Enhanced epsilon-poly-L-lysine production from Streptomyces ahygroscopicus by a combination of cell immobilization and in situ adsorption.
Epsilon-poly-L-lysine (epsilon-PL), produced by Streptomyces or Kitasatospora strains, is a homo-poly-amino acid of Llysine, which is used as a safe food preservative. The present study investigates the combined use of cell immobilization and in situ adsorption (ISA) to produce epsilon-PL in shaken flasks. Loofah sponge-immobilized Streptomyces ahygroscopicus GIM8 produced slightly more epsilon-PL than those immobilized on synthetic sponge, and sugarcane bagasse. Moreover, loofah sponge supported the maximum biomass. Hence, loofah sponge was chosen for cell immobilization. Meanwhile, the ion-exchange resin D152 was employed for ISA. The loofah sponge-immobilized cells produced 0.54 +/- 0.1 g/l epsilon-PL, which significantly increased to 3.64 +/- 0.32 g/l after combining with ISA through the addition of resin bags. The free cells with ISA using the dispersed resin yielded 2.73 +/- 0.26 g/l of epsilon-PL, an increase from 0.82 +/- 0.08 g/l. These data illustrate that the proposed combination method improved production most significantly compared with either immobilization or ISA only. Moreover, the immobilized cells could be repeatedly used and an epsilon-PL total amount of 8.05 +/- 0.84 g/l was obtained. The proposed combination method offers promising perspectives for epsilon-PL production.
School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China.
Shengrong
S
Liu
Qingping
Q
Wu
Jumei
J
Zhang
Shuping
S
Mo
Xiaojuan
X
Yang
Chun
C
Xiao
D000327:Adsorption; D018533:Biomass; D018914:Cells, Immobilized / Q000166:cytology / Q000378:metabolism*; D017743:Equipment Reuse; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D029776:Luffa; D011107:Polylysine / Q000032:analysis / Q000096:biosynthesis*; D013302:Streptomyces / Q000166:cytology / Q000378:metabolism*
D011107:Polylysine; D005947:Glucose