Material conversion, microbial community composition and metabolic functional succession during green soybean hull...

Area of Science:

• Agricultural Science
• Environmental Microbiology
• Biotechnology

Background:

• Composting agricultural waste like soybean hulls and maize straw is crucial for sustainable waste management.
• Understanding microbial community dynamics is essential for optimizing composting efficiency and nutrient cycling.

Purpose of the Study:

• To investigate the temporal succession of bacterial and fungal communities during composting.
• To identify key microbial biomarkers and physicochemical factors influencing the composting process.
• To elucidate the metabolic functions and trophic modes of microbial communities.

Main Methods:

• Composting of green soybean hulls and maize straw.
• Analysis of bacterial and fungal community composition and succession.
• Identification of microbial biomarkers using statistical analysis.
• Correlation analysis between microbial communities and physicochemical parameters (e.g., germination index, pH, temperature, fulvic acid).
• Metabolic pathway analysis and fungal trophic mode determination.

Main Results:

• Bacterial and fungal communities exhibited distinct temporal successions.
• Streptosporangiaceae (bacterium) and Chaetomiaceae (fungus) were identified as biomarkers for thermophilic and cooling stages.
• Germination index (GI) showed a time-delayed association with specific bacterial genera (Truepera, Pseudomonas, Methylococcaceae).
• Fungal community dynamics were jointly influenced by GI, pH, fulvic acid (FA), and temperature.
• Carbohydrate and amino acid metabolism were dominant pathways, with saprotrophs being the primary fungal mode.

Conclusions:

• Specific microbial taxa can serve as indicators for different composting stages.
• Physicochemical factors significantly shape microbial community structure and function during composting.
• This research provides insights for selecting efficient microbial agents to enhance vegetable composting.