Assessment on the oil accumulation by knockdown of triacylglycerol lipase in the oleaginous diatom Fistulifera solaris.

Microalgae are promising producers of biofuel due to higher accumulation of triacylglycerol (TAG). However, further improvement of the lipid metabolism is critical for feasible application of microalgae in industrial production of biofuel. Suppression of lipid degradation pathways is a promising way to remarkably increase the lipid production in model diatoms. In this study, we established an antisense-based knockdown (KD) technique in the marine oleaginous diatom, Fistulifera solaris. This species has a capability to accumulate high content of lipids. Tgl1 KD showed positive impact on cell growth and lipid accumulation in conventional culture in f/2 medium, resulting in higher oil contents compared to wild type strain. However, these impacts of Tgl1 KD were slight when the cells were subjected to the two-stage growth system. The Tgl1 KD resulted in slight change of fatty acid composition; increasing in C14:0, C16:0 and C16:1, and decreasing in C20:5. This study indicates that, although Tgl1 played a certain role in lipid degradation in F. solaris, suppression of only a single type of TAG lipase was not significantly effective to improve the lipid production. Comprehensive understanding of the lipid catabolism in this microalga is essential to further improve the lipid production.

Measurement of interferon-gamma by high-throughput fluorometric microvolume assay technology system.

Interferon gamma (IFN-gamma) has various immunoregulatory effects and its measurement is widely used for monitoring immune response in many clinical trials for cancer vaccines. In this study, we developed a fluorescent-linked immunosorbent assay (FLISA) for the measurement of IFN-gamma. The FLISA can accurately measure IFN-gamma concentrations and the linear dynamic range of standard curve is 15.6-2000 pg/ml (2.1 log range). Because the FLISA needs only a small amount of antibodies and there is no washing process, it is able to reduce hands-on time and running costs compared with traditional enzyme-linked immunosorbent assay (ELISA). The FLISA can be readily performed in both 96- and 384-well plates, and up to 60 plates can be handled automatically by a robotic arm. Measurement of IFN-gamma by fluorometric microvolume assay technology (FMAT) may be a high-throughput screening method for a large number of samples.