Ethanol fermentation of Saccharomyces cerevisiae usually occurs at 30-32°C. I would like to know if the temperature is increased (45°C), most contaminants will increase the growth rate?
Hi José
The published optimum for yeast fermenting sugar is 28 to 32°C. The yeast itself is not positiv effected, the optimum for coli-forme bacteria is 37°C increasing temperature results in heat-stress-protein formation like the GroE Chaperone, a higher cell stress and for sure not an increased growth. Thats why usually the "fever" situation arround up to 42°C body temparature is a way of our organism, to get rid of bacteria....a permanent temperature over 42°C is "toxic" for natural E.colis, possibly for other natural MOs too.
I think the answer can be a more or less generalized "No", even if some bacteria are able to tolerate 45°C for a longer time or even increase growing under this conditions.
Hi Jose,
The answer depends specifically on the stain that is contaminating the yeast fermentation that you are interested in growing faster. Some contaminants found in these fermentations like Lactobacillus may grow faster at 42 to 45°C but this will be strain specific. Others such as some Bacillus strains will grow faster at this temperature but may require even higher temperatures to reach their max growth rate, this can be up as high as 55°C.
Unfortunately without knowing the strains you hope to grow faster its difficult to give a more definitive answer.
It's about 28-37oC for LAB contaminants and arround 30-37oC for yeast contaminants
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