Preliminary Study on Biethanol Production from Starchy Foodwastes by Immobilized Saccharomyces cerevisiae

Abstract

Dumping of food wastes into the landfill resulted in major environmental pollution. However, attempted had been made to develop these wastes into a new renewable and sustainable energy. Liquid biofuels, bioethanol can be produced from a variety of feedstock including biomass and food crops or wastes. Therefore, in this study, starchy food wastes of bread, rice and potatoes were utilized as a potential feedstock for the bioethanol production. Yeast Saccharomyces cerevisiae was immobilized in 2% calcium alginate beads using entrapment technique. Then, the effect of temperature on bioethanol efficiency was investigated using the immobilized yeasts. From the result, highest fermentation efficiency of 1.24% was obtained at temperature 30°C, 48 h with agitation speed of 150 rpm. However, further research and studies are required in order to optimize the bioethanol production from fermentation process of starchy foodwastes.

Optimization of bioethanol production from papaya waste through fermentation using response surface methodology (RSM)

“…3. The ethanol concentration decreased with increasing pH and decreasing temperature, which is in agreement with previous study by Abdulla et al [13]. The maximum ethanol concentration of 0.2247 g/ml was achieved at 45℃ with pH 3.0.…”

“…These two parameters were varied in the range of pH 3.0 -6.0, and 25 -45℃, while the incubation time was kept constant at 60 h. It was observed that pH and temperature have great effect on the ethanol concentration. This was further proven by the ANOVA which shows both pH and temperature have p-values <0.0001.The ethanol concentration decreased with increasing pH and decreasing temperature, which is in agreement with previous study by Abdulla et al[13]. The maximum ethanol concentration of 0.2247 g/ml was achieved at 45℃ with pH 3.0.…”

“…The minimum ethanol concentration of 0.1754 g/ml was obtained at 25℃ with 6.0. According to Abdulla et al[13] , the yield of bioethanol will have an increasing trend until pH 5, which will then decrease beyond pH 5[13,14]. Hence, the response obtained partially agreed with the previous studies, where pH above 5 did not support fermentation process effectively.…”

“…A research has been done to produce bioethanol using papaya peels through fermentation using the one-variable-at-a-time (OVAT) approach to optimize yield [13]. OVAT is often used in bioethanol production experiments.…”

Fruit residues as biomass for bioethanol production using enzymatic hydrolysis as pretreatment

“…Degradation of hemicellulose gives rise to both glucose and other sugars such as xylose, arabinose, mannose, galactose, and rhamnose prior to fermentation, which converts the released sugars into bioethanol and CO 2 [6,20]. [21] tested the heating and acid treatment of papaya peel and only 0.8 g/L of bioethanol was produced. [22] tested acidic and alkaline conditions, followed by enzymatic hydrolysis with a cellulase complex to release free sugars from mango peel to produce bioethanol.…”