Transduction of Lactose Metabolism in Streptococcus lactis C2

Abstract

Ultraviolet (UV)-induced phage lysates, from lactose-positive (lac+) Streptococcus lactis C2, transduced lactose fermenting ability to lac-recipient cells of this organism. Although the phage titer could not be determined due to the absence of an appropriate indicator strain, the number of transductants was proportional to the amount of phage lysate added. Treatment of the lysate with deoxyribonuclease had no effect on this conversion, indicating the observed genetic change was not mediated by free deoxyribonucleic acid. When the lac+ transductants were isolated and exposed to UV irradiation, lysates with higher transducing ability were obtained. The transducing ability of this lysate was about 100-fold higher than that observed in the original lysates. The lac+ transductants were unstable since lacsegregants occurred at high frequency. The phage lysate from S. lactis C2 also transduced maltose and mannose metabolism to the respective negative recipient cells. The results demonstrate the transduction of carbohydrate markers by a streptococcal phage and establish a genetic transfer system in group N streptococci.on August 1, 2020 by guest

In vivo genetic systems in lactic acid bacteria

“…Transduction in lactococci was first described using a virulent bacteriophage and chromosomal genetic markers for tryptophan biosynthesis and streptomycin resistance [2,3]. Most, however, has been achieved with temperate bacteriophages and in addition to relatively well characterized systems in Lactococcus lactis strains C2 and 712, transduction into a number of other strains was observed using temperate bacteriophage lysates from strain C2 [4]. Also bacteriophages induced from L lactis ssp.…”

Cheese starters

“…Other possible consequences of lysogeny are difficult to evaluate. Since strains cured of prophages have not yet been isolated (383), there is no way of assessing the effects of prophage loss. As lactic streptococci grow as diplococci or in chains, cured cells may be exceedingly difficult to isolate.…”

Genetics of proteinases of lactic acid bacteria

“…This, in turn, initiated an intensive study of plasmids of lactic streptococci. Subsequently, when it was demonstrated that natural gene transfer systems, such as transduction and conjugation, operate in these organisms [8][9][10], evidence was provided for the plasmid-linkage of a number of additional traits important for dairying, such as proteinase production, resistance to nisin and bacteriophage, production of bacteriocin and diplococcin, and restriction / modification systems [1,2,11,12].…”