An engineered polysaccharide lyase to combat harmful algal blooms
An engineered polysaccharide lyase to combat harmful algal blooms
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DOI：
10.1016/j.bej.2018.01.005
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发表时间：
2018-04-15
影响因子：
3.9
通讯作者：
Berger, Bryan W.
中科院分区：
文献类型：
--
作者：
Eckersley, Evan;Berger, Bryan W.
全球人口和工业化的增长是以引起气候变化和自然资源污染为代价的，导致淡水资源中形成有毒的藻华。仅在美国，每年的修复费用就高达15亿美元。目前对抗藻华的方法如硫酸铜处理是昂贵、无效且对环境有害的，这促使生物化学杀藻剂作为绿色替代品的发展。我们之前的研究鉴定了来自嗜麦芽寡养单胞菌SmIt2602 （WT）的多糖裂解酶（PL）酶H208F突变体，该突变体对多糖聚葡萄糖醛酸的活性增加。聚葡萄糖醛酸是藻类细胞壁的主要成分。本研究的重点是将这两种酶应用于一种常见的形成水华、产生毒素的藻类——铜绿微囊藻。我们假设这两种酶可以通过破坏细胞壁来杀死藻类，其中H208F在WT上显示出更高的杀死效果。我们使用荧光法结合活/死染色来量化每种酶处理过的藻类的杀死效果。通过扫描电镜观察细胞壁形态，验证其杀伤机制。突变体H208F被证实具有潜在的生物化学、酶促杀藻剂的应用潜力，其杀藻效果比WT高17%。扫描电镜图像显示藻细胞壁变形，证实了据称的机制。(C) 2018 Elsevier B.V.版权所有
A growing global population and industrialization have come at the cost of induced climate change and pollution of natural resources, resulting in formation of toxic algal blooms in fresh water sources. In the US alone, these blooms cost an estimated $1.5 billion dollars each year to remediate. Current methods to combat such blooms such as copper sulfate treatment are expensive, ineffective, and environmentally toxic, motivating development of biochemical algaecides as green alternatives. Our previous research led to identification of mutant polysaccharide lyase (PL) enzyme H208F derived from Stenotrophomonas maltophilia SmIt2602 (WT), which displays increased activity on the polysaccharide polyglucuronic acid. Polyglucuronic acid is a major component of the algal cell wall. This study focused on applying the two enzymes to a common bloom-forming, toxin-producing algae, Microcystis aeruginosa. We hypothesized the 2 enzymes would kill algae through disrupting the cell wall, with H208F displaying a higher killing efficacy over WT. A fluorescence assay in conjunction with live/dead staining was used to quantify killing of algae treated with each enzyme. SEM analysis was used to observe cell wall morphology in order to verify the killing mechanism. The mutant H208F was confirmed as having potential application as a biochemical, enzymatic algaecide with a 17% greater algicidal efficacy than the WT. SEM images revealed deformities in the algal cell wall, confirming the purported mechanism. (C) 2018 Elsevier B.V. All rights reserved.