Bioethanol production by baker's yeast in opts - effect of temperature and ph

This paper presented bioethanol production in oil palm trunk sap (OPTS) by
using baker's yeast - effect of temperature and pH. Baker's yeast as known as
Saccharomyces cerevisiae.
Due to rapid growth in population and industrialization, ecofriendly
bioethanol demand is rising rapidly wbrldwide. Bioethanol
offers more
advantages than fossil fuel since it provides renewable and sustainable sources of
energy. The most commonly. employed methods for bioethanol generation are
fermentation using baker's yeast (Ahrnad
et al., 2011). Baker's yeast is commonly used
because it is the cheapest strain available for conversion of
V
V
biomass substrate and
produces high yield of ethanol. Due to
the cost of raw materials, the cheap renewable
agricultural wastes are chosen as alternative substrates to produce ethanol. This study is
focused on studying the parameters of temperature, (27 t-39 °C) and pH (3-7) for
bioethanol production from oil palm trunk sap (OPTS) by baker's yeast,
Saccharomyces
cerevisiae. The yeast is grown in nutrient broth (NB) and ferment in oil palm trunk sap
(OPTS) medium at- different conditions. By analyzing temperature and pH parameters,
specific growth rate, glucose consumption rate, specific ethanol production- and
production yield of ethanol can be determined. The analytical technique involved is
high-performance liquid chromatography (HPLC) for glucose consumption and ethanol
production while cell dry weight (CDW) is determined for growth. From this study, the
maximum pH and temperature for bioethanol production were determined to be pH. 6
and 30 °C respectively. The maximum concentration of bioethanol for pH was 34.4 g/L
while maximum concentration of bioethanol for temperature, it was 43.4 g/L. In
addition, the maximum bioethanol production yield was 0.6 g/g at pH 6 and the
maximum bioethanol production yield at temperature at 33 °C was 0.46 g/g. The
maximum production yield was contrast with to maximum bioethanol production. This
is because the total sugar concentration at 30 °C was too high compared to others: This
level might exceed sugar critical level and cause substrate, inhibition to occur. This
factor inhibited the ethanol productivity to be produced in high level. Last but not least,
it could be concluded that the optimum pH and temperature for growth and production
of bioethanol using S.
cerevisiae
in OPTS were in the range of pH
5-6 and temperature
30 -36°C.