Malachite-green-removing properties of a bacterial strain isolated from fish ponds in Thailand

Malachite green (MG) has been focused on as a biotreatment target and its biological properties have also been an issue in food fish aquaculture. An MG-removing bacterium was isolated from aquaculture fish pond sediment samples in Thailand. The isolate, strain T-5-2, is a Gram-negative, aerobic rod-shaped bacterium, and has been identified as a member of the Pseudomonas putida group. Proton nuclear magnetic resonance spectroscopy (¹H-NMR) analysis of a broth culture medium containing MG showed that the concentration of MG decreased markedly and that other molecules, including leucomalachite green (LMG), were generated. Moreover, liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis showed that the MG concentration in the broth culture medium continuously decreased. This analysis also demonstrated that the concentration of LMG initially increased and then gradually decreased. Furthermore, gas chromatography–mass spectrometry (GC–MS) analysis showed 4-(dimethylamino)benzophenone (4DABP) as a degradation component of MG, which was confirmed by ¹H-NMR and LC–MS/MS analysis. These findings suggest that this bacterial strain can remove MG in broth culture and degrade it to certain metabolites, including LMG and 4DABP. This study is the first detailed evaluation by the combination of LC–MS/MS, GC–MS, and ¹H-NMR analyses of an MG-removing bacterium isolated from Thai aquaculture fish ponds.     

Chemical changes in terpenes of sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) wood during steam drying in kiln at high temperature

Sawdusts of sugi (Cryptomeria japonica) wood prepared before and after steam drying at 120°C in a kiln were extracted with n-hexane and ethyl acetate to give n-hexane extracts and ethyl acetate extracts. From gas chromatography-mass spectrometry analysis of the ethyl acetate extracts from woods before and after steam drying, the components of 4-epi-cubebol, cubebol, and 2,7(14),10-bis-abolatrien-1-ol-4-one, which existed in the raw sugi wood, were proved to disappear in the steam-dried wood. These components were also absent in the ethyl acetate extract of the steam-condensed solution of waste steam from the kiln outlet. When these three components were treated with 0.2% (v/v) acetic acid solution at 120°C, δ-cadinene was produced as a major product from both 4-epi-cubebol and cubebol by dehydration and cleavage of the cyclopropane ring, and cryptomerone from 2,7(14),10-bisabolatrien-1-ol-4-one by hydration. The chemical changes of the three components presumably occur during steam drying of the sugi wood. This study was presented in part at the 85th Spring Meeting of the Chemical Society of Japan, Kanagawa, Japan, March 26–29, 2005     

Prognostic factors for dogs with surgically resected gastrointestinal stromal tumors

Few reports have investigated prognosis of canine gastrointestinal stromal tumor (GIST) cases treated by surgical resection alone. In the present study, we investigated the overall survival (OS) and prognostic factors for dogs with GIST treated by surgical complete resection alone. Fifty-three dogs were included, and the median OS was 18 months. Multivariate analysis showed that primary tumors in small intestine (P=0.04) is significantly associated with shorter OS, and median OS of the cases with cecum lesion and those with small intestine lesion was 22 and 6 months, respectively. The present study suggested primary tumor site was a novel prognostic factor for dogs with GIST treated by surgical complete resection alone.     

Molecular evidence of the hybrid origins of leyland cypress (×Cupressocyparis leylandii)

Leyland cypress (×Cupressocyparis leylandii) has been regarded as an intergeneric hybrid between Monterey cypress (Cupressus macrocarpa) and Alaska cypress (Chamaecyparis nootkatensis) in the Cupressaceae. Each partial sequence of the 18S-rDNA from nuclear and therbcL from chloroplast DNA genomes was determined using above three species. At the 59th site from the 5′ end of the 152 bp of the determined 18S-rDNA sequence, one base difference was identified between Monterey cypress (T) and Alaska cypress (A). However, Leyland cypress showed either nucleotide A or T at this site. Since nuclear DNA is inherited by biparental mode, this result shows genetic evidence that the nucleic genome of Leyland cypress originates from Monterey cypress and Alaska cypress and that this species is of hybrid origin.     

Isolation and characterization of an additional crustacean hyperglycemic hormone from the greasyback shrimp <Emphasis Type="Italic">Metapenaeus ensis</Emphasis>

Crustacean hyperglycemic hormone (CHH) is released from the X-organ/sinus gland complex located in the eyestalks. In this study, the most abundant CHH in the sinus gland of the greasyback shrimp Metapenaeus ensis was purified by reversed-phase HPLC and identified by N-terminal amino acid sequencing. Although two CHH molecules (Mee-CHH-A and Mee-CHH-B) have already been identified from M. ensis by cDNA cloning, this study revealed the presence of an additional CHH peptide based on differences in the N-terminal amino acid sequences of the CHH-A and CHH-B. Therefore, this novel CHH was designated as Mee-CHH-C. A cDNA encoding the Mee-CHH-C precursor was cloned by RT-PCR coupled with 5′- and 3′-RACE, and it was found that the mature Mee-CHH-C consisted of 72 amino acid residues containing 6 conserved cysteine residues and possessed an amidated C terminus. Mee-CHH-C had 62 and 68% identities with Mee-CHH-A and Mee-CHH-B, respectively, and was highly homologous to CHHs characterized from other penaeid shrimp species. The hyperglycemic activity of Mee-CHH-C was examined by an in vivo bioassay using the kuruma prawn Marsupenaeus japonicus. Injection of Mee-CHH-C increased hemolymph glucose levels significantly and dose-dependently. These results indicate that Mee-CHH-C is possibly one of the major molecules in M. ensis that regulate glucose levels in the hemolymph.     

Reproductive cycle of the venerid clam <Emphasis Type="Italic">Meretrix lusoria</Emphasis> in Ariake Sound and Tokyo Bay,Japan

We assessed the reproductive cycle of the venerid clam Meretrix lusoria by histological analysis of the gonads. Individuals for study were collected from natural populations on the Shirakawa tidal flat, Ariake Sound, and from populations that had been transplanted from the Shirakawa flat to the Oi flat in Tokyo Bay. In both study areas, the reproductive cycle was synchronized between sexes. Gonads of the clam started to develop in early spring and matured during the summer. Mass spawning occurred in the late summer/early fall. The clam matured at a shell length of 17–20 mm, which is much smaller than previously considered. While trophic conditions and salinity differed considerably in the two study areas, water temperatures showed similar seasonal changes (12°C during the winter and around 30°C during the summer). Thus, temperature probably controlled gonadal development. The coincidence of the period of spawning with the period of frequent intrusion of hypoxic waters into the tidal flats in Tokyo Bay suggests that such hypoxic events interfere with clam recruitment and are at least partly responsible for the disappearance of the natural population at this location.     

Bacterial and chemical properties of Japanese traditional anchovy product,salted Etari

Fisheries Science - We analyzed the bacterial flora and chemical properties of the Japanese traditional anchovy product called salted Etari, which is distributed in Nagasaki Prefecture in the...     

Seasonal variations in major components of Crassostrea gigas from Seto Inland Sea

Fisheries Science - The proximate composition and nutritional content of oysters define their quality and commercial value. Cultivation site and harvest date may impact these characteristics. We...     

Purification and immunochemical detection of a quantitatively major collagen in the dermis of sea cucumber Apostichopus japonicus

Pepsin-solubilized collagen (PSC) was prepared from the dermis of sea cucumber Apostichopus japonicus (green type) by performing pepsin digestion to collagen fiber pretreated with disaggregating solution (0.1 M Tris–HCl, pH 8.0, containing 0.5 M NaCl, 0.05 M ethylenediaminetetraacetic acid (EDTA), and 0.2 M 2-mercaptoethanol) and 0.1 M NaOH. On sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), the PSC clearly showed two alpha bands under phosphate buffer system in the presence of 3.5 M urea. An antiserum was raised against chromatographically purified major molecular species in the PSC, and immunoblot analyses were performed for the soluble fractions at 4 M guanidine hydrochloride treatment and disaggregation as well as the collagen fiber before and after treatment. These fractions and collagen fibers showed quite similar band patterns to that of the PSC, showing mainly two alpha bands. These combined results suggest that the major molecular species of collagen contains at least two distinct alpha components and that the effect of pepsin digestion is relatively small on the structure of this collagen type.

     

DNA methylation-dependent modulator of Gsg2/Haspin gene expression

The Gsg2 (Haspin) gene encodes a serine/threonine protein kinase and is predominantly expressed in haploid germ cells. In proliferating somatic cells, Gsg2 is shown to be expressed weakly but plays an essential role in mitosis. Although the Gsg2 minimal promoter recognized by the spermatogenic cell-specific nuclear factor(s) has been found, to date, the molecular mechanism that differentially controls Gsg2 expression levels in germ and somatic cells remains to be sufficiently clarified. In this study, we analyzed the DNA methylation status of the upstream region containing the Gsg2 promoter. We found a tissue-dependent and differentially methylated region (T-DMR) upstream (-641 to -517) of the authentic promoter that is hypomethylated in germ cells but hypermethylated in other somatic tissues. Profiling of Gsg2 expression and DNA methylation status at the T-DMR in spermatogenic cells indicated that the hypomethylation of the T-DMR is maintained during spermatogenesis. Using the reporter assay, we also demonstrated that DNA methylation at the T-DMR of Gsg2 reduced the promoter activity by 60-80%, but did not fully suppress it. Therefore, the T-DMR functions as a modulator in a DNA methylation-dependent manner. In conclusion, Gsg2 is under epigenetic control.