Journal Article

Screening for proteolytically active lactic acid bacteria and bioactivity of peptide hydrolysates obtained with selected strains

Li, B., Heller, K. J., Klempt, M., Kliche, T., Habermann, D., de Vrese, M., Wutkowski, A., Clawin-Raedecker, I., Bockelmann, W.

2017

Overview

In a screening for proteolytically active lactic acid bacteria, three strains, Lactobacillus delbrueckii ssp. lactis 92202, Lactobacillus helveticus 92201, and Lactobacillus delbrueckii ssp. bulgaricus 92059, showed the highest activities following growth in milk. All three strains degraded α- and β-casein, but did not hydrolyse κ-casein. HPLC analysis of skim milk fermentation revealed increasing amounts of peptides after 5 and 10 h with Lb. d. ssp. bulgaricus 92059. Hydrolysates obtained with Lb. d. ssp. lactis 92202 and Lb. d. ssp. bulgaricus 92059 revealed the highest angiotensin-converting enzyme-inhibitory effect. The effect was dose dependent. Almost no effect (<10%) was seen for Lb. helveticus 92201. For Lb. d. ssp. bulgaricus 92059, maximal inhibition of approx. 65% was reached after 25 h of fermentation. In an in vitro assay measuring potential immunomodulation, hydrolysates of the three strains yielded anti-inflammatory activities in the presence of TNF-α. However, the effects were more pronounced at lower hydrolysate concentrations. In the absence of TNF-α, slight pro-inflammatory effects were observed. The hydrolysate of Lb. d. ssp. bulgaricus 92059, when purified by means of solid-phase extraction, exhibited pro-inflammatory activity. Sour whey containing Lb. d. ssp. bulgaricus 92059 cells showed pro-inflammatory activity while cell-free sour whey was clearly anti-inflammatory. In the purified hydrolysate, 20 different α- and β-casein (CN)-derived peptides could be identified by LC-MS. Most peptides originated from the central and C-terminal regions of β-casein. Peptide length was between 9 (β-CN(f 59–67)) and 22 amino acids (β-CN(f 117–138)).

• Publisher: Springer Berlin Heidelberg,Springer,Springer Nature B.V
• Subject: Amino acids / Angiotensin / Animals / anti-inflammatory activity / Applied Microbial and Cell Physiology / Bacteria / beta-casein / Biological activity / Biological Factors - metabolism / Biomedical and Life Sciences / Biotechnology / Casein / dose response / Enzyme Inhibitors - isolation & purification / Enzyme Inhibitors - metabolism / Fermentation / Health aspects / High-performance liquid chromatography / Hydrolysates / Hydrolysis / Immunologic Factors - isolation & purification / Immunologic Factors - metabolism / Immunomodulation / in vitro studies / Inflammation / kappa-casein / Lactic acid / Lactic acid bacteria / Lactobacilli / Lactobacillus / Lactobacillus delbrueckii / Lactobacillus delbrueckii - enzymology / Lactobacillus delbrueckii - growth & development / Lactobacillus delbrueckii - isolation & purification / Lactobacillus delbrueckii - metabolism / Lactobacillus delbrueckii subsp. lactis / Lactobacillus helveticus / Lactobacillus helveticus - enzymology / Lactobacillus helveticus - growth & development / Lactobacillus helveticus - isolation & purification / Lactobacillus helveticus - metabolism / Life Sciences / Liquid chromatography / Mass Screening / mass spectrometry / Methods / Microbial Genetics and Genomics / Microbiological assay / Microbiology / Milk - microbiology / Observations / Peptide Hydrolases - metabolism / Peptides / Peptides - metabolism / Peptidyl-dipeptidase A / Peptidyl-Dipeptidase A - metabolism / protein hydrolysates / Proteolysis / Screening / Skim milk / solid phase extraction / Solid phases / Strains (organisms) / Tumor necrosis factor / tumor necrosis factor-alpha / Tumor Necrosis Factor-alpha - antagonists & inhibitors / Whey / Yogurt