Bioethanol production from Lignocellulosic biomass by a novel Kluyveromyces marxianus strain.

The yeast Kluyveromyces marxianus is considered as a potential alternative to Saccharomyces cerevisiae in producing ethanol as a biofuel. In this study, we investigated the ethanol fermentation properties of novel K. marxianus strain DMB1, isolated from bagasse hydrolysates. This strain utilized sorbitol as well as various pentoses and hexoses as single carbon sources under aerobic conditions and produced ethanol from glucose in hydrolysates of the Japanese cedar at 42 °C. Reference strains K. marxianus NBRC1777 and S. cerevisiae BY4743 did not assimilate sorbitol or ferment lignocellulosic hydrolysates to ethanol at this temperature. Thus strain DMB1 appears to be optimal for producing bioethanol at high temperatures, and might provide a valuable means of increasing the efficiency of ethanol fermentation.

Direct ethanol fermentation from lignocellulosic biomass by Antarctic basidiomycetous yeast Mrakia blollopis under a low temperature condition.

Antarctic basidiomycetous yeast Mrakia blollopis SK-4 has unique fermentability for various sugars under a low temperature condition. Hence, this yeast was used for ethanol fermentation from glucose and also for direct ethanol fermentation (DEF) from cellulosic biomass without/with Tween 80 at 10°C. Maximally, 48.2 g/l ethanol was formed from 12% (w/v) glucose. DEF converted filter paper, Japanese cedar and Eucalyptus to 12.2 g/l, 12.5 g/l and 7.2 g/l ethanol, respectively. In the presence of 1% (v/v) Tween 80, ethanol concentration increased by about 1.1-1.6-fold compared to that without Tween 80. This is the first report on DEF using cryophilic fungi under a low temperature condition. We consider that M. blollopis SK-4 has a good potential for ethanol fermentation in cold environments.

Poly(N-vinyl-2-pyrrolidone) (PVP)-capped dendritic gold nanoparticles by a one-step hydrothermal route and their high SERS effect.

Dendritic gold (Au) nanoparticles have been successfully synthesized by the one-step hydrothermal reduction of HAuCl4.4H2O using ammonium formate (AF) as a reducing agent in the presence of PVP. Effects of different reactant concentrations on the morphologies of obtained products have been systematically investigated. On the basis of the morphologies of the products observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), it has been found that an excessive number of AF molecules are the origin of the dendritic Au particles besides PVP as a stabilizer. AF molecules serve not only as a reductant but probably also as a capping reagent. The study implies that the use of two or more capping reagents with different adsorption abilities will be beneficial to the formation of hyperbranched Au nanoparticles. The new finding will have the potential to be extended to the construction of other highly branched noble metal nanoparticles only by one-step synthesis. In addition, as an example, application of the dendritic particles as an active material in surface-enhanced Raman scattering has been investigated by employing 4-aminothiophenol molecules as a probe.