Italian scientists have found out where winter yeast: these microscopic fungi waiting time and the appearance of warm fruit in the intestines of social wasps, according to a paper published in the journal Proceedings of the National Academy of Sciences.
Baker's yeast — unicellular fungi Saccharomyces cerevisiae — were "tamed" the man in the ancient times. Thus, during excavations in China in the early 2000s, traces of yeast DNA was found on potsherds age from 9 to 7.5 thousand years. However, until now it was not clear what's inside the cycle distribution of these fungi.
In particular, scientists have known that the immature grapes yeast is almost absent, while in mature they are found in 25% of cases. And this despite the fact that the air they can not propagate. Some researchers have suggested that carriers of microorganisms may be a bird, but then found out that microbes can exist in the digestive tract of birds no longer than 12 hours.
Duccio Cavalieri (Duccio Cavalieri) from the University of Florence and his colleagues decided to test the assumption of some scientists that the carriers of these organisms can be public wasps.
To do this, the authors conducted a series of experiments with wasps in the laboratory, and with the wasps found in nature — in the Italian region of Tuscany, near Lake Garda, on the island of Elba. In particular, in the bowels of "natural" operating system — only 61 were studied insect — cells were found 393 different strains of yeast.
To test whether the yeast "permanent residents" of internal insects, the researchers used a special genetic tags that are "tagged" microorganisms. The results showed that the microorganisms migrate freely and are not tied to these insects. However, yeast wasps live in, not only during ripening when fungi multiply actively in mature berries — their cells were found in the intestine of fallen into hibernation hibernating wasps.
"Wasps can support a potentially endless chain of transmission of microorganisms … and serve them to a suitable carrier targets (summer fruit) and in the right season (late summer)," — concluded the researchers.
They emphasize that the wasps can not be the only place of wintering yeast, however, in their opinion, these insects may play a major role in the spread of these organisms.