Molecular investigation of bacterial communities during the manufacturing and ripening of semi-hard Iranian Liqvan cheese

Liqvan (or Lighvan) is a traditional Iranian cheese from the East Azerbaijan province of Iran, which is made of raw ewe's milk without the addition of a starter. The grazing pastures, environmental conditions and the ancient regional production methods allocate a distinctive microbial ecology to this type of cheese, and these factors are consequently associated with the quality of the product. In this study, the microbiota of the milk, curd and cheese has been investigated using culture independent approaches. Denaturing gradient gel electrophoresis (DGGE) of the bacteria, 16S rRNA based high-throughput sequencing and enumeration of the live bacterial community by means of quantitative PCR (qPCR) have been used for this purpose. The results showed that the main bacterial population in the milk belonged to both microbial contaminants and lactic acid bacteria (LAB). However, both of these populations were totally replaced by LAB during ripening. The present survey contributes by describing the microbiota of this ancient cheese in more detail during fermentation and ripening.