Screening And Identification Of A Novel Xylanase-producing Strains, Purification And Enzymatic Character Analysis Of The Xylanase

Xylanase is a kind of glucosidase with the ability to hydrolysisβ-1, 4 bond of xylanases in an endo-manner, whose hydrolysate are mostly dimmer and oligomer of xylose, as well as some xylose and arabinose. Researches on xylanase had begun early in 1960s, so far many genes encoding kinds of xylanase had been cloned, a lot of attempts had also been done on effectively expression of those genes. Xylanases applicating in different fields have various zymologic characters, for example, alkaline xylanase can be used in pulp processing, while acidic xylanase is more suitable in feed industry. In addition, some basic properties of the enzyme, such as specific activity, stability and the capable of resisting chemical compounds play a key role in its practical application. With the development of gene engineering and protein technology, it is proved of significant importance in industry application to explore new xylanase gene and optimism its expression.In this paper, two xylanase-producing strains named strain Hainan Hand Hainan 12 respectively was isolated from soil sample No.1 collected from bagasse laydown area, one glycoside factory in Hainan province. Experiments were done according to Martin's culture project, using xylanase as the unique carbon source. Strain Hainan 12 was identified as mucor through morphology methods, named mocor HN0512.orthogonal experiments revealed that mocor HN0512 grows best in the culture consisting of 1.5% xylan, 1% peptone, 1% yeast extract, 0.03% MgSO₄·7H₂O, 0.03% CaCL₂, 0.03%FeSO₄, 0.5% tween80, 0.01% vitaminB₁, with the enzyme activity of 5330.13U/L. A single protein band was purified via 75% saturated ammonium sulfate precipitation, hydrophobic interaction chromatography, Native-PAGE in order. SDS-PAGE showed that molecule weight of the protein was 74.7KD. enzymology analysis demonstrated the enzyme had optimal temperaturei of 45℃, optimal pH...