Screening Of Trichoderma Which Can Use Lignocellulose To Produce Microbial Oil And The Optimization Of Its Fermentation Conditions

Trichoderma spp. can secrete cellulases, xylanases, and ligninases, meanwhile, They can produce and accumulate microbial lipids. Therefore, crop straw of lignocellulosic type can be decomposed and utilized to accumulate microbial oil by Trichodenna strains. This paper introduced the significance of producing micriobial lipids by decomposing lignocellulosic materials, summarizes the advantages of Trichoderma spp. as a tool transform lignocellulosic materials to biodiesel, and reviews the progresses of using Trichoderma as the producer of microbial oil.1. Trichoderma harzianum isolate Q2-37and Trichoderma citrinoviride isolate ACCC30152were found to be the best two among52Trichoderm isolates when tested on their lipid productivity by Nile red staining and mycelial biomass extracting, cellulose and lignase activity assay. The dry mycelial biomass of Q2-37contained lipid by20.5%of the total. Q2-37was cultured on com straw meals as the sole carbon source and produced1.188g lipid from100g of the straw. The dry mycelial biomass of ACCC30152contained lipid by22.7%of the total. ACCC30152was cultured on com straw meals as the sole carbon source and produced1.0g lipid from100g of the straw. The oil content of dry hyphae of the tested strains ranged from22.7%±0.36%to12.6%±0.31%. The result showed that Trichodenna isolates could be promised to produce cheaper bio-diesel materials by decomposing plant stubbles.2.We Used Trichoderma harzianum Q2-37as an experimental object because of its high capability of producting lipid. We studied many factors that influenced Trichodenna harzianum Q2-37solid state fermentation. The optimum conditions for Trichoderma harzianum Q2-37solid state fermentation to produce lipid were:used10g basic solid culture medium that the wheat bran and com straw powder are mixed according to the proportion of9:1,added0.125g sodium nitrate0.28g yeast extract and then added and20μl trace elements,15mL water,inoculated with15%(v/w) cultivated seed liquid. On the basis of these conditions, along with pH6,30℃and8d2s fermentation, the percentage of lipid content could remain about3.7%in dry substrate.3.The main purpose of this research was to screen one Trichodenna sp which can use maize stalk powder to produce microbial oil.After we have ascertained the best culture conditions,we used maize stalk powder to instead the best culture medium to compare the volum of microbial oil produced by Trichoderma harzianum Q2-37that cultured on maize stalk powder with that produced by Trichoderma harzianum Q2-37that cultured on best culture medium,the result indicated that Trichoderma harzianum Q2-37had the potential of producing microbial oil with maize stalk powder, the percentage of lipid content could remain about2.8%in dry substrate which was almost twice as much as that of before optimization.4. Trichoderma harzianum isolate Q2-37was cultivated on maize straw solid.Extracts were obtained by acid-heat method extraction and Methylene dichloride extraction from the mycelia and conidia,the constituents of the extracts were analyzed by Gas Chroma tography—Mass Spectrometry(GC-MS),and the relative content of each known constituent in the extracts were determined by area normalization method. After the examination,we found that the main composition of the extracts is fatty acids.There were23compounds of fatty acids found in the extracts,in which there were8unsaturated fatty acid comprised of50.26%,2PUFA s comprised of13.19%. In addition a small amount of alkane also detected from extracts, there were14compounds of alkane found in the extracts,nine of which are alkanes of C9-C18, and these compounds were similar to the main constituents of fossil diese. It was shown that there is a potential importance in fatty acids and alkanes production by Trichoderma harzianum.