Enhanced Cellulase Production from Bacillus subtilis by Optimizing Physical Parameters for Bioethanol Production

Table 5

Bioethanol production by SSF from wild grass employing B. subtilis cellulase and Z. mobilis.

Pretreatment	Substrate concentration (%, w/v)	Mode of SSF	SSF process parameters
			Reducing sugar* (g/L)	Ethanol yield (g/g)	Ethanol titre* (g/L)
Acid acetone	1%	Shake flask	1.10 ± 0.07	0.093	0.93 ± 0.07
Alkali	1%	Shake flask	1.25 ± 0.04	0.098	0.98 ± 0.06
Alkali	1%	Bioreactor	2.51 ± 0.03	0.22	2.23 ± 0.08
Alkali	5%	Shake flask	9.08 ± 0.06	0.15	7.56 ± 0.05
Alkali	5%	Bioreactor	13.22 ± 0.04	0.23	11.65 ± 0.04

^∗The values correspond to the maximum reducing sugar and maximum ethanol titre at a particular time.
Values are mean ± SE (𝑛=3).