In recent years, short-term composting techniques have been widely applied in oyster mushroom cultivation, but there is still a lack of systematic research on their impact on the nutritional and functional properties of fruiting bodies. In this study, the microbial inoculant Streptomyces thermoviolaceus BUA-FM01 (ST) was applied in the short-term composting process for oyster mushroom cultivation. The agronomic traits, nutritional composition, flavor compounds, and antioxidant activity of fruiting bodies from the first three flushes were evaluated. The results show that microbial inoculation significantly (p < 0.05) reduced the total carbon content and C/N ratio of the composted substrates and, furthermore, increased the total yield of the fruiting bodies. Moreover, microbial inoculation significantly (p < 0.05) increased the crude protein, crude polysaccharide, total amino acid, and essential amino acid contents of the fruiting bodies. The fruiting bodies of the first flush of ST treatment possessed the highest umami amino acid content and equivalent umami concentration value. Furthermore, microbial inoculation significantly (p < 0.05) enhanced the scavenging ability of crude polysaccharides toward free radicals. The results indicate that microbial inoculation has many benefits for the composting cultivating process of oyster mushrooms and good application prospects.

The synthesis and symbiotic mechanisms of truffle ectomycorrhizae have attracted considerable scientific interest in recent decades. Although previous research has successfully identified the symbiotic partners of truffles (Tuber spp.) and characterized their mature morphological features, the dynamic processes involved in truffle ectomycorrhizal formation remain insufficiently understood. In this study, we established an ectomycorrhizal synthesis system using Castanea mollissima seedlings inoculated with Tuber sinense spore suspensions under controlled greenhouse conditions, followed by an eight-month observation period. To systematically characterize and model the morphological changes during ectomycorrhizal development, we employed an innovative approach integrating resin sectioning with confocal microscopy. Ectomycorrhizal formation was initially observed two months post inoculation, with a colonization rate reaching 24.4 ± 5.3% by the third month. The ectomycorrhizae displayed a distinct color progression from light brown through ochre and finally dark brown, typically manifesting either monopodial or branched structures. Early developmental stages (2–3 months) were characterized by a thin mycelial membrane enveloping the root surface, accompanied by limited hyphal penetration into the root system. By the eighth month, the colonization rate stabilized at 45.2 ± 8.6%, with enhanced organization and density of the fungal mantle and extended Hartig nets reaching the periphery of outer cortical cells. The continuous growth and differentiation of mycorrhizal root tips generated repetitive root architectures, significantly enhancing symbiotic efficiency. These findings provide critical insights into the morphological development and symbiotic effectiveness of truffle ectomycorrhizae while establishing a methodological framework for investigating ectomycorrhizal associations in other economically significant plant–fungal systems.

The Chinese black truffle (Tuber sinense) is an economically vital ectomycorrhizal fungus threatened by unsustainable harvesting. Cultivating truffles using mycorrhizal seedlings is essential for sustainable production, yet the rhizosphere microbiome dynamics remain unclear. This study explored microbial community succession in the rhizosphere of Chinese chestnut (Castanea mollissima) seedlings inoculated with T. sinense over 8 months. High-throughput sequencing and soil physicochemical analysis were conducted at 1, 3, and 8 months post-inoculation. Significant changes in soil properties, such as decreased pH and increased total nitrogen (TN), total potassium (TK), available phosphorus (AP), and calcium (Ca), influenced microbial assembly. Tuber relative abundance rose from 0.02% in non-inoculated samples to 8.81% at 8 months. Inoculation altered microbial structures, enriching fungal genera like Tuber, Staphylotrichum, and Sphaerosporella. Network analysis showed 79.23% positive bacterial-fungal interactions, crucial for rhizosphere stability. Tuber correlated positively with Staphylotrichum and Spizellomyces, indicating potential synergies in mycorrhizal development and nutrient cycling. Tuber also showed significant positive correlations with TN, TK, AP, and Ca, highlighting its preference for nutrient-enriched conditions. This study provides the first comprehensive profile of microbial succession during the mycorrhizal development of T. sinense on chestnut, offering a scientific basis for optimizing truffle seedling production and supporting sustainable cultivation.