Sixty-four lactococcal strains isolated from natural whey starters were screened for the presence of the nisin structural gene by polymerase chain reaction. Seven of them showed a specific PCR product of 320 bp; only two produced antagonistic activity and were resistant to nisin. Southern blots of SmaI-digested DNA from PCR-positive strains hybridized with a nisA probe displayed a location of the gene on different SmaI fragments. Among PCR-positive strains, nisin producers showed specific transcript after reverse transcriptase-PCR, as well as some non-nisin-producing strains. The RT-PCR product could not be shown in one non-nisin-producing PCR-positive strain
Presence of non-functional nisin genes in Lactococcus lactis subsp. lactis isolated from natural starters / Moschetti, G.; Villani, Francesco; Blaiotta, Giuseppe; Baldinelli, A.; Coppola, Salvatore. - In: FEMS MICROBIOLOGY LETTERS. - ISSN 0378-1097. - STAMPA. - 145:(1996), pp. 27-32.
Presence of non-functional nisin genes in Lactococcus lactis subsp. lactis isolated from natural starters.
VILLANI, FRANCESCO;BLAIOTTA, GIUSEPPE;COPPOLA, SALVATORE
1996
Abstract
Sixty-four lactococcal strains isolated from natural whey starters were screened for the presence of the nisin structural gene by polymerase chain reaction. Seven of them showed a specific PCR product of 320 bp; only two produced antagonistic activity and were resistant to nisin. Southern blots of SmaI-digested DNA from PCR-positive strains hybridized with a nisA probe displayed a location of the gene on different SmaI fragments. Among PCR-positive strains, nisin producers showed specific transcript after reverse transcriptase-PCR, as well as some non-nisin-producing strains. The RT-PCR product could not be shown in one non-nisin-producing PCR-positive strainI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
