A marine bacterial enzymatic cascade degrades the algal polysaccharide ulvan
A marine bacterial enzymatic cascade degrades the algal polysaccharide ulvan
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DOI：
10.1038/s41589-019-0311-9
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发表时间：
2019-08-01
影响因子：
14.8
通讯作者：
Hehemann, Jan-Hendrik
中科院分区：
文献类型：
--
作者：
Reisky, Lukas;Prechoux, Aurelie;Hehemann, Jan-Hendrik
海洋海藻越来越多地生长成大面积的藻华，这对沿海生态系统、旅游业和水产养殖业有害。然而，藻类生物质也正在成为生物经济的可持续原材料。藻类的潜在开发受到我们对微生物途径的有限了解的阻碍，因此涉及的酶的独特生化功能将藻类多糖转化为寡糖和单糖。然而，了解这些过程对于将藻类生物质发酵成生物乙醇或其他增值化合物等应用至关重要。在这里，我们描述的代谢途径，使海洋黄杆菌福尔摩沙agariphila降解石莼多糖，主要的细胞壁多糖的水华形成石莼物种。该途径涉及12个生化特征的碳水化合物活性酶，包括两个多糖裂解酶，三个硫酸酯酶和七个糖苷水解酶，依次将石莼多糖分解为可发酵的单糖。通过这种方式，酶将以前未开发的可再生资源转化为有价值的生态可持续生物资源。
Marine seaweeds increasingly grow into extensive algal blooms, which are detrimental to coastal ecosystems, tourism and aquaculture. However, algal biomass is also emerging as a sustainable raw material for the bioeconomy. The potential exploitation of algae is hindered by our limited knowledge of the microbial pathways-and hence the distinct biochemical functions of the enzymes involved-that convert algal polysaccharides into oligo- and monosaccharides. Understanding these processes would be essential, however, for applications such as the fermentation of algal biomass into bioethanol or other value-added compounds. Here, we describe the metabolic pathway that enables the marine flavobacterium Formosa agariphila to degrade ulvan, the main cell wall polysaccharide of bloom-forming Ulva species. The pathway involves 12 biochemically characterized carbohydrate-active enzymes, including two polysaccharide lyases, three sulfatases and seven glycoside hydrolases that sequentially break down ulvan into fermentable monosaccharides. This way, the enzymes turn a previously unexploited renewable into a valuable and ecologically sustainable bioresource.