Examination of some technological properties of lactic acid bacteria of the genera Lactiplantibacillus and Levilactobacillus isolated from spontaneously fermented sourdough. Part 1: Enzymatic profile

¹ Department of Technology of Grain, Fodder, Bakery and Confectionery Products, University of Food Technologies, 26 Maritza Blvd., 4002, Plovdiv, Bulgaria
² * Department of Biochemistry and Molecular Biology, University of Food Technologies, 26 Maritza boulevard, 4002, Plovdiv, Bulgaria
³ Department of Microbiology, University of Food Technologies, 26 Maritza boulevard, 4002, Plovdiv, Bulgaria
⁴ Department of Technology of Wine and Beer, University of Food Technologies, 26 Maritza boulevard, 4002, Plovdiv, Bulgaria

^* Corresponding author: rositsa_denkova@uft-plovdiv.com

Abstract

In the development of symbiotic sourdough starters, it is necessary to examine the enzymatic profile of all potential lactic acid bacteria (LAB) strains. The enzymatic profile of 3 strains of the genus Lactiplantibacillus and 2 strains of the genus Levilactobacillus was investigated using the API ZYM system (Biomerieux®, France) and in separate experiments the amylolytic and proteolytic activity were determined by the agar-diffusion method with wells. All Lactiplantibacillus strains possessed: leucine arylamidase, valine arylamidase, cysteine arylamidase, acid phosphatase, phosphohydrolase, β-galactosidase, α- glucosidase, β-glucosidase and α-glucosaminidase. The two Levilactobacillus brevis strains possessed: lipase C4, esterase lipase C8, leucine arylamidase, valine arylamidase, cysteine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase, α-galactosidase, β-galactosidase, α-glucosidase, β- glucosidase. Lactiplantibacillus plantarum L1 demonstrated the highest amylolytic activity, and Levilactobacillus brevis X4 has the lowest. Lactiplantibacillus plantarum L1 exhibited the highest proteolytic activity, and Levilactobacillus brevis X4 - the lowest. The proteolysis was due to the production of inducible proteolytic enzymes by the LAB cells, as well as acid hydrolysis resulting from the lactic, acetic and other organic acids produced by the strains. The five LAB strains possess a rich and diverse enzyme profile, which is a prerequisite for their application in the development of symbiotic starters for sourdough bread.