Studies On Solid-state Fermentation Technology And Preparation Of Fermentation Products Of Muscodor Fengyangensis Strain ZJQY709

Plant endophytic fungi are microorganisms that colonise in healthy plant tissues and cause asymptomatic infections. In terms of taxonomy, most of these fungi belong to the Ascomycetes, while some of them are of Basidiomycetes and Oomycetes. These microorganisms can establish mutualistic plant-microbe interactions with hosts that benefit for both fungi and plants. The benefits of mutualism for host plants results in increased resistance against pathogens, promoted growth of the host and improved tolerance to abiotic stress. Since the isolation of the endophyte Taxomyces andreana from Taxus brevifolia that can produce taxol, studies of endophytes have been valued gradually.Endophytic fungi Muscodor are endophytes have known distribution from tropical and subtropical plants in Central America, South America, East Asia, South east Asia and Australia. One of the characteristics of Muscodor spp. is the volatile organic compounds (VOCs) produced by them that are inhibitive or even lethal to a wide variety of plant pathogens, nematodes, even certain insects and some human pathogens. For this reason, more and more people follow the interest in the study of this area.In this study, we conducted the solid-state fermentation (SSF) for fungus in the genus Muscodor for the first time in China. The main purpose of the study is to try the solid-state fermentation of Muscodor fengyangensis Strain ZJQY709in1L Erlenmeyer flask, by which to optimize the fermentation technology, and also to try and explore the preparation of the fermentation products. During a systematic study, we have found the optimization of solid-state fermentation of ZJQY709in1L Erlenmeyer flask and tried the preliminary exploration of the methods of preparation and maintenance of the production of SSF. The main results are as follows:1) We measured the growing rates of all the strains in this study under different temperature, thus determined the optimum growth temperature of four strains including ZJQY709, M25, M112and M113. The optimum growth temperature of Strain ZJQY709is25℃, while the optimum growth temperature of both M153 and M112is20℃, and the optimum growth temperature of M25is23℃.2) In this study, we explored the solid-state fermentation technology of Strain ZJQY709on five aspects of culture medium formula, pH of nutrient solution, fermentation temperature, inoculum size and seed age, by orthogonal design and single fact design. The optimum fermentation technology is as follows: Culture medium formula: For every100g cooked millet (millet:potato solution(mass:volume)=1:0.60): perlite (mass ratio)20%glucose (mass ratio)0.5%defatted soy flour (mass ratio)7.0%peptone (mass ratio)1.0%KH2PO4(mass ratio)0.55%MgSO4(mass ratio)0.15%Potato solution (volume ratio)25%Using5mol/L NaOH solution to regulate the pH of nutrient solution to6. Fermentation technology: Fermentation temperature is25℃, seed age is6days and inoculum size is0.2%.3) In this study, we measured the level of reducing sugar, total sugar, soluble phosphorus, ammonia nitrogen, mass loss rate and water content in different fermentation time by methods of DNS method, ammonium molybdate colorimetric method, neutral formaldehyde method and quality difference method. Finally, we got the fermentation curve of these parameters. By analyzing these fermentation curve, we inferred that during solid-state fermentaion in1L Erlenmeyer flask, the logarithmic growth phase of the fungus starts at the fifth-sixth day of fermentation while ends at the eighth day of fermentation.4) In this study, we designed two routes for preparation of the production of SSF due to the consideration of reducing water content, lowering storage temperature and isolated from air to explore the preparation of fermentation products of Strain ZJQY709by methods of Silica gel drying, fermentation products vacuum-packed and preservation in4℃refrigerator, thus we made the preliminary conclusion of preparation method and preservation conditions of fermentation products:Fermentation products are dried for14h under normal temperature (moisture8.09%) and vacuum-packed, finally preserved in4℃refrigerator.