title: Production of nattokinase by high cell density fed-batch culture of Bacillus subtilis.
abstract: Bacillus subtilis was cultivated to high cell density for nattokinase production by pH-stat fed-batch culture. A concentrated mixture solution of glucose and peptone was automatically added by acid-supplying pump when culture pH rose above high limit. Effect of the ratio of glucose to peptone in feeding solution was investigated on cell growth and nattokinase production by changing the ratio from 0.2 to 5 g glucose/g peptone. The highest cell concentration was 77 g/L when the ratio was 0.2 g glucose/g peptone. Cell concentration decreased with increasing the ratio of glucose to peptone in feeding solution, while the optimum condition existed for nattokinase production. The highest nattokinase activity was 14,500 unit/mL at a ratio of 0.33 g glucose/g peptone, which was 4.3 times higher than that in batch culture.
authors.affiliation: Department of Chemical Engineering, Chungbuk National University, Cheongju, 361-763, Chungbuk, Korea.
authors.forename: Eun-Yeong
authors.initials: EY
authors.lastname: Kwon
authors.forename: Kyung Mi
authors.initials: KM
authors.lastname: Kim
authors.forename: Mi Kyoung
authors.initials: MK
authors.lastname: Kim
authors.forename: In Young
authors.initials: IY
authors.lastname: Lee
authors.forename: Beom Soo
authors.initials: BS
authors.lastname: Kim
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000254:growth & development*; D061249:Batch Cell Culture Techniques / Q000379:methods*; D002452:Cell Count; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010461:Peptones / Q000737:chemistry / Q000378:metabolism; D013381:Subtilisins / Q000096:biosynthesis* / Q000737:chemistry*
chemical_list: D003470:Culture Media; D010461:Peptones; D013381:Subtilisins; C053771:nattokinase; D005947:Glucose