New Insights Into Microbial Diversity Of The Traditional Packed Table Olives Alorena De Malaga Through Metataxonomic Analysis

Alorena de Malaga is a table olive especially characterised by its natural freshness and short shelf-life. In this work, we applied a metataxonomic approach to unravel the microbial diversity of bacterial and fungi populations through the shelf-life of traditionally packed Alorena de Malaga. A significant increase in lactic acid bacteria and mesophilic aerobic populations was observed during shelf-life, reaching the maximum population levels (4-5 log(10) CFU) at the end of the study (260 days). On the contrary, a rapid reduction in yeast and mould populations was reported. The use of a metataxonomic analysis based on the amplification of 16S (bacteria) and internal transcribed spacer (ITS) region (fungi) regions revealed a low diversity for both microbial groups. Lactiplantibacillus (65.05 +/- 8.65% in brine vs. 58.70 +/- 15.70% in fruit), Pediococcus (28.17 +/- 7.36% in brine vs. 27.20 +/- 15.95% in fruit), and Celerinatantimonas (4.64 +/- 1.08% in brine vs. 11.82 +/- 18.17% in fruit) were the main genera found among bacteria, and an increase in Lactiplantibacillus and a reduction in Celerinatantimonas populations during the shelf-life were observed. On the other hand, Citeromyces was the dominant fungi genus (54.11 +/- 2.00% in brine vs. 50.91 +/- 16.14% in fruit), followed by Candida (8.80 +/- 2.57% in brine vs. 12.32 +/- 8.61% in fruit) and Penicillium (6.48 +/- 1.87% vs. 8.48 +/- 4.43% in fruit). No food-borne pathogen genera were detected in any of the samples analysed, indicating the high level of food safety found in this ready-to-eat fermented vegetable. Data obtained in this work will help in the design of new strategies for the control of microbial populations during the shelf-life of Alorena de Malaga.