真菌及混合菌对玉米秸秆类腐殖质形成和转化的影响

针对3类真菌(木霉、黑曲霉和青霉)及混合菌在液体培养条件下对玉米秸秆类腐殖质形成和转化的影响,重点研究接种后秸秆类腐殖质组成的变化情况,以期为秸秆的生物降解、转化与土壤有机质的形成、更新提供理论参考和依据.结果表明:(1)接种可迅速减少代谢液和增加菌体-秸秆残留物的含碳量,随菌体繁殖,代谢液中含碳量持续降低,随后,降解作用促使小分子进入代谢液使其碳量增加,后期呼吸作用显著,代谢液碳量再度降低.此外,残留物可被黑曲霉和混合菌有效降解,木霉和青霉在培养初期的较强繁殖能力使残留物中碳量先增加,后又被降解.(2)培养初期,木霉、青霉和混合菌对残留物中有机碳组分的降解使小分子物质进入WSS(水溶性物质),随后菌体的繁殖迫使WSS再度降低,而黑曲霉则以利用WSS合成其自身组分为主.(3)起初,FLA(类富里酸)的形成速度大于HLA(类胡敏酸),而后FLA逐渐向HLA转化,木霉处理HLA在类腐植酸中所占比例最大.(4)培养过程中,FLA分子向简单化方向发展,而HLA分子先简单,而后渐变复杂.HLA单位碳芳香环的缩合程度随培养进行先逐渐降低而后增大,总趋势为增大,木霉处理HLA的复杂程度最高.(5)残留物HLu(类胡敏素)的碳含量在整个培养过程中先增高后降低,最终均有“净损失”,损失最大的为木霉处理.

Effect of Fungi and Mixed Strains on the Formation and Transformation of Humic-like Substances of the Corn Stalks

This paper discussed the effects of three kinds of fungus(Trichoderma,Aspergillus and Penicillium) and mixed strains on the formation and transformation of the humic-like substances of corn stalks under the condition of liquid culture.Primary focus was on the changes of humus compositions from thalli-corn stalk residue after inoculation.Its objective was that it could provide a theoretical reference and basis for the biodegradation and transformation of corn stalks,besides,also for the formation and update of soil organic matter.The results showed that:(1)The inoculation of four microbial suspensions could rapidly decrease the C content of metabolic liquid and increase the C content of thalli-corn stalk residue.Along with the tested strains reproducing,the C content of metabolic liquid was consumed continuously.Then the small molecules came into the liquid as a result of the microbial degradation,which resulted in the increase of C content of metabolic liquid,at last,the enhanced respiration promoted the C content decreasing again.In addition,the residue could be decomposed by Aspergillus and mixed strains effectively.The increasing amounts of Trichoderma and Penicillium could increase the C content of residue respectively,then whose contents were reduced by the biodegradation.(2)At the initial stage,the transformation of other organic components to the water soluble substances(WSS) in the residue was caused by Trichoderma,Penicillium and mixed strains,whose propagations could reduce the C contents of WSS later,while Aspergillus could take advantage of WSS fraction to synthetize its components.(3)At first,the formed rate of fulvic-like acid(FLA) was faster than humic-like acid(HLA),and then FLA was gradually transformed to HLA.The role of Trichoderma was the largest in increasing the proportion of HLA in humic-like acids.(4)The simplification of FLA molecules happened after the culture,while HLA experienced the conversion process of simplification into complication.The condensation of aromatic rings of HLA was lowered first and enhanced later,which could be increased finally.The HLA molecule treated by the Trichoderma was the most complicated.(5)The C content of humin-like(HLu) in the thalli-corn stalk residue was increased firstly and then decreased,finally "net loss" was found,of which the biggest effect was Trichoderma treatment.