title: Culture medium containing glucose and glycerol as a mixed carbon source improves ε-poly-L-lysine production by Streptomyces sp. M-Z18.
abstract: To improve the efficiency of ε-poly-L-lysine (ε-PL) production by Streptomyces sp. M-Z18, batch and fed-batch fermentations with glucose and glycerol (co-fermentations) were performed. The batch fermentations showed that the initial ratio of glucose to glycerol plays an important role in glucose/glycerol co-fermentation. The optimal glucose/glycerol weight ratio was 30/30; this resulted in a maximum ε-PL productivity of 5.26 g/L/d. Glucose and glycerol were consumed synergistically during the co-fermentation process, and the length of time during which the substrate was exhausted was significantly shortened compared with the single carbon source fermentation. Under optimized conditions, fed-batch fermentations with glucose and glycerol as a mixed carbon source achieved maximum ε-PL concentration and productivity values of 35.14 g/L and 4.85 g/L/d, respectively. These values were respectively 1.43- and 1.39-, and 1.17- and 1.16-folds higher than those obtained from fermentations with glucose and glycerol as single carbon sources. The present study is the first to suggest that glucose/glycerol co-fermentation may be an efficient strategy for ε-PL production by Streptomyces sp. M-Z18.
authors: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, China.
authors: Xu-Sheng
authors: XS
authors: Chen
authors: Xi-Dong
authors: XD
authors: Ren
authors: Nan
authors: N
authors: Dong
authors: Shu
authors: S
authors: Li
authors: Feng
authors: F
authors: Li
authors: Fu-Lin
authors: FL
authors: Zhao
authors: Lei
authors: L
authors: Tang
authors: Jian-Hua
authors: JH
authors: Zhang
authors: Zhong-Gui
authors: ZG
authors: Mao
mesh_terms: D003470:Culture Media / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D005285:Fermentation / Q000187:drug effects / Q000502:physiology; D005947:Glucose / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D005990:Glycerol / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D011107:Polylysine / Q000096:biosynthesis*; D012997:Solvents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D013302:Streptomyces / Q000254:growth & development* / Q000378:metabolism; D013549:Sweetening Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology
chemical_list: D003470:Culture Media; D012997:Solvents; D013549:Sweetening Agents; D011107:Polylysine; D005947:Glucose; D005990:Glycerol