Science News 06/08/2012

In the intestine of wasps and hornets the secret of typical wines

The analysis has shown how the strains isolated from insects and wines were better correlated than areal strains of different microbial biodiversity by identifying a characteristic of a vineyard or region

Social wasps and hornets are the protagonists of the typical beer, wine and bread. In the gut of these insects, in fact, "living" natural yeasts responsible for fermentation and vinarie panarie characterizing the typical. This is the result of a research published in the prestigious American journal PNAS - Proceedings of the Academy of Natural Sciences, designed by a group of researchers at the Edmund Mach Foundation of San Michele in collaboration with the' University of Florence and the CNRS in Montpellier.

The importance of this work is contained in the fact that, for the first time, the closed ecological cycle of the yeasts responsible for fermentation of wine, beer and bread. Up to now, in fact, the life cycle of these yeasts was known only during the production phase and fermentation of these products. It was unknown where they now live micro-organisms when fermentations are not there, or in the winter and spring months. This research shows that these yeasts "live" in the intestines of bees and social wasps. These insects are therefore their most important vehicle. "It 's amazing - says Duccio Cavalieri, coordinator of the Department of Computational Biology and among the researchers who participated in this work - like" microbiota ", ie the set of fungal species of bumblebees in the month of September includes the same species that are located on the surface of the grapes at the beginning of the fermentation vinaria. These yeasts "spend" a period of their life cycle within the intestine of social wasps and hornets, outside of the fermentation. Then - continues Knights - when the fruits ripen, these insects are attracted by the smell of them, break them thanks to their powerful jaw apparatus and injecting these micro-organisms in them. " This survey is linked to a research started in 1998 and closes, in fact, the ecological cycle of the yeast was still shrouded in mystery. To arrive at this result was also sequenced the genomes of these yeasts carried by bumblebees and it was possible to identify strains of yeasts in periods of the year in which they had never been isolated or from December to February.

The most interesting discovery was made by comparing, at the genomic level, the strains of hornets with other strains isolated from grapes and fermentation of the natural areas of isolation of insects, than a collection of 400 strains isolated from natural and industrial environments in France, United States, Chile, New Zealand and Japan. The analysis has shown how the strains isolated from social wasps, hornets, grapes and wines of a specific distribution area were better correlated than areal strains of different microbial biodiversity by identifying a characteristic of a vineyard or region. "Today - he says the Knights - the use of genomics and bioinformatics to identify a yeast or a microorganism isolated from a natural environment and compare it with other microorganisms in other parts of the world" simply "by comparing the sequence of marker genes, just as happens to the man for paternity analysis. "

And 'emerged, then, that these insects - wasps, hornets and social - are the protagonists of the products. The fact bumblebee carries the characteristics of a certain distribution area over another and this ensures the maintenance of essential richness, or biodiversity of micro-organisms that are critical to the typical products of fermentation such as wine and beer. "This discovery - concludes Roberto Viola, Director of Research and Innovation Centre of the Edmund Mach Foundation of San Michele - opens the way for other studies that intend to understand how this microcosm of micro-organisms may be associated with typical products, and how important to know, to protect, preserve and make available to human activities ".

The study was conducted by three researchers from the Foundation Mach Duccio Cavalieri, Carlotta De Filippo and Roberto Viola, in collaboration with the Department of Animal Biology and Genetics, and Pharmacology, University of Florence (Irene Stefanini, Leonardo Dapporto, Stephen Turillazzi , Mario Polsinelli, Antonio Calabretta, Monica Di Paola and Paolo Kids) and the CNRS of Montpellier (Jean-Luc Legras).

di Graziano Alderighi