Dynamic changes in bacterial microbiota succession and flavour development during milk fermentation of Kazak artisanal cheese

Kazak cheese is a characteristic handcrafted fermented dairy product from the Uyghur Autonomous Region in China. The bacterial microbiota and volatile components during milk fermentation of Kazak artisanal cheese were investigated using Illumina MiSeq sequencing technology and headspace solid-phase microextraction (HS-SPME) with gas chromatography/mass spectrometry (GC–MS), respectively. Lactobacillus and Lactococcus were found to be the main populations during milk fermentation. The relationships between microbiome succession and flavour dynamics were constructed based on bidirectional orthogonal partial least squares (O2PLS), which identified eight bacterial genera as key functional microbes for flavour production. Among these genera, Lactobacillus was positively correlated with benzoic acid and isoamyl alcohol, while Macrococcus and Anoxybacillus were negatively correlated with acetic acid, butanoic acid and isoamyl alcohol. This study provides a foundation for uncovering the mechanisms underlying the formation of the microbiota and flavour components in Kazak fermented cheese.