title: Optimization of bacteriocin production by Lactobacillus plantarum AA135.
abstract: Growth of Lactobacillus plantarum AA135 in MRS broth at 30 degrees C yielded maximal plantaricin AA13 activity of 10000 AU/ml at pH 3.8 after 16 hours. Maximal activity (10000 AU/ml) of plantaricin AA13 was recorded in MRS broth at initial pH of 5 or 5.5. Optimal production (10000 AU/ml) was recorded in the presence of tryptone (20 g/l), a combination of tryptone plus meat extract (1:0.6) or tryptone with yeast extract (1:0.6) as sole nitrogen source. Growth of Lactobacillus plantarum AA135 in the presence of 20 g/l glucose yielded bacteriocin activity of 10000 AU/ml. Moreover, when 40 g/l glucose was added, the plantaricin AA13 levels doubled to 20000 AU/ml. Concentrations of 5, 10 and 20 g/l K2HPO4 lowered bacteriocin activity by 60%. Supplementing MRS with 1 g/l or more glycerol repressed bacteriocin production. Maximal activity of 20000 AU/ml was recorded in MRS supplemented with Vitamin DL-6,8-thioctic acid.
authors.affiliation: Department of Biology, Faculty of Science, University of Taif, Saudi Arabia Kingdom. abo-amer@lycos.com
authors.forename: Aly E
authors.initials: AE
authors.lastname: Abo-Amer
authors.forename: Bahig A
authors.initials: BA
authors.lastname: El-Deep
authors.forename: Abdullah D
authors.initials: AD
authors.lastname: Altalhi
mesh_terms: D001430:Bacteriocins / Q000096:biosynthesis*; D003470:Culture Media / Q000737:chemistry; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D048191:Lactiplantibacillus plantarum / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D013696:Temperature; D014815:Vitamins / Q000494:pharmacology; D015014:Yogurt
chemical_list: D001430:Bacteriocins; D003470:Culture Media; D013431:Sulfates; D014815:Vitamins; D005947:Glucose; D005990:Glycerol