Microbial dynamics and biodiversity in table olive fermentation: culture-dependent and -independent approaches

Abstract

The microbial ecology of the table olive fermentation process is a complex set of dynamics in which the roles of the lactic acid bacteria (LAB) and yeast populations are closely related, and this synergism is of fundamental importance to obtain high quality products. Several studies on the ecology of table olives, both in spontaneous fermentations and in inoculated ones, have focused on the identification and characterization of yeasts, as they play a key role in the definition of the final organoleptic profiles through the production of volatile compounds. Moreover, these are able to promote the growth of LAB, which is responsible for the stabilization of the final product through the acidification activity and the inhibition of the growth of pathogenic bacteria. The current empirical production process of table olives could be improved through the development of mixed starter cultures. These can only be developed after a deep study of the population dynamics of yeasts and LAB by means of molecular methods. Until now, most studies have exploited culture-dependent approaches to define the natural microbiota of brine and olives. These approaches have identified two main species of LAB, namely Lactobacillus plantarum and L. pentosus, while, as far as yeasts are concerned, the most frequently isolated genera are Candida, Pichia, and Saccharomyces. However, there are a few studies in literature in which a culture-independent approach has been employed. This review summarizes the state of the art of the microbial ecology of table olive fermentations and it focuses on the different approaches and molecular methods that have been applied.

Sourdough microbial community dynamics: An analysis during French organic bread-making processes

“…Hence, the genome of L. sanfranciscensis enables it to grow easily in this environment and contributes to its ability to out-compete other bacteria in traditional sourdough (Vogel et al, 2011). Unlike L. sanfranciscensis, the other LAB species detected in this study, L pentosus, L. sakei, L. plantarum and L. kimchii, have already been detected in sourdough and are also frequently isolated from other habitats (Botta and Cocolin, 2012;Chaillou et al, 2013;Corsetti and Gobbetti, 2002;Yoon et al, 2000).…”

Microbiota and metabolome of un-started and started Greek-type fermentation of Bella di Cerignola table olives

“…The microbiota of processed olives and/or brines is composed of a complex association of bacteria, such as lactic acid bacteria, Enterobacteriaceae, Clostridium, Staphylococcus, yeasts and, occasionally, molds. More than twenty lactic acid bacteria species belonging to the Leuconostoc, Pediococcus, Enterococcus, Streptococcus, Weissella, and, particularly, Lactobacillus genera have been isolated from olives and/or brines (Botta and Cocolin, 2012;Heperkan, 2013). The most commonly isolated genera of yeasts are Candida, Pichia, Debaryomyces, Saccharomyces, Issatchenkia, Rhodotorula and Wickerhamomyces.…”

“…The microbial composition of some table olives during fermentation was previously characterized and reviewed (Botta and Cocolin, 2012;Heperkan, 2013). The microbiota of processed olives and/or brines is composed of a complex association of bacteria, such as lactic acid bacteria, Enterobacteriaceae, Clostridium, Staphylococcus, yeasts and, occasionally, molds.…”

Transcriptome-Based Characterization of Interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaricus in Lactose-Grown Chemostat Cocultures

“…These, however, represent an extreme simplification of the situation in nature as well as in many food and beverage fermentations, where mixed microbial populations confer product characteristics such as flavor, aroma, nutritional value, and storage stability (11)(12)(13)(14). While food fermentation processes have been intensively investigated, the mechanisms governing population composition, dynamics, and performance remain largely elusive.…”