Overproduction of Thermoalkalophilic Lipase Secreted by Bacillus Atrophaeus Fshm2 Using Uv-Induced Mutagenesis and Statistical Optimization of Medium Components Publisher Pubmed



Ameri A¹ ; Shakibaie M^{2, 3} ; Soleimanikermani M⁴ ; Faramarzi MA⁵ ; Forootanfar H^{1, 2} Show Affiliations
Source: Preparative Biochemistry and Biotechnology Published:2019

Abstract

Microbial enzymes of extremophilic origin serve as a vital source of stable industrial enzymes. The present study focused on overproduction of a thermoalkalophilic lipase produced by Bacillus atrophaeus FSHM2 through UV-induced random mutagenesis (5–45 min exposure to UV light) and factorial experimental design augmented to response surface methodology. Firstly, a UV-induced mutant (designated as UV-45) was developed after the exposure of wild strain to UV irradiation for 45 min which was able to secrete 3484.8 U/L lipase. Afterward, Plackett–Burman experimental approach augmented to central composite design was employed to optimize medium components (olive oil, maltose, glucose, sucrose, yeast extract, tryptone, urea, (NH 4 ) 2 SO 4 , NaCl, CaCl 2 , and ZnSO 4 ) for lipase production by the UV-45 mutant strain. The maximum lipase production of 5505.3 U/L were predicted in medium containing 5% of olive oil, 0.69% of glucose, 0.69% of sucrose, 2.5% of maltose, yeast extract (0.7 g/L), urea (0.44 g/L), (NH 4 ) 2 SO 4 (2.44 g/L), tryptone (1.19 g/L), NaCl (1.61 g/L), CaCl 2 (3.81 g/L), and ZnSO 4 (1.42 g/L). A mean value of 5161.3 ± 83.3 U/L of lipolytic activity was acquired from real experiments. To sum up, the lipolytic activity of wild type strain (1720.4 U/L) increased by 3-fold after UV-induced mutagenesis and medium components optimization (5161.3 U/L). © 2019, © 2019 Taylor & Francis Group, LLC.