Oxidative degradation of bisphenol a by crude enzyme prepared from potato

When crude enzymes prepared from some vegetables and fruits were incubated with bisphenol A (2,2-bis(4-hydroxyphenyl)propane, BPA) at 37 degrees C, BPA was oxidized by crude enzymes from potato, eggplant, and lettuce. The crude enzyme prepared from potato (Solanum tuberosum) had the strongest oxidative activity for BPA. Its optimal temperature and pH were 40-45 degrees C and 8.0, respectively. More than 95% of BPA was oxidized after the incubation with potato enzyme for 60 min. BPA gave two oxidation products besides insoluble compounds during the oxidation by potato enzyme. The oxidation products were identified to be 4[1-(4-hydroxyphenyl)-1-methyl-ethyl]-benzene-1,2-diol and 4[1-(4-hydroxyphenyl)-1-methyl-ethyl]-benzene-1,3-diol. Enzymatically oxidized BPA lost the estrogen-like activity to enhance the growth of human breast cancer (MCF-7) cells.     

Artificially induced tetraploid masu salmon have the ability to form primordial germ cells

Diploid gametes generated with tetraploid animals are a stepping stone to improving chromosome manipulation techniques. However, artificially induced tetraploid individuals generally die soon after hatching. Diploid gametes could be induced by in vivo cultures of tetraploid primordial germ cells (PGCs) through germ-line chimera. In the present study, characteristics of PGCs were studied in inviable tetraploid masu salmon, Oncorhynchus masou. Histological observation of tetraploid embryos revealed that the same or smaller numbers of PGCs were observed and they migrate into the genital ridges as did diploid PGCs during gonadogenesis. By whole-mount in situ hybridization using vasa messenger RNA (mRNA), 4–35 vasa-positive signals were detected in a pair of genital ridges of tetraploids. By cytological observation of genital ridge cell suspensions, several large round cells were observed, some of which extended pseudopodia. They also contained large nuclei and round granules in their cytoplasm, characteristics of PGCs. As the results suggest that inviable artificial tetraploids have PGCs, we expect to achieve diploid gamete production through surrogate propagation and tetraploid fish production.     

Triploid Induction in the Yellowtail Tetra,Astyanax altiparanae,Using Temperature Shock: Tools for Conservation and Aquaculture

Triploidization is an interesting tool to produce sterile fish. In the yellowtail tetra, Astyanax altiparanae, this can be applied for aquaculture and surrogate technologies. In this study, we compared the efficacy of cold (2 C) or heat shock (38 C, 40 C, and 42 C) on triploid induction in the yellowtail tetra. The eggs were treated with cold or heat shock, 2 min postfertilization (30 min in cold shock or 2 min in heat shock). Intact embryos served as the control group. Ploidy status was confirmed by karyotyping, flow cytometry, and nuclear diameter of erythrocytes. The hatching rate decreased after cold shock (12.69 ± 15.76%) and heat shock at 42 C (0.35 ± 0.69%) in comparison with the control group (63.19 ± 16.82%). At 38 C and 40 C, hatching rates (61.29 ± 17.73% and 61.75 ± 22.1%, respectively) were not decreased. Only one triploid arose at 38 C (1/80). At 40 C, a high number of triploids arose (72/78). At 42 C, very few embryos developed into the hatching stage. A large number of haploid individuals arose after cold shock (61/75), with only one triploid. Our results indicate that heat shocking of embryos at 40 C is optimum for triploid production in the yellowtail tetra.     

Quantitative structure-activity studies of benzoylphenylurea larvicides: I. Effect of substituents at aniline moiety against Chilo suppressalis walker

The larvicidal activity of a series of N-2,6-difluoro- and N-2,6-dichlorobenzoyl-N′-(4-substituted phenyl)ureas against nondiapause larvae of the rice stem borer, Chilo suppressalis Walker, was measured by topical application and oral administration methods under conditions with and without piperonyl butoxide as an inhibitor of oxidative metabolism. The effects of substituents at the anilide moiety on the larvicidal activity were analyzed quantitatively using physicochemical substituent parameters and regression analysis. The results indicate that the oxidative metabolism in the larval body which is favored by electron-donating substituents is significant in determining the activity. The activity, when the metabolic factor is eliminated, is enhanced by electron-with-drawing and hydrophobic substituents and lowered by bulky groups. The inhibitory activity against new cuticle formation of the same series of compounds was also measured using cultured integument of the rice stem borer diapause larva. The comparison of the quantitative analyses between larvicidal and integument-level activities shows that inhibition of cuticular development is the most important factor governing larvicidal activity.     

Change in flower morphology of Torenia fournieri Lind. induced by forchlorfenuron application

We induced various flower morphologies in torenia (Torenia fournieri Lind.) by the application of forchlorfenuron (CPPU). Those morphologies were the combination of four basic morphological changes, the development of serrate petals, incised petals, a paracorolla, and an increased number of floral organs. These morphological changes occurred systematically depending on the floral stage at the time of CPPU application. Serrate petals were induced when CPPU was applied during the stages of corolla development, whereas application at younger stages induced petal incision. The serrate petal margin resulted from preferential proliferation of cells around the vascular bundles, whereas petal incision likely resulted from the lateral outgrowths of petal. A paracorolla was induced at the adaxial petal face when CPPU was applied between the sepal development stage and early corolla development. The paracorolla appears to have arisen from the lateral outgrowths of the stamen. The numbers of stamens, petals, and sepals increased when CPPU was applied at and before the differentiation of sex organs and the corolla. Enlargement of the floral meristem probably caused this increase. Application of N⁶-benzylaminopurine and zeatin did not induce these morphological changes.     

Poxvirus infection in Nile crocodiles (Crocodylus niloticus)

An outbreak was encountered of numerous yellowish cutaneous nodules in one- to two-year-old farmed Nile crocodiles (Crocodylus niloticus) in Kasaba Bay Crocodile Farm at Lake Tanganyika in Zambia during 1988. Out of 4000 crocodiles of different age groups, 300 yearlings were affected and 82 of those affected died. The lesions were prominent on the head, especially around the eyelids, the nostrils, both sides of the mouth, ventral neck, ventral pale belly, limbs and the root of the tail. Histologically, the epidermal lesions revealed large focal areas of marked acanthosis accompanied by hyperkeratosis and parakeratosis. In the prickle cells, there were multiple small neutrophilic granular inclusions and large eosinophilic homogeneous cytoplasmic inclusions. Electron microscopically, there were numerous poxvirus particles and matrices in the cytoplasm of many prickle cells. Dark blue homogeneous cytoplasmic inclusions in toluidine blue sections consisted of an electron opaque matrix with mature viral particles (160 x 200 x 230 nm). Furthermore, there were clumps of granular matrix containing immature viral particles (200 x 399 nm) in the cytoplasm. Various features of viral developing processes were observed.     

Mangrove Habitat Formation and Response to Holocene Sea-level Changes on Kosrae Island,Micronesia

Mangrove habitats on Kosrae are divided into three types, i.e., an estuary or delta type, a backmarsh or lagoon type and a coral reef or tidal-flat type. Most of the mangrove forests of Kosrae have been developed during the last 2000 years by accumulating mangrove peat with the gradual sea-level rise of 1 to 2 mm/yr except the landward part of the estuary or delta type. On the other hand, during the period of rapid sea-level rise of about 10 mm/yr between 4100 and 3700 yr B.P., the mangrove forests ceased peat accumulation and retreated landward. Until 3500 yr B.P., mangrove forests were distributed only in narrow bands in the inlets. Therefore, the critical rate of mangrove peat accretion with sea-level rise is estimated at more than 2 mm/yr and less than 10 mm/yr. If the anticipated sea-level rise exceeds this critical rate, all of the mangrove forests of Kosrae will retreat landward and reduce rapidly.     

Age trends in the genetic parameters of wood density and the relationship with growth rates in hybrid larch (Larix gmelinii var. japonica × L. kaempferi) F1

Age trends in variance components and heritability of overall wood density, earlywood and latewood density, and latewood proportion were investigated in 29-year-old trees of 19 full-sib families of hybrid larch (Larix gmelinii var. japonica × Larix kaempferi) F₁. The age–age correlation and optimum selection age for these traits were also estimated and genetic and phenotypic correlations between wood density and radial growth rate were calculated for each growth ring. Intraring wood density data were obtained using X-ray densitometry. The coefficient of additive genetic variance was stable over all ages, whereas the coefficient of environmental variances gradually decreased with increasing age, resulting in increases in heritability estimates with age for overall density. The latewood proportion had the highest heritability estimates at all ages, ranging from 0.44 to 0.66. Overall density and its various components at 28 years of age showed strong genetic correlations with their respective traits at all younger ages. Optimum selection ages for the wood density traits ranged from 8 to 14 years, at which point maximum gain efficiencies per year were obtained. There were negative correlations between wood density and radial growth rate at early ages, although these relationships tended to be weaker with increasing age. These results suggest that selection at a young age is effective for wood density, but particular care must be taken in selecting trees with an improved radial growth rate because rapid growth will result in a low-density wood product, especially in the early growth period.     

Lignin-degrading activity of edible mushroom <Emphasis Type="Italic">Strobilurus ohshimae</Emphasis> that forms fruiting bodies on buried sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) twigs

Strobilurus ohshimae is an edible mushroom, and it specifically forms its fruiting bodies on buried sugi (Cryptomeria japonica) twigs. In this research, we studied lignindegrading activity of S. ohshimae. We isolated 18 strains of S. ohshimae from various regions of Japan, and determined their lignin degradation rates on sugi wood meal medium. All the strains of S. ohshimae degraded approximately 6%–12% of sugi lignin in 30 days, and these lignin degradation rates were 1.5–3 times higher than those of Trametes versicolor, which is a typical lignin-degrading fungus. Among the three main lignin-degrading enzymes, activity of lignin peroxidase and manganese peroxidase was not observed, while 4340U/g of laccase was produced in 30 days. To investigate the effect of wood species on lignin degradation by S. ohshimae, the lignin degradation rate and laccase productivity on sugi wood meal medium were compared with those on beech (Fagus crenata). In T. versicolor, both lignin degradation rate and laccase productivity were higher on beech than on sugi. Conversely, in S. ohshimae, lignin degradation rate and laccase productivity were higher on sugi than on beech. Therefore, it was suggested that coniferous lignin is not always difficult to degrade for the fungi that inhabit softwood. Part of this article presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004     

Determination of bacteria constituting ruminal fibrolytic consortia developed on orchard grass hay stem

To determine the relationship between Fibrobacter succinogenes and other rumen bacteria, the bacterial community structure on fiber was analyzed by using two different materials. These were ruminally incubated orchard grass hay stems without and with preincubation with F. succinogenes (natural and artificial consortia, respectively). The natural consortium mainly consisted of Firmicutes (56.6%) and Bacteroidetes (33.1%), while the artificial consortium showed a significantly higher proportion of Firmicutes (85.5%) and a lower proportion of Bacteroidetes (4.6%). At species or genus level, Butyrivibrio fibrisolvens, the U2 group, Ruminococcus albus and Lachnospiraceae incertae sedis made up a higher proportion in the artificial consortium. The most dominant bacterial group was the Butyrivibrio‐Pseudobutyrivibrio‐Lachnospiraceae incertae sedis group, which accounted for 19.7% in the natural and 29.5% in the artificial consortium. Within the genus Butyrivibrio, the phylogenetic groups SA and VA2 and phylogeny‐undefined Butyribivrio, but not VA1, were detected at high frequency in the artificial consortium. These results suggest that ecological and possibly functional relationships exist in the rumen among F. succinogenes, a subset of B. fibrisolvens, the U2 group, R. albus and Lachnospiraceae incertae sedis.