Oil Production from Yarrowia lipolytica Po1g Using Rice Bran Hydrolysate

The purpose of this study was to produce microbial oil from Yarrowia lipolytica Po1g grown in defatted rice bran hydrolysate. After removing oil from rice bran by Soxhlet extraction, the bran is subjected to acid hydrolysis with various sulfuric acid concentrations (1–4% v/v), reaction times (1–8 h), and reaction temperatures (60–120°C). The optimal conditions for maximum total sugar production from the hydrolysate were found to be 3% sulfuric acid at 90°C for 6 h. Glucose was the predominant sugar (43.20 ± 0.28 g/L) followed by xylose (4.93 ± 0.03 g/L) and arabinose (2.09 ± 0.01 g/L). The hydrolysate was subsequently detoxified by neutralization to reduce the amount of inhibitors such as 5-hydroxymethylfurfural (HMF) and furfural to increase its potential as a medium for culturing Y. lipolytica Po1g. Dry cell mass and lipid content of Y. lipolytica Po1g grown in detoxified defatted rice bran hydrolysate (DRBH) under optimum conditions were 10.75 g/L and 48.02%, respectively

Bioethanol production from finger millet (Eleusine coracana) straw

The possibility of producing bioethanol from the biomass of finger millet straw was studied. The effects of temperature, acid concentration, hydrolysis time, and substrate concentration were investigated. The result showed that a maximum sugar content of 79.04 and 82.01 %w/w was achieved using phenol-sulfuric acid and Fehling method, respectively, from hydrolysis of 10 % biomass concentration at 2 % sulfuric acid, 35oC reaction temperature, and 4 days of hydrolysis time. The optimized hydrolyzate sample was fermented at optimized pH 6.0, 4 g/L yeast concentration, 32.5 oC reaction temperature, 4 days of fermentation time, and maximum of 7.28 %w/v of ethanol content was obtained using Pycnometer measurement. In general, the bioethanol achieved from FMS (7.28 %) at optimized conditions were highly promising and hence, it can be employed as an alternative lignocellulosic feedstock for bioethanol production rather than using food crops such as corn, sugarcane, etc.Keywords: Acid hydrolysis, bioethanol, finger millet straw, fermentation, Saccharomyces cerevisia

In situ biodiesel production from wet Chlorella vulgaris under subcritical condition

The conventional base catalyzed biodiesel production process uses refined vegetable oil as feedstock oil and is not environmentally friendly. The supercritical methanol technology does not require the use of catalyst but it is energy intensive due to the high temperature and pressure required in the process. In this work, a process was developed for producing biodiesel directly from wet Chlorella vulgaris biomass (80% moisture content) using subcritical water as catalyst. Under the following conditions: The ratio of wet biomass to methanol is 1/4 (g/mL), the reaction temperature is 175° C and after 4 h, the reaction product contained 89.71% fatty acid methyl esters (FAMEs). The yield is 0.29 g FAME per g dry biomass. This is considerably higher than the yield of 0.20 g FAME per g dry biomass obtained when the neutral lipid of C. vulgaris biomass was extracted and converted into FAME

Purification of Azadirachtin via Silica Gel Column Chromatography

Separation efficiency for purifying azadirachtin from the mixture of neem limonoids was investigated by silica gel column chromatography in this study. The reliability of this method was confirmed by using limonoid powders A and B with initial azadirachtin purities of 18% and 7%, respectively. The silica gel chromatography employed in this study was capable of increasing the azadirachtin purity up to 4-fold with an azadirachtin recovery of approximately 50%. Powders with an azadirachtin content of approximately 50% and 28% were produced from limonoid powders A and B, respectively. Meanwhile, low separation efficiency was produced when starting material contained 50% azadirachtin. Therefore, this method is effective in increasing azadirachtin purity using starting materials with azadirachtin content below 20%

Extraction, identification and quantitative HPLC analysis of flavonoids from sarang semut (Myrmecodia pendan)

The objective of this study was to extract and determine total contents of phenolic and flavonoid compounds as well as to identify and quantify some flavonoids from sarang semut (Myrmecodia pendan). Water bath extraction at 55 °C was employed for extracting flavonoids from sarang semut. The effects of parameters such as extraction time, composition of solvent mixture and solvent to sample ratio on extraction were investigated. From (33) factorial design the optimum extracting parameters were determined as follows: extraction time, 4 h; ethanol/water composition, 80%; and solvent to sample ratio, 50 ml/g. Under these optimal conditions, a yield of 13.82% was obtained. The free radical scavenging activity (antioxidant activity) of the extract was evaluated using DPPH radical and it was found that the IC50 occurred at 96.21 ± 9.03 μg/ml of extract. The total phenol and flavonoid contents were determined using designed methods and found to be 330.61 ± 2.13 mg GAE/g and 63.28 ± 1.75 mg QE/g of dry extract, respectively. The extract obtained under optimum conditions was analyzed by HPLC and five flavonoid compounds were identified and quantified; they are kaempferol (13.767 mg/g), luteoline (0.005 mg/g), rutine (0.003 mg/g), quercetin (0.030 mg/g) and apigenin (4.700 mg/g) of dry extract