The unusual microbiota of the traditional Bulgarian dairy product Krokmach – A pilot metagenomics study

Abstract

Krokmach is a traditional Bulgarian fermented dairy product. The microbiota composition was investigated for the first time by next‐generation sequencing. The results revealed a quite specific constitution comprising several bacterial species never reported before for fermented dairy products. It resembles those of soft and smear cheeses rather than that of yoghurt. The dominant species was Lactococcus lactis subsp. lactis (75% of the operational taxonomic unit (OTU) counts). The overall composition was quite unusual with 8.5% of Exiguobacterium sp. OTU counts, as well as the presence of Apiactobacillus kunkeei, Megamonas sp. and Kluyvera georgiana among the dominant and subdominant species and genera.

The assessment of bacterial diversity in CO2 treated and untreated raw milk during cold storage using high‐throughput sequencing technology

“…Microbial DNA was extracted using the HiPure Soil DNA Kits (or HiPure Stool DNA Kits) (Magen, Guangzhou, China) following the manufacturer's protocols. The 16S rDNA V3–V4 region of the ribosomal RNA gene was amplified through PCR (Biçer et al ., 2021; Dimov, 2022). The PCR reaction involved cycles of 94 °C for 2 min, followed by 30 cycles at 98 °C for 10 s, 62 °C for 30 s and 68 °C for 30 s, with a final extension at 68 °C for 5 min using primers 341F: CCTACGGGNGGCWGCAG; 806R: GGACTACHVGGGTATCTAAT (Witzke et al ., 2020; Shaffer et al ., 2021; Ferreira et al ., 2022).…”

Artisanal cheeses relying on spontaneous fermentation as sources of unusual microbiota – The example of the Bulgarian ‘mehovo sirene’ skin bag cheese

“…Cheese (120 mg) were sampled in sterile conditions from the interior of the cheese's volume and used immediately for DNA extraction. Further analyses were performed as described previously (Dimov 2022).…”

Effects of microbial preparation on production performance and rumen microbial communities of goat

“…Biçer et al (2021) performed the comparison of commercial and traditional kefir microbiota using metagenomic analysis, proving the latter has higher microbial diversity compared to former (Biçer et al, 2021). As for the microflora, Krokmach possesses specific and distinctive characteristics, therefore, Dimov (2022) conducted the study about analyzing the unusual microbiota of the traditional Bulgarian dairy product Krokmach via metagenomics study. The result demonstrated microbiota's composition was quite specific at species level---high content of Exiguobacterium (Dimov, 2022).…”

“…As for the microflora, Krokmach possesses specific and distinctive characteristics, therefore, Dimov (2022) conducted the study about analyzing the unusual microbiota of the traditional Bulgarian dairy product Krokmach via metagenomics study. The result demonstrated microbiota's composition was quite specific at species level---high content of Exiguobacterium (Dimov, 2022). Méndez-Romero et al (2021) characterized the physicochemical and the microbiota composition of the artisanal Fresco cheese from Sonora, the result for characterization of microbiota illustrated more of 80 genera, of which the LAB as Lactococcus, Streptococcus, Lactobacillus and Leuconostoc were the most abundant may be considering for future items (Méndez-Romero et al, 2021).…”