Thirty randomized samples of sugar materials were collected from different
places (Tartous, Damascus, Homs) in Syria for isolation and identification of
some yeasts. These yeasts were classified physiologically by API technique
to identify the spe
cies of Yeasts found in these materials. Results showed that
the isolated materials contained 17 isolated yeasts distributed in 3 genus and 7
species and named as follows: One isolated yeast from Geotrichum capitatum,
Candida krusei,Candida guilliermondi, Candida fumata and Candida zeylanoides
and 4 isolated yeasts from Candida lusitaniae and 7 isolated yeasts from
Saccharomyces cerevisiae. The classified yeasts were screened to investigate the
activity of internal and external invertase produced by them using
spectrophotometer at 540 nm. The results showed that there were differences in
the ability of yeasts to produce invertase enzyme. Candida Lusitaniae-2 and
Saccharomyces cerevisiae-4 were found the best yeasts for production of
external invertase, whereas Candida Lusitaniae1 was the best for internal
invertase.
This study was conducted at the laboratories of the Faculty of Agriculture,
Damascus University and the National Commission of Biotechnology in 2012 to
investigate he possibility of Production of bioethanol using local isolate of
Saccharomyces cer
evisiae from raw sugar refining molasses and to determine
the effect of different temperatures, pH and concentration of Dry matter (Brix
degree) in molasses on the amount of ethanol produced. A local isolate (R1) of
Saccharomyces cerevisiae selected previously due to its superiority in ethanol
production was taken from wine brewing residues and exposed to different
temperatures (20, 25, 30 and 35OC), pH (4, 4.5, 5 and 5.5) and the Brix degrees
(16, 20, 24 and 28%) during fermentation.
Results revealed that the best amount of ethanol was produced at
temperature of 30 º C, pH 5, and Brix degree in molasses 16%.
