3.2.2
Gas production
This present study was tested for film yeasts to form gas. All strains were quite similar in YPD media containing 2 and 15% glucose. S. cerevisiae J1 was grow and showed a high gas production more than 12 ml in YPD containing 18% glucose and 3.2 ml in 2% glucose. C. krusei J2 and C. krusei J3 produced a volume of gas in YPD containing 2% glucose about 5.4 ml and decreased the gas production in high glucose media. These results demonstrate that S. cerevisiae J1 was a high gas producer and spoilage capability.
Anothor feature which contribute to the spoilage capacity of yeast, Zygosaccharomyces genus is ability to ferment hexose sugars, such as glucose and fructose (8,15).