Marine Agriculture Research Center, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
Tobacco Research Institute of Nanping, Nanping, Fujian 353000, China.
Biomolecules. 2019 Nov 20;9(12):753. doi: 10.3390/biom9120753.
sp., a plant pathogen, causing soft rot with strong pectin degradation capacity was taken for the comprehensive analysis of its corresponding biomass degradative system, which has not been analyzed yet. Whole genome sequence analysis of the isolated soft-rotten plant pathogen sp. WS52, revealed various coding genes which involved in vegetable stalk degradation-related properties. A total of 122 genes were found to be encoded for putative carbohydrate-active enzymes (CAZy) in sp. WS52. The number of pectin degradation-related genes, was higher than that of cellulolytic bacteria as well as other spp. strains. The CAZy in sp.WS52 contains a complete repertoire of enzymes required for hemicellulose degradation, especially pectinases. In addition, WS52 strain possessed plenty of genes encoding potential ligninolytic relevant enzymes, such as multicopper oxidase, catalase/hydroperoxidase, glutathione S-transferase, and quinone oxidoreductase. Transcriptome analysis revealed that parts of genes encoding lignocellulolytic enzymes were significantly upregulated in the presence of minimal salt medium with vegetable stalks. However, most of the genes were related to lignocellulolytic enzymes, especially pectate lyases and were downregulated due to the slow growth and downregulated secretion systems. The assay of lignocellulolytic enzymes including CMCase and pectinase activities were identified to be more active in vegetable stalk relative to MSM + glucose. However, compared with nutrient LB medium, it needed sufficient nutrient to promote growth and to improve the secretion system. Further identification of enzyme activities of sp.WS52 by HPLC confirmed that monosaccharides were produced during degradation of tomato stalk. This identified degradative system is valuable for the application in the lignocellulosic bioenergy industry and animal production.
sp. 是一种植物病原菌，具有很强的果胶降解能力，可引起软腐病。为了对其相应的生物量降解系统进行综合分析，目前尚未对其进行分析。对分离出的软腐病病原菌 sp. WS52 的全基因组序列分析，揭示了各种编码基因，这些基因涉及蔬菜秸秆降解相关特性。在 sp. WS52 中发现了总共 122 个编码假定碳水化合物活性酶 (CAZy) 的基因。果胶降解相关基因的数量高于纤维素分解菌和其他 spp.菌株。sp.WS52 中的 CAZy 包含了用于半纤维素降解所需的完整酶谱，特别是果胶酶。此外，WS52 菌株拥有大量编码潜在木质素降解相关酶的基因，如多铜氧化酶、过氧化氢酶/过氧化物酶、谷胱甘肽 S-转移酶和醌氧化还原酶。转录组分析显示，在含有最小盐培养基和蔬菜秸秆的条件下，部分编码木质纤维素酶的基因显著上调。然而，大多数基因与木质纤维素酶有关，特别是果胶裂解酶，由于生长缓慢和下调的分泌系统，其表达下调。木质纤维素酶的测定，包括 CMCase 和果胶酶活性，在蔬菜秸秆中比在 MSM+葡萄糖中更为活跃。然而，与营养 LB 培养基相比，它需要足够的营养来促进生长和改善分泌系统。通过 HPLC 进一步鉴定 sp.WS52 的酶活性，证实了在番茄秸秆降解过程中产生了单糖。这个被鉴定的降解系统在木质纤维素生物能源工业和动物生产中具有应用价值。
