title: Feeding strategy design for recombinant human growth hormone production by Bacillus subtilis.
abstract: Defined and semi-defined medium-based feeding strategies were developed to enhance recombinant human growth hormone (rhGH) production by Bacillus subtilis BGSC-1A178 (scoC (-)) strain carrying pMK4::pre(subC)::hGH. Defined medium-based feeding strategies were designed by exponential feeding of glucose and (NH4)2HPO4 at two pre-determined specific growth rates, µ 0 = 0.10 and 0.17 h(-1). Semi-defined medium-based feeding strategies were designed by exponential feeding of substrate solution consisting of glucose, (NH4)2HPO4, peptone, and trace salt solution (PTM1) at three pre-determined specific growth rates, µ 0 = 0.10, 0.17, and 0.25 h(-1). At all the strategies applied, transition cultivation time from batch to fed-batch operation was t T = 4 h. The highest rhGH concentration was obtained as C rhGH = 0.5 g L(-1) with semi-defined medium-based feeding strategy designed with µ 0 = 0.25 h(-1) using feed substrate stock solution containing 200 g L(-1) glucose, 117 g L(-1) (NH4)2HPO4, 100 g L(-1) peptone, and 5 mL L(-1) PTM1 at t = 22 h when the cell concentration reached to C X = 8.29 g L(-1). The overall product and cell yields on glucose were obtained as [Formula: see text] = 7.21 mg g(-1) and [Formula: see text] = 0.12 g g(-1), respectively. The results indicate the requirement of designing continuous feed stream in fed-batch production to enhance rhGH production by r-B. subtilis.
authors.affiliation: Industrial Biotechnology and Metabolic Engineering Laboratory, Department of Chemical Engineering, Middle East Technical University, 06800, Ankara, Turkey.
authors.forename: Burcu
authors.initials: B
authors.lastname: Şahin
authors.affiliation: Department of Biotechnology, Graduate School of Natural and Applied Sciences, Middle East Technical University, 06800, Ankara, Turkey.
authors.forename: Sibel
authors.initials: S
authors.lastname: Öztürk
authors.affiliation: Industrial Biotechnology and Metabolic Engineering Laboratory, Department of Chemical Engineering, Middle East Technical University, 06800, Ankara, Turkey. pcalik@metu.edu.tr.|Department of Biotechnology, Graduate School of Natural and Applied Sciences, Middle East Technical University, 06800, Ankara, Turkey. pcalik@metu.edu.tr.
authors.forename: Pınar
authors.initials: P
authors.lastname: Çalık
authors.affiliation: Biochemical Reaction Engineering Laboratory, Chemical Engineering Department, Ankara University, Tandoğan, 06100, Ankara, Turkey.
authors.forename: Tunçer H
authors.initials: TH
authors.lastname: Özdamar
mesh_terms: D001412:Bacillus subtilis / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D061249:Batch Cell Culture Techniques / Q000379:methods*; D019149:Bioreactors / Q000382:microbiology*; D003470:Culture Media / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D019382:Human Growth Hormone / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D003470:Culture Media; D019382:Human Growth Hormone; D005947:Glucose
keywords: Bacillus subtilis; Exponential feeding; Fed-batch operation; Glucose; Human growth hormone; Semi-defined medium