Improving Sugar Conversion and Bioethanol Yield through Transgenic Sugarcane Clone in South Africa

摘要

This paper reports on agronomic properties and sugar conversion of bagasse from two sugarcane clones (transgenic and wild type). Transgenic clone showed higher stalk height (144.8 cm), stalk population (129 603), soluble sugar content in the juice (147 kg/ton cane) than the wild type (123 cm, 104 039, 140 kg/ton cane, respectively), but stalk diameter and cane yield per hectare were similar. The bagasse from transgenic clone was more digestible (up to 98.7% of potential glucose) than the wild type (84.8%). The total sugar yield from the bagasse after pretreatment and enzymatic hydrolysis was also higher for transgenic clone (88% of potential sugar) than the wild type (82.7%). It was further observed that ethanol yield after simultaneous saccharification and fermentation of pretreated bagasse based on best condition was higher for transgenic clone (29.6 g/L, corresponding to 75.8% of potential glucose in pretreated material) compared to the wild type (26.8 g/L, corresponding to 69.2% of potential glucose). The observed differences could be attributed to chemical composition differences among the clones. The bagasse from transgenic clone showed lower lignin content (16.4 % dry weight) compared to wild type (21.3 %). The results provide evidence that the use of bagasse from transgenic clone yields more ethanol than conventional varieties, therefore, increasing ethanol production per feedstock.