Isolation and partial characterization of an antifungal protein produced by Bacillus licheniformis BS-3.
An antifungal protein produced by Bacillus licheniformis strain BS-3 was purified to homogeneity by ammonium sulfate precipitation, DEAE-52 column chromatography and Sephadex G-75 column chromatography. The purified protein was designated as F2 protein, inhibited the growth of Aspergillus niger, Magnaporthe oryzae and Rhizoctonia solani. F2 protein was a monomer with approximately molecular weight of 31 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gave a single peak on High Performance Liquid Chromatography (HPLC). Using Rhizoctonia solani as the indicator strain, the EC50 of F2 protein was 35.82 µg/mL, displaying a higher antifungal activity in a range of pH 6.0 to pH 10.0, and at a temperature below 70 °C for 30 min. F2 protein was moderately resistant to hydrolysis by trypsin, proteinase K, after which its relative activities were 41.7% and 59.5%, respectively. F2 protein was assayed using various substrates to determine the enzymatic activities, the results showed the hydrolyzing activity on casein, however, no enzymatic activities on colloidal chitin, CM-cellulose, xylan, M. lysodeikticus, and p-nitrophenyl-N-acetylglucosaminide.
School of Biological Science and Bioengineering, South China University of Technology, Guangzhou 510006, China. fetbcui@scut.edu.cn
Tang-Bing
TB
Cui
Hai-Yun
HY
Chai
Li-Xiang
LX
Jiang
D000935:Antifungal Agents / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D001407:Bacillus / Q000737:chemistry*; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D013379:Substrate Specificity; D013696:Temperature
D000935:Antifungal Agents; D001426:Bacterial Proteins