Enzyme profile of lactobacilli from traditional Bulgarian fermented milk products
No Thumbnail Available
Date
2019-01-01
External link to pdf file
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85076616376&origin=inward
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
In recent years, scientific community has focused the attention on the non-starter lactic acid microbiota of home-made dairy products as a source of new candidate-probiotic strains. Lactic acid bacteria (LAB) and in particular Lactobacillus spp. play a major role in acquiring the specific taste and aroma of the final product during the fermentation. For this purpose, 43 Lactobacillus strains, isolated from traditional Bulgarian katak, curd, yoghurt, white-brined and yellow cheese, were subjected to screening of their enzyme capacity. Twenty-five of the strains were pre-selected for determination of their enzyme profile by API ZYM system. It was established that most of the strains showed high leucine and valine arylamidase, β-galactosidase and α-glucosidase activity. Only a few strains showed N-acetyl-β-glucosaminidase, α-galactosidase, β-glucosidase and Naphtol-AS-BI-phospho-hydrolase activity. Alkaline phosphatase, trypsin, α-chymotrypsin, α-mannosidase, lipase (except L. lactis OC2), β-glucuronidase (except L. salicinus KC2) and α-fucosidase (except L. plantarum BS41 and L. lactis OC2) activity were not observed. In order to complete the obtained results, two qualitative tests for determination of the β-galactosidase and proteolytic activity of more than 30 Lactobacillus strains were also applied. Most of the investigated lactobacilli showed moderate proteolytic activity. According to their β-galactosidase activity, 34 % could be defined as active lactose fermenters, 23 %-as late lactose fermenters and 43 %-could not ferment lactose. The investigated Lactobacillus strains showed strain-specific enzyme capacity.