Effect of Thermophilic Microbial Agents on Crude Fiber Content, Carbohydrate-Active Enzyme Genes, and Microbial Communities during Chinese Medicine Residue Composting

Xiaojia Chen; Yijun Zou; Qinyu Li; Chengjian Wu; Peng Zhou; Zheng Chen; Jiping Shi; Zhijun Zhao

doi:10.1021/acsomega.3c05442

Effect of Thermophilic Microbial Agents on Crude Fiber Content, Carbohydrate-Active Enzyme Genes, and Microbial Communities during Chinese Medicine Residue Composting

ACS Omega. 2023 Oct 11;8(42):39570-39582. doi: 10.1021/acsomega.3c05442. eCollection 2023 Oct 24.

Authors

Xiaojia Chen^{1

2

3}, Yijun Zou^{1

3}, Qinyu Li^{1

2

3}, Chengjian Wu⁴, Peng Zhou⁵, Zheng Chen⁵, Jiping Shi^{1

2

3}, Zhijun Zhao^{1

3}

Affiliations

¹ Laboratory of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China.
² School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
³ University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Fuzhou Kaijie Foodstuff Development Co., Ltd., Fuzhou 350003, China.
⁵ School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.

Abstract

The objective of this study was to investigate the impact of thermophilic bacteria on crude fiber content, carbohydrate-active enzyme (CAZyme) genes, and associated microbial communities during Chinese medicine residues composting. The study examines changes over 15 days of composting with (T) and without (CK) thermophilic microbial agents. Results show that the group T compost temperature reached a maximum of 71.0 °C and remained above 70 °C for 2 days, while the group CK maximum temperature was only 60.9 °C. On Day 15, the seed germination index (GI) of group T reached 98.7%, while the group CK GI was only 56.7%. After composting, the degradation rates of cellulose, hemicellulose, and lignin in group T increased by 5.1, 22.5, and 18.5%, respectively, compared to those in group CK. Thermophilic microbial agents changed the microbial communities related to CAZymes, increasing unclassified_o_Myxococcales and Sphaerobacter abundance and reducing Acinetobacter and Sphingobacterium abundance. Thermophilic microbial agents also increased the abundance of the GT4, GT2_Glycos_transf_2, and AA3 gene families. These results show that thermophilic microbial agents can increase composting temperature, accelerate compost maturation, and promote crude fiber degradation. Therefore, they have broad application potential.