Ammonia removal from livestock wastewater by ammonia-assimilating microorganisms immobilized in polyvinyl alcohol

We isolated ammonia-assimilating microorganisms from the livestock manure treatment systems and evaluated their ammonia-assimilating ability. Many isolates utilized ammonia at high rates when they were purely cultivated in a nitrogen-limited medium to which sterilized lagoon extract had been added. Some isolates that were immobilized in polyvinyl alcohol (PVA) utilized ammonia present in the media containing viable lagoon microorganisms. Staining with 4′,6′-diamidino-2-phenylindole (DAPI) indicated that the immobilized high ammonia-assimilating isolates grew dominantly within the PVA beads. High ammonia-assimilating isolates in the mixed culture containing viable lagoon microorganisms were identified as Pseudomonas spp. and member of Rhizobiaceae species by partial sequencing of the 16S ribosomal DNA.     

Effective killing of the human pathogen Candida albicans by a specific inhibitor of non-essential mitotic kinesin Kip1p

Kinesins from the bipolar (Kinesin-5) family are conserved in eukaryotic organisms and play critical roles during the earliest stages of mitosis to mediate spindle pole body separation and formation of a bipolar mitotic spindle. To date, genes encoding bipolar kinesins have been reported to be essential in all organisms studied. We report the characterization of CaKip1p, the sole member of this family in the human pathogenic yeast Candida albicans. C. albicans Kip1p appears to localize to the mitotic spindle and loss of CaKip1p function interferes with normal progression through mitosis. Inducible excision of CaKIP1 revealed phenotypes unique to C. albicans, including viable homozygous Cakip1 mutants and an aberrant spindle morphology in which multiple spindle poles accumulate in close proximity to each other. Expression of the C. albicans Kip1 motor domain in Escherichia coli produced a protein with microtubule-stimulated ATPase activity that was inhibited by an aminobenzothiazole (ABT) compound in an ATP-competitive fashion. This inhibition results in 'rigor-like', tight association with microtubules in vitro. Upon treatment of C. albicans cells with the ABT compound, cells were killed, and terminal phenotype analysis revealed an aberrant spindle morphology similar to that induced by loss of the CaKIP1 gene. The ABT compound discovered is the first example of a fungal spindle inhibitor targeted to a mitotic kinesin. Our results also show that the non-essential nature and implementation of the bipolar motor in C. albicans differs from that seen in other organisms, and suggest that inhibitors of a non-essential mitotic kinesin may offer promise as cidal agents for antifungal drug discovery.     

Superoxide anion radical scavenging activities of herbs and pastures in northern Japan determined using electron spin resonance spectrometry

Free radicals are not only destructive to the living cells but also reduce the quality of animal products through oxidation. As a result the superoxide anion radical (O2-), one of the most destructive reactive oxygen species, is a matter of concern for the animal scientists as well as feed manufacturers to ensure the quality of product to reach consumers demand. The superoxide anion radical scavenging activities (SOSA) of water and MeOH extracts of 2 herbs and 9 pasture samples collected from lowland and highland swards were determined against a 5,5-dimethyl-1-pyroline-N-oxide-O2-spin adduct based on a hypoxanthine-xanthine oxidase reaction using electron spin resonance spectrometry. Both the water and MeOH extracted SOSA differed among the herbs and pastures. Species and altitudinal variations were observed between extraction methods. The herbs were higher in both water and MeOH extracted SOSA than the pastures except for water extracts of one pasture, white clover (Trifolium repens L.). Among the pastures, quackgrass (Agrophyron repens L.) showed higher SOSA in both the MeOH and water extracts, and timothy (Phleum pretense L.) showed higher MeOH extracted SOSA. It is apparent that the kind and amount of antioxidants differ among herbs and pastures. Animal health and quality of animal products could be improved by adequate selection and combining of herbs and pastures having higher SOSA.     

Role of the Cytosolic Heat Shock Protein 70 Ssa5 in the Ciliate Protozoan Tetrahymena thermophila

Heat shock protein 70 (Hsp70) is a member of a family of conserved chaperone proteins whose function is well investigated in many model organisms. Here we focus on an Hsp70 called Ssa5 in the ciliate protozoan Tetrahymena thermophila, and reveal that its translation is heat inducible as for general Hsps. Moreover, the protein is abundantly expressed in the cytoplasm during sexual reproduction (conjugation) as well as in response to heat‐stress. Knocking out of SSA5 (ΔSSA5) does not affect the survival of the cell under heat‐stress, likely due to other Hsp70 paralogs compensating for the defect. During conjugation, ΔSSA5 leads to a fertilization defect in which the two pronuclei are in close proximity but never fuse. The unfertilized pronuclei differentiate, resulting in a heterokaryon with developed haploid germline and somatic nuclei. In addition, degeneration of the parental somatic nucleus is not affected. These results suggest a specific involvement of Ssa5 in pronuclear fusion and fertilization.     

Experimental and theoretical investigations of circular dichroism of donor-acceptor 1,1'-binaphthyls: influence of substitution on the coupling amplitude and cotton effect of the charge-transfer band

The electronic circular dichroism (CD) spectra of donor-acceptor binaphthyls were investigated experimentally and theoretically. The enantiomerically pure forms of 1-(2-methoxy-1-naphthyl)- and 1-(2,3-dimethoxy-1-naphthyl)-2-methylisoquinolinium tetrafluoroborates (DA and D'A) were prepared, and their UV-vis and CD spectra were compared. The donor-acceptor interaction was apparent from the absorption at longer wavelengths, whereas its strength was not very different from each other. In addition, very similar structures were obtained for the two aromatic planes in DA and D'A when the geometry was optimized by the density functional theory. The additional methoxy group in the latter spices scarcely disturbed the UV-vis spectrum but significantly affected the CD spectrum. Thus, the observed CD spectra were considerably different from each other, especially in the (1) B(b) band couplet, where the amplitude was reduced to almost one-fourth in D'A. The theoretical investigations led to the following conclusions: (1) The potential curve associated with the central C-C dihedral angle of 1,1'-binaphthyl is fairly flat at the bottom for both DA and D'A and freely rotating at an ambient temperature. The potential curve of D'A is, however, significantly different from that of DA, in which the curve is much steeper and biased to the s-cis side. As the observed CD spectrum is an ensemble of conformers of various dihedral angles, such difference in potential certainly affects the overall spectrum; (2) The additional methoxy group introduced at the 3-position effectively altered the CD spectral pattern, which was theoretically supported by the calculation at the RI-CC2/TZVPP level; (3) Consequently, the classical coupled oscillator theory, in which the angle between the transition dipole moments of two aromatic planes is solely considered, is not applicable to the quantitative evaluation of the chiroptical properties of 1,1'-binaphthyls; rather, the quantum chemical approach is preferred, permitting a direct comparison with the experiment.     

Hepatic oxidoreduction-related genes are upregulated by administration of hydrogen-saturated drinking water

The effects of the administration of molecular hydrogen-saturated drinking water (hydrogen water) on hepatic gene expression were investigated in rats. Using DNA microarrays, 548 upregulated and 695 downregulated genes were detected in the liver after 4 weeks of administration of hydrogen water. Gene Ontology analysis revealed that genes for oxidoreduction-related proteins, including hydroxymethylglutaryl CoA reductase, were significantly enriched in the upregulated genes.     

Cascading effects of larval Crucian carp introduction on phytoplankton and microbial communities in a paddy field: top-down and bottom-up controls

Effects of fish predation propagate through aquatic food webs, where the classical grazing food chain and microbial loop are interwoven by trophic interactions. The overall impact on aquatic food webs is further complicated because fish may also exert bottom-up controls through nutrient regeneration. Yet, we still have limited information about cascading effects among fish, zooplankton, phytoplankton, and microbes. In this study, we performed a mesocosm experiment to evaluate effects of fish introduction on plankton communities. Six plots were set in factorial combination with fish introduction and rice straw plowing in a paddy field, and the experiment was continued for 4 weeks. Introduction of fish significantly increased chlorophyll a concentrations in smaller size fractions (<15 μm) and abundances of filamentous bacteria (>5 μm in length) and heterotrophic nanoflagellates in 3–15 μm fraction. Microbes in 0.8–3 μm fraction showed increasing but not significant trends in response to fish introduction. These results indicate cascading effects of fish predation operating via two pathways, one through grazing food chain and the other through microbial food web. Phytoplankton community compositions shifted in similar fashion in all plots until 1 week after fish introduction, and then diverged between plots with and without fish thereafter. Bottom-up effects of fish introduction were suggested by increases of total chlorophyll a and inedible phytoplankton species in response to fish introduction. This study provides an example of how fish predation regulates biomass and structure of phytoplankton and microbial communities.     

6,7-Dihydro-5H-cyclopenta[d]pyrazolo[1,5-a]pyrimidines and their derivatives as novel corticotropin-releasing factor 1 receptor antagonists

To identify an orally active corticotropin-releasing factor 1 receptor antagonist, a series of 6,7-dihydro-5H-cyclopenta[d]pyrazolo[1,5-a]pyrimidines and their derivatives were designed, synthesized and evaluated. An in vitro study followed by in vivo and pharmacokinetic studies of these heterotricyclic compounds led us to the discovery of an orally active CRF1 receptor antagonist. The results of a structure-activity relationship study are presented.     

Discovery of selective indole-based prostaglandin D₂ receptor antagonist

A series of N-benzoyl-2-methylindole-3-acetic acids were synthesized and biologically evaluated as prostaglandin (PG) D? receptor antagonists. Some of the selected compounds significantly inhibited OVA-induced vascular permeability in guinea pig conjunctiva after oral dosing. Structure-activity relationship study is presented.