title: The effect of alpha-lactalbumin and beta-lactoglobulin hydrolysates on the metabolic activity of Escherichia coli JM103.
abstract: Bovine milk proteins alpha-lactalbumin (alpha-la) and beta-lactoglobulin (beta-lg) were hydrolysed with seven different proteolytic enzymes, and the effect of various hydrolysates on a genetically modified luminous Escherichia coli JM103 was tested in vitro with a bioluminescence assay for bacterial growth and metabolism. Undigested proteins did not inhibit the activity of tested E. coli JM103 at a concentration as high as 0.1 g ml-1. At the same concentrations, alpha-la hydrolysed with pepsin or trypsin and beta-lg hydrolysed with alcalase, pepsin or trypsin, showed a lower metabolic activity during the first 8 h of growth. The activity of E. coli JM103 in the presence of 25 mg ml-1 alpha-la or beta-lg hydrolysed with pepsin and trypsin was only 21% of the control after incubation for 6 h. The preliminary results indicated that ultrafiltration through 10 kDa and 1 kDa molecular mass cut-off membranes may be used to enrich bacteriostatic properties.
authors.affiliation: Agricultural Research Centre of Finland, Jokionen. anne.pihlanto-leppala@mtt.fi
authors.forename: A
authors.initials: A
authors.lastname: Pihlanto-Leppälä
authors.forename: P
authors.initials: P
authors.lastname: Marnila
authors.forename: L
authors.initials: L
authors.lastname: Hubert
authors.forename: T
authors.initials: T
authors.lastname: Rokka
authors.forename: H J
authors.initials: HJ
authors.lastname: Korhonen
authors.forename: M
authors.initials: M
authors.lastname: Karp
mesh_terms: D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism*; D006868:Hydrolysis; D007768:Lactalbumin / Q000378:metabolism*; D007782:Lactoglobulins / Q000378:metabolism*; D008163:Luminescent Measurements; D010434:Pepsin A / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism; D014462:Ultrafiltration
chemical_list: D007782:Lactoglobulins; D007768:Lactalbumin; D014357:Trypsin; D010434:Pepsin A