Sorghum biomass is a potential feedstock for lignocellulosic bioethanol production. The selection of suitable sorghum variety is essential to obtain high ethanol yield. In this paper we screened sorghum varieties belonging to sweet sorghum, post rainy sorghum, and hybrid sorghum. These varieties were screened based on their agronomic traits, amenability to pretreatment methods, and enzymatic digestibility. The sorghum biomass was pretreated using glycerol (60 %) at 190 ̊C for 60 min and aqueous ammonia (15 %) at 120 ̊C for 60 min. The digestibility of the pretreated biomass was determined using commercial cellulase (Cellic CTec2) at 10U/g loading, and the structural changes in the pretreated biomass were analyzed by spectroscopy and scanning electron microscopy. Sweet sorghum varieties showed significant variations in phenotypic traits such as fresh stalk yield, dry fodder yield, and juice yield. The cellulose digestibility among the sorghum varieties after the pretreatment also differed significantly. The cellulose digestibility levels of glycerol range from 64 % to 89 % and ammonia pretreated sorghum from 63 % to 81 %. The total sugar yields varied from 227 mg/g to 356 mg/g and 209 mg/g to 313 mg/g for sorghum pretreated with ammonia and glycerol, respectively. Although the delignification of sorghum varieties was higher (31%–65%) after ammonia pretreatment than glycerol pretreatment, the cellulose digestibility was higher for the glycerol pretreated biomass. These results indicated that effect of delignification on cellulose digestibility is trivial. This study explores factors affecting pretreatment and cellulose digestibility of sorghum varieties for maximum sugar yield in the cellulosic ethanol process.

高粱生物质是木质纤维素生物乙醇生产的潜在原料。选择合适的高粱品种对于获得高乙醇产量至关重要。在本文中，我们筛选了属于甜高粱，雨后高粱和杂交高粱的高粱品种。根据其农艺性状，对预处理方法的适应性和酶消化率筛选这些品种。高粱生物质在190°C下用甘油（60％）预处理60分钟，在120°C下用氨水（15％）预处理60分钟。使用市售纤维素酶（Cellic CTec2）以10U / g的载量测定预处理过的生物质的消化率，并通过光谱学和扫描电子显微镜分析了预处理过的生物质的结构变化。甜高粱品种在表型性状上表现出显着变化，例如新鲜秸秆产量，干饲料产量和果汁产量。预处理后高粱品种之间的纤维素消化率也显着不同。甘油的纤维素消化率范围为64％至89％，氨水预处理的高粱为63％至81％。对于用氨和甘油预处理的高粱，总糖产量分别为227 mg / g至356 mg / g和209 mg / g至313 mg / g。尽管氨预处理后高粱品种的去木质度比甘油预处理高（31％–65％），但甘油预处理的生物质的纤维素消化率更高。这些结果表明脱木质素对纤维素消化率的影响很小。