TABLE 2.

Switchgrass composition for raw, nontreated material and material exposed to two microbial and hydrothermal treatments

Switchgrass	Treatmenta	Glucan		Xylan		Arabinan		Inert material
		Concn (%)b	Mass (g)c	Concn (%)	Mass (g)	Concn (%)	Mass (g)	Concn (%)	Mass (g)
COMT3(−)	Raw	36 ± 0.8	1.8	26 ± 1.3	1.3	3.9 ± 0.3	0.2	34 ± 2.4	1.7
	T→M→T→M	46 ± 1.3	0.7	17 ± 0.8	0.4	0.8 ± 0.0	0.0	37 ± 2.1	0.5
COMT3(+)	Raw	34 ± 7.0	1.7	26 ± 0.3	1.3	3.5 ± 0.1	0.2	37 ± 0.9	1.9
	T→M→T→M	45 ± 1.2	0.6	11 ± 0.2	0.1	NDd	0.0	44 ± 1.4	0.5
MYB WT	Raw	37 ± 1.4	1.8	24 ± 0.3	1.1	2.6 ± 0.1	0.1	37 ± 1.6	1.9
	T→M→T→M	60 ± 0.9	1.3	12 ± 0.4	0.3	ND	0.0	27 ± 1.3	0.6
MYB Trans	Raw	37 ± 1.6	1.9	25 ± 0.3	1.3	3.3 ± 0.4	0.2	35 ± 1.5	1.7
	T→M→T→M	53 ± 1.1	0.9	8.8 ± 0.4	0.2	ND	0.0	38 ± 1.3	0.7
Cave-in-Rock	Raw	37 ± 1.1	1.9	25 ± 0.8	1.2	3.2 ± 0.3	0.2	35 ± 2.1	1.8
	T→M→T→M	55 ± 1.4	0.9	8.6 ± 0.2	0.1	ND	0.0	36 ± 1.5	0.5

^aM, microbial treatment; T, hydrothermal treatment. Switchgrass was washed following each treatment step, and the material after washing was used for the next planned treatment.

^bValues are means ± standard deviations.

^cThe average mass compositional values were calculated based on a 5-g/liter initial loading.

^dND, none detected.