Production and Characterization of a Novel Bioflocculant from Bacillus licheniformis
Production and Characterization of a Novel Bioflocculant from Bacillus licheniformis
复制标题
地衣芽孢杆菌新型生物絮凝剂的生产和表征
DOI：
10.1128/aem.02558-09
复制
发表时间：
2010-05-01
影响因子：
4.4
通讯作者：
He, Ning
中科院分区：
文献类型：
--
作者：
Xiong, Yuyan;Wang, Yuanpeng;He, Ning
摘要从污染的LB培养基中分离到一株产胞外絮凝剂的细菌，经16 S rRNA基因测序和生理生化特性鉴定，该细菌为地衣芽孢杆菌。絮凝剂产生的最佳培养条件是初始培养基pH值为7.2，接种量为4%（体积/体积）。在37 ℃培养48 h，酶活最高，达700 U/ml。纯化的生物絮凝剂的化学分析表明，它是由89%的碳水化合物和11%的蛋白质（重量/重量）的蛋白多糖。中性糖、氨基糖和糖醛酸的质量比测量为7.9：4：1。红外光谱进一步表明存在羧基、羟基和氨基，这是杂多糖的典型特征。该絮凝剂的平均分子量为1.76 × 106 Da，扫描电镜（SEM）显示絮凝剂为网状结构的不规则结构。其高效的絮凝能力表明其在工业上的潜在应用。
ABSTRACT A bacterium producing an extracellular bioflocculant was isolated from contaminated LB medium and identified as Bacillus licheniformis by 16S rRNA gene sequencing and its biochemical/physiological characteristics. The optimum culture conditions for flocculant production were an initial medium pH of 7.2 and an inoculum size of 4% (vol/vol). The maximum flocculating activity (700 U/ml) was obtained after cultivation at 37°C for 48 h. Chemical analyses of the purified bioflocculant revealed that it was a proteoglycan composed of 89% carbohydrate and 11% protein (wt/wt). The mass ratio of neutral sugar, amino sugar, and uronic acid was measured at 7.9:4:1. Infrared spectrometry further indicated the presence of carboxyl, hydroxyl, and amino groups, typical of heteropolysaccharide. The average mass of the bioflocculant was calculated to be 1.76 × 106 Da. Scanning electron microscopy (SEM) images of the bioflocculant showed an irregular structure with netted texture. Its efficient flocculation capabilities suggest potential applications in industry.