Properties of Klebsiella Phage P13 and Associated Exopolysaccharide Depolymerase

来源 :Journal of Ocean University of China | 被引量 : 0次 | 上传用户:chaba
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The bacteriophage P13 that infects Klebsiella serotype K13 contains a heat-stable depolymerase capable of effective degradation of exopolysaccharide(EPS) produced by this microorganism. In this study, the titer of phage P13, initially 2.0 × 107 pfu mL-1, was found increasing 20 min after infection and reached 5.0 × 109 pfu mL-1 in 60 min. Accordingly, the enzyme activity of depolymerase approached the maximum 60 min after infection. Treatment at 70℃ for 30 min inactivated all the phage, but retained over 90% of the depolymerase activity. Addition of acetone into the crude phage lysate led to precipitation of the protein, with a marked increase in bacterial EPS degradation activity and a rapid drop in the titer of phage. After partial purification by acetone precipitation and ultrafiltration centrifugation, the enzyme was separated from the phage particles, showing two components with enzyme activity on Q-Sepharose Fast Flow. The soluble enzyme had an optimum degradation activity at 60℃ and pH 6.5. Transmission electron microscopy demonstrated that the phage P13 particles were spherical with a diameter of 50 nm and a short stumpy tail. It was a double-strand DNA virus consisting of a nucleic acid molecule of 45976 bp. This work provides an efficient purification operation including thermal treatment and ultrafiltration centrifugation, to dissociate depolymerase from phage particles. The characterization of phage P13 and associated EPS depolymerase is beneficial for further application of this enzyme. The bacteriophage P13 that infects Klebsiella serotype K13 contains a heat-stable depolymerase capable of effective degradation of exopolysaccharide (EPS) produced by this microorganism. In this study, the titer of phage P13, initially found 2.0 × 107 pfu mL-1, was found increasing 20 min after infection and reached 5.0 × 109 pfu mL-1 in 60 min. After the enzyme activity of depolymerase approached the maximum 60 min after infection. Treatment at 70 ℃ for 30 min inactivated all the phage, but retained over 90% of the depolymerase activity. Addition of acetone into the crude phage lysate led to precipitation of the protein, with a marked increase in bacterial EPS degradation activity and a rapid drop in the titer of phage. After partial purification by acetone precipitation and ultrafiltration centrifugation, the enzyme was separated from the phage particles, showing two components with enzyme activity on Q-Sepharose Fast Flow. The soluble enzyme had an optimum degradation activity at 60 ° C and pH 6.5. Transmission electron microscopy demonstrated that the phage P13 particles were spherical with a diameter of 50 nm and a short stumpy tail. It was a double-strand DNA virus consisting of a nucleic acid molecule of 45976 bp. This work provides an efficient purification operation including thermal treatment and ultrafiltration centrifugation, to dissociate depolymerase from phage particles. The characterization of phage P13 and associated EPS depolymerase is beneficial for further application of this enzyme.
其他文献
以固定化脂肪酶为催化剂,在丙酮体系中合成抗坏血酸柠檬酸酯AC.采用薄层色谱(TLC)和高效液相色谱(HPLC)对产物进行定性、定量分析,并就其抗氧化活性进行测定.正交试验结果表
目的 构建表达鼠疫耶尔森杆菌(Yersinia Pestis)YP01668的重组蛋白,为鼠疫耶尔森杆菌诊断试剂的研究提供依据.方法 用经典PCR方法扩增,ypo1668基因,通过双酶切、连接反应,将
以青海省西宁市市政污水出水为研究对象,初步调查了污水中的绿藻资源,并从形态学上进行初步鉴定.结果显示,污水中含有绿藻门小球藻科蹄形藻、小球藻、顶棘藻,栅藻科栅藻,卵囊
科技特派员制度创新了农业科技推广模式,对于科技兴农起到了一定的促进作用.本文对我国科技推广效率问题进行了分析,以宁夏科技特派员制度为例,通过对问卷调查数据进行计量分
目的:探讨沁河镇≥40以人群脑卒中危险因素暴露水平及其人群分布特征。方法在沁源县整群抽取年龄≥40岁的人群作为目标人群。设计统一的卒中危险因素调查表,对符合入选标准者进
采用2.4 U/mL Dispase酶消化和机械切割法分离毛囊隆突部,经胰酶(0.5 mg/mL胰酶+0.2mg/mL EDTA)消化,从山羊耳部皮肤分离得到毛囊干细胞,并检测了不同浓度的IGF-1对山羊毛囊
目的研究缺氧对PC12细胞HIF-1/JAK2/NF-κB信号级联的影响。方法制备缺氧细胞模型,采用EMSA、半定量RT-PCR技术和Western blot法检测JAK2、HIF-1α、HIF-1β基因mRNA和蛋白表
Constructed wetlands (CWs) were integrated into an indoor recirculating aquaculture system of obscure puffer (Takifugu obscurus) for effluent treatment. The eff
Fucoidan, a polysaccharide containing abundant fucose and sulfate ester group, was prepared from Laminaria japonica. In order to obtain fucoidan-degrading enzym
The swimming endurance of whiteleg shrimp (Litopenaeus vannamei, 87.66 mm ± 0.25 mm, 7.73 g ± 0.06 g) was exam-ined at various concentrations of dissolved oxy