Current Research Journal of Biological Sciences 3(1): 42-51, 2011
ISSN: 2041-0778
© Maxwell Scientific Organization, 2011
Received: October 19, 2010 Accepted: November 22, 2010 Published: January 15, 2011
Corresponding Author: Dr. K. Suthindhiran, Assistant Professor, School of Biosciences and Technology, VIT University,
Vellore-632014, Tamil Nadu, India. Tel.: +91 9944367090; Fax: +91-416- 2243092 / 2240411
42
Ethanol Production from Sago Waste Using Saccharomyces cerevisiae Vits-M1
D. Subashini, J. Ejilane, A. Radha, M.A. Jayasri and K. Suthindhiran
School of Biosciences and Technology, VIT University, Vellore-632014, Tamil Nadu, India
Abstract: The present study deals with the biotechnological production of ethanol from sago waste materials.
As petroleum has become depleted, renewable energy production has started to gain attention all over the
world, including the production of ethanol from sago wastes. In our research we have standardized the
production of ethanol from sago wastes using Saccharomyces cerevisiae strain isolated from molasses. The
production of ethanol was carried out by means of simultaneous saccharification with acids, followed by
fermentation. The yeast strains were isolated from either batter or molasses and the taxonomy was studied by
phenotypic characters in comparison with the standard strain Saccharomyces cerevisiae MTCC 173. Among
the two isolated strains, S. cerevisiae VITS-M1 isolated from molasses showed better survival rate in different
sugars such as glucose, sucrose, maltose and galactose except lactose; it also showed better survival rate at high
ethanol concentration and at acidic pH. The saccharification process of sago liquid waste and solid waste was
standardized using hydrochloric acid and sulphuric acid under different treatments. The fermented product,
ethanol was distilled using laboratory model distillation unit and measured qualitatively using gas
chromatography in comparison with the standard analytical grade ethanol. The overall experimental data
indicates that the sago liquid waste yielded more ethanol by simultaneous saccharification with 0.3N HCl and
0.3N H
2
SO
4
and fermentation with the S. cerevisiae VITS-M1 isolated from molasses.
Key words: Ethanol, fermentation, saccharification, Saccharomyces cerevisiae VITS-M1, sago wastes
INTRODUCTION
Ethanol, also known as grain alcohol, can be made
from any sugary (or) starchy agricultural crop such as
corn, barley, wheat or from cellulosic biomass such as
wood, paper pulp or agricultural waste (Thomas and
Kwong, 2001). Large quantities of ethanol are used as
solvent and chemical feed stock in various industries.
Although most of the industrial ethanol is currently
produced from the catalytic conversion of ethylene,
considerable research has been focused on fermentation
based ethanol production from various renewable
biomass sources (Ladisch and Svarczkopf, 1991;
Worley et al ., 1992; Sosulski and Sosulski, 1994;
Ingledew et al., 1995; Wang et al., 1997). During energy
crisis in 1970s, there were numerous research efforts
directed towards the development of alternative energy
sources, and ethanol production from agricultural
products (Nagashima et al., 1984). Consequently, this
technology has been successfully used in Brazil where a
large number of cars are run on either Gasohol (76%
gasoline and 24% ethanol) or pure ethanol. Furthermore,
the use of lead in gasoline has been prohibited in many
countries and ethanol is now used in place of lead as an
octane enhancer. The world ethyl alcohol production has
reached about 51,000 mL (Renewable Fuels
Association, 2007), being the USA and Brazil the first
producers. In average, 73% of produced ethanol
worldwide corresponds to fuel ethanol, 17% to beverage
ethanol and 10% to industrial ethanol.
Tapioca cassava (Manihot esculenta crantz ) was
introduced in India during the later part of the 17
th
century
by the Portuguese living in the state of Kerala. Cassava,
a tuber crop which is also known as manioc, sagu, yucca
and tapioca is one of the most potential root crops with
great potentials for bioethanol production. It is one of the
most important subsistence food and industrial crop for
the developing countries (Balagopalan et al., 1988).
Cassava starch costs 15-30% less to produce per acre than
corn starch making cassava an alternate and strategic
source of renewable energy, raising the possibility that it
could be used globally to alleviate dependence on fossil
fuels (Hankoua and Besong, 2009). Tapioca is valued for
its starch content and mainly used by sago industries.
Recently cassava has emerged as the primary starch based
feed stock for future fuel ethanol production in Africa and
Asia (Drapoch, 2008). It has been vital for many
industries with the application of biotechnology,
especially in the fermentation industries. There are about
800 sago and starch units situated throughout the state of
Tamilnadu, India. The sago industry is spread over Salem,
Namakkal, Dharmapuri, Erode, Trichy and Perambalur
districts of Tamilnadu, India. Cassava is one of the
main sources for ethanol production (Lindeman and