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The production of biodiesel to substitute fossil fuels has been challenging to apply in many countries especially developing countries. Given the importance of this fact, this study includes the production of biodiesel from waste vegetable oils by pre-treatment followed by transesterification reaction with methanol using a KM micro-mixer reactor. KM micro-mixer happened to give noticeable enhancement for the production of biodiesel quality compared to the normal batch reactor at optimum conditions. The parameters affecting biodiesel production process such as alcohol to oil molar ratio, catalyst concentration, the presence of tetra-hydrofuran (THF) as a co-solvents and the volumetric flow rates of inlet fluids were optimized. The properties of the produced biodiesel were compared with its parent waste oil through different characterization techniques. The presence of methyl ester groups at the produced biodiesel was confirmed using both the Gas chromatography–mass spectrometry (GC-MS) and infrared spectroscopy (FT-IR). Moreover, the thermal analysis of the produced biodiesel and the comparable waste oil indicated that the product after the transesterification process began to vaporize at 120oC which makes it lighter than its parent oil which started to vaporize at around 300oC. The maximum biodiesel production yield of 97% was recorded using 12:1 methanol to oil molar ratio in presence of both 1% NaOH and THF/methanol volume ratio 0.3 at 60 mL/h flow rate.

Recently, the wild type yeast Kloeckera sp. strain KY1 was equipped in their cytoplasm with the phaABC operon containing genes phbA, phbB and phbC of the PHA biosynthetic pathway of Ralstonia eutropha. Unpredicted, resulted transgenic yeast strain KY1/PHA was able to synthesize another exopolymer beside the production of PHA. Subsequently, produced exopolymer was subject for further identification, characterization and analysis. Partial purification of exopolymer was performed and characterized as glycoprotein. HPLC analysis of the polymer revealed the presence of a fructose chain. The functional group analysis by FT-IR spectroscopy showed the presence of carboxyl, hydroxyl and amid groups. The exopolymer was soluble in water and insoluble in any tested organic solvents and could flocculate kaolin suspension (5 g/l) over a wide range of pH (pH 3 to 9) and temperature (5 to 50°C) tested in the presence of CaCl2. The highest flocculation activity of 99% for kaolin suspension was achieved at a dosage of 13 mg/l. Thus, it is possible that this glycoprotein could be substituted for a commercial polymer with respect to flocculation.Key word: Transgenic yeast, bioflocculant, exopolymer, glycoprotein, spectroscopic analysis.