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Utilization of bioethanol generated from papaw peel waste for hand sanitizer production

2023-06-08T07:57:02Z

Title: Utilization of bioethanol generated from papaw peel waste for hand sanitizer production Authors: Amanullah, A.; Kapilan, R. Abstract: Hands are the primary mode for the spread of microbes. For infection control, the first-line of defense as well as personal hygiene, are mandatory. Hand sanitizers that contain ethanol as the main constituent are used to kill a broad range of microbes. Demand for petroleum-derived ethanol is increasing with the COVID-19 outbreak and primary suppliers are searching for alternatives to overcome this problem. Objective of this study is to produce bioethanol from ripen papaw peel waste using Saccharomyces cerevisiae and to determine the potential utilization of bioethanol generated from papaw peel waste for a pilot study of which the end aim is hand sanitizer production. The blended ripened papaw (Carica papaya) fruit peel (100g/L) was inoculated with the S. cerevisiae (2g/L) in a fermentation medium that contains 10 g/L yeast extract, 10 g/L KH2PO4, 2 g/L (NH4)2SO4 and 0.5 g/L MgSO4•7H2O and allowed to ferment for 6-36 hours at room temperature. The bioethanol yield obtained after 12 hours, was 0.6% (V/V). The fermentation conditions were optimized by changing one factor at a time, while keeping the other variables constant. Significantly higher bioethanol yield (6.2 times, 3.7% V/V [p<0.05]) was obtained from papaya peels at the optimized conditions of 12 hours of incubation period, 5:1 ratio between air space and fermentation solution, 5g/L of yeast inoculum, 15g/100ml of papaw fruit peel, 1g/100ml of soybean powder as nitrogen source, 60ml/100ml of diluted sulfuric acid at pH 5. When the agar well diffusion assay was performed against pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, Bacillus spp. and Pseudomonas spp, all the bacterial strains showed an inhibition zone, i.e., they were sensitive for the bioethanol extract.

The effects of acid and cellulose concentrations on the acid hydrolysis efficiency of waste cellulose from Palmyrah fruit husk

2023-06-08T07:51:08Z

Title: The effects of acid and cellulose concentrations on the acid hydrolysis efficiency of waste cellulose from Palmyrah fruit husk Authors: Srithevi, S.; Sashikesh, G. Abstract: Underutilized cellulose from the Palmyrah Fruit Husk (PFH) was the source of the environmental problems. However, converting waste cellulose into glucose through acid hydrolysis to produce value-added fuels and chemicals has the potential to be both cost-effective and environmentally sustainable. The objective of this research study is to extract the cellulose from waste PFH and convert it to glucose monosaccharide using acid hydrolysis processes. Cellulose was extracted from the PFH using 1.5 % (w/v) of NaOH and 0.5 % (w/v) of Na2S solutions and it was identified using the Schultz reagent test. In the presence of DNS reagent, the yield percentage of glucose from the acid hydrolysis processes was measured using the Jasco V −570 UV-VIS-NIR spectrophotometer. The yield percentage of glucose increased when both the acid concentration and the extracted PFH cellulose solution were increased to a certain level. Furthermore, the optimal conditions were found to be 7.0 mol L −1 concentration of H2SO4 , 1.0 × 104 ppm of extracted cellulose solution and 4 hours of acid hydrolysis, yielding 59.36 % glucose monosaccharides. As a result, PFH can be used to produce glucose monosaccharide as a suitable feedstock.

Isolation and Identification of Indigenous Yeast Strain and Its Potential for Yeast Extract Production

2023-06-08T07:12:27Z

Title: Isolation and Identification of Indigenous Yeast Strain and Its Potential for Yeast Extract Production Authors: Mahilrajan, S.; Jeyaseelan, E.C.; Srivijeindran, S. Abstract: The growing demand for protein-rich food forces humans to search for alternative protein sources. Yeasts are among the preferred candidates due to their well-balanced source of amino acids and vitamins. The present study aimed to identify an indigenous yeast strain that can be used as a protein source. Yeast strains were isolated from Palmyrah toddy sediments collected from different regions in the Jaffna Peninsula. One yeast strain, named A3, was selected as a potential strain based on the maximum cell size and optical density among the 55 yeast strains isolated. The biochemical analysis and sequencing of the ITS region (including 5.8S rRNA gene) and the LSU rRNA gene D1/D2 domains confirmed the yeast isolate as a strain of Saccharomyces cerevisiae. The optimum growth conditions for the yeast strain were determined using Taguchi L16 orthogonal array. Yeast cell autolysis was conducted with and without papain, and the yield of soluble matter and total protein were measured. The strain yielded a maximum of 70.7 % soluble mater and 56.9 % of total protein when autolysis with papain. The yield is significantly higher (p<0.05) than obtained with the baker's yeast used in the control experiment.

Antimicrobial Activity of Leaf and Bark Extracts of Cassia fistula

2023-06-08T06:21:41Z

Title: Antimicrobial Activity of Leaf and Bark Extracts of Cassia fistula Authors: Prabagar, S.; Nanthakumar, J.; Thuraisingam, S.; Prabagar, J. Abstract: Cassia fistula L is a medium sized tree and its parts are used in folk medicines for bacterial and fungal diseases. Aqueous extraction of plant materials such as leaf and bark were investigated for anti-microbial property without changing concentration. Results of this study revealed that all extracts had good inhibitory activity against gram positive and gram negative bacteria. The clear zone for Staphylococcus aureus and E. coli were found with the diameter of 2.5 cm and 2.9 cm respectively, though the inhibitory diameter of Staphylococcus aureus was smaller than the streptomycin control. Antifungal activity of bark and leaf extract of C. fistula against Aspergillus showed the highest inhibitory growth (64.3%). The findings exhibit that leaf and bark extracts have broad spectrum activity and there is a possibility in treatment of infectious diseases.