Yang C-X, Wang T, Gao L-N, Yin H-J, Lü X
College of Food Science and Engineering, Northwest A&F University, Yangling District, Shaanxi Province, China.
J Appl Microbiol. 2017 Dec;123(6):1447-1460. doi: 10.1111/jam.13562. Epub 2017 Oct 22.
Lignin is an aromatic heteropolymer forming a physical barrier and it is a big challenge in biomass utilization. This paper first investigated lignin-degradation bacteria from rotten wood in Qinling Mountain.
Nineteen potential strains were selected and ligninolytic enzyme activities were determined over 84 h. Strains that had higher enzyme activities were selected. Further, the biodegradation of wheat straw lignin and alkali lignin was evaluated indicating that Burkholderia sp. H1 had the highest capability. It was confirmed by gel permeation chromatography and field emission scanning electron microscope that alkali lignin was depolymerized into small fragments. The degraded products were analysed using gas chromatography-mass spectrometry. The total ion chromatograph of products treated for 7 days showed the formation of aromatic compounds, an important intermediate from lignin degradation. Interestingly, they disappeared in 15 days while the aldehyde and ester compounds increased.
The results suggest that the lignin-degrading bacteria are abundant in rotten wood and strain H1 has high potential to break down lignin.
The diversity of lignin-degrading bacteria in Qinling Mountain is revealed. The study of Burkholderia sp. H1 expands the range of bacteria for lignin degradation and provides novel bacteria for application to lignocellulosic biomass.
木质素是一种形成物理屏障的芳香族杂聚物，是生物质利用中的一大挑战。本文首次对秦岭地区腐烂木材中的木质素降解细菌进行了研究。
筛选出19株潜在菌株，并在84小时内测定其木质素分解酶活性。选择酶活性较高的菌株。此外，对小麦秸秆木质素和碱木质素的生物降解进行了评估，结果表明伯克霍尔德氏菌属H1具有最高的降解能力。凝胶渗透色谱法和场发射扫描电子显微镜证实碱木质素解聚为小片段。使用气相色谱-质谱联用仪对降解产物进行分析。处理7天的产物的总离子色谱图显示形成了芳香族化合物，这是木质素降解的重要中间体。有趣的是，它们在15天内消失，而醛类和酯类化合物增加。
结果表明腐烂木材中存在丰富的木质素降解细菌，菌株H1具有很高的分解木质素的潜力。
揭示了秦岭地区木质素降解细菌的多样性。对伯克霍尔德氏菌属H1的研究扩大了木质素降解细菌的范围，并为木质纤维素生物质的应用提供了新的细菌。
