Evaluation of
sugarcane-based byproducts media for improvement in production of Bacillus thuringiensis
israelensis
Gopinathan C. and Hana mol K.E.
Res. J. Biotech.; Vol. 21(1); 262-268;
doi: https://doi.org/10.25303/211rjbt2620268; (2026)
Abstract
This study optimized Bacillus thuringiensis israelensis (Bti)-based biopesticide
production using cost-effective substrates molasses, jaggery and sugarcane juice,
in batch and fed-batch fermentations. Molasses was pre-treated to hydrolyse sucrose
into glucose and fructose using enzyme invertase, produced via solid-state fermentation
using Aspergillus niger, enhancing substrate suitability. Bti growth was evaluated
under varying substrate concentrations, aeration conditions and nutrient supplements.
Fed-batch fermentation proved superior to batch fermentation, mitigating catabolite
repression at high substrate concentrations and supporting enhanced growth and toxin
production. Sugarcane juice at 10 g/L sugar concentration yielded the highest optical
density (OD) in fed-batch mode. Calcium chloride supplementation (0.1%) further
improved Bti biomass yield and sporulation.
Larvicidal assays against Aedes aegypti larvae revealed 90% mortality rate for media
supplemented with sugarcane juice and molasses under fed-batch conditions with calcium
chloride while 70% mortality was observed in batch fermentation. These findings
highlight fed-batch fermentation as an efficient strategy to maximize Bti productivity
and bioactivity. The study emphasises on the economic viability of using sugarcane-derived
substrates, leveraging India’s position as the second-largest sugarcane producer
globally. By integrating low-cost substrates and optimized fermentation, this scalable
approach offers a sustainable solution for mosquito control programs.
