Microbial dynamics in durum wheat kernels during aging
| Autor: | Raimondo Gaglio, Giancarlo Moschetti, Fortunato Cirlincione, Rosalia Di Gerlando, Elena Franciosi, Nicola Francesca, Giuseppe Di Miceli, Luca Settanni |
|---|---|
| Přispěvatelé: | Gaglio R., Cirlincione F., Di Miceli G., Franciosi E., Di Gerlando R., Francesca N., Settanni L., Moschetti G. |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Time Factors
Genotype Lactobacillus pentosus Microbiology 03 medical and health sciences Lactobacillus Yeasts Durum wheat kernels Lactic acid bacteria Food science Durum wheat kernel Triticum 030304 developmental biology 0303 health sciences biology Bacteria 030306 microbiology Lactobacillus brevis Microbiota Microbial persistence food and beverages General Medicine Bread biology.organism_classification Enterococcus durans Settore AGR/02 - Agronomia E Coltivazioni Erbacee Settore AGR/15 - SCIENZE E TECNOLOGIE ALIMENTARI Enterococcus Food Storage Sourdough MiSeq Illumina Food Microbiology Pediococcus Stenotrophomonas Edible Grain Food Science Enterococcus faecium Settore AGR/16 - Microbiologia Agraria |
| Popis: | In the present work the microbial dynamics in wheat kernels were evaluated over time. The main aim of this research was to study the resistance of lactic acid bacteria (LAB) and yeasts associated to unprocessed cereals used for bread making during long term conservation. To this purpose four Triticum durum Desf. genotypes including two modern varieties (Claudio and Simeto) and two Sicilian wheat landraces (Russello and Timilia) were analysed by a combined culture-independent and -dependent microbiological approach after one, two or three years from cultivation and threshing. DNA based MiSeq Illumina technology was applied to reveal the entire bacterial composition of all semolina samples. The samples showed a different distribution of bacterial taxa per variety and time of storage. The groups mostly represented were Stenotrophomonas, Pseudomonas, Erwinia, Delftia and Sphingomonas genera, Enterobacteriaceae and Oxalobacteriaceae families, and Actinobacteria phylum. Among LAB, only Enterococcus genus was detected barely in a single sample (Simeto stored for one year) by the next generation sequencing, indicating that LAB remained unassigned or their abundances were below 0.1% or their DNAs were rendered inaccessible. Plate counts showed consistent differences in relation to genotypes and duration of storage, with the highest levels found for total mesophilic microorganisms detected up 6.8 Log CFU/g. Colonies of presumptive sourdough LAB were detected only in a few samples. Cocci constituted the major group of LAB in almost all samples. Following the enrichment procedure, almost all samples were characterised by the presence of acidifying microorganisms. All isolates collected before and after enrichment represented 28 different strains belonging to 10 species of Enterococcus, Lactobacillus and Pediococcus genera. The most resistant species during aging were Enterococcus faecium, Enterococcus durans, Lactobacillus brevis, Lactobacillus pentosus and Lactobacillus paracasei demonstrating that lactobacilli and enterococci are able to overcome the stressing conditions represented by cereal storage better than other LAB genera commonly found associated to cereals after harvest. Yeast community included mostly species with no interest in bread making. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|