Broth depending production of extracellular enzymes by enterobacteria isolated from dairy food (Serbian cheese)

Katarina Mladenović,Ljiljana Čomić,Violeta Jakovljević,Mirjana Grujović

doi:10.5937/kgjsci2042123m

Abstract

In this paper, we investigated, for the first time, the enzyme activity of enterobacteria from cheese from Southeastern Serbia (Sokobanja), which was produced in a traditional way. The tested bacteria were selected from the spring, summer, and autumn collections and grown in two different broths. The enzyme activity was investigated in the two broths and measured using spectrophotometry method. It was concluded that there were differences in the amount of extracellular enzymes depending on the broths. A statistically significant rise in the amount of enzymes was demonstrated in Tripton soy broth. Bacteria in cheese do not possess the ability to produce extracellular enzymes in large amounts. Therefore, they do not change the organoleptic characteristics of the cheese. There is a possibility that if they are found outside their natural environment (cheese), without interactions with antagonists, they may exhibit stronger enzyme activity.

Highlights

Gram-negative bacteria release proteins into the growth medium (PUGSLEY et al, 1986)
The aim of this paper was to evaluate and quantify the enzymes of bacteria isolated from cheese produced in traditionally way in Sokobanja (Southeastern Serbia) and determine the dependence of the amount of enzymes on the substrate where the bacteria were grown
The higher concentration of proteins was measured in Tripton soy broth (TSB) than in Mueller Hinton broth (MH)

Summary

Introduction

Gram-negative bacteria release proteins (extracellular enzymes) into the growth medium (PUGSLEY et al, 1986). Extracellular enzymes of the pathogen increase its virulence (SHARMA and TIWARI, 2005) It is well-known that bacteria from family Enterobacteriaceae could affect the organoleptic properties of milk products (HERVERT et al, 2017). Starch-debranching pullulanase, produced by some strains of Klebsiella pneumoniae is one example of a protein secreted by gram-negative bacteria (EISELE et al, 1972). One of the studies was focused on examining DNA exonuclease from Escherichia coli and their roles in metabolism (LOVETT, 2011) Extracellular hydrolytic enzymes such as amylases, proteases, lipases, pullulanase, and DNases, xylanases, have potential use in various areas such as the food industry, feed additive, biomedical sciences and chemical industries (SANCHEZ-PORRO et al, 2003). All of the above isolates are potential sources of proteolytic enzymes that can be used for industrial purposes (ALEMU, 2015)

Objectives

Methods

Results