Huang Chao, Lai Cui, Zeng Guangming, Huang Danlian, Xu Piao, Zhang Chen, Cheng Min, Wan Jia
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.
Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha, 410082, China.
Appl Microbiol Biotechnol. 2017 Aug;101(16):6541-6549. doi: 10.1007/s00253-017-8371-9. Epub 2017 Jun 30.
Lignolytic fungi initiate lignocellulose decay by producing extracellular oxidative enzymes. For better understanding the enzymatic degradation of lignocellulose by white-rot fungi, we investigated the effect of manganese on the organic matter loss, manganese peroxidase (MnP) activity, and manganese peroxidase gene (mnp) transcription levels during solid-state fermentation of rice straw with Phanerochaete chrysosporium. The results showed that the addition of manganese improved MnP activity and made it reach the peak earlier, promoted fungal growth at the early period (0-9 days), and enhanced the degradation of lignocellulosic waste. The total organic matter loss had a good correlation with fungal biomass during 30 days of cultivation, and manganese amendment promoted the ability of P. chrysosporium to degrade lignocellulose. Quantitative real-time RT-PCR revealed the differential expression of mnp1, mnp2, and mnp3: manganese amendment increased the transcription of mnp1 and mnp2 but not mnp3. The results indicated that manganese stimulated mnp transcription levels and played a post-transcriptional role in MnP production. These findings provide opportunity of development in enzymatic degradation of lignocellulosic waste by P. chrysosporium amended with manganese.
木质素分解真菌通过产生细胞外氧化酶引发木质纤维素的降解。为了更好地理解白腐真菌对木质纤维素的酶促降解作用，我们研究了在黄孢原毛平革菌对稻草进行固态发酵过程中，锰对有机质损失、锰过氧化物酶（MnP）活性以及锰过氧化物酶基因（mnp）转录水平的影响。结果表明，添加锰提高了MnP活性并使其更早达到峰值，在前期（0 - 9天）促进了真菌生长，增强了木质纤维素废弃物的降解。在30天的培养过程中，总有机质损失与真菌生物量具有良好的相关性，并且添加锰提高了黄孢原毛平革菌降解木质纤维素的能力。实时定量RT - PCR揭示了mnp1、mnp2和mnp3的差异表达：添加锰增加了mnp1和mnp2的转录，但未增加mnp3的转录。结果表明，锰刺激了mnp转录水平，并在MnP产生中发挥转录后作用。这些发现为利用添加锰的黄孢原毛平革菌对木质纤维素废弃物进行酶促降解提供了发展机遇。
