ABSTRACT

In the view of studying humus formation in corn straw under the action of microorganism, three fungi (Trichoderma reesei, Trichoderma harzianum, Phanerochaete chrysosporium) were selected to compare the humification effects and structural changes of humic acid-like (HAL). The structural characteristics of HAL formed by fungi from corn straw were assessed by elemental, thermogravimetric analyzer, Fourier transform infrared (FTIR) and ¹³C CPMAS NMR spectroscopies. The results showed that Phanerochaete chrysosporium had a strong ability to increase aliphatic C (increasing to 60.02%) within 30 days, and utilised aromatic C in HAL during the humification process. The Trichoderma harzianum selectively preserved relatively large quantities of aromatic C in HAL and reduced aliphatic C to 56.49%. Trichoderma reesei enhanced aromaticity and I ₂₉₂₀/I ₁₆₂₀ ratio of HAL to 38.48% and 0.80, respectively, and intensified the humification effect (PQ=63.75%) within 30 days. Moreover, the elemental composition of HAL in Trichoderma reesei was closest to that of soil humic acid. We concluded that treating corn straw with Trichoderma reesei could reduce aliphatic C and enhance aromatisation, thermal stability, and accumulation of alkyl C, phenolic and aromatic C, which can promote the humification process of corn straw and contribute to the accumulation and storage of soil organic matter.

摘要

为了研究玉米秸秆在微生物作用下的腐殖质形成，选择了三种真菌（里氏木霉，哈茨木霉，金黄色葡萄球菌）比较腐殖酸样（HAL）的增湿效果和结构变化。用元素热重分析仪，傅里叶变换红外（FTIR）和¹³ C CPMAS NMR光谱仪评估了由玉米秸秆真菌形成的HAL的结构特征。结果表明，Phanerochaete chrysosporium具有很强的在30天内增加脂肪族C（增加至60.02％）的能力，并且在腐殖化过程中利用了HAL中的芳香族C。该哈茨木霉选择性地在HAL中保留相对大量的芳族C，并将脂肪族C降低至56.49％。里氏木霉将HAL的芳香性和I ₂₉₂₀ / I ₁₆₂₀比率分别提高到38.48％和0.80，并在30天内增强了增湿效果（PQ = 63.75％）。而且，里氏木霉中HAL的元素组成最接近土壤腐殖酸。我们得出结论，用里氏木霉处理玉米秸秆 可以减少脂肪族碳，增强芳香化，热稳定性以及烷基碳，酚类和芳香族碳的积累，可以促进玉米秸秆的腐殖化过程，有助于土壤有机质的积累和储存。