Pediocin production by recombinant lactic acid bacteria.
Production of the anti-listerial bacteriocin, pediocin, by lactic acid bacteria (LAB) transformed with the cloning vector pPC418 (Ped+, 9.1 kb) was influenced by composition of media and incubation temperature. Maximum pediocin production, tested against Listeria innocua, by electrotransformants of Lactococcus lactis ssp. lactis was measured in tryptone/lactose/yeast extract medium after 24 h growth at 30 degrees C, while incubation at 40 degrees C was optimum for Ped+ transformants of Streptococcus thermophilus and Enterococcus faecalis. The amount of pediocin produced by S. thermophilus in skim milk and cheese whey supplemented with 0.5% yeast extract was estimated as 51,000 units ml(-1) and 25,000 units ml(-1), respectively. Pediocin production remained essentially unchanged in reconstituted skim milk or whey media diluted up to 10-fold. The results demonstrate the capacity of recombinant strains of LAB to produce pediocin in a variety of growth media including skim milk and inexpensive cheese whey-based media, requiring minimum nutritional supplementation.
Somkuti
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Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA. gsomkuti@arserrc.gov
Steinberg
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DH
D000818:Animals; D001430:Bacteriocins / Q000096:biosynthesis*; D002611:Cheese; D003470:Culture Media / Q000378:metabolism; D018274:Electroporation / Q000379:methods; D013293:Enterococcus faecalis / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D013294:Lactococcus lactis / Q000235:genetics / Q000378:metabolism*; D007785:Lactose / Q000378:metabolism; D008892:Milk / Q000378:metabolism; D000070017:Pediocins; D010376:Pediococcus / Q000235:genetics / Q000378:metabolism*; D010461:Peptones / Q000378:metabolism; D011995:Recombination, Genetic; D013045:Species Specificity; D013291:Streptococcus / Q000235:genetics / Q000378:metabolism*; D013696:Temperature
D001430:Bacteriocins; D003470:Culture Media; D000070017:Pediocins; D010461:Peptones; C074288:pediocin PA-1; C001830:tryptones; D007785:Lactose