Li Guoqing, Wang Yahui, Yu Deshui, Zhu Peilei, Zhao Guiyun, Liu Caiyu, Zhao Hongyuan
State Key Laboratory of Horticultural Crop Germplasm Resources Creation and Utilization of Ministry of Agriculture and Rural Affairs, Institute of Horticulture Research, Anhui Academy of Agricultural Sciences, Hefei, China.
College of Life Science, Anhui Agricultural University, Hefei, China.
Front Microbiol. 2022 Nov 23;13:1035040. doi: 10.3389/fmicb.2022.1035040. eCollection 2022.
Biodelignification is widely regarded as a low-efficiency process because it is usually slow and difficult to control. To improve its efficiency and understand its mechanism, the present study analyzed the delignification characteristics of grown on a cotton stalk medium. The results demonstrated that all strains of can selectively degrade the cotton stalk lignin. When cultured in a cotton stalk medium for 60 days, degraded lignin primarily during its mycelium growth with up to 54.04% lignin degradation and produced laccase and manganese dependent peroxidase with high activity levels at the peaks of 70.17 U/ml and 62.39 U/ml, respectively, but no detectable lignin peroxidase. The results of nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy analyses of significant changes in lignin structure revealed that syringyl (S) lignin units were more degraded than guaiacyl (G) lignin units, with a significantly elevated G/S ratio. The Gas Chromatography-Mass Spectrometer analysis of low-molecular-weight compounds revealed that the delignification resulted in the formation of alcohols, organic acids, benzodiazepines, and alkanes. Identified benzodiazepines implied the degradation of G and S units of lignin. These findings will help to improve the efficiency of biodelignification and expand our understanding of its mechanism.
生物脱木质素通常被认为是一个低效的过程，因为它通常缓慢且难以控制。为了提高其效率并了解其机制，本研究分析了在棉秆培养基上生长的[具体菌株名称未给出]的脱木质素特性。结果表明，所有[具体菌株名称未给出]菌株都能选择性地降解棉秆木质素。在棉秆培养基中培养60天时，[具体菌株名称未给出]主要在其菌丝体生长期间降解木质素，木质素降解率高达54.04%，并产生漆酶和锰依赖性过氧化物酶，活性水平分别在峰值70.17 U/ml和62.39 U/ml时达到最高，但未检测到木质素过氧化物酶。核磁共振光谱和傅里叶变换红外光谱分析木质素结构显著变化的结果表明，紫丁香基（S）木质素单元比愈创木基（G）木质素单元降解得更多，G/S比显著升高。气相色谱-质谱仪对低分子量化合物的分析表明，脱木质素导致了醇类、有机酸、苯二氮卓类和烷烃的形成。鉴定出的苯二氮卓类表明木质素的G和S单元发生了降解。这些发现将有助于提高生物脱木质素的效率，并扩展我们对其机制的理解。
