title: Detection of antibacterial activity of an enzymatic hydrolysate generated by processing rainbow trout by-products with trout pepsin.
abstract: Trout by-product hydrolysates, generated using trout pepsin, were characterized and studied in terms of their antibacterial effects against food contaminants and fish farming pathogens. After a hydrolysis time of 25 min, the hydrolysates demonstrated inhibitory activity against several gram-positive and gram-negative bacteria. The degree of hydrolysis (DH) was found to exert a considerable influence on antibacterial activity, with a significant increase in the observed inhibitory effect at the beginning of hydrolysis. The highest antibacterial activity was obtained at a DH of 30% (enzyme/protein ratio 0.04 U/mg of protein, enzyme activity 6.5 U/mg protein, hydrolysis conditions 37°C, pH 3.0). The highest antibacterial activity detected was against the fish farming bacteria Flavobacterium psychrophilum and Renibacterium salmoninarum, with minimal inhibition concentrations of 2mg/ml and 5mg/ml, respectively. The amino acid determination of the hydrolysate (DH 30%) revealed that lysine, leucine, alanine, arginine, glycine, aspartic acid and glutamic acid residues represented the major amino acids.
authors.affiliation: University of Kiel, Department of Food Technology, Institute of Human Nutrition and Food Science, Heinrich-Hecht Platz 10, 24118 Kiel, Germany; Fulda University of Applied Sciences, Faculty of Food Technology, Leipziger Straße 123, 36037 Fulda, Germany. Electronic address: maleen.wald@lt.hs-fulda.de.
authors.forename: Maleen
authors.initials: M
authors.lastname: Wald
authors.affiliation: University of Kiel, Department of Food Technology, Institute of Human Nutrition and Food Science, Heinrich-Hecht Platz 10, 24118 Kiel, Germany. Electronic address: info@foodtech.uni-kiel.de.
authors.forename: Karin
authors.initials: K
authors.lastname: Schwarz
authors.affiliation: Max Rubner-Institute, Department of Safety and Quality of Milk and Fish, Palmaille 9, 22767 Hamburg, Germany(1). Electronic address: hum.rehbein@t-online.de.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Rehbein
authors.affiliation: Fulda University of Applied Sciences, Faculty of Food Technology, Leipziger Straße 123, 36037 Fulda, Germany. Electronic address: bettina.bussmann@lt.hs-fulda.de.
authors.forename: Bettina
authors.initials: B
authors.lastname: Bußmann
authors.affiliation: Fulda University of Applied Sciences, Faculty of Food Technology, Leipziger Straße 123, 36037 Fulda, Germany. Electronic address: christopher.beermann@lt.hs-fulda.de.
authors.forename: Christopher
authors.initials: C
authors.lastname: Beermann
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D005511:Food Handling; D017686:Oncorhynchus mykiss / Q000382:microbiology*; D010434:Pepsin A / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D010434:Pepsin A
keywords: Antibacterial peptides; Fish diseases; Food spoilage; Trout by-product hydrolysate; Trout pepsin