Rapid fermentation of beer using an immobilized yeast multistage bioreactor system

A multistage bioreactor system for rapid beer fermentation was developed. The main fermentation process, which conventionally requires 7 d, could be shortened to 2 d by this system. The concentration of esters and higher alcohols are major factors in brewery fermentation, their production being closely related to the yeast growth phase. Yeast metabolism was successfully subdivided into a growth and a restricted phase through a combination of a continuous stirredtank reactor (CSTR) and an immobilized yeast packed-bed reactor (PBR). Production of higher alcohols was high in the CSTR because of its association with the level of biosynthetic activityde novo. A small amount was also produced in the PBR, however, possibly a result of an overflow in carbohydrate metabolism. Ester formation mainly occurred in the PBR, a linear increase in the level of ester being observed with flow through the PBR. The reactor system control strategy was to maximize the level of both higher alcohol and ester formation. The CSTR/PBR control range, based on extract consumption, was varied between 1:1 and 1:2. A ratio of 1:1 tended to create a flat beer, whereas a ratio 1:2 gave a beer of richer quality. Amino acid uptake by the yeast directly contributed to a reduction in the wort pH, whereas no relation could be observed between the level of organic acid production and pH.     

Construction of dihydropyrimidine skeleton using 1,2,4-trisubstituted-1,3-diaza-1,3-butadienes

Construction of a dihydropyrimidine ring was developed that involved the cyclization of 1,3-diaza-1,3-butadienes having an N-protecting group (N-Cbz, N-Boc, N-alkyl, or N-benzyl) with α,β-unsaturated carbonyl compounds such as ethyl acrylate and p-chlorophenyl vinyl ketone. Consequently, 4-dimethylamino-2-phenyl-1,4,5,6-tetrahydropyrimidines were synthesized in good yields. Subsequently, the β-elimination of the dimethylamino group was carried out with MeI or SiO₂ to afford various N-protecting-2,5-disubstituted-1,6-dihydropyrimidines in good yields. Remarkably, the use of 4-chlorophenyl vinyl ketone directly provided the dihydropyrimidine without the tetrahydropyrimidine intermediate in excellent yield.     

A comparison of the ultraslow relaxation processes at the ionic liquid|water interface for three hydrophobic ionic liquids

The ultraslow relaxation, on the order of a few seconds or longer, of the structure of the electrical double layer in response to the change in the phase-boundary potential across the ionic liquid (IL)|water(W) interface, which was recently reported for trioctylmethylammonium bis(nonafluorobutanesulfonyl)amide, has been confirmed in two new hydrophobic ionic liquids, trihexyltetradecylphosphonium bis(nonafluorobutanesulfonyl)amide and trihexyltetradecylphosphonium tetrakis(pentafluorophenyl)borate. A comparison of the degree of the hysteresis in electrocapillary curves for these ILs with those for trioctylmethylammonium bis(nonafluorobutanesulfonyl)amide demonstrates that the degree of the hysteresis is not correlated with the viscosity of these ILs. The ultraslow relaxation of the electrical double layer seems to be a general feature of ILs at electrified interfaces.     

Fabrication of nanosized Pt on rutile TiO2 using a standing wave sonochemical reactor (SWSR) – observation of an enhanced catalytic oxidation of CO

Fine particles of rutile TiO₂ supporting nanosized particles of Pt were prepared by a simultaneous in situ sonochemical reduction and deposition method using a standing wave sonochemical reactor (SWSR). The mean diameter of sonochemically obtained Pt particles are of 2 nm. Following this sonochemical technique, rutile TiO₂ was also deposited with different weight percentages of Pt. Catalytic function of the prepared composite catalysts were tested by the oxidation of CO to CO₂. From the catalytic activity results, it has been found out that the catalysts prepared by the sonochemical method exhibited higher catalytic activity for CO oxidation, probably attributed to the higher Pt particle distribution achieved under sonication. Transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), and diffuse reflectance spectroscopy (DRS) were employed to characterize the resulting material.     

Self-assembled meso-helicates of linear trinuclear nickel(II)-radical complexes with triple pyrazolate bridges

Complexation of 3-nitronyl-nitroxide-substituted pyrazolate (pzNN) and 3-imino-nitroxide-substituted pyrazolate (pzIN) with nickel(II) gave [Ni3(pzNN)6] and [Ni3(pzIN)6], respectively. They were practically isomorphous and characterized as a linear trinuclear structure with neighboring nickel ions triply bridged by pyrazolate moieties. The space groups were P2(1)/n but the molecules have a pseudo three-fold axis. We found polymorphs in the crystals of [Ni3(pzIN)6] depending on the solvate molecules; another space group was a cubic Pa3[combining macron]. The opposite chirality around the inversion center at the central nickel(II) ion leads to a meso-helical symmetry in the whole molecule. The radical oxygen atoms participate in the 6-membered chelation at the terminal nickel(II) ions. Antiferromagnetic couplings were observed in both complexes, which are ascribable to interactions between the nickel and radical spins and between the nickel spins across the pyrazolate bridges.     

Reaction of Trivalent Phosphorus Compounds with Viologens

When trivalent phosphorus compounds (Z 3 P) reacted with viologens, either a single-electron transfer (SET) or a polar reaction takes place, depending on the kind of substituents of viologens.     

Reaction of triarylphosphine radical cations generated from photoinduced electron transfer in the presence of oxygen

[reaction: see text] The 9,10-dicyanoanthracene (DCA)-sensitized photoreaction of triarylphosphines (1) was carried out in acetonitrile under aerobic conditions. Phosphine 1 was oxidized to the corresponding phosphine oxide with no appreciable side reactions. Product analysis and laser flash photolysis experiments suggest that the radical cation of 1 formed by the electron transfer from 1 to DCA in the singlet excited state ((1)DCA) reacts with O(2) to eventually afford the phosphine oxide.