Improved sugar yields from biomass sorghum feedstocks: comparing low-lignin mutants and pretreatment chemistries

Table 1 Chemical composition of the sorghum feedstocks (g/g TS)

	Wild type	Stacked mutant	bmr6 mutant	bmr12 mutant
Glucan	0.243 ± 0.007a	0.252 ± 0.010a	0.226 ± 0.002b	0.253 ± 0.001a
Xylan	0.144 ± 0.004b	0.150 ± 0.005b	0.135 ± 0.001c	0.163 ± 0.001a
Galactan	0.0110 ± 0.0003b	0.0112 ± 0.0005ab	0.0114 ± 0.0004ab	0.0119 ± 0.0005a
Arabinan	0.0255 ± 0.0009bc	0.0266 ± 0.0012ab	0.0246 ± 0.0003c	0.0277 ± 0.0003a
Acetyl	0.0312 ± 0.0007a	0.0227 ± 0.0003b	0.0182 ± 0.0002d	0.0200 ± 0.0002c
Soluble Klason lignin	0.0095 ± 0.0007a	0.0105 ± 0.0025a	0.0106 ± 0.0002a	0.0097 ± 0.0009a
Insoluble Klason lignin	0.103 ± 0.002a	0.0833 ± 0.0010d	0.0880 ± 0.0009c	0.0967 ± 0.0016b
Total Klason lignin	0.113 ± 0.002a	0.0939 ± 0.0030d	0.0985 ± 0.0009c	0.106 ± 0.001b
Starch	0.0313 ± 0.0015a	0.0286 ± 0.0002a	0.0229 ± 0.0013b	0.0250 ± 0.0007b
Total soluble sugars	0.153 ± 0.001c	0.158 ± 0.001b	0.169 ± 0.002a	0.124 ± 0.001d
Water extractives	0.285 ± 0.020b	0.290 ± 0.027b	0.338 ± 0.005a	0.260 ± 0.006b
Ethanol extractives	0.0327 ± 0.0008ab	0.0321 ± 0.0007b	0.0329 ± 0.0013ab	0.0342 ± 0.0002a
Protein	0.0506	0.0547	0.0543	0.0534
Mineral compounds	0.0929 ± 0.0007b	0.0881 ± 0.0022c	0.0989 ± 0.0012a	0.0931 ± 0.0028b

All samples analyzed in triplicate except for starch (duplicate) and protein (singlet). Total soluble sugars = sucrose + free glucose + free fructose. The uncertainty corresponds to 95% confidence interval of the mean. For each chemical compound, sorghum feedstocks with the same letter are not significantly different with the Tukey–Kramer multiple comparison test

ISSN: 2731-3654