Enzymatic Digestion of Algal Carbohydrates for Biofuel Applications

Abstract

As the globe is hurtled into the era of global warming, humanity is becoming more conscious of its dependency on petroleum and its unsustainable depleting supply. The once wonderful fuel of petroleum is the main cause for the vast accumulation of carbon dioxide throughout the Earth’s environment. The search for the magic bullet for renewable, clean energy is enveloping society. A variety of alternative fuel sources have and are being investigated. Biodiesel from terrestrial crops such as corn, palm oil, switchgrass, and soybeans were strong contenders, until their use as biodiesel threatened the global food supply. Algae has quickly become the front-runner for the candidacy of the next global fuel source. The previously mentioned terrestrial crops are not capable of meeting the global demand for transport fuels, but microalgae have the potential to keep vehicles running. Algae are incredibly efficient; they use energy from the sun to reproduce and produce a natural oil. The quantity of oil produced by the algae exceeds the capability of the terrestrial plants. Additionally, the algal biomass itself contains complex carbohydrates that can be broken into simple sugars, like glucose, and turned into ethanol. This study focuses on an enzymatic digestion of algal carbohydrates. Using three enzymes, α-amylase, cellulase, and pectinase, the algae was digested while controlling pH, temperature, duration of incubation, and sonication of the algae. The concentration of glucose present in each sample was measured using a glucose assay with UV/Vis spectroscopy. Certain conditions allowed the enzymes to work more efficiently than other, but overll, the addition iv of enzymes in all conditions increased the amount of glucose present in the algae when compared to control groups.