Valorization of banana leaves as low cost substrate for the production of butanol
aRakesh Sajjanshetty, aNeelkant S. Kulkarni, aKumar Shankar, bS.K. Jayalakshmi and a*Kuruba Sreeramulu
aDepartment of Biochemistry, Gulbarga University, Kalaburagi-585106, Karnataka, (India) bCollege of Agriculture, (University of Agricultural Sciences- Raichur), Kalaburagi-585104 (India) a*Corresponding author: Email: ksramu@rediffmail.com
ABSTRACT
Banana leaves, often disposed off as agro-waste, were used as a low-cost feedstock for butanol production. Steam pretreated banana leaves hydrolyzed by lignocellulolytic enzymes produced by Sphingobacterium sp. ksn 11, and obtained 35.36 g/L of fermentable sugars. Phenolic compounds from the banana hydrolysate were removed or detoxified using corn husk residue as an adsorbent. The hydrolyzate was then fermented by Clostridium acetobutylicum 2337 (NCIM) and obtained 1.56 g/L butanol, which was further improved upon detoxification and obtained a total ABE of 4.45g/L with 2.28 g/L butanol. Furthermore, addition of 0.55% proline and histidine aminoacids to the fermentation medium increased butanol production to 3.97 g/L and total ABE to 7.57 g/L.