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The effect of αα‐lactalbumin and ββ‐lactoglobulin hydrolysates on the metabolic activity of Escherichia coli JM103
Author(s) -
PihlantoLeppälä A.,
Marnila P.,
Hubert L.,
Rokka T.,
Korhonen H. J. T.,
Karp M.
Publication year - 1999
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1046/j.1365-2672.1999.00849.x
Subject(s) - lactalbumin , escherichia coli , hydrolysate , chemistry , biochemistry , alpha lactalbumin , food science , hydrolysis , gene
Bovine milk proteins α‐lactalbumin (α‐la) and β‐lactoglobulin (β‐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, α‐la hydrolysed with pepsin or trypsin and β‐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 α‐la or β‐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.