populations

Summary

Introduction

Environmental disturbances are important factors in shaping the structure of plant, animal or microbial populations. There has been a dramatic proliferation of research concerned with the issue of whether microbial communities stay resistant to disturbance, where various disturbances from experimental designs or environmental events were considered The majority of these studies had a long-term experimental period and had concluded that the microbial composition was sensitive to disturbance, such as CO2 enrichment[1], fertilization with mineral nutrients[2], enrichment with C substrates[3], or climate change[4,5]. One common pattern in these researches is that they considered only a single biological feature, for example, effects of a disturbance on changes in microbial community[15], genomic properties[16] or microbial interactions[14], which may be intertwined with the response to environmental changes. Results of this study could have a considerable impact on realizing the roles that microbial communities play under a long-term stress in ecology and will serve as the foundation for system control to maintain stable AnD process

Methods

Results

Conclusion