Synergistic bioconversion of organic waste by black soldier fly (Hermetia illucens) larvae and thermophilic cellulose-degrading bacteria

Mingying Shao; Xiao Zhao; Kashif Ur Rehman; Minmin Cai; Longyu Zheng; Feng Huang; Jibin Zhang

doi:10.3389/fmicb.2023.1288227

Synergistic bioconversion of organic waste by black soldier fly (Hermetia illucens) larvae and thermophilic cellulose-degrading bacteria

Front Microbiol. 2024 Jan 10:14:1288227. doi: 10.3389/fmicb.2023.1288227. eCollection 2023.

Authors

Mingying Shao^{1

2

3}, Xiao Zhao^{2

3}, Kashif Ur Rehman^{4

5}, Minmin Cai^{2

3}, Longyu Zheng^{2

3}, Feng Huang^{2

3}, Jibin Zhang^{2

3}

Affiliations

¹ Institute of Tropical Agricultural Technology, Hainan Vocational University, Haikou, Hainan, China.
² National Key Laboratory of Agricultural Microbiology, National Engineering Research Center of Microbial Pesticides, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
³ Hubei Hongshan Laboratory, Wuhan, China.
⁴ Department of Microbiology, Faculty of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur, Pakistan.
⁵ German Institute of Food Technologies, Quakenbrück, Germany.

Abstract

Introduction: This study examines the optimum conversion of Wuzhishan pig manure by Black Soldier Fly Larvae (BSFL) at various phases of development, as well as the impact of gut microbiota on conversion efficiency.

Method and results: In terms of conversion efficiency, BSFL outperformed the growing pig stage (GP) group, with significantly higher survival rates (96.75%), fresh weight (0.23 g), and larval conversion rate (19.96%) compared to the other groups. Notably, the GP group showed significant dry matter reductions (43.27%) and improved feed conversion rates (2.17). Nutritional composition varied, with the GP group having a lower organic carbon content. High throughput 16S rRNA sequencing revealed unique profiles, with the GP group exhibiting an excess of Lactobacillus and Clostridium. Promising cellulose-degrading bacteria in pig manure and BSFL intestines, including Bacillus cereus and Bacillus subtilis, showed superior cellulose degradation capabilities. The synergy of these thermophilic bacteria with BSFL greatly increased conversion efficiency. The BSFL1-10 group demonstrated high growth and conversion efficiency under specific conditions, with remarkable larval moisture content (71.11%), residual moisture content (63.20%), and waste reduction rate (42.28%).

Discussion: This study sheds light on the optimal stages for BSFL conversion of pig manure, gut microbiota dynamics, promising thermophilic cellulose-degrading bacteria, and the significant enhancement of efficiency through synergistic interactions. These findings hold great potential for sustainable waste management and efficient biomass conversion, contributing to environmental preservation and resource recovery.

Keywords: BSFL; Wuzhishan pig; bioconversion; fiber degradation; gut microbe; manure.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Key Technology R&D Program of Hainan Province, China (ZDYF2023XDNY033), the Key Technology R&D Program of Hubei Province, China (2021BBA258), the Major Project of Hubei Hongshan Laboratory (2022hszd013), and National Key Technology R&D Program of China (2018YFD0500203).