RESUMO
With the aim of screening proteolytic strains of lactic acid bacteria to evaluate their potential for the reduction of allergenicity of the major bovine milk proteins, we isolated a new proteolytic strain of Enterococcus faecalis (Ent. faecalis VB63F) from raw bovine milk. The proteases produced by this strain had strong activity against caseins (αS1-, αS2-, and ß-casein), in both skim milk and sodium caseinate. However, only partial hydrolysis of whey proteins was observed. Proteolysis of Na-caseinate and whey proteins, observed after sodium dodecyl sulfate-PAGE, was confirmed by analysis of peptide profiles by reversed-phase HPLC. Inhibition of proteolysis with EDTA indicated that the proteases produced by Ent. faecalis VB63F belonged to the group of metalloproteases. The optimal conditions for their activity were 42°C and pH 6.5. The majority of assessed virulence genes were absent in Ent. faecalis VB63F. The obtained results suggest that Ent. faecalis VB63F could be efficient in reducing the immunoreactivity of bovine milk proteins.
Assuntos
Proteínas de Bactérias/metabolismo , Enterococcus faecalis/metabolismo , Leite/imunologia , Leite/microbiologia , Peptídeo Hidrolases/metabolismo , Proteólise , Alérgenos/imunologia , Alérgenos/metabolismo , Animais , Caseínas/metabolismo , Proteínas do Leite/imunologia , Proteínas do Leite/metabolismo , Proteínas do Soro do Leite/metabolismoRESUMO
Bacteriocins are ribosomally produced peptides useful for food biopreservation. An improved adsorption-desorption process is proposed for the partial purification of the bacteriocin produced by the fish isolate Carnobacterium maltaromaticum C2. Analyzis of extract by SDS-PAGE indicated this method may offer an alternative to improve the yield of purification of bacteriocins.
Assuntos
Humanos , Bacteriocinas , Fermentação , Peixes , Conservação de Alimentos , Alimentos de Origem Animal , Eletroforese , Amostras de Alimentos , Métodos , MétodosRESUMO
Bacteriocins are ribosomally produced peptides useful for food biopreservation. An improved adsorption-desorption process is proposed for the partial purification of the bacteriocin produced by the fish isolate Carnobacterium maltaromaticum C2. Analyzis of extract by SDS-PAGE indicated this method may offer an alternative to improve the yield of purification of bacteriocins.
