Marine Biology and Biotechnology Program, Department of Life Sciences, Ben-Gurion University of the Negevgrid.7489.2 Eilat Campus, Eilat, Israel.
Israel Oceanographic and Limnological Researchgrid.419264.c, The National Center for Mariculture, Eilat, Israel.
Microbiol Spectr. 2022 Aug 31;10(4):e0107822. doi: 10.1128/spectrum.01078-22. Epub 2022 Jul 11.
Halotolerant bacteria capable of starch hydrolysis by their amylases will benefit various industries, specifically since the hydrolytic activity of current industrial amylases is inhibited or even absent in salt-rich or alkaline environments. Seeking novel enzymes, we analyzed the entire genome content of a marine bacterium isolated from the gut of sea urchins to compare it against other bacterial genomes. Conditions underlying α-amylase activity were examined at various salinities (0 to 4%) and temperatures (25°C to 37°C). Genomic analyses revealed the isolated bacterium as a new species of . Comparative analysis of the contents of carbohydrate-active enzymes revealed various α-amylases, each with its respective carbohydrate-binding module for starch hydrolysis. Functional analysis identified the hydrolysis of starch and the maltooligosaccharides maltose and dextrin into d- and UDP-glucose. The fastest growth and α-amylase production occurred at 3% salinity at a temperature of 30°C. The sp. consists of exclusive contents of α-amylases and other enzymes that may be valuable in the hydrolysis of the algal polysaccharides cellulose and laminarin. Toward the discovery of novel carbohydrate-active enzymes that may be useful in the hydrolysis of starch, we examined a halotolerant bacterial isolate of sp. regarding its genomic content and conditions underlying the production of active α-amylases. The production of α-amylases was measured in bacterial cultures at relatively high temperature (37°C) and salinity (4%). The sp. revealed an exclusive content of amylases and other carbohydrate-active enzymes compared to other relevant bacteria. These enzymes may be valuable for the hydrolysis of algal polysaccharides. The enzymatic cascade of the sp. for starch metabolism allows polysaccharide degradation into monosugars while preventing the accumulation of intermediate inhibitors of maltose or dextrin.
耐盐细菌能够通过其淀粉酶水解淀粉，这将使各个行业受益，特别是因为当前工业用淀粉酶的水解活性在富含盐或碱性的环境中受到抑制甚至缺失。为了寻找新的酶，我们分析了从海胆肠道中分离出的海洋细菌的整个基因组内容，并将其与其他细菌基因组进行了比较。在各种盐度（0 至 4%）和温度（25°C 至 37°C）下检查了α-淀粉酶活性的条件。基因组分析显示，分离出的细菌是一种新的 。对碳水化合物活性酶含量的比较分析显示，存在各种α-淀粉酶，每种酶都有其各自用于淀粉水解的碳水化合物结合模块。功能分析确定了淀粉以及麦芽寡糖麦芽糖和糊精水解为 d-和 UDP-葡萄糖。在 30°C 的 3%盐度下，生长和α-淀粉酶的产生最快。 属由α-淀粉酶和其他可能在藻多糖纤维素和昆布多糖水解中有用的酶的特有含量组成。为了发现可能在淀粉水解中有用的新型碳水化合物活性酶，我们研究了耐盐细菌 属的分离株，研究了其基因组内容以及产生活性α-淀粉酶的条件。在相对较高的温度（37°C）和盐度（4%）下测量了细菌培养物中α-淀粉酶的产生。与其他相关细菌相比， 属显示出淀粉酶和其他碳水化合物活性酶的特有含量。这些酶可能对藻多糖的水解有价值。属的淀粉代谢的酶级联反应允许多糖降解为单糖，同时防止麦芽糖或糊精的中间抑制剂积累。
