Microbial community composition turnover and function in the mesophilic phase predetermine chicken manure composting...

Area of Science:

• Environmental Microbiology
• Soil Science
• Biotechnology

Background:

• Composting is a vital process for waste management and soil amendment.
• Optimizing composting efficiency is crucial for sustainable agriculture and environmental protection.
• Microbial communities play a key role in the decomposition and humification of organic matter.

Purpose of the Study:

• To investigate the impact of microbial inoculants (MI) and mature compost (MC) on composting efficiency compared to a non-inoculated control (CK).
• To analyze the effects of MI and MC on bacterial and fungal community dynamics during composting.
• To identify key microbial taxa responsible for humic and fulvic acid-like substance formation.

Main Methods:

• Composting experiments with three treatments: microbial inoculants (MI), mature compost (MC), and control (CK).
• Fluorescence excitation-emission matrix (EEM) detection to monitor composting process progression.
• Germination index testing to assess compost maturity and quality.
• 16S rRNA gene sequencing to analyze bacterial and fungal community composition and identify key operational taxonomic units (OTUs).

Main Results:

• Both MI and MC significantly accelerated the composting process compared to CK.
• Bacterial and fungal community compositions varied significantly throughout the composting period.
• Specific OTUs, such as Thermicanus (OTU_26) with MI and Tepidimicrobium (OTU_48) with MC, were identified as key drivers for humic and fulvic acid-like substance formation, respectively.

Conclusions:

• Microbial inoculation, using either MI or MC, effectively accelerates the composting process.
• The initial bacterial community turnover is significant, with specific OTUs playing crucial roles in the formation of valuable organic compounds.
• Stimulating key resident microbes through inoculation is a viable strategy to enhance composting efficiency and the quality of the final compost product.