Microbial Diversity of a Camembert-Type Cheese Using Freeze-Dried Tibetan Kefir Coculture as Starter Culture by Culture-Dependent and Culture-Independent Methods

Abstract

The biochemical changes occurring during cheese ripening are directly and indirectly dependent on the microbial associations of starter cultures. Freeze-dried Tibetan kefir coculture was used as a starter culture in the Camembert-type cheese production for the first time. Therefore, it's necessary to elucidate the stability, organization and identification of the dominant microbiota presented in the cheese. Bacteria and yeasts were subjected to culture-dependent on selective media and culture-independent polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) analysis and sequencing of dominant bands to assess the microbial structure and dynamics through ripening. In further studies, kefir grains were observed using scanning electron microscopy (SEM) methods. A total of 147 bacteria and 129 yeasts were obtained from the cheese during ripening. Lactobacillus paracasei represents the most commonly identified lactic acid bacteria isolates, with 59 of a total of 147 isolates, followed by Lactococcus lactis (29 isolates). Meanwhile, Kazachstania servazzii (51 isolates) represented the mainly identified yeast isolate, followed by Saccharomyces cerevisiae (40 isolates). However, some lactic acid bacteria detected by sequence analysis of DGGE bands were not recovered by plating. The yeast S. cerevisiae and K. servazzii are described for the first time with kefir starter culture. SEM showed that the microbiota were dominated by a variety of lactobacilli (long and curved) cells growing in close association with a few yeasts in the inner portion of the grain and the short lactobacilli were observed along with yeast cells on the exterior portion. Results indicated that conventional culture method and PCR-DGGE should be combined to describe in maximal detail the microbiological composition in the cheese during ripening. The data could help in the selection of appropriate commercial starters for Camembert-type cheese.

Fermente Salamura Otlardan İzole Edi̇len Mayalarin Enzi̇mati̇k Karakteri̇zasyonu

“…As, it can grow in high salt concentrations (Aponte et al, 2010;Karasu-Yalcin et al, 2017;Padilla et al, 2014). Similar to our results, Mei et al (2014) found that K. servazzii was the dominant species along with S. cerevisiae in a Camembert-type cheese type by cultureindependent PCR-denaturating gel electrophoresis (PCR-DGGE). However, Lavoie et al (2012) reported that K. servazzii could be found in non-dominant microflora of milk and cheese along with P. membranifaciens.…”

Lactobacillus kefiranofaciens, the sole dominant and stable bacterial species, exhibits distinct morphotypes upon colonization in Tibetan kefir grains

“…The microbial community of TKGs constantly undergoes changes, which could mainly be attributed to different sub-culturing conditions. To date, based on various culture-dependent and culture-independent methods, approximately 15 bacterial species have been identified in TKGs collected from different Chinese regions, with most of them belonging to the Lactobacillus family ( Gao et al., 2012 ; Huang et al., 2013 ; Mei et al., 2014 ; Zheng et al., 2013 ; Zhou et al., 2009 ). In addition, other KGs also appear to comprise diverse bacterial species ( Nalbantoglu et al., 2014 ).…”

Formation of In Vitro Mixed-Species Biofilms by Lactobacillus pentosus and Yeasts Isolated from Spanish-Style Green Table Olive Fermentations

“…Instead, they are composed of mixed species of bacteria and eukaryotes, which are thought to be more stable than monospecies films (3,4). This behavior is also the case with microbial communities in food environments (5)(6)(7)(8)(9)(10). In the particular case of olive table fermentations, the presence of polymicrobial communities composed of yeasts and lactic acid bacteria (LAB) attached to both biotic (skin of the olives) and abiotic (inner fermenter walls) surfaces has been reported (11)(12)(13)(14).…”