Whole-cell Immobilization of Engineered <Emphasis Type="Italic">Escherichia coli</Emphasis> JY001 with Barium-alginate for Itaconic Acid Production

Itaconic acid is an important organic acid and a major component of various polymers. It is used in resins, superabsorbent polymers, and substitutes for petrochemicalbased monomers such as acrylic and methacrylic acids. Itaconic acid is primarily produced by the fungus Aspergillus terreus, which yields a high titer with albeit long fermentation period and by-products. In our previous study, Escherichia coli JY001 was reported to produce itaconic acid using citric acid in whole-cell reaction resulting in higher itaconic acid productivity with less by-products formation. The present study aimed to increase whole-cell enzyme stability and reusability, via immobilization of E. coli JY001 using barium-alginate beads. We optimized the cations, temperature, pH, alginate, BaCl₂ concentration, cell density per bead, and CTAB content to improve transfer rate of substrates and products. Under the optimized conditions, immobilized whole cells were stable for four repeated cycles of itaconic acid production. The present results would strengthen the basis for a continuous itaconic acid production.     

An omnivorous arthropod, <Emphasis Type="Italic">Nesidiocoris tenuis</Emphasis>, induces gender-specific plant volatiles to which conspecific males and females respond differently

Nesidiocoris tenuis Reuter (Heteroptera: Miridae) is an omnivorous mirid bug that preys on diverse generalist herbivorous arthropods. N. tenuis adults are attracted to volatiles from plants induced by their prey, such as tobacco cutworms (CCW) (Spodoptera litura larvae) and two-spotted spider mites (Tetranychus urticae). N. tenuis adults also induce volatiles when they infest plants. In this study, we focused on olfactory responses of N. tenuis males and females to volatiles from eggplants and sesame plants induced by conspecifics of the same or different gender by using a Y-tube olfactometer. Males were attracted to volatiles from plants of both species induced by either males or females. The male preference was biased to volatiles from plants of both species induced by females, probably because the biased response would facilitate their mate-finding. Females were attracted only to volatiles from plants of both species induced by females. Mating occurs multiple times in this species. Thus, the responses would indirectly affect mating of males and females. Slight but significant qualitative and quantitative differences were detected between the volatiles of plants of both species induced by N. tenuis females and those of the plants induced by conspecific males. N. tenuis might use such differences in their gender-specific responses.     

Molecular Characterization of Hobo-Mediated Inversions in Drosophila Melanogaster

The structure of chromosomal inversions mediated by hobo transposable elements in the Uc-1 X chromosome was investigated using cytogenetic and molecular methods. Uc-1 contains a phenotypically silent hobo element inserted in an intron of the Notch locus. Cytological screening identified six independent Notch mutations resulting from chromosomal inversions with one breakpoint at cytological position 3C7, the location of Notch. In situ hybridization to salivary gland polytene chromosomes determined that both ends of each inversion contained hobo and Notch sequences. Southern blot analyses showed that both breakpoints in each inversion had hobo-Notch junction fragments indistinguishable in structure from those present in the Uc-1 X chromosome prior to the rearrangements. Polymerase chain reaction amplification of the 12 hobo-Notch junction fragments in the six inversions, followed by DNA sequence analysis, determined that each was identical to one of the two hobo-Notch junctions present in Uc-1. These results are consistent with a model in which hobo-mediated inversions result from homologous pairing and recombination between a pair of hobo elements in reverse orientation.     

The effects of Chamaecyparis obtusa essential oil on pain-related behavior and expression of pro-inflammatory cytokines in carrageenan-induced arthritis in rats

Chamaecyparis obtusa essential oil (COE) has been widely used to treat allergic diseases and was suggested to exert anti-inflammatory, antioxidant, and antimicrobial effects. This study evaluated the effects of COE on pain-related behavior and pro-inflammatory cytokines in rats with carrageenan (CGN)-induced arthritis. Reduced dynamic weight load on inflamed joint in voluntarily walking rats was used as the behavior test for arthritic pain; 10% COE-treated group was significantly attenuated pain (6–8 h post-CGN injection) compared to VEH (mineral oil)-treated group. In addition, the protein levels of interleukin (IL)-1β, tumor necrosis factor-α, IL-6 (6–8 h), and cyclooxygenase (COX)-2 (8 h) within the synovial membrane, as well as IL-1β, COX-2 (6–8 h), and IL-6 (5–7 h) within the meniscus, of 10% COE-treated group were significantly reduced. The current results implicate that COE has anti-inflammatory and anti-nociceptive effects on arthritis in rats.     

A numerical taxonomic study on heterophyid trematodes

A numerical taxonomy was studied on a group of heterophyid trematodes and analysis was made on the following species: Metagonimus yokogawai (3 OTU, Operational Taxonomic Unit), Metagonimus Miyata Type (3 OTU), Metagonimus takahashii (2 OTU), Heterophyes dispar (2 OTU), Heterophyes heterophyes (1 OTU), Heterophyes nocens (2 OTU), Heterophyopsis continua (1 OTU), Pygidiopsis summa (3 OTU), Stellantchasmus falcatus (2 OTU) and Stictodora lari (2 OTU). Twenty-six morphological characters were measured and their values were expressed as relative ratios. Similarity and correlation matrix among each individuals were calculated. Clustering analysis by Ward's method and factor analysis were performed using the SAS (Statistical Analysis System) package. As a result, the groups belonging to the genus of Metagonimus were divided into three phenons (Metagonimus yokogawai, Metagonimus Miyata Type, M. takahashii), and Metagonimus Miyata Type was classified as the level of subspecies of M. takahashii. The groups belonging to the genus Heterophyes were clearly divided into three phenons (Heterophyes dispar, H. heterophyes, H. nocens), and H. nocens was classified as not a subspecies level of H. heterophyes but a distinct species. Other species were classified as distinct phenons. From these results, the application of numerical taxonomy on trematode classification is considered to be a great aid to determine the limit of taxa.     

1H, 13C, and 15N resonance assignments of FK506-binding domain of Plasmodium falciparum FKBP35

The immunosuppressant FK506 binds Plasmodium falciparum FK-506 binding protein 35 (PfFKBP35) and shows anti-malarial activity. To understand molecular mechanism of the drug on the parasite, we have done NMR studies. Here, we report the assignment of FK506-binding domain of PfFKBP35.