【目的】分离海洋来源的琼胶酶产生菌,确定其分类地位,研究其所产琼胶酶粗酶的酶学性质及酶解产物的抗氧化活性,为琼胶酶的进一步开发应用提供理论依据。【方法】利用以琼胶为唯一碳源的筛选培养基筛选分离产琼胶酶的菌株;采用16S r RN...【目的】分离海洋来源的琼胶酶产生菌,确定其分类地位,研究其所产琼胶酶粗酶的酶学性质及酶解产物的抗氧化活性,为琼胶酶的进一步开发应用提供理论依据。【方法】利用以琼胶为唯一碳源的筛选培养基筛选分离产琼胶酶的菌株;采用16S r RNA基因序列分析确定菌株的分类地位;研究菌株所产琼胶酶粗酶的酶学性质;通过测定酶解产物的还原能力和清除自由基ABTS·+的能力,分析酶解产物的抗氧化活性。【结果】分离到一株产胞外琼胶酶的菌株JMUAZ5,根据16S r RNA基因序列分析,该菌株归属于弧菌属(Vibrio sp.);菌株JMUAZ5琼胶酶粗酶具有良好的底物专一性;最适反应温度为40°C,在20°C和25°C条件下稳定;最适反应p H值为8.0,在p H 6.0~10.0范围内稳定;Ca^(2+)和Al^(3+)对酶活性具有强烈促进作用,而Zn^(2+)和Fe^(3+)对酶具有强烈抑制作用;琼胶酶粗酶对测试的抑制剂、去垢剂和变性剂均具有好的抗性;酶解产物琼胶低聚糖具有还原能力和清除ABTS·+的能力。【结论】海洋细菌弧菌属JMUAZ5可产胞外琼胶酶,酶解产物有一定的抗氧化活性,具有潜在应用价值。展开更多
The chitin is extracted from the cuttlebone of S. inermis and the mineral contents are predictable. The structure and degree of deacetylation of extracted cuttlebone chitin is dogged through Fourier Transform Infrared...The chitin is extracted from the cuttlebone of S. inermis and the mineral contents are predictable. The structure and degree of deacetylation of extracted cuttlebone chitin is dogged through Fourier Transform Infrared (FT-IR) spectroscopy. The extracted cuttlebone chitin is used as the substrate for the production of chitinase from Vibrio sp. The extra cellular proteins are concentrated by ammonium sulphate precipitation, dialysed and then purified by using gel (sephadex G-100) chromatography. Among the 40 fractions, only two fractions (active fractions) showed maximum absorbance at 280 nm, which are pooled, dialysed and free-dried. The enzyme activity (0.104 μmoles/ml) and molecular weight (50 - 60 kDa) of purified chitinase is also determined through SDS- PAGE. The optimal condition for chitinase activity is pH between 6.0 - 6.5 and 45℃.展开更多
从患病拟穴青蟹(Scylla paramamosain)肝胰腺中分离到2种优势菌株,对2种优势菌株进行了鉴定和特性分析。利用形态学观察、生理生化特性分析和16S r DNA序列测定法对细菌类别进行判定,并采用药敏试验对细菌的耐药性进行分析。结果表明,这...从患病拟穴青蟹(Scylla paramamosain)肝胰腺中分离到2种优势菌株,对2种优势菌株进行了鉴定和特性分析。利用形态学观察、生理生化特性分析和16S r DNA序列测定法对细菌类别进行判定,并采用药敏试验对细菌的耐药性进行分析。结果表明,这2种细菌分别为弧菌(Vibrio sp.)和希瓦氏菌(Shewanella),利用15种抗生素对2种细菌进行药敏试验分析,发现2种细菌对恩诺沙星、氟苯尼考、强力霉素高度敏感,对其他几种抗生素则有一定的耐受性。研究进一步证实了海水致病性弧菌是拟穴青蟹细菌性疾病高发的主要原因,也表明希瓦氏菌可能是一种潜在病原菌,与弧菌协同作用,对拟穴青蟹规模化养殖造成危害,同时也为拟穴青蟹养殖过程中细菌性病害的确定和防治提供参考依据。展开更多
文摘【目的】分离海洋来源的琼胶酶产生菌,确定其分类地位,研究其所产琼胶酶粗酶的酶学性质及酶解产物的抗氧化活性,为琼胶酶的进一步开发应用提供理论依据。【方法】利用以琼胶为唯一碳源的筛选培养基筛选分离产琼胶酶的菌株;采用16S r RNA基因序列分析确定菌株的分类地位;研究菌株所产琼胶酶粗酶的酶学性质;通过测定酶解产物的还原能力和清除自由基ABTS·+的能力,分析酶解产物的抗氧化活性。【结果】分离到一株产胞外琼胶酶的菌株JMUAZ5,根据16S r RNA基因序列分析,该菌株归属于弧菌属(Vibrio sp.);菌株JMUAZ5琼胶酶粗酶具有良好的底物专一性;最适反应温度为40°C,在20°C和25°C条件下稳定;最适反应p H值为8.0,在p H 6.0~10.0范围内稳定;Ca^(2+)和Al^(3+)对酶活性具有强烈促进作用,而Zn^(2+)和Fe^(3+)对酶具有强烈抑制作用;琼胶酶粗酶对测试的抑制剂、去垢剂和变性剂均具有好的抗性;酶解产物琼胶低聚糖具有还原能力和清除ABTS·+的能力。【结论】海洋细菌弧菌属JMUAZ5可产胞外琼胶酶,酶解产物有一定的抗氧化活性,具有潜在应用价值。
文摘The chitin is extracted from the cuttlebone of S. inermis and the mineral contents are predictable. The structure and degree of deacetylation of extracted cuttlebone chitin is dogged through Fourier Transform Infrared (FT-IR) spectroscopy. The extracted cuttlebone chitin is used as the substrate for the production of chitinase from Vibrio sp. The extra cellular proteins are concentrated by ammonium sulphate precipitation, dialysed and then purified by using gel (sephadex G-100) chromatography. Among the 40 fractions, only two fractions (active fractions) showed maximum absorbance at 280 nm, which are pooled, dialysed and free-dried. The enzyme activity (0.104 μmoles/ml) and molecular weight (50 - 60 kDa) of purified chitinase is also determined through SDS- PAGE. The optimal condition for chitinase activity is pH between 6.0 - 6.5 and 45℃.
文摘从患病拟穴青蟹(Scylla paramamosain)肝胰腺中分离到2种优势菌株,对2种优势菌株进行了鉴定和特性分析。利用形态学观察、生理生化特性分析和16S r DNA序列测定法对细菌类别进行判定,并采用药敏试验对细菌的耐药性进行分析。结果表明,这2种细菌分别为弧菌(Vibrio sp.)和希瓦氏菌(Shewanella),利用15种抗生素对2种细菌进行药敏试验分析,发现2种细菌对恩诺沙星、氟苯尼考、强力霉素高度敏感,对其他几种抗生素则有一定的耐受性。研究进一步证实了海水致病性弧菌是拟穴青蟹细菌性疾病高发的主要原因,也表明希瓦氏菌可能是一种潜在病原菌,与弧菌协同作用,对拟穴青蟹规模化养殖造成危害,同时也为拟穴青蟹养殖过程中细菌性病害的确定和防治提供参考依据。
