Akeed Yasser, Atrash Faiza, Naffaa Walid
Plant Biology Department, Faculty of Science, University of Damascus, Syria.
Plant Protection Department, Faculty of Agriculture, University of Damascus, 30621 Damascus, Syria.
Heliyon. 2020 May 3;6(5):e03858. doi: 10.1016/j.heliyon.2020.e03858. eCollection 2020 May.
The optimal conditions required for chitinase production from B307 strain, obtained from Syrian soil, were studied. Optimization experiments were carried out under submerged fermentation conditions, and colloidal chitin was the source of carbon. Luria broth medium supplied with 0.5% colloidal chitin was the optimum medium for chitinase production. The maximum chitinase yield was obtained at 30 °C, pH6, incubation time 14 days, and 150 rpm. The optimum chitinase activity was achieved at 60 °C and pH6. The chitinase activity with unmodified medium was 1.9 U/mL which then enhanced about eight folds to reach 14.2 U/mL under optimized submerged fermentation conditions. An extracellular chitinase of B307 was partially purified using ammonium sulfate precipitation followed by concentration with various sizes of concentrator tubes. The chitinase was partially purified 8.24 fold and specific enzyme activity increased 2.08 fold (2 U/mg). Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of partial purified chitinase exhibited a molecular weight ( ) near to 36 and 42kDa. These results make it possible to invest in this strain to produce chitinase to be used as antifungal, food additives and other applications.
对从叙利亚土壤中分离得到的B307菌株生产几丁质酶所需的最佳条件进行了研究。在深层发酵条件下开展优化实验，以胶体几丁质作为碳源。添加0.5%胶体几丁质的Luria肉汤培养基是生产几丁质酶的最佳培养基。在30℃、pH6、培养时间14天和转速150转/分钟的条件下可获得最大几丁质酶产量。在60℃和pH6时可实现最佳几丁质酶活性。未改良培养基中的几丁质酶活性为1.9 U/mL，在优化的深层发酵条件下，其活性提高了约8倍，达到14.2 U/mL。采用硫酸铵沉淀法，随后用不同尺寸的浓缩管进行浓缩，对B307的一种胞外几丁质酶进行了部分纯化。几丁质酶得到了8.24倍的部分纯化，比酶活性提高了2.08倍（2 U/mg）。部分纯化的几丁质酶的十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）显示分子量接近36 kDa和42 kDa。这些结果使得投资利用该菌株生产几丁质酶用于抗真菌、食品添加剂及其他应用成为可能。
