The theoretical maximum amount of ethanol is calculated based on the mass of sugars that are consumed (difference between the initial total sugars and the final total sugars). The theoretical amount of the sugar mass being converted into
ethanol is about 51% . The bacterium Zymomonas mobilis NRRL 806 produced about 96% of the maximum theoretical amount of ethanol (Table 8). It is in agreement with other similar works that attempted to reuse agro industrial wastes (reported 98% yield of ethanol from hydrolyzed waste starch in 9 h of batch fermentation with Zymomonas mobilis ATCC 31821 ; reported 92.4% yield of ethanol from pineapple juice in 21 h of batch fermentation with Zymomonas mobilis ATCC 10988) and it is also similar to other works dealing with strains of Zymomonas mobilis using other kinds of carbon sources . reported a 95% yield in synthetic non sterilized media containing glucose, peptone and yeast extract with a low pH
tolerant strain, derived from Zymomonas mobilis ATCC 31821, and [14] reported 90% yield from hydrolyzed waste starch in 11 h batch fermentation with a local industrial strain of Saccharomyces cerevisiae, while the yeast Saccharomyces cerevisiae LPB1 produced about 89% (Table 8)