A kinetic study on the plasmid stability of three Lactococcus lactis strains

Avsaroglu, M. Dilek; Buzrul, Sencer; Şanlibaba, Pınar; Alpas, Hami; Akçelik, Mustafa

doi:10.1007/s10295-007-0249-x

Cited by 3 publications

(2 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on the growth profile, the cells took about ~60 h to reach 100 generations. Recently, both incubation time and temperature were reported to have substantial effects on plasmid loss [49]. The researchers found that the incubation time had the most extreme effect on the stability of low molecular weight plasmids in Lactococcus cells where plasmid loss was observed after 72 h of cultivation while temperatures in the range of 15-40°C also stimulated plasmid instability.…”

Section: Discussionmentioning

confidence: 99%

Lactococcus lactis M4, a potential host for the expression of heterologous proteins

et al. 2011

View full text Add to dashboard Cite

BackgroundMany plasmid-harbouring strains of Lactococcus lactis have been isolated from milk and other sources. Plasmids of Lactococcus have been shown to harbour antibiotic resistance genes and those that express some important proteins. The generally regarded as safe (GRAS) status of L. lactis also makes it an attractive host for the production of proteins that are beneficial in numerous applications such as the production of biopharmaceutical and nutraceutical. In the present work, strains of L. lactis were isolated from cow's milk, plasmids were isolated and characterised and one of the strains was identified as a potential new lactococcal host for the expression of heterologous proteins.ResultsSeveral bacterial strains were isolated from cow's milk and eight of those were identified as Lactococcus lactis by 16S rRNA sequence analysis. Antibiotic susceptibility tests that were carried out showed that 50% of the isolates had almost identical antibiotic resistance patterns compared to the control strains MG1363 and ATCC 11454. Plasmid profiling results indicated the lack of low molecular weight plasmids for strain M4. Competent L. lactis M4 and MG1363 were prepared and electrotransformed with several lactococcal plasmids such as pMG36e, pAR1411, pAJ01 and pMG36e-GFP. Plasmid isolation and RE analyses showed the presence of these plasmids in both M4 and the control strain after several generations, indicating the ability of M4 to maintain heterologous plasmids. SDS-PAGE and Western blot analyses also confirmed the presence of GFP, demonstrating the potential of heterologous protein expression in M4.ConclusionsBased on the 16S rRNA gene molecular analysis, eight Gram-positive cocci milk isolates were identified as L. lactis subsp. lactis. One of the strains, L. lactis M4 was able to maintain transformed low molecular weight plasmid vectors and expressed the GFP gene. This strain has the potential to be developed into a new lactococcal host for the expression of heterologous proteins.

show abstract

Section: Discussionmentioning

confidence: 99%

Lactococcus lactis M4, a potential host for the expression of heterologous proteins

et al. 2011

View full text Add to dashboard Cite

show abstract

“…All assays were performed in triplicates and the results are the means of three independent experiments. The plasmid genetics stability of the recombinant pHT43-SjLys/WB600 for continuous passage culture with chloramphenicol was determined through the method of Avsaroglu et al [2] and Leen et al [10]. For the strain, stability experiments were performed in triplicate too.…”

Section: The Growth Curve and Genetic Stability Of The Pht43-sjlys/ Wmentioning

confidence: 99%

Expression of Stichopus japonicus Lysozyme Gene in Bacillus subtilis WB600

Liu

Liao

Sun

et al. 2015

Lecture Notes in Electrical Engineering

View full text Add to dashboard Cite

In this study, a genetic engineering bacteria Bacillus subtilis pHT43-SjLys/ WB600 was successfully constructed for the expression of the lysozyme gene from sea cucumber (Stichopus japonicus) by the method of recombinant DNA technique. The growth trend of engineering bacteria was consistent with the wild-type strain WB600, and the results demonstrated that insertion of foreign gene did not affect its physiological and biochemical metabolism. In the absence of selection pressure, the analysis of the stability revealed that there was no gene rearrangement and lost of the recombinant plasmid in the bacteria which showed that it has high genetic stability. The SDS-PAGE results demonstrated that pHT43-SjLys/WB600 successfully expressed soluble SjLys protein after incubated for 48 h induced by ITPG. The heterologous expression protein of pHT43-SjLys/WB600 displayed remarkable inhibitive effect on the growth of the Vibrio parahaemolyticus. To our knowledge, this is the first report about the SjLys gene authentic heterologous expression in B. subtilis. It should provide a robust secretion expression system for genetic engineering of B. subtilis and was thus proposed a potentially new way for producing recombinant SjLys protein.

show abstract

Determination of metabolic plasmids and their effects on the growth of Lactococcus lactis ssp. lactis MN24

Akkoç

Şimşek

Akçelik

2009

Int J of Dairy Tech

View full text Add to dashboard Cite

Mutational analyses revealed the 21.5 kb plasmid-encoded lactose fermentation and proteolytic activity properties in Lactococcus lactis ssp. lactis MN24. Reductions in maximum specific growth rate and population density of the 21.5 kb plasmid-cured mutant of MN24 confirmed the data obtained by mutation tests. Plasmid curing, polymerase chain reaction and DNA sequence analyses data showed that the lacticin 481 operon was located on 22.4 kb plasmid. The phage resistance system in strain MN24 was identified as an adsorption inhibition type and chromosomally encoded via phage-host interaction tests and mutation analyses.

show abstract

A kinetic study on the plasmid stability of three Lactococcus lactis strains

Cited by 3 publications

References 33 publications

Lactococcus lactis M4, a potential host for the expression of heterologous proteins

Lactococcus lactis M4, a potential host for the expression of heterologous proteins

Expression of Stichopus japonicus Lysozyme Gene in Bacillus subtilis WB600

Determination of metabolic plasmids and their effects on the growth of Lactococcus lactis ssp. lactis MN24

Contact Info

Product

Resources

About