【摘要】 为探明里氏木霉(Trichoderma reesei)在腐殖化过程中,不同培养时间下利用玉米秸秆得到的培养产物(HLS)的碱提取物——类胡敏酸(HAL)的结构特征是否具有与土壤胡敏酸相似的特异性,通过固体培养的方式模拟秸秆堆肥,在玉米秸秆中添加里氏木霉进行为期30 d的腐殖化培养,并以灭菌后不添加微生物的处理作为对照,在培养的0、15、30 d采样观察研究。通过元素组成、红外光谱及差热的技术手段对里氏木霉利用玉米秸秆形成的类胡敏酸(HAL)进行分析,与土壤的胡敏酸(HA)比较观察其特异性。对比CK,在模拟腐殖化的过程中,接种里氏木霉可以显著改变其HAL的结构特征,其芳香性/脂族性的比例变化符合多酚学说。里氏木霉可以在30 d内将HAL的元素结构集中在O/C=0.528、H/C=1.322左右,与土壤HA的O/C值、H/C值差异缩减了71.08%、49.25%,使其更加接近土壤HA的结构特征。总体来看,里氏木霉在分解矿化玉米秸秆中纤维素和木质素的同时,可以有效促进玉米秸秆向腐殖质的转化,其形成的HAL的结构变化支持了多酚学说。里氏木霉培养下的HAL可随着腐殖化培养时间的增加,与土壤HA的结构特征差异持续缩小,逐渐具有特异性。更多还原

【Abstract】 To investigate the structural features of humic acid-like(HAL)substance from corn straw during the humification process of Trichoderma reesei, the alkaline extract of the culture product(Humic-like substances, HLS)was obtained. The extract demonstrated similar specificities to soil HA. Corn straw composting was simulated using solid culture. The humification process of corn straw was simulated for a period of 30 d using two treatments:(1)adding T. reesei and(2)uninoculated control after sterilization(CK). Samples were collected at 0, 15 d, and 30 d for observation. The HAL substance formed by T. reesei using corn straw were analyzed using elemental composition, infrared spectroscopy, and differential thermal techniques, and the specificity was determined from comparison with soil HA. The results showed that, compared with CK, inoculation with T. reesei significantly changed the structural characteristics of HAL substances and the ratio of aromatics/aliphatics during humification, which is in accordance with polyphenol theory. T. reesei concentrated the elemental structure of the HAL substance at O/C=0.528 and H/C=1.322 on day 30, and the difference between HAL and HA was reduced by 71.08% and49.25%, with the HAL displaying similarity with the structural characteristics of HA. In general, T. reesei can effectively promote the conversion of corn straw to humus through cellulose and lignin decomposition and structural changes in HAL substances. The differences between the structural characteristics of soil HA and HAL from T. reesei culture decrease significantly during the humification process.更多还原