Chernyshevsky Saratov State University, 83 Ulitsa Astrakhanskaya, Saratov, 410012, Russia.
Department of Agricultural Microbiology, Faculty of Agriculture, Fayoum University, Fayoum, 63514, Egypt.
Extremophiles. 2020 Jan;24(1):157-166. doi: 10.1007/s00792-019-01143-2. Epub 2019 Nov 7.
A halophilic bacterial strain, EG1HP4QL, was isolated from a salt sample from Lake Qarun, Fayoum Province, Egypt. Morphological, physiological, biochemical, and phylogenetic analyses indicated that the strain belonged to the genus Halobacillus. Strain EG1HP4QL produced an extracellular polysaccharide (EPS), with production peaking (5.9 g L) during growth on medium S-G containing 2% (w/v) sucrose at 35 °C (pH 8.0). The EPS had significant emulsifying activity (E %) against kerosene (65.7 ± 0.8%), o-xylene (64.0 ± 1%), and sunflower oil (44.7 ± 0.5%). The composition of the EPS included two polymers-a negatively charged and a neutral one (~ 3:1)-in which mannose and glucose were the main neutral monosaccharide constituents. Strain EG1HP4QL was able to utilize crude oil (35.3%) as the sole carbon source within 12 days. The minimum inhibitory concentrations of heavy metals [Zn(II), Cd(II), Pb(II), Ni(II), and Cu(II)] for strain EG1HP4QL were 1.0, 2.0, 2.0, 2.5, and 5 mM, respectively.
从埃及法尤姆省卡隆湖的盐样本中分离到一株嗜盐细菌菌株 EG1HP4QL。形态学、生理学、生物化学和系统发育分析表明，该菌株属于盐杆菌属。菌株 EG1HP4QL 产生一种胞外多糖 (EPS)，在含有 2%（w/v）蔗糖的 S-G 培养基中于 35°C（pH 8.0）生长时产量达到峰值（5.9 g/L）。EPS 对煤油（65.7 ± 0.8%）、邻二甲苯（64.0 ± 1%）和葵花籽油（44.7 ± 0.5%）具有显著的乳化活性 (E%)。EPS 的组成包括两种聚合物-一种带负电荷和一种中性聚合物（~3:1），其中甘露糖和葡萄糖是主要的中性单糖成分。菌株 EG1HP4QL 能够在 12 天内利用原油（35.3%）作为唯一的碳源。重金属 [Zn(II)、Cd(II)、Pb(II)、Ni(II) 和 Cu(II)] 对菌株 EG1HP4QL 的最小抑制浓度分别为 1.0、2.0、2.0、2.5 和 5 mM。
