Genetic diversity, safety and technological characterization of lactic acid bacteria isolated from artisanal Pico cheese.

Genetic diversity, safety and technological characterization of lactic acid bacteria isolated from artisanal Pico cheese. Food Microbiol. 2017 May;63:178-190 Authors: Domingos-Lopes MF, Stanton C, Ross PR, Dapkevicius ML, Silva CC Abstract A total of 114 lactic acid bacteria were isolated at one and 21 days of ripening from a traditional raw cow's milk cheese without the addition of starter culture, produced by three artisanal cheese-makers in Azores Island (Pico, Portugal). Identification to species and strain level was accomplished by16S rRNA gene and PFGE analysis. Carbohydrate utilization profiles were obtained with the relevant API kits. Isolates were evaluated according to safety and technological criteria. The most frequently observed genus identified by 16S rRNA sequencing analysis was Enterococcus, whereas API system mostly identified Lactobacillus. The highest percentages of antibiotic resistance were to nalidixic acid (95%), and aminoglycosides (64-87%). All isolates were sensitive to several beta-lactam antibiotics and negative for histamine and DNase production. Gelatinase activity was detected in 49.1% of isolates, 43% were able to degrade casein and 93% were α-hemolytic. Most enterococci presented virulence genes, such as gelE, asaI, ace. Diacetyl production was found to be species dependent and one strain (Leu. citreum) produced exopolysaccharides. Selected strains were further studied for technological application a...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research