Abstract：
Lignocellulose biomass raw materials have a high value in energy conversion. Recently, there has been growing interest in using microorganisms to secret a series of enzymes for converting low-cost biomass into high-value products such as biofuels. We previously isolated a strain of Penicillium oxalicun 5-18 with promising lignocellulose-degrading capability. However, the mechanisms of lignocellulosic degradation of this fungus on various substrates are still unclear. In this study, we performed transcriptome-wide profiling and comparative analysis of strain 5-18 cultivated in liquid media with glucose (Glu), xylan (Xyl) or wheat bran (WB) as sole carbon source. In comparison to Glu culture, the number of differentially expressed genes (DEGs) induced by WB and Xyl was 4134 and 1484, respectively, with 1176 and 868 genes upregulated. Identified DEGs were enriched in many of the same pathways in both comparison groups (WB vs. Glu and Xly vs. Glu). Specially, 118 and 82 CAZyme coding genes were highly upregulated in WB and Xyl cultures, respectively. Some specific pathways including (Hemi)cellulose metabolic processes were enriched in both comparison groups. The high upregulation of these genes also confirmed the ability of strain 5-18 to degrade lignocellulose. Co-expression and co-upregulated of genes encoding CE and AA CAZy families, as well as other (hemi)cellulase revealed a complex degradation strategy in this strain. Our findings provide new insights into critical genes, key pathways and enzyme arsenal involved in the biomass degradation of P. oxalicum 5-18.
摘要：
木质纤维素生物质原料具有较高的能量转化价值。最近,人们越来越感兴趣的是使用微生物来秘密一系列酶，以将低成本的生物质转化为高价值的产品，如生物燃料。我们先前分离出了一种具有良好的木质纤维素降解能力的草酸青霉5-18菌株。然而,该真菌在各种底物上的木质纤维素降解机制尚不清楚。在这项研究中,我们进行了全转录组分析和比较分析的菌株5-18在液体培养基中培养的葡萄糖（Glu），木聚糖(Xyl)或麦麸(WB)作为唯一碳源。与Glu文化相比，WB和Xyl诱导的差异表达基因(DEGs)数量分别为4134和1484,1176和868个基因上调。在两个比较组中，鉴定的DEGs在许多相同的途径中富集(WB与Glu和Xlyvs.Glu）。特别是,118和82个CAZyme编码基因在WB和Xyl培养物中高度上调，分别。在两个比较组中富集了包括(Hemi)纤维素代谢过程的一些特定途径。这些基因的高度上调也证实了菌株5-18降解木质纤维素的能力。编码CE和AACAZy家族的基因的共表达和上调，以及其他（半）纤维素酶在该菌株中揭示了复杂的降解策略。我们的发现为关键基因提供了新的见解，草酸草生物质降解的关键途径和酶库5-18。
