Production improvement of an antioxidant in cariogenic Streptococcus mutans UA140.
J Appl Microbiol
; 135(2)2024 Feb 01.
Article
in En
| MEDLINE
| ID: mdl-38268415
ABSTRACT
AIMS:
This study aimed to improve the production of mutantioxidin, an antioxidant encoded by a biosynthetic gene cluster (mao) in Streptococcus mutans UA140, through a series of optimization methods. METHOD ANDRESULTS:
Through the construction of mao knockout strain S. mutans UA140∆mao, we identified mutantioxidin as the antioxidant encoded by mao and verified its antioxidant activity through a reactive oxygen species (ROS) tolerance assay. By optimizing the culture medium and fermentation time, 72 h of fermentation in chemically defined medium (CDM) medium was determined as the optimal fermentation conditions. Based on two promoters commonly used in Streptococcus (ldhp and xylS1p), eight promoter refactoring strains were constructed, nevertheless all showed impaired antioxidant production. In-frame deletion and complementation experiments demonstrated the positive regulatory role of mao1 and mao2, on mao. Afterward, the mao1 and mao2, overexpression strain S. mutans UA140/pDL278 mao1mao2, were constructed, in which the production of mutantioxidin was improved significantly.CONCLUSIONS:
In this study, through a combination of varied strategies such as optimization of fermentation conditions and overexpression of regulatory genes, production of mutantioxidin was increased by 10.5 times ultimately.Key words
Full text:
1
Database:
MEDLINE
Main subject:
Streptococcus mutans
/
Dental Caries
Limits:
Humans
Language:
En
Journal:
J Appl Microbiol
Journal subject:
MICROBIOLOGIA
Year:
2024
Type:
Article
Affiliation country: