Production of epsilon-poly-L-lysine by newly isolated Kitasatospora sp. PL6-3.
A novel epsilon-poly-L-lysine (epsilon-PL)-producing strain PL6-3 was isolated from soil, and was identified as a strain of Kitasatospora sp. This is the first detailed report of production of epsilon-PL by a strain in the genera of Kitasatospora. By controlling the culture pH at 4.0, the yield of epsilon-PL from PL6-3 reached 13.9 g/L after 120 h of cultivation in fed-batch fermentation. The morphological characteristics of Kitasatospora sp. PL6-3 in culture broth were different from those reported from strains of Streptomycetaceae, as no mycelium pellets were observed during the course of fermentation of PL6-3, which was beneficial to the assimilation of nutrition and secretion of the products. Furthermore, the molecular mass of the purified epsilon-PL from PL6-3 was determined to be 5.01 kDa by SDS-PAGE and 5.05 kDa by gel permeation chromatography, indicating that the epsilon-PL produced by this strain might be composed of 40 lysine residues. Usually, epsilon-PL with more lysine residues showed higher antimicrobial activity; however, it was difficult to obtain epsilon-PL with more than 36 lysine residues in this study. As a result, epsilon-PL from Kitasatospora sp. PL6-3, which contains more lysine residues than that from other strains, is more promising in the field of food preservatives.
Ouyang
Jia
J
College of Life Science and Pharmacy, Nanjing University of Technology, Nanjing, PR China.
Xu
Hong
H
Li
Sha
S
Zhu
Hongyang
H
Chen
Weiwei
W
Zhou
Jun
J
Wu
Qun
Q
Xu
Lin
L
Ouyang
Pingkai
P
D011107:Polylysine / Q000302:isolation & purification* / Q000378:metabolism*; D012988:Soil Microbiology; D013045:Species Specificity; D013306:Streptomycetaceae / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism*
D011107:Polylysine