Dried and milled bagasse was pretreated and hydrolysed in
a single step. Sulphuric acid (H2SO4) (10e70 g kg1) in a water
solution was used during pretreatment and hydrolysis of the
bagasse. The appropriate mixture was made up to a total
volume of 100 cm3 containing 5 g kg1 bagasse and then
subjected to irradiation in a standard domestic microwave
oven at different power inputs of 18e72 kJ g1 of dry biomass.
The temperature of the mixture was measured before and
after treatment and was found to remain constant at 82 1 C
throughout the duration of each experiment. After pretreatment
and hydrolysis, the hydrolysate was filtered and the
solid fraction was analysed using scanning electron microscopy
(SEM) and Fourier Transform Infrared (FT-IR) to determine
the effectiveness of pretreatment and hydrolysis on the
liberation of cellulose and hemicellulose from the bagasse
plant material. The liquid fraction was analysed for total as
well as 5 and 6 carbon sugar content using high performance
liquid chromatography (HPLC) with a Shodex SP0810 column
and a refractive index detector. The cell count of the broth was
monitored during fermentation using ultraviolet spectrometry
(UV). Fermentation of liquid hydrolysates was done in
250 cm3 Duran bottles in an incubator at 32 C and pH of 4.8 for
24 h. Z. mobilis (5 g dry weight per litre of hydrolysate) and S.
cerevisiae (10 g dry weight per litre of hydrolysate) were added
to the hydrolysates to convert both 5- and 6-carbon sugars in
the hydrolysate to ethanol.