Bacterial diversity of two types of Wagashi, a traditional Beninese cheese, using High-Throughput Amplicon Sequencing

Abstract

Wagashi, also called Gassiréin the local Fulfulde language, is a traditional cheese produced from cow milk in Benin. For its preparation, milk is heated and coagulated with Calotropis procera extract. After coagulation, the heated curd obtained is drained, moulded and stained, or not, using Sorghum vulgare or Sorghum codatum panicles. It is the most commonly consumed dairy product as surrogate for meat or fish. In order to get better insights into the bacterial diversity of Wagashi, Illumina MiSeq amplicon sequencing targeting the V1-V2 region of the bacterial 16S rRNA gene was performed on two different Wagashi types (stained and not stained) from Benin. The results showed that the Lactobacillaceae (60%) and Streptococcaceae (38%), were the most abundant bacteria in the unstained cheese, whereas Streptococcaceae (89%) and Bacillaceae (10%) were the most prevalent in stained cheese. Moreover, at the species level, the microbial community structures of stained and unstained cheeses were significantly different. The main differentiating species were Lactobacillus bulgaricus, Streptococcus thermophilus, and Lactobacillus fermentum in unstained cheese, compared to Streptococcus infantarius, Aeromonas sp., Bacillus cereus, Bacillus subtilis and S. thermophilus in stained cheese. This work provides valuable insights into microbiology of cheese Wagashi and shows that the staining of this dairy product affects its bacterial composition. In particular, the presence of potential useful Lactobacilli and Streptococci in unstained cheese is to be further investigated for selecting functional bacteria for potential biotechnology applications. On the contrary, the presence of Bacilli in stained cheese needs additional study to detect potential foodborne strains or pathotypes.