Tianlong Bai1,2, Teng Wang3, Yan Li2, Na L Gao3, Lixin Zhang4, Wei-Hua Chen5,6, Xiushan Yin7. 1. Applied Biology Laboratory, Shenyang University of Chemical Technology, Shenyang, 110142, China. 2. Liaoning Province Key Laboratory of Green Functional Molecule Design and Development, Shenyang University of Chemical Technology, Shenyang, 110142, China. 3. Key Laboratory of Molecular Biophysics of the Ministry of Education, Hubei Key Laboratory of Bioinformatics and Molecular Imaging, Department of Bioinformatics and Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China. 4. Liaoning Province Key Laboratory of Green Functional Molecule Design and Development, Shenyang University of Chemical Technology, Shenyang, 110142, China. zhanglixin@syuct.edu.cn. 5. Key Laboratory of Molecular Biophysics of the Ministry of Education, Hubei Key Laboratory of Bioinformatics and Molecular Imaging, Department of Bioinformatics and Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China. weihuachen@hust.edu.cn. 6. College of Life Science, HeNan Normal University, Xinxiang, 453007, Henan, China. weihuachen@hust.edu.cn. 7. Applied Biology Laboratory, Shenyang University of Chemical Technology, Shenyang, 110142, China. xiushanyin@gmail.com.
Abstract
BACKGROUND: Sclerotium rolfsii is a potent producer of many secondary metabolites, one of which like scleroglucan is an exopolysaccharide (EPS) appreciated as a multipurpose compound applicable in many industrial fields. RESULTS: Aspartate transaminase (AAT1) catalyzes the interconversion of aspartate and α-ketoglutarate to glutamate and oxaloacetate. We selected AAT1 in the oxalate metabolic pathway as a target of CRISPR/Cas9. Disruption of AAT1 leads to the accumulation of oxalate, rather than its conversion to α-ketoglutarate (AKG). Therefore, AAT1-mutant serves to lower the pH (pH 3-4) so as to increase the production of the pH-sensitive metabolite scleroglucan to 21.03 g L-1 with a productivity of up to 0.25 g L-1·h-1. CONCLUSIONS: We established a platform for gene editing that could rapidly generate and select mutants to provide a new beneficial strain of S. rolfsii as a scleroglucan hyper-producer, which is expected to reduce the cost of controlling the optimum pH condition in the fermentation industry.
BACKGROUND:Sclerotium rolfsii is a potent producer of many secondary metabolites, one of which like scleroglucan is an exopolysaccharide (EPS) appreciated as a multipurpose compound applicable in many industrial fields. RESULTS:Aspartate transaminase (AAT1) catalyzes the interconversion of aspartate and α-ketoglutarate to glutamate and oxaloacetate. We selected AAT1 in the oxalate metabolic pathway as a target of CRISPR/Cas9. Disruption of AAT1 leads to the accumulation of oxalate, rather than its conversion to α-ketoglutarate (AKG). Therefore, AAT1-mutant serves to lower the pH (pH 3-4) so as to increase the production of the pH-sensitive metabolite scleroglucan to 21.03 g L-1 with a productivity of up to 0.25 g L-1·h-1. CONCLUSIONS: We established a platform for gene editing that could rapidly generate and select mutants to provide a new beneficial strain of S. rolfsii as a scleroglucan hyper-producer, which is expected to reduce the cost of controlling the optimum pH condition in the fermentation industry.
Authors: Larissa Pereira Brumano; Felipe Antonio Fernandes Antunes; Sara Galeno Souto; Júlio Cesar Dos Santos; Joachim Venus; Roland Schneider; Silvio Silvério da Silva Journal: Bioresour Technol Date: 2017-06-19 Impact factor: 9.642
Authors: Boris V Skryabin; Delf-Magnus Kummerfeld; Leonid Gubar; Birte Seeger; Helena Kaiser; Anja Stegemann; Johannes Roth; Sven G Meuth; Hermann Pavenstädt; Joanna Sherwood; Thomas Pap; Roland Wedlich-Söldner; Cord Sunderkötter; Yuri B Schwartz; Juergen Brosius; Timofey S Rozhdestvensky Journal: Sci Adv Date: 2020-02-12 Impact factor: 14.136