Microbial Community Dynamics Driven by Different Nitrogen Sources During Forestry Waste Composting for Pleurotus ostreatus Cultivation

TL;DR

This study explores how different nitrogen sources affect composting of forestry waste for mushroom cultivation, showing that organic sources improve microbial activity and compost quality.

Contribution

The study reveals how organic nitrogen sources enhance microbial networks and lignocellulose degradation during composting for Pleurotus ostreatus cultivation.

Findings

Organic nitrogen sources like bran promote stable microbial communities and efficient lignocellulose degradation.

Inorganic nitrogen sources result in slower compost heating and less lignocellulose breakdown.

Higher bacterial diversity correlates with improved mushroom biological efficiency.

Abstract

Bioconversion of lignocellulosic biomass into edible, nutrient-rich products using low-cost forestry waste offers substantial ecological and economic benefits. Composting forestry waste as a substrate for oyster mushroom (Pleurotus ostreatus) cultivation is an effective recovery strategy. However, the specific microbial-driven mechanisms by which nitrogen sources regulate lignocellulose degradation and compost quality during forestry waste composting for Pleurotus ostreatus substrate preparation remain to be elucidated. We evaluated three organic nitrogen sources (bran, soybean meal, and chicken manure) and one inorganic source (diammonium phosphate, DAP) during composting of forest-waste-based substrates. Composting performance and cultivation outcomes were assessed using physicochemical analyses, lignocellulose degradation measurements, high-throughput sequencing of bacterial 16S rRNA and fungal ITS, and biological efficiency. Organic nitrogen sources enhanced compost temperature and lignocellulose degradation by providing sustained nitrogen release, promoting stable colonization of core microbial communities and cooperative bacteria–fungi networks. In contrast, inorganic nitrogen resulted in slower heating, minimal lignocellulose degradation (0.75%), and unstable, competition-dominated microbial networks. Nitrogen sources indirectly shaped microbial communities by regulating the C/N ratio, pH, and electrical conductivity. Lignocellulose degradation and bacterial diversity significantly influenced mushroom biological efficiency, with bacterial diversity strongly regulating degradation rates. The forest waste–bran treatment achieved the highest biological efficiency (78.35%). These findings offer a practical strategy for optimizing forestry waste bioconversion into fungal protein.

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