链孢囊菌利用纤维素形成菌体及其碱提取组分研究

Characteristics of Streptosporangium Mycelia and Their Alkali Extractable Components During Cellulose Decomposition

通过液体摇床振荡培养实验,获得了链孢囊菌降解纤维素形成的菌体,采用元素组成、差热分析和红外光谱法,初步研究其化学结构和碱提取组分碳的分配状况,旨在探索链孢囊菌降解纤维素后是否能形成腐殖质及其碱提取组分是否为腐殖质组分。结果表明:(1)链孢囊菌降解纤维素后形成的菌体各组分碳量的分配主要集中于"水溶性组分"与"碱溶酸不溶组分"(相当于类胡敏酸),"碱溶酸溶组分"(相当于类富里酸)最少,培养后期(38～60 d)各组分碳,随着培养时间的延长,先形成"碱溶酸溶组分"后转化为"碱溶酸不溶组分"的速率减慢;(2)接种链孢囊菌后,培养初期(7～28 d),菌体C含量、H/C、O+S/C、放热高/中比,均呈现不规律的动态变化,培养后期(38～60 d),随着培养时间的延长,菌体缩合程度升高,氧化程度降低,芳香性增强;(3)菌体(60 d)的H/C、O+S/C均高于黑土胡敏酸(HA),而菌体的C含量、放热高/中比均低于黑土胡敏酸(HA),且分子结构较黑土胡敏酸(HA)简单。

It has been observed that Streptosporangium sp.grow on decomposing cellulous.In this study,using elementary analysis,differential thermal analysis and infrared spectrometry,we examined the chemical structure of the mycelia of Streptosporangium sp.during cellulose decomposition.Carbon-containing components of alkali extraction from the mycelia were analyzed by modified humus composition method.The production rate of mycelia increased significantly with incubation time.The carbon in alkali extracts of the mycelia was mainly in ＂water-soluble＂and＂alkali-soluble but acid-insoluble（humic acid）＂fractions.However,there was little carbon in＂alkali soluble and acid soluble（fulvic acid）＂fraction.During the 38th～60thday of incubation,C in＂alkali soluble and acid soluble＂and＂residue（equivalent of humin）＂increased,but the proportion of＂alkali-soluble but acid-insoluble＂to alkali-extractable fraction decreased gradually with incubation time,indicating slowdown in formation of＂alkali soluble but acid insoluble components＂.At later stage of incubation（38 ～60 d）,mycelia had reduced oxidation but increased condensation and aromaticity.The C/N,H/C,and O＋S/C molar ratios of Streptsporangium sp.mycelia（60 d）were higher,but C content and exothermal high to medium ratios were lower than those of humic acid from black soil.The mycelia had relatively simple molecular structure as compared to humic acid from black soil.A longer incubation time is necessary to determine whether during cellulose decomposition Streptosporangium could produce substances that have similar properties and structures to humic acid from black soil.