Cider Apple Native Microbiota Characterization by PCR-DGGE

Abstract

The surface microbiota of different recognized apple varieties used to elaborate a Protected Designation of Origin cider was studied to analyse the microbial diversity and its potential link to the microorganisms involved in the cider fermentation process. The V3 region of the bacterial 16S gene and the D1 domain of the eukaryotic 26S gene were amplified by polymerase chain reaction (PCR) and analysed by denaturing gradient gel electrophoresis (DGGE). The most intense bands found in the DGGE profiles were sequenced and compared with those in the GenBank database. The profiles showed a high microbial diversity, but little variation was found among the varieties. Identification of the bands showed that the usual species associated with an apple juice fermentation were not found, suggesting that the microorganisms responsible for spontaneous fermentation come from the equipment and the production environment.

Microorganisms in Fermented Apple Beverages: Current Knowledge and Future Directions

“…Some of the fungi species on apples can be phytopathogenic species mainly included in the class Dothideomycetes, with about 95% of these in the order Capnodiales that causes damaging blemishes on apples [ 25 , 26 ]. A PCR-DGGE based-study of the microbiota of five varieties of Asturian apples used for the production of PDO (Protected Designation of Origin) ciders in Spain also identified Exobasidium sp., responsible for galls and leaf malformations, and Mycosphaerellaceae and Dissoconiaceae families, which produce sooty blotch and flyspeck on apples [ 27 ]. In this work, little variation in microbial diversity was found amongst the five apple varieties studied, without identifying the usual species associated with spontaneous fermentation.…”

“…Focusing on cider apples, Alonso et al used PCR-DGGE to study the native microbiota of five apple varieties commonly used in the Asturian cider-making process. Predictably, Enterobacteriaceae were present due to the ubiquity in nature of this genus, but bacterial species usually associated with spontaneous fermentation were not [ 27 ]. The apple surface microbiota may not be a determinant in the fermentation process.…”

Effect of different starter cultures on chemical and microbial parameters of buckwheat honey fermentation

“…The microbial species found in the batch inoculated with cider lees are the same that can be found on apples or in cider itself (mainly Candida) (Suárez Valles et al, 2007;Alonso et al, 2015). The PCR-based technique applied to the analysis of the cider apple microbiota showed that the fungal community there was quite homogenous as compared to the heterogeneous bacterial profile (Alonso et al, 2015). Further, Saccharomyces cerevisiae and Saccharomyces bayanus have already been reported to be present in Asturian cider by classical culturing (Suárez Valles et al, 2007).…”

“…Further, Candida species were also detected by this method in batches inoculated with sourdough and cider lees. The microbial species found in the batch inoculated with cider lees are the same that can be found on apples or in cider itself (mainly Candida) (Suárez Valles et al, 2007;Alonso et al, 2015). The PCR-based technique applied to the analysis of the cider apple microbiota showed that the fungal community there was quite homogenous as compared to the heterogeneous bacterial profile (Alonso et al, 2015).…”

“…Among all these populations, only enterobacteria counts were detected at the beginning of the fermentation of batches inoculated with the sourdough and cider lees. These bacterial types have been shown to be frequent contaminants in these foods (Alonso et al, 2015;Ercolini et al, 2013). The low pH of the wort (which continues to drop over the course of the fermentation process) may explain the inability of these populations to progress in the honey wort, which suggests that mead can be considered an unsuitable product for the development of food pathogens.…”