Levan Production in Shake Flask and Fermenter Influence of Feeding Strategy on Levan Yield and Molecular Weight Distribution

Effect of feeding strategy on levan production was studied in a shake flask and a 5 L lab scale fermenter. In a shake flask, levan specific substrate yield (YP/S) increased from 0.35 g levan/g sucrose to 0.48 g levan/g sucrose with repeated batch feeding. In a 3 L reactor, levan productivity of 7.18 g/L h was obtained with the fed-batch mode of fermentation. The gel permeation chromatography results indicate that higher initial sucrose concentration under the fed-batch mode operation resulted in the formation of low molecular weight fractions (4 and 10 kDa). Thus, fed-batch fermentation favors levan production resulting in higher yield and productivity and also affects the molecular weight distribution of the biopolymer

Understanding the pyrolysis kinetics, thermodynamic, and environmental sustainability parameters of Sesamum indicum crop residue

In this work, the physiochemical characteristics, thermodynamics, and sustainability of the pyrolysis of Sesamum indicum biomass were assessed. The pyrolysis kinetics of sesame agro-residues performed using isoconversional techniques such as Kissinger, KAS, and OFW methods showed activation energies of 192, 120, and 123 kJ mol ^−1 , respectively. The impact of the pyrolysis temperature (550, 650, 750 °C) on the generation of biochar, bio-oil, and gas is also studied; the exergy efficiency increased from 82.7 at 550 °C to 87.3% at 750 °C with an increase in the temperature. Sesame biochar’s Van Krevalan diagram showed how its fuel-like characteristics also grew with rising temperatures. The input and output parameters showed a high agreement in the mass, energy, and exergy balance closures. However, it was shown that the overall energy efficiency was greater at 750 °C (71.2%) compared to 55.5% and 69.8% at 550 °C and 650 °C, respectively. Sustainability analysis showed that lower temperatures had a smaller impact on the environment

Levan Production in Shake Flask and Fermenter Influence of Feeding Strategy on Levan Yield and Molecular Weight Distribution

Effect of feeding strategy on levan production was studied in a shake flask and a 5 L lab scale fermenter. In a shake flask, levan specific substrate yield (YP/S) increased from 0.35 g levan/g sucrose to 0.48 g levan/g sucrose with repeated batch feeding. In a 3 L reactor, levan productivity of 7.18 g/L h was obtained with the fed-batch mode of fermentation. The gel permeation chromatography results indicate that higher initial sucrose concentration under the fed-batch mode operation resulted in the formation of low molecular weight fractions (4 and 10 kDa). Thus, fed-batch fermentation favors levan production resulting in higher yield and productivity and also affects the molecular weight distribution of the biopolymer