Efficient production of pullulan using rice hull hydrolysate by adaptive laboratory evolution of Aureobasidium pullulans.
Pullulan production by Aureobasidium pullulans CCTCC M 2012259 using rice hull hydrolysate as the carbon source was conducted. The acetic acid in the hydrolysate was demonstrated to exert a negative effect on pullulan biosynthesis. Instead of employing expensive methods to remove acetic acid from the hydrolysate, a mutant A. pullulans ARH-1 was isolated following 20 cycles of adaptive laboratory evolution of the parental strain on medium containing acetic acid. The maximum pullulan production achieved by the adapted mutant at 48 h using the hydrolysate of untreated rice hull was 22.2 g L(-1), while that obtained by the parental strain at 60 h was 15.6 g L(-1). The assay of key enzymes associated with pullulan biosynthesis revealed that acetic acid inhibited enzyme activity rather than suppressing enzyme synthesis. These results demonstrated that adaptive evolution highly improved the efficiency of pullulan production by A. pullulans using the hydrolysate of untreated rice hull.
School of Biology and Basic Medical Sciences, Soochow University, Suzhou 215123, PR China.
Dahui
D
Wang
School of Biology and Basic Medical Sciences, Soochow University, Suzhou 215123, PR China.
Xiaomin
X
Ju
School of Biology and Basic Medical Sciences, Soochow University, Suzhou 215123, PR China.
Donghai
D
Zhou
School of Biology and Basic Medical Sciences, Soochow University, Suzhou 215123, PR China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China. Electronic address: weigy@suda.edu.cn.
Gongyuan
G
Wei
D019342:Acetic Acid / Q000378:metabolism; D000383:Agriculture; D001203:Ascomycota / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D001709:Biotechnology / Q000191:economics / Q000379:methods*; D002241:Carbohydrates; D002244:Carbon / Q000494:pharmacology; D019020:Directed Molecular Evolution / Q000379:methods*; D005285:Fermentation / Q000187:drug effects; D005502:Food; D005936:Glucans / Q000096:biosynthesis*; D006868:Hydrolysis / Q000187:drug effects; D007220:Industrial Waste / Q000032:analysis; D012275:Oryza / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014866:Waste Products / Q000032:analysis*
D002241:Carbohydrates; D005936:Glucans; D007220:Industrial Waste; D014866:Waste Products; D002244:Carbon; C009109:pullulan; D019342:Acetic Acid
Acetic acid; Adaptive laboratory evolution; Aureobasidium pullulans; Pullulan; Rice hull hydrolysate