Fermentation of Sweet Sorghum (Sorghum bicolor L. Moench) Using Immobilized Yeast (Saccharomyces cerevisiae) Entrapped in Calcium Alginate Beads

Abstract

As the population grows, there is a need to address the continuous depletion of non-renewable energy sources and their negative effects on the environment. This led to a substantial assessment of possible innovations and raw materials to increase the volumetric productivity of alternative fuels to supply the energy needed worldwide. In addition to its environment-friendly properties, a biofuel derived from plant-based sources is also a sustainable material. For high ethanol production from plant-based biofuel, several techniques have been developed, including cell or enzyme immobilization. The key purposes of utilizing immobilized cells or enzymes are to improve bioreactor yield with upgraded enzyme establishment and to increase enzyme utilization. The fermentation of sweet sorghum extract to produce ethanol was conducted in this study, and it was found that the optimum sodium alginate concentration for immobilizing yeast is 3% w/v. It was also found that the free yeast has a shorter optimum fermentation period which is four days (96 h), in comparison with the immobilized yeast, which is five days (120 h). The immobilized yeast has a higher ethanol concentration produced and percent conversion compared to the free yeast. The immobilized yeast entrapped in calcium alginate beads permitted ten five-day (120 h) reuse cycles which are still in stable final ethanol concentration and percent conversion. Due to a lack of experimental support in the necessary condition (optimum level of the number of fermentation days and the concentration of sodium alginate) for the optimal ethanol yield from the extract of sweet sorghum, this study was conducted. This study also tried to address the global demand for ethanol by specifying the optimum conditions necessary for efficient fermentation, specifically for ethanol production using an extract from sweet sorghum. Furthermore, this experimental work serves as a basis for further investigations concerning ethanol production from Agri-based materials, such as sweet sorghum.

Production of Chemically Modified Bio-Based Wood Adhesive from Camote and Cassava Peels

“…Numerous studies on these biomass sources have been explored to find out their potential as renewable sources. Some of these are sweet sorghum juice as a potential raw material for alcohol production [ 17 ] and peanut shell and cornick industry wastewater as raw materials for briquette production [ 18 ]. Optimization studies on these biomass sources have also been explored [ 19 ].…”

Preparation of glucoamylase microcapsule beads and application in solid‐state fermentation

“…Zong et al 5 prepared glucoamylase microcapsules using the water/oil/water (W/O/W) complex coacervation freeze-drying method. The solid-state sustained-release results showed that the glucoamylase microcapsules could slowly release in the solid state for over 336 h. Cadiz et al 6 used sodium alginate to immobilize yeast and found that immobilized yeast has a longer action time. The earlier research proves that immobilization technology can endow enzymes with slow-release properties and effectively extend the action time of enzymes.…”

“…prepared glucoamylase microcapsules using the water/oil/water (W/O/W) complex coacervation freeze‐drying method. The solid‐state sustained‐release results showed that the glucoamylase microcapsules could slowly release in the solid state for over 336 h. Cadiz et al 6 . used sodium alginate to immobilize yeast and found that immobilized yeast has a longer action time.…”