Biswas Jhuma, Ganguly J, Paul A K
a Microbiology Laboratory, Department of Botany , University of Calcutta , Kolkata , India.
b Natural Polysaccharide Laboratory, Department of Chemistry , Indian Institute of Engineering Science and Technology , Shibpur , India.
Biofouling. 2015;31(9-10):735-44. doi: 10.1080/08927014.2015.1106479.
A moderately halophilic bacterium, Halomonas xianhensis SUR308 (Genbank Accession No. KJ933394) was isolated from a multi-pond solar saltern at Surala, Ganjam district, Odisha, India. The isolate produced a significant amount (7.87 g l(-1)) of extracellular polysaccharides (EPS) when grown in malt extract-yeast extract medium supplemented with 2.5% NaCl, 0.5% casein hydrolysate and 3% glucose. The EPS was isolated and purified following the conventional method of precipitation and dialysis. Chromatographic analysis (paper, GC and GC-MS) of the hydrolyzed EPS confirmed its heteropolymeric nature and showed that it is composed mainly of glucose (45.74 mol%), galactose (33.67 mol %) and mannose (17.83 mol%). Fourier-transform infrared spectroscopy indicated the presence of methylene and carboxyl groups as characteristic functional groups. In addition, its proton nuclear magnetic resonance spectrum revealed functional groups specific for extracellular polysaccharides. X-ray diffraction analysis revealed the amorphous nature (CIxrd, 0.56) of the EPS. It was thermostable up to 250 °C and displayed pseudoplastic rheology and remarkable stability against pH and salts. These unique properties of the EPS produced by H. xianhensis indicate its potential to act as an agent for detoxification, emulsification and diverse biological activities.
从印度奥里萨邦甘贾姆区苏拉拉的一个多池太阳能盐场中分离出了一株中度嗜盐细菌——咸海盐单胞菌SUR308（Genbank登录号：KJ933394）。当该菌株在添加了2.5%氯化钠、0.5%酪蛋白水解物和3%葡萄糖的麦芽提取物-酵母提取物培养基中生长时，能产生大量（7.87 g l⁻¹）的胞外多糖（EPS）。按照传统的沉淀和透析方法对EPS进行分离和纯化。对水解后的EPS进行色谱分析（纸色谱、气相色谱和气相色谱-质谱联用），证实了其杂聚性质，并表明它主要由葡萄糖（45.74 mol%）、半乳糖（33.67 mol%）和甘露糖（17.83 mol%）组成。傅里叶变换红外光谱表明存在亚甲基和羧基作为特征官能团。此外，其质子核磁共振谱揭示了胞外多糖特有的官能团。X射线衍射分析表明EPS具有无定形性质（CIxrd，0.56）。它在高达250℃时具有热稳定性，表现出假塑性流变学特性，并且对pH值和盐具有显著的稳定性。咸海盐单胞菌产生的EPS的这些独特性质表明其有潜力作为解毒、乳化和多种生物活性的试剂。
