tailieunhanh - Optimization, purification, and characterization of an extracellular antifungal protein from Serratia marcescens DT3 isolated from soil in Vietnam

Gram-negative Serratia marcescens is a potential biological control agent of fungal plant diseases in many tropical regions. Its antifungal activity is due to the production of prodigiosin, protease, chitinase, and other substances that act to weaken the fungal cell wall and cause lysis. | Turkish Journal of Biology Research Article Turk J Biol (2017) 41: 448-457 © TÜBİTAK doi: Optimization, purification, and characterization of an extracellular antifungal protein from Serratia marcescens DT3 isolated from soil in Vietnam Tuyen Thi DO*, Thao Thi NGUYEN, Thanh Le Sy NGUYEN, Hoang Thanh LE Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam Received: Accepted/Published Online: Final Version: Abstract: Gram-negative Serratia marcescens is a potential biological control agent of fungal plant diseases in many tropical regions. Its antifungal activity is due to the production of prodigiosin, protease, chitinase, and other substances that act to weaken the fungal cell wall and cause lysis. In the following investigation, a novel extracellular protein with antifungal activity against Rhizoctonia solani and Fusarium oxysporum was optimally produced, purified, and characterized from a native Serratia marcescens DT3. Under optimal conditions (medium containing peptone, yeast extract; temperature of 28 °C; initial pH of 7; culture time of 28 h), the antifungal activity of the extracellular extract was increased by a factor of – in comparison with the initial condition. The purified protein had an apparent molecular mass of 55 kDa. Its antifungal activity was retained at 80 °C for 30 min and after having been treated with proteinase K (–4 µg/mL). The results of protein identification using a MALDI-TOF/TOF mass spectrometer suggested that the purified protein is indeed a serine 3-dehydrogenase. Key words: Antifungal protein, Serratia marcescens DT3, serine 3-hydroxylase 1. Introduction Occupying the first position in every food chain, plants play vital roles in the lives of all creatures on this planet including human beings. Unfortunately, this important element is easily attacked by various pathogens, leading .