caa a22 4500 606212205 CHVBK 20210128101041.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s10295-015-1640-7 doi (NATIONALLICENCE)springer-10.1007/s10295-015-1640-7 Influence of nitrogen source and pH value on undesired poly(γ-glutamic acid) formation of a protease producing Bacillus licheniformis strain [Elektronische Daten] [Lena Meissner, Kira Kauffmann, Timo Wengeler, Hitoshi Mitsunaga, Eiichiro Fukusaki, Jochen Büchs] Bacillus spp. are used for the production of industrial enzymes but are also known to be capable of producing biopolymers such as poly(γ-glutamic acid). Biopolymers increase the viscosity of the fermentation broth, thereby impairing mixing, gas/liquid mass and heat transfer in any bioreactor system. Undesired biopolymer formation has a significant impact on the fermentation and downstream processing performance. This study shows how undesirable poly(γ-glutamic acid) formation of an industrial protease producing Bacillus licheniformis strain was prevented by switching the nitrogen source from ammonium to nitrate. The viscosity was reduced from 32 to 2.5mPas. A constant or changing pH value did not influence the poly(γ-glutamic acid) production. Protease production was not affected: protease activities of 38 and 46UmL−1 were obtained for ammonium and nitrate, respectively. With the presented results, protease production with industrial Bacillus strains is now possible without the negative impact on fermentation and downstream processing by undesired poly(γ-glutamic acid) formation. Society for Industrial Microbiology and Biotechnology, 2015 Protease and amylase production nationallicence Bacillus licheniformis nationallicence Poly(γ-glutamic acid) nationallicence Ammonium nationallicence Nitrate nationallicence γ-PGA : Poly(γ-glutamic acid) nationallicence DOT : Dissolved oxygen tension (%) nationallicence OD600 : Optical density at 600nm (−) nationallicence OTR : Oxygen transfer rate (mmolL−1h−1) nationallicence Meissner Lena AVT. Biochemical Engineering, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany aut Kauffmann Kira AVT. Biochemical Engineering, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany aut Wengeler Timo AVT. Biochemical Engineering, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany aut Mitsunaga Hitoshi Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, 565-0871, Suita, Osaka, Japan aut Fukusaki Eiichiro Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, 565-0871, Suita, Osaka, Japan aut Büchs Jochen AVT. Biochemical Engineering, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany aut Journal of Industrial Microbiology & Biotechnology Springer Berlin Heidelberg 42/9(2015-09-01), 1203-1215 1367-5435 42:9<1203 2015 42 10295 https://doi.org/10.1007/s10295-015-1640-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10295-015-1640-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Meissner Lena AVT. Biochemical Engineering, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany aut NATIONALLICENCE 700 1- Kauffmann Kira AVT. Biochemical Engineering, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany aut NATIONALLICENCE 700 1- Wengeler Timo AVT. Biochemical Engineering, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany aut NATIONALLICENCE 700 1- Mitsunaga Hitoshi Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, 565-0871, Suita, Osaka, Japan aut NATIONALLICENCE 700 1- Fukusaki Eiichiro Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, 565-0871, Suita, Osaka, Japan aut NATIONALLICENCE 700 1- Büchs Jochen AVT. Biochemical Engineering, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany aut NATIONALLICENCE 773 0- Journal of Industrial Microbiology & Biotechnology Springer Berlin Heidelberg 42/9(2015-09-01), 1203-1215 1367-5435 42:9<1203 2015 42 10295