Developing a mesophilic co-culture for direct conversion of cellulose to butanol in consolidated bioprocess

Table 1 Cellulose degradation and cellulase activities for different microbial consortiums

	CK^a	Consortium N3	Strain N3-1^b	Strain N3-2^b	Strain N3-3^b	Strain N3-4^b	Strain N3-5^b	Combination of isolated strains^c	Pooled SEM
Degradation (%)	4.76 f	63.35 a	7.08 e	29.83 b	11.57 d	18.36 c	12.33 d	21.77 c	1.63
Endoglucanase activity (U/mL)	0 f	0.67 a	0.13 cd	0.26 b	0.11 de	0.08 e	0.19 bc	0.22 bc	0.04
Exoglucanase activity (U/mL)	0 d	0.54 a	0.08 c	0.16 b	0.02 d	0.03 d	0.09 c	0.17 b	0.05
β-Glucosidase activity(U/mL)	0 d	0.25 a	0.12 b	0.23 a	0.06 c	0.10 b	0.14 b	0.13 b	0.02

For each row of the table, values with the different lowercase letters are significantly different (P < 0.05) while values with the same letter mean no significant difference (P > 0.05)
^aCK means a control without any inoculum
^bStrains N3-1, N3-2, N3-3, N3-4, and N3-5 stand for five different isolations screened from consortium N3, corresponding to Proteiniphilum acetatigenes, C. celerecrescens, C. saccharolyticum, C. ramosum, and Clostridium sp., respectively
^cCombination of isolated strains was a recombination of the isolated strains from N3-1 to N3-5 in the same ratio as an artificial consortium