The identification of phaC which encodes PHA synthase, that is involved in the formation of polyhydroxyalkanoate (PHA) containing 3-hydroxy-2-methylvalerate (3H2MV), was attempted. As of now, PHA containing 3H2MV has been reported to be produced only by mixed microbial cultures in activated sludge, but no pure bacterial cultures. A laboratory-scale activated sludge process was operated for 67 days. During the operation of the activated sludge process, its capacity to produce PHA containing 3H2MV, and the diversity of the partial phaC genes in the activated sludge microorganisms were monitored periodically. Analysis of the partial phaC genes was conducted by PCR followed by cloning and DNA sequencing, or by PCR followed by terminal-restriction fragment length polymorphism (T-RFLP). The cloning-sequencing of the 263 clones gave 11 distinct genetic groups (GGs). All of the genetic groups had similarities to known phaC higher than 48%, and one of them had similarity as high as 96% to that of Alcaligenes sp. The behavior of each of the genetic groups during the operation of the activated sludge process was monitored by the T-RFLP method. The restriction enzyme AccII, with the help of MboI, enabled the monitoring of each of the genetic groups. One of the genetic groups was found to have a strong correlation with the capability of the activated sludge to produce PHA containing 3H2MV, and its DNA sequence together with its amino acid sequence are reported.

Structure−property correlations of the following model compounds for oligomer liquid crystals (LCs) have been investigated:  monomers, C6H5O(CH2) x CH3 (x = 4 and 5); dimers, C6H5O(CH2) x OC6H5 (x = 3, 4, 5, and 6); and tetramers, C6H5O(CH2) x OC6H4O(CH2) x OC6H4O(CH2) x OC6H5 (x = 5 and 6). Deuterium NMR quadrupolar splittings observed from the deuterated model compounds dissolved in a nematic solvent, 4‘-methoxybenzylidene-4-n-butylaniline (MBBA) or p-azoxyanisole (PAA), were analyzed by the rotational isomeric state scheme with the maximum entropy method to yield the orientational order parameters, bond conformations, and molecular dimensions. For the dimers in particular, the solute shapes were estimated from phase diagrams of the dimer/MBBA systems, the crystal structures were determined by X-ray diffraction, and the melting points and enthalpies of fusion were evaluated from DSC measurements. From the dimers, the so-called odd−even effect was clearly observed in not only the orientational order and molecular shape in the nematic solution but also the crystal structure and thermal properties; that is, the dimers of x = 4 and 6 have larger order parameters, more anisotropic shapes, better-arranged crystal structures, higher melting points, and larger enthalpies of fusion than those of x = 3 and 5. In the nematic solution, the model compounds preserve the inherent conformational preferences of the ether chain and enhance the shape anisotropy by increasing the trans fractions. As the orientational correlation is expected to persist only within a short range, conformations of the tetramers may represent those of polymer LCs with the same ethereal spacers. The chainlike molecules adjust their spatial configuration to the LC environment, and consequently, physical properties of the LC system are affected.