engleski

Bacterial communities associated with the production of artisinal Istrian cheese

Traditional Istrian cheese is one of the most important Croatian products with a long history of manufacturing. It is made by farmers on a small scale across the entire Istria region, located in west-south Croatia. Production of Istrian cheese includes usage of raw ewes' milk. The milk is not pasteurized and no starter cultures are applied. Consequently if no starter cultures are applied, the cheese quality is highly variable. Therefore, in order to preserve the specificity of Istrian cheese and to minimize variations in quality, it is necessary to investigate the composition of bacterial communities during the production process. Therefore it was the aim of this study to investigate the dynamic of the autochthonous bacterial communities present in Istrian cheese and to identify the dominant species during the ripening process. To achieve this aim milk and cheese samples from four different farms located in different areas of Istria were collected. The raw milk, fresh cheese and cheese samples after 30, 60, 90 and 120 days of ripening were analyzed using culture independent molecular fingerprinting methods (DGGE, clone librieries construction, sequencing) and plate count approach. Our results indicate main changes in bacterial diversity pattern during the ripening process. Differences in bacterial diversity pattern at the same ripening stage among different farms investigated were comparable low. Sequence analysis of the most prominent bands of the fingerprints revealed dominance of Lactococcus lactis subs. lactis in all samples and a strong presence of Enterococcus spp. which was also confirmed by plate count analysis. The 44 sequences derived from DGGE bands were divided into three phyla: Proteobacteria, Fusobacteria and Firmicutes. Gram positive Firmicutes were most abundant in Istrian cheese.

Istrian cheese; DGGE; clone librieries construction

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