Marine microalga, Scenedesmus sp., which is known to be suitable for biodiesel production because of its high lipid content, was subjected to the conventional Folch method of lipid extraction combined with high-pressure homogenization pretreatment process at 1200 psi and 35°C. Algal lipid yield was about 24.9% through this process, whereas only 19.8% lipid can be obtained by following a conventional lipid extraction procedure using the solvent, chloroform : methanol (2 : 1, v/v). Present approach requires 30 min process time and a moderate working temperature of 35°C as compared to the conventional extraction method which usually requires >5 hrs and 65°C temperature. It was found that this combined extraction process followed second-order reaction kinetics, which means most of the cellular lipids were extracted during initial periods of extraction, mostly within 30 min. In contrast, during the conventional extraction process, the cellular lipids were slowly and continuously extracted for >5 hrs by following first-order kinetics. Confocal and scanning electron microscopy revealed altered texture of algal biomass pretreated with high-pressure homogenization. These results clearly demonstrate that the Folch method coupled with high-pressure homogenization pretreatment can easily destruct the rigid cell walls of microalgae and release the intact lipids, with minimized extraction time and temperature, both of which are essential for maintaining good quality of the lipids for biodiesel production.

The goal of this study was to determine the optimal pretreatment process for the extraction of lipids and reducing sugars to facilitate the simultaneous production of biodiesel and bioethanol from the marine microalga Chorella sp. With a single pretreatment process, the optimal ultrasonication pretreatment process was 10 min at 47 KHz, and extraction yields of 6.5 and 7.1 (percentage, w/w) of the lipids and reducing sugars, respectively, were obtained. The optimal microwave pretreatment process was 10 min at 2,450 MHz, and extraction yields of 6.6 and 7.0 (percentage, w/w) of the lipids and reducing sugars, respectively, were obtained. Lastly, the optimal high-pressure homogenization pretreatment process was two cycles at a pressure of 20,000 psi, and extraction yields of 12.5 and 12.8 (percentage, w/w) of the lipids and reducing sugars, respectively, were obtained. However, because the single pretreatment processes did not markedly improve the extraction yields compared to the results of previous studies, a combination of two pretreatment processes was applied. The yields of lipids and reducing sugars from the combined application of the high-pressure homogenization process and the microwave process were 24.4 and 24.9 % (w/w), respectively, which was up to three times greater than the yields obtained using the single pretreatment processes. Furthermore, the oleic acid content, which is a fatty acid suitable for biodiesel production, was 23.39 % of the fatty acids (w/w). The contents of glucose and xylose, which are among the fermentable sugars useful for bioethanol production, were 77.5 and 13.3 % (w/w) of the fermentable sugars, respectively, suggesting the possibility of simultaneously producing biodiesel and bioethanol. Based on the results of this study, the combined application of the high-pressure homogenization and microwave pretreatment processes is the optimal method to increase the extraction yields of lipids and reducing sugars that are essential for the simultaneous production of biodiesel and bioethanol.

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: Conventional Thiamine Dilauryl Sulfate (TDS) powder has a low stability. In order to solve this problem, this study was performed to improve the solubility of TDS. The process for enhance solubility of TDS was nano grinding mill and ultrasonic dispersion process. TDS paticle was manufactured to nano size through nano grinding mill process. The size of TDS nanoparticle was measured as average 220 ㎚ by DLS. And The TDS nanoparticle in water solution manufactured through ultrasonic dispersion process. The TDS nanoparticle in water solution was showed the highest solubility with 40% ethanol. These results was increased the concentration of TDS from 200 ppm to 240 ppm in water solution. The TDS nanoparticle in water solution showed diameter of Colletotrichum gloeosporioides growth with smaller than about 1.56 ㎝ compared to the TDS paticle in water solution at same concentration. Also, TDS nanoparticle in water solution showed growth inhibition activity as 59.2% with higher than about 10% compared to the TDS paticle water solution in same concentration. Finally, TDS nanoparticle in water solution was increased solubility through nano grinding mill and ultrasonic dispersion process. Also, the increase of concentration in TDS nanopaticle in water solution according to solubility enhancement lead to an result enhancement of antifungal activity. Consequently, we suggested that the TDS nanoparticle in water solution was more effective than TDS particle in water solution owing to the sub-cellular particle size, ability to persistence and targeting to cell membrane of Colletotrichum gloeosporioides. Furthermore we expected the applicating possibility with bio pesticide.