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allied
academies
Archives of Industrial Biotechnology | Volume 2
May 14-15, 2018 | Montreal, Canada
World Yeast Congress
I
n an effort to establish a holistic and S & T-based village-
scale nipa bioethanol industry, an effort to identify super
indigenous yeast species to improve ethanol fermentation
and to identify microbial community structure residing in
and responsible for natural fermentation of nipa sap. A total
of 13 yeast isolates were obtained from the natural nipa
sap fermentation in two selected sites of the Philippines,
Brgy. Cabaggan, Pamplona Cagayan and Brgy. Tapucan,
Mauban Quezon. They were purified and categorized
into groups based on the combinations of cultural and
molecular characteristics. Based on the banding patterns of
isolates generated by microsatellite (GTG)5 fingerprinting,
the thirteen isolates were clustered into four groups.
Representatives of each group were sequenced using
Internal Transcribed Spacer (ITS). After sequencing the ITS
PCR genes and phylogenetic analysis using MEGA7, three
isolates shared 99% identity of the ITS rDNA genes with
Saccharomyces cerevisiae
and the other one isolate showed
99% match with two P.
kudriavzevii
strains. These four
representative yeast isolates were subjected to different
stress tolerance tests. Among all yeasts, YC03 strain was
the most highly acid tolerant (tolerated pH 2.0) and high
temperature tolerant (tolerated 45°C). These interesting
characteristics may find applications in further molecular
biology researches such as the use of this strain as ‘yeast cell
factory’. The four profiled yeasts were evaluated for ethanol
production efficiency using different ethanol production
media and top ethanol producer was chosen. YMU1 strain
gave the highest ethanol produced using different media
with comparable ethanol yield (51.70 g L-
1
) against reference
strain
HBY3
(51.90 g L-
1
) after 48 hour fermentation using
synthetic media (YPD broth). However, using molasses-based
medium and simulated nipa sap medium, ethanol produced
by yeast strain YMU1 was observed to be significantly
different from HBY3 after 48 hours of fermentation. Ethanol
yield coefficient and specific growth rate of YMU1 were
computed as 0.51 g g-1 and 0.0072 h-1, respectively. The
application of selected isolates as fermenting organism in
bioethanol production from various feedstock in addition to
nipa sap could be investigated in further studies.
e:
cigfah22@yahoo.comScreening and characterization of stress tolerant yeasts in Nipa Sap fermentation from Cagayan and
Quezon Provinces, Philippines
James Paul T Madigal
and
Shirley C Agrupis
Mariano Marcos State University, philippines