title: Growth kinetics of Lactococcus lactis ssp diacetylactis harboring different plasmid content.
abstract: The effect of plasmid content on growth of Lactococcus lactis ssp. diacetylactis harboring different plasmids and on plasmid stability was studied. Strain DRC-2C is a plasmid Lac(+)- and Prt(+)-free strain. Strain DRC-2 utilizes lactose as carbohydrate and has proteinase activity. The plasmid-free strain DRC-2C exhibited none of these features. Plasmid-encoded properties were clearly identified. Results showed that plasmid content decreased bacterial growth in terms of the specific growth rate determined. Slightly lower specific growth rate and lactic acid production were observed in the strain of higher plasmid content owing to the plasmid presence, causing metabolic burden to the host cell. The plasmid profile results showed that the number of bands in the two strains before and after fermentation were the same. This indicated that the plasmids were stably maintained and unchanged during the fermentation.
authors.affiliation: Department of Environmental Science and Engineering, Kwangju Institute of Science and Engineering, Kwangju, South Korea. klee@wistar.upenn.edu
authors.forename: Kibeom
authors.initials: K
authors.lastname: Lee
authors.forename: Seung-Hyeon
authors.initials: SH
authors.lastname: Moon
mesh_terms: D003470:Culture Media; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism; D013294:Lactococcus lactis / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D010957:Plasmids
chemical_list: D003470:Culture Media; D019344:Lactic Acid; D005947:Glucose