To improve the efficiency of ethanol production in a batch fermentation from sweet sorghum juice under a very high gravity (VHG) condition (~290 g/L of total sugar) by

Saccharomyces cerevisiae

NP01

repeatedbatch fermentation under an aerated condition (2.5 vvm for the first 4 h during every cycle) was done in a 5-L fermenter. The average ethanol concentration (

P

)

productivity (

Q

p

) and yield (

Y

p/s

) for five successive cycles were 112.31 g/L

1.55 g/L·h

-1

and 0.44

respectively with 80.97% sugar consumption. To complete sugar consumption

the total sugar of the juice was reduced to a high gravity (HG) level (~240 g/L). The results showed that yeast extract was not necessary for ethanol production

and aeration during every other cycle

i.e

.

alternating cycles

was sufficient to promote both yeast growth and ethanol production. The average

P

Q

p

and

Y

p/s

values for eight successive cycles with aeration during alternating cycles were 97.58 g/L

1.98 g/L·h and 0.41

respectively with 91.21% sugar consumption. The total fatty acids in the yeast cells under the aerated condition we

re~50% higher than without aeration

irrespective the initial sugar concentration

whereas the ergosterol contents under aeration condition were~29% to 49% higher than those without aeration.