Ethanol Assay Kit (Liquid Ready)

The Ethanol Assay Kit is an enzymatic test kit developed by Megazyme for the determination of ethanol in a variety of samples. The kit has been validated in a single laboratory for use with Kombucha fermented drinks, fruit juices and low-alcohol beer samples. The commercially available Ethanol Assay Kit (Megazyme catalogue no. K-ETOH) contains all components required for the analysis. Quantification is based on the oxidation of ethanol to acetaldehyde by alcohol dehydrogenase and further oxidation of acetaldehyde by acetaldehyde dehydrogenase with conversion of NAD⁺ to NADH. The single laboratory validation (SLV) outlined in this document was performed on a sample set of eight different commercial Kombucha products purchased in Ireland, a set of five Cerilliant aqueous ethanol solutions, two BCR low-alcohol beer reference materials, two alcohol-free beer samples and two fruit juice samples against SMPR 2016.001 (1). Parameters examined during the validation included Working range, Selectivity, Limit of Detection (LOD), Limit of Quantification (LOQ), Trueness (bias), Precision (reproducibility and repeatability), Robustness and Stability.

Marine macroalgae and aquaculture organisms have in common to form problematic biomass, either when washed ashore after extensive blooms or as processing remains, which accumulate in aquaculture facilities. Both sources of biomass are commonly regarded as waste. This study aimed to investigate whether both sources of waste can be combined in a beneficial way to yield value-added products. Crude extracts of shrimp (Penaeus vannamei) and crayfish (Cherax quadricarinatus) remains were analyzed for their catalytic potential and functional properties. Shrimp extracts showed a high potential for degrading β-1,3-glycosidic bonds (laminarin), while crayfish extracts showed a high potential for degrading β-1,4-glycosidic bonds (cellulose). The highest activities were observed at pH 4 to pH 6 and at 50 to 60°C, with an optimum range between 30 and 40°C. Pre-treated brown algae, Sargassum horridum, were incubated with the crude crustacean extracts. The extracts were capable of hydrolyzing brown algae biomass, thereby liberating glucose. Blends of shrimp and crayfish extracts were more efficient than shrimp extracts alone. The produced glucose was fermented by common yeast to bio-ethanol. This “proof of concept” showed that putative bio-waste can be utilized to extract active enzymes and suitable substrates for the production of value-added products such as bio-ethanol. This approach of combining two different sources of waste in a complementary process may contribute to the mitigation of marine bio-waste and be considered a valuable feedstock for biotechnological applications.

The rapid growth of the world population led to an exponential growth in industrial activity all around the world. Consequently, CO₂ emissions have risen almost 400% since 1950 due to human activities. In this context, microalgae biomass has emerged as a renewable and sustainable feedstock for producing third-generation biofuels. This study explores the laboratory-scale production of bioethanol and biomethane from dried algal biomass. The first step was to evaluate and optimize the production of glucose from the biomass. Thus, three different techniques with three different solvents were tested to identify the most effective and efficient in terms of saccharification yield. With the assistance of an autoclave or a high-temperature water bath and 0.2 M NaOH as a solvent, yields of 79.16 ± 3.03% and 85.73 ± 3.23% were achieved which correspond to 9.24 and 9.80 g/L of glucose, respectively. Furthermore, the most efficient method from the pretreatment step was chosen to carry out a factorial design to produce bioethanol. The experiments showed that the loading of cellulase was of crucial importance to the optimization of the process. Optimized ethanolic fermentation yielded ethanol concentrations up to 4.40 ± 0.28 g/L (76.12 ± 4.90%) (0.3 Μ NaOH, 750 μL/g_cellulose and 65 μL/g_starch), demonstrating the critical role of cellulase loading. Biomethane potential (BMP) assays on fermentation residues showed increased yields compared to untreated feedstock, with a maximum methane yield of 217.88 ± 10.40 mL/gVS. Combined energy production from bioethanol and biomethane was calculated at up to 1044.48 kWh/tn of algae feedstock, with biomethane contributing 75.26% to the total output. These findings highlight the potential of integrated algae-based biorefineries to provide scalable and sustainable biofuel solutions, aligning with circular economy principles.

The symbiotic culture of bacteria and yeast (SCOBY) encompasses a diverse array of microorganisms that play a pivotal role in the biochemical transformations during Kombucha fermentation. This study aims to investigate how various combinations of acetic acid bacteria (AAB) and specific yeast strains influence SCOBY formation and the biochemical characteristics of Kombucha. Thirteen combinations of AAB and yeasts formed SCOBY. The pH of Kombucha decreased to 2.31, and titratable acidity content increased to 20.76 g/L. Acetic and gluconic acid contents of Kombucha were 1.96 g/L and 6.9 g/L, respectively. The total phenolic and flavonoid contents increased by 3.53- and 5.2 fold, whereas the condensed tannin content decreased by 31.3 fold. Chlorogenic, p-coumaric, and ferulic acids were newly detected. Catechin, epicatechin, caffeine, caffeic acid, gallic acid, and rutin contents in Kombucha were increased. The antioxidant activity of Kombucha was enhanced up to 2.88 fold. The use of AAB and yeast has potential value in the industrial production of Kombucha.