[Isolation and characterization of a new epsilon-poly-L-lysine-producing strain TUST-2].
OBJECTIVE
Epsilon-Poly-L-Lysine (epsilon-PL) is a natural amino acid homopolymer. The study aimed at isolating new epsilon-PL-producing strains.


METHODS
epsilon-PL-producing strains were screened from the soil by using a new isolation approach which had three steps, (1) enrichment culturing epsilon-PL toleranting strains; (2) screening by improved Nishikawa's method; (3) selection of strains with higher epsilon-PL tolerant ability.


RESULTS
A new epsilon-PL-producing strain TUST-2 was isolated from the soil collected from Hainan province, China. Chemotaxonomic and morphological characteristics of the isolate were typical of strain of the genus Streptomyces. The strain TUST-2 was found to belong to Streptomyces diastatochromogenes by comparative 16S rRNA gene sequence analysis. The purified fermentation product of the strain TUST-2 was confirmed as epsilon-PL by characteristic analysis, hydrolysate analysis, infrared spectrum, 1H NMR Spectrum, 13C NMR Spectrum, and MALDI-TOF-MS.


CONCLUSIONS
On the basis of 16S rRNA gene sequence analysis and its morphological and physiological characteristics, epsilon-PL-producing strain TUST-2 is a new isolate of Streptomyces diastatochromogenes, named as Streptomyces diastatochromogenes TUST-2.
Jia
Shiru
S
School of Biotechnology, Tianjin University of Science & Technology, Key Laboratory of Industrial Microbiology of Ministry of Education, Tianjin 300457, China. jiashiru@tust.edu.cn
Xu
Chunying
C
Tan
Zhilei
Z
Cao
Weifeng
W
Ou
Hongyu
H
He
Xinyi
X
Deng
Zixin
Z
D002681:China; D008969:Molecular Sequence Data; D010802:Phylogeny; D011107:Polylysine / Q000378:metabolism*; D012988:Soil Microbiology; D013302:Streptomyces / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*
D011107:Polylysine