Chemical analysis of poly-γ-glutamic acid produced by plasmid-free Bacillus subtilis (natto): Evidence that plasmids are not involved in poly-γ-glutamic acid production

The Journal of General and Applied Microbiology

Kumiko Koguchi¹  Yoshifumi Itoh³  Toshirou Nagai² 

[1] Institute for Food Technology of Tochigi Prefecture;Genetic Resource Center, National Institute of Agrobiological Resources, MAFF;Division of Applied Microbiology, National Food Research Institute, Ministry of Agriculture, Forestry and Fisheries

关键词: acridine orange;    Bacillus subtilis (natto);    D-glutamic acid;    nalidixic acid;    plasmid curing;    poly-γ-glutamic acid;   

DOI  :  10.2323/jgam.43.139

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

It has been postulated that the psf gene on a small plasmid, pUH1 (5.8kb), regulates positively the synthesis of capsular poly-γ-glutamic acid (γPGA) in Bacillus subtilis (natto) Asahikawa. We found that this strain harbored a second plasmid, named pNAGL1 (ca. 50kb), in addition to pUH1. The growth conditions that cure pUH1 or pNAGL1 were established. The plasmid-free NAF4 strain derived from B. subtilis (natto) Asahikawa was found to produce γPGA which was the same as the parent strain in terms of quantity and chemical properties having the same molecular mass and content of D-glutamic acid. Furthermore, as in the case of the parent cells, the D-glutamic acid in γPGA, which is known to increase up to ca. 80% of the total glutamic acid as Mn2+ ion concentration increases in growth medium, was found to make up 80% of the total glutamic acid of the γPGA produced by NAF4 cells grown in the presence of 0.1mM MnCl2. Thus, these results led us to conclude that the plasmids do not encode any gene important for γPGA production.

【 授权许可】

Unknown