Nauka Przyroda Technologie

2011 volume 5 issue 2 #12

Anna Sip, Michał Więckowicz, Justyna Jarka, Agnieszka Olejnik-Schmidt, Włodzimierz Grajek

Evaluation of class IIa bacteriocinogenic potential of lactic acid bacteria isolated from the oscypek cheese

Summary.

The main objective of the study was the phylogenetic identification on the genus level of the main LAB isolated from the oscypek cheese and the assessment of their bacteriocinogenic potential. Primarily, a routine qualitative analysis of the microbiota was performed. Nine oscypek cheese samples were subjected to the analysis. The quantitative analysis of the cheese microbiota was performed using culture-based techniques, while the qualitative assessment was made using PCR-based analysis of total DNA preparations. Metagenomic DNA isolates derived from the cheese natural microbiota were screened for the existence of DNA sequence fragments typical for seven main potentially bacteriocinogenic LAB genera. Moreover, metagenomic DNA extracts were also screened for class IIa bacteriocin-coding gene sequences. The presence of seven main LAB genera was determined using primers originating from reference publications, while the class IIa bacteriocin-coding gene was detected using custom-designed primer panel created in the Department of Biotechnology and Food Microbiology at the Poznań University of Life Sciences. The study revealed, that in most cheese samples the counts of LAB exceeded 108 cfu·g-1. The counts of aerobic bacteria and yeasts was lower 1 and 2 log cycles, respectively. In all metagenomic DNA extracts, sequences typical for Lactococcus and Leuconostoc genera were found.
In addition to this, eight cheese samples revealed the presence of Lactobacillus- and Enterococcus-specific sequences. The DNA sequences typical for the genera Carnobacterium, Pediococcus and Weissella were not present in any of the analysed material. Class IIa bacteriocin-coding sequences were detected in all metagenomic DNA preparations subjected to this study. It is essential to undertake further isolation procedures in order to determine, whether LAB rich in class IIa bacteriocin-coding genes are able to synthesize active bacteriocins and reveal inhibitory activity towards Listeria.

Key words: oscypek cheese, lactic acid bacteria, IIa class bacteriocins, metagenomic analysis

Full text available in Polish in Adobe Acrobat format:
https://www.npt.up-poznan.net/pub/art_5_12.pdf

Streszczenie w języku polskim:
https://www.npt.up-poznan.net/tom5/zeszyt2/streszczenie-12.html

Corresponding address:
Anna Sip
Katedra Biotechnologii i Mikrobiologii Żywności
Uniwersytet Przyrodniczy w Poznaniu
ul. Wojska Polskiego 48
60-627 Poznań
Poland
e-mail: aniasip@up.poznan.pl

Accepted for print: 18.01.2011