Researchers from Spain have identified a gene that helps baker's yeast survive freezing temperatures. They report their results in the June 2002 issue of the journal Applied and Environmental Microbiology.
In the study, the scientists identified a number of genes in the yeast Saccharomyces cerevisiae, commonly known as baker's yeast, which appeared to be turned on when the yeast was exposed to sub-freezing temperatures. Further investigation revealed that one of the genes, ERG10, helped protect the yeast from freezing.
Commercial bread dough is often stored frozen, which can kill yeast cells and severely reduce the dough's ability to rise after thawing. "Consequently, the improvement of the freeze tolerance in baker's yeast is of significant commercial importance," say the researchers, adding that their findings could "open up the possibility of design strategies to improve the freeze tolerance of baker's yeast."
S. Rodriguez-Vargas, F. Estruch and F. Randez Gil. 2002. Gene expression analysis of cold and freeze stress in baker's yeast. Applied and Environmental Microbiology, 68: 3024-3030.)
Measuring contamination in meat using infrared light
A real-time method that rapidly tests meat for spoilage uses a spectroscope to measure compounds produced by microorganisms on the meat. Researchers from the University of Wales present this new methodology in the June 2002 issue of the journal Applied and Environmental Microbiology.
The process, called fourier transform infrared spectroscopy (FT-IR), uses infrared light waves to identify specific organic compounds within the meat. The technique measures the absorption of various wavelengths of infrared light by the meat. The pattern of absorption creates a unique fingerprint for each compound.