Study on the community structure and function of symbiotic bacteria at different growth and developmental stages of Hypsizygus marmoreus

Abstract Background: The symbiotic bacteria associated with edible fungi are valuable microbial resources worthy of in-depth exploration. It is important to analyze the community structure and succession of symbiotic bacteria in mushrooms. This can also assist in the isolation of growth-promoting strains that have an essential relationship with the cultivation cycle as well as the agronomic traits and yields of fruiting bodies.Results: In all of the samples from cultivation bags of Hypsizygus marmoreus, 34 bacterial phyla were detected. Firmicutes was the most abundant bacterial phylum (78.85%). The genus Serratia showed an exponential increase in abundance in the cultivation bags in the mature period, reaching a peak abundance of 55.74% and becoming the dominant symbiotic flora. The most predominant strain was Serratia odorifera HZSO-1, and its abundance increased with the amount of hyphae of H. marmoreus. Serratia odorifera HZSO-1 could reside in the hyphae of H. marmoreus, promote growth and development, shorten the fruiting cycle by 3-4 days, and further increase the fruiting body yield by 12%. Conclusions: This study is a pioneering demonstration of the community structure of the symbiotic microbiota and bacteria-mushroom interaction in the growth and development of edible fungi. This work lays a theoretical foundation to improve the industrial production of mushrooms with symbiotic bacteria as assisting agents.