Industrial Biotechnology and Systems Biology Research Group-IBSB, Bioengineering Department, Göztepe Campus, Marmara University, Istanbul, Turkey.
J Appl Microbiol. 2021 Sep;131(3):1391-1404. doi: 10.1111/jam.15015. Epub 2021 Feb 9.
Isolating a novel bacterial source of fructan from a saltern and analysis of its genome to better understand the possible roles of fructans in hypersaline environments.
Bacteria were isolated from crude salt samples originating from Çamaltı Saltern in Western Turkey and screened for fructanogenic traits in high-salt and sucrose-rich selective medium. Exopolysaccharide accumulated in the presence of sucrose by isolate OK12 was purified and chemically characterized via HPLC, FT-IR and NMR, which revealed that it was a levan-type fructan (β-2,6 linked homopolymer of fructose). The isolate was taxonomically classified as Bacillus licheniformis OK12 through 16S rRNA gene and whole-genome sequencing methods. Strain OK12 harbours one levansucrase and two different levanase genes, which altogether were predicted to significantly contribute to intracellular glucose and fructose pools. The isolate could withstand 15% NaCl, and thus classified as a halotolerant.
Fructanogenic traits in halotolerant B. licheniformis OK12 are significant due to predicted influx of glucose and fructose as a result of levan biosynthesis and levan hydrolysis, respectively.
Fructans from the residents of hypersaline habitats are underexplored compounds and are expected to demonstrate physicochemical properties different from their non-halophilic counterparts. Revealing fructanogenic traits in the genome of a halotolerant bacterium brings up a new perspective in physiological roles of fructans.
从盐田分离一种新型的果糖来源细菌，并分析其基因组，以更好地了解果糖在高盐环境中的可能作用。
从土耳其西部恰米尔盐田的粗盐样本中分离出细菌，并在高盐和富含蔗糖的选择性培养基中筛选出产果聚糖的特性。在蔗糖存在下，分离株 OK12 积累的胞外多糖通过 HPLC、FT-IR 和 NMR 进行了纯化和化学表征，结果表明它是一种果聚糖（β-2,6 连接的果糖均聚物）。通过 16S rRNA 基因和全基因组测序方法，将分离株分类为地衣芽孢杆菌 OK12。菌株 OK12 含有一个蔗糖酶和两个不同的纤维二糖酶基因，它们共同被预测对细胞内葡萄糖和果糖池有显著贡献。该分离株能耐受 15%的 NaCl，因此被归类为耐盐菌。
耐盐地衣芽孢杆菌 OK12 中的产果聚糖特性很重要，因为预测蔗糖生物合成和纤维二糖水解分别会导致葡萄糖和果糖的流入。
来自高盐生境居民的果聚糖是一种研究不足的化合物，预计它们的物理化学性质与非嗜盐性果聚糖不同。在耐盐细菌的基因组中揭示出果聚糖的特性，为果聚糖的生理作用带来了新的视角。
