Showing papers on "Lactococcus lactis published in 1986"
TL;DR: The results indicate that the Suc+ Nip+ Nisr phenotype is plasmid encoded, but no physical evidence linking this phenotype to a distinct plasmids was obtained.
Abstract: We attempted to identify the genetic loci for sucrose-fermenting ability (Suc+), nisin-producing ability (Nip+), and nisin resistance (Nisr) in certain strains of Streptococcus lactis. To obtain genetic evidence linking the Suc+ Nip+ Nisr phenotype to a distinct plasmid, both conjugal transfer and transformation were attempted. A conjugation procedure modified to protect the recipients against the inhibitory action of nisin allowed the conjugal transfer of the Suc+ Nip+ Nisr marker from three Suc+ Nip+ Nisr donors to various recipients. The frequency of transfer ranged from 1.7 x 10(-4) to 5.6 x 10(-8) per input donor, depending on the mating pair. However, no additional plasmid DNA was apparent in these transconjugants. Transformation of S. lactis LM0230 to the Suc+ Nip+ Nisr phenotype by using the plasmid pool of S. lactis ATCC 11454 was not achieved, even though other plasmids present in the pool were successfully transferred. However, two results imply the involvement of plasmid DNA in coding for the Suc+ Nip+ Nisr phenotype. The Suc+ Nip+ Nisr marker was capable of conjugal transfer to a recipient deficient in host-mediated homologous recombination (Rec-), and the Suc+ Nip+ Nisr marker exhibited bilateral plasmid incompatibility with a number of lactose plasmids found in S. lactis. Although our results indicate that the Suc+ Nip+ Nisr phenotype is plasmid encoded, no physical evidence linking this phenotype to a distinct plasmid was obtained.
100 citations
TL;DR: Chang et al. as mentioned in this paper used plasmid pIL204 (5.5 kilobases) to transform Streptococcus lactis IL1403 protoplasts into Erythromycin resistance with an average efficiency of 5 X 10 6 transformants per microgram of supercoiled DNA.
Abstract: Streptococcus lactis IL1403 protoplasts were transformed by plasmid pIL204 (5.5 kilobases), which conferred erythromycin resistance with an average efficiency of 5 X 10(6) transformants per microgram of supercoiled DNA. The procedure used and transformation efficiencies obtained were close to those described for Bacillus subtilis (G. Chang and S. N. Cohen, Mol. Gen. Genet. 168:111-115, 1979).
63 citations
TL;DR: A method to obtain gene transfer in lactic acid bacteria is described and plasmid pAMβ 1 and trehalose-fermenting ability are transferred into L. reuteri.
Abstract: A method to obtain gene transfer in lactic acid bacteria is described. When Streptococcus lactis SH4174 and Lactobacillus reuteri DSM20016 protoplasts undergo fusion by exposure to polyethylene glycol, plasmid pAMβ 1 and trehalose-fermenting ability are transferred into L. reuteri .
38 citations
TL;DR: Plasmid pIL7 (33 kilobases) from Streptococcus lactis enhances UV resistance and prophage stability and was subsequently transferred to three other S. lactis strains by transformation or protoplast fusion.
Abstract: Plasmid pIL7 (33 kilobases) from Streptococcus lactis enhances UV resistance and prophage stability. A 5.4-kilobase pIL7 fragment carrying genes coding for both characters was cloned into S. lactis, using plasmid pHV1301 as the cloning vector. The recombinant plasmid was subsequently transferred to three other S. lactis strains by transformation or protoplast fusion. Cloned genes were expressed in all tested strains.
24 citations
TL;DR: A 4.4 kb Eco RI DNA fragment of the Streptococcus lactis H1 plasmid pDI1 was cloned into the Escherichia coli plasmids pACYC 184 and expressed d-tagatose 1,6-bisphosphate aldolase activity in E. coli.
Abstract: A 4.4 kb Eco RI DNA fragment of the Streptococcus lactis H1 plasmid pDI1 was cloned into the Escherichia coli plasmid pACYC 184. The recombinant plasmid expressed d-tagatose 1,6-bisphosphate aldolase activity in E. coli . Enzyme activity was at the same level as in the original S. lactis host but was not repressed by glucose.
14 citations
Journal Article•
TL;DR: In simultaneous inoculation of the medium for nisin biosynthesis with Streptococcus lactis (strain MSU) and yeasts such as Rhodotorula colostri, Zigowilliopsis californicus, Hansenuia anomala, Saccharomyces ludvigii, Kluyveromyces lactis and Endomyces magnusi the quantitative ratio of the inoculates in the mixed cultures is not in principle important for the antibiotic synthesis by the
Abstract: In simultaneous inoculation of the medium for nisin biosynthesis with Streptococcus lactis (strain MSU) and yeasts such as Rhodotorula colostri, Zigowilliopsis californicus, Hansenuia anomala, Saccharomyces ludvigii, Kluyveromyces lactis and Endomyces magnusi the quantitative ratio of the inoculates in the mixed cultures is not in principle important for the antibiotic synthesis by the Streptococcus. When 6-, 12-, 18- and 24-hour inoculates of the yeasts were added simultaneously to 3-, 6-, 9-, 12- and 18-hour cultures of S. lactis biosynthesis of nisin was at the control level. The fractional composition of the fermentation broth of the above yeast species had no significant effect on biosynthesis of nisin.
1 citations