The marine microalga Chlorella sp. was cultivated under mixotrophic conditions using methanol as an organic carbon source, which may also act to maintain the sterility of the medium for long-term outdoor cultivation. The optimal methanol concentration was determined to be 1% (v/v) for both cell growth and lipid production when supplying 5% CO 2 with 450 µE/m 2 /sec of continuous illumination. Under these conditions, the maximal cell biomass and total lipid production were 4.2 g dry wt/L and 17.5% (w/w), respectively, compared to 2.2 g dry wt/L and 12.5% (w/w) from autotrophic growth. Cell growth was inhibited at methanol concentrations above 1% (v/v) due to increased toxicity, whereas 1% methanol alone sustained 1.0 g dry wt/L and 4.8% total lipid production. We found that methanol was preferentially consumed during the initial period of cultivation, and carbon dioxide was consumed when the methanol was depleted. A 12:12 h (light:dark) cyclic illumination period produced favorable cell growth (3.6 g dry wt/L). Higher lipid production was observed with cyclic illumination than with continuous illumination (18.6% (w/w) vs 17.5% (w/w)), and better lipid production was also obtained under mixotrophic rather than autotrophic conditions. Interestingly, under mixotrophic conditions with 12:12 (h) cyclic illumination, high proportions of C 16:0 , C 18:0 , and C 18:1 were observed, which are beneficial for biodiesel production. These results strongly indicate that the carbon source is important for controlling both lipid composition and cell growth under mixotrophic conditions, and they suggest that methanol could be utilized to scale up production to an open pond type system for outdoor cultivation where light illumination changes periodically.

No abstract

No abstract

: 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.

No abstract