Lactic acid bacteria with antimicrobial, proteolytic and lipolytic activities isolated from ovine dairy products

Evandro Oliveira Onofre E Silva,Cássia Regina Nespolo,Franciane Cabral Pinheiro,Lenita Moura Stefani,Carla Pohl Sehn

doi:10.1590/fst.11019

Abstract

Abstract This study aimed to isolate lactic acid bacteria from sheep milk products and to characterize these microorganisms with a focus on their antimicrobial, proteolytic and lipolytic activities. Raw milk, pasteurized milk, pasteurized cream, and butter samples were collected, lactic acid bacteria were isolated and their proteolytic, lipolytic and antimicrobial activities were evaluated. Lactic acid bacteria counts were higher in raw milk collected at the farm number 4 (8.91 ± 0.05 log CFU/mL), in which adequate hygienic practices were observed for pre- and post-milking. A total of 253 isolates were obtained, and among them 37 were lactic acid bacteria, where 19 showed some type of activity, most of which from raw milk. Among the isolates of lactic acid bacteria, 48.65% (n=18) showed proteolytic activity, 13.51% (n=5) lipolytic activity, 10.81% (n=4) showed both proteolytic and lipolytic activities, and only 2.70% (n=1) showed antimicrobial activity. Isolation of lactic acid bacteria with technological properties demonstrated their potential use as starter cultures in processing of fermented dairy products.

Highlights

Milk is a source of lipids, proteins and carbohydrates despite their variable composition depending on the animal species (Food and Agriculture Organization of the United Nations, 2013)
The American continent produces 42,095 tons of the worlds production of sheep milk, and Brazil contributes to 21.72% of this total (Food and Agriculture Organization of the United Nations, 2017)
In the Southern and South-eastern regions of Brazil, there is a large production of sheep milk that is processed in registered dairy plants or even with homemade processing (Santos et al, 2016)

Summary

Introduction

Milk is a source of lipids, proteins and carbohydrates despite their variable composition depending on the animal species (Food and Agriculture Organization of the United Nations, 2013). In the Southern and South-eastern regions of Brazil, there is a large production of sheep milk that is processed in registered dairy plants or even with homemade processing (Santos et al, 2016). This activity increased its participation in the Brazilian agribusiness, with great potential for cheese production, which are highly valued in the Brazilian market (Santos et al, 2016). Sheep dairy farming is considered a productive system well adapted to small farms, but this economic activity has not yet reached its full capacity in Brazil, especially regarding dairy products such as cheese and yogurt (Balthazar et al, 2017; Nespolo et al, 2010; Santos et al, 2016)

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Conclusion