Degradation of lignocelluloses in straw using AC-1, a thermophilic composite microbial system

Hongdou Liu; Liqiang Zhang; Yu Sun; Guangbo Xu; Weidong Wang; Renzhe Piao; Zongjun Cui; Hongyan Zhao

doi:10.7717/peerj.12364

Degradation of lignocelluloses in straw using AC-1, a thermophilic composite microbial system

PeerJ. 2021 Nov 1:9:e12364. doi: 10.7717/peerj.12364. eCollection 2021.

Authors

Hongdou Liu^{1

2}, Liqiang Zhang³, Yu Sun¹, Guangbo Xu¹, Weidong Wang³, Renzhe Piao¹, Zongjun Cui⁴, Hongyan Zhao¹

Affiliations

¹ Yanbian University, Yanji, China.
² College of Land and Environment, Shenyang Agricultural University, Shenyang, China.
³ Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, China.
⁴ China Agricultural University, Beijing, China.

Abstract

In composting, the degradation of lignocellulose in straw is problematic due to its complex structures such as lignin. A common solution to this problem is the addition of exogenous inoculants. AC-1, a stable thermophilic microbial composite, was isolated from high temperature compost samples that can decompose lignocellulose at 50-70 °C. AC-1 had a best degradation efficiency of rice straw at 60 °C (78.92%), of hemicellulose, cellulose and lignin were 82.49%, 97.20% and 20.12%, respectively. It showed degrad-ability on both simple (filter paper, absorbent cotton) and complex (rice straw) cellulose materials. It produced acetic and formic acid during decomposition process and the pH had a trend of first downward then upward. High throughput sequencing revealed the main bacterial components of AC-1 were Tepidimicrobium, Haloplasma, norank-f-Limnochordaceae, Ruminiclostridium and Rhodothermus which provides major theoretical basis for further application of AC-1.

Keywords: Lignin; Microbial community; Straw degradation; Thermophilic.

Grants and funding

This research was supported by the Special Fund for Agro-scientific Research in the Public Interest (No. 201503137), the Department of Science & Technology of Jilin Province (No. JJKH20191130KJ), the Department of Key R&D Project of Jilin Province Science and Technology (No. 20200402040N C) and supported by Open Foundation of the Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region (No. 201711). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.