From the graphs showed growth and ethanol production,
On the equal time.The rate of increase of the two graphs do not differ much.
Then you see graph A the first time are micro-organisms are same grown up.If adding supplements the growth of micro-organisms start growing,
But then you consider the graph that without supplementation is the best grow too micro-organisms.
So graph B is the ethanol production this graph show the micro-organisms cause ethanol, So the volume increases then supplemented with 0.5% yeast extract thiamine and micronutrients , the rate of increase in microbial affect the ethanol in the graph B. Both variable corresponding graph