| Abstrakt: |
This study investigated the production of levan biopolymer utilizing cane molasses, an agro-industrial waste, as a substrate. The kinetics of growth, substrate consumption, and levan production by Bacillus megaterium KM3 were examined in bioreactor design employing cane molasses-based media. Experiments were conducted in triplicate to ensure reproducibility, first in a 1L shake flask under optimized conditions, followed by scale-up to a 5L bioreactor, achieving a maximum levan yield as 18.5 g/L. The logistic model for microbial growth and Luedeking–Piret equation for product formation and substrate utilization were found to fit the experimental data, with a maximum specific growth rate constant (µm) as 0.6 h−1. The obtained levan was purified, and monosaccharide analysis by HPLC, confirmed the presence of the fructose monomer. Further structural characterization for the presence of functional group was performed using FTIR. Congo red analysis reveals a triple-helix structure. XRD analysis indicated the levan's non-crystalline amorphous nature, while thermogravimetric analysis demonstrated its high thermal stability. In addition, the in vitro biological activity of levan was evaluated, where it showed strong antioxidant activities to scavenge DPPH radical, hydroxyl radical, and reducing power in dose-dependent manner. The results showcased the promising structural and functional properties of the obtained levan, positioning it as an attractive biopolymer for a wide range of industrial applications. By turning trash into gold, this study provides a model of clean technology's potential to boost productivity while simultaneously lessening its negative effects on the environment. [ABSTRACT FROM AUTHOR] |
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