Classified locality Yeasts have been culturing in plantology
department at the Faculty of Science-University of Damascus,
from genera of Pichia, Candida, Geotrichum, Rhodotorula, Phaffia
on solid Czhapek agar medium, and after incubated in appropr
iate
conditions their colonies showed evidence of different colors to
produce a variety of pigments. Then it cultured in liquid Czhapek
medium to increase biomass and the genera producing
endocellular pigment separated from the medium by filtration with
added ethanol on them and blasting cells by ultrasonic waves to
get a pigment, while the genera producing exocellular pigment is
separated about the liquid medium also by filtration but the solvent
was added to the medium containing the pigment.
Rhodotorula yeast was isolated from various local sources. Fifty isolates
were collected during the years 2012-2013 where 13 were isolated from soil, 23
from tree leaves and 14 from food. The isolates AUX system. Were classified
into three Rhodoto
rula species: R. mucilaginosa, R. glutinis and R. minuta with
76%, 20% and 4% respectively using API 20c. Six methods were applied in
breaking down the yeast cells and extracting the carotenoids. It was shown the
quantity of carotenoides extracted with the modified method by adding DMSO
to the yeast biomass and incubating for 24 hrs at 4˚C yielded in higher
quantities when compared with the other five methods. All isolates were able to
produce carotenoides but they varied in their efficiency where the isolate A24
(R.mucilaginosa) isolated from food was distinguished by its high level of
production which reached 658.23 μg/g dry weight compared with the others.
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.
