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Biosci Biotechnol Biochem [journal]
- The iron content and ferritin contribution in fresh, dried, and toasted nori, Pyropia yezoensis. [JOURNAL ARTICLE]
- Biosci Biotechnol Biochem 2014 Oct 15.:1-8.
Iron is one of the essential trace elements for humans. In this study, the iron contents in fresh, dried, and toasted nori (Pyropia yezoensis) were analyzed. The mean iron content of fresh, dried, and toasted nori were 19.0, 22.6, and 26.2 mg/100 g (dry weight), respectively. These values were superior to other food of plant origin. Furthermore, most of the iron in nori was maintained during processing, such as washing, drying, and toasting. Then, the form of iron in fresh, dried, and toasted nori was analyzed. As a result, an iron storage protein ferritin contributed to iron storage in raw and dried nori, although the precise rate of its contribution is yet to be determined, while ferritin protein cage was degraded in the toasted nori. It is the first report that verified the ferritin contribution to iron storage in such edible macroalgae with commercial importance.
- Functional improvements in β-lactoglobulin by conjugating with soybean soluble polysaccharide. [JOURNAL ARTICLE]
- Biosci Biotechnol Biochem 2014 Oct 15.:1-6.
Soybean soluble polysaccharide (SSPS) was hydrolyzed by autoclaving for 6 and 12 h to obtain SSPS (6 h) and SSPS (12 h). Bovine β-lactoglobulin (BLG) was conjugated with each SSPS by the Maillard reaction to improve its function. Conjugation between BLG and each SSPS was confirmed by Sodium dodecyl sulfate polyacrylamide gel electrophoresis and isoelectric focusing. BLG-SSPS (6 h) and BLG-SSPS (12 h), respectively, retained approximately 56 and 43% of the retinol-binding activity of BLG. Structural analyses by intrinsic fluorescence and enzyme-linked immunosorbent assay with monoclonal antibodies indicated that the native structure of BLG had almost been maintained in each conjugate and that the surface structure was covered by conjugated SSPS. The emulsifying properties of BLG were improved in each conjugate at pH 3, 5, and 7 in the presence of 0.2 M NaCl. The antibody responses to BLG-SSPS (6 h) and BLG-SSPS (12 h) were considerably reduced in BALB/c mice. We conclude that conjugation with SSPS was very effective for improving the function of BLG and this study would contribute to greater utilization of SSPS.
- Biotin-deficient diet induces chromosome misalignment and spindle defects in mouse oocytes. [JOURNAL ARTICLE]
- Biosci Biotechnol Biochem 2014 Oct 10.:1-8.
Increased abnormal oocytes due to meiotic chromosome misalignment and spindle defects lead to elevated rates of infertility, miscarriage, and trisomic conceptions. Here, we investigated the effect of biotin deficiency on oocyte quality. Three-week-old female ICR mice were fed a biotin-deficient or control diet (0, 0.004 g biotin/kg diet) for 21 days. On day 22, these mouse oocytes were analyzed by immunofluorescence. Due to biotin, undernutrition increased the frequency of abnormal oocytes (the biotin deficient vs. control: 40 vs. 16%). Next, the remaining mice in the biotin-deficient group were fed a control or biotin-deficient diet from day 22 to 42. Although biotin nutritional status in the recovery group was restored, the frequency of abnormal oocytes in the recovery group was still higher than that in the control group (48 vs. 18%). Our results indicate that steady, sufficient biotin intake is required for the production of high-quality oocytes in mice.
- Poly(3-hydroxybutyrate) Production by Isolated Halomonas sp. KM-1 Using Waste Glycerol. [Journal Article]
- Biosci Biotechnol Biochem 2014 Oct; 78(10):1803.
- Fungal colonization and enzyme-mediated metabolism of waste coal by Neosartorya fischeri strain ECCN 84. [Journal Article]
- Biosci Biotechnol Biochem 2014 Oct; 78(10):1797-802.
Colonization and oxidative metabolism of South African low-rank discard coal by the fungal strain ECCN 84 previously isolated from a coal environment and identified as Neosartorya fischeri was investigated. Results show that waste coal supported fungal growth. Colonization of waste coal particles by N. fischeri ECCN 84 was associated with the formation of compact spherical pellets or sclerotia-like structures. Dissection of the pellets from liquid cultures revealed a nucleus of "engulfed" coal which when analyzed by energy dispersive X-ray spectroscopy showed a time-dependent decline in weight percentage of elemental carbon and an increase in elemental oxygen. Proliferation of peroxisomes in hyphae attached to coal particles and increased extracellular laccase activity occurred after addition of waste coal to cultures of N. fischeri ECCN 84. These results support a role for oxidative enzyme action in the biodegradation of coal and suggest that extracellular laccase is a key component in this process.
- Screening micro-organisms for cadmium absorption from aqueous solution and cadmium absorption properties of Arthrobacter nicotianae. [Journal Article]
- Biosci Biotechnol Biochem 2014 Oct; 78(10):1791-6.
To obtain basic information on how microbial cells absorb cadmium from aqueous solution, we examined cadmium absorption in various micro-organisms. Of 51 micro-organism strains tested, we found that some Gram-positive bacteria, such as, Arthrobacter nicotianae and Bacillus subtilis, and some actinomycetes, such as, Streptomyces flavoviridis and S. levoris were highly capable of absorbing cadmium from an aqueous solution. A. nicotianae absorbed the largest amount of cadmium, over 800 μmol cadmium per gram of dry wt. cells. However, cadmium absorption by A. nicotianae was affected by the solution pH, cadmium concentration, and cell density. The absorption of cadmium was very rapid. Some factors that affected cadmium absorption by A. nicotianae cells were also discussed.
- Metabolically driven equilibrium shift of asymmetric amination of ketones by ω-transaminase using alanine as an amino donor. [Journal Article]
- Biosci Biotechnol Biochem 2014 Oct; 78(10):1788-90.
Removal of a side product to overcome unfavorable equilibrium is a prerequisite for the asymmetric amination of ketones using ω-transaminase (ω-TA). Alanine has been preferred as an amino donor because its deamination product (i.e. pyruvate) is easily removable by several enzymatic methods. Here, we demonstrated that the removal of pyruvate by an innate metabolic pathway could afford equilibrium shift of the ω-TA reactions.
- Identification and characterization of Aeromonas hydrophila genes encoding the outer membrane receptor of ferrioxamine B and an AraC-type transcriptional regulator. [Journal Article]
- Biosci Biotechnol Biochem 2014 Oct; 78(10):1777-87.
We found that, under iron-limiting conditions, Aeromonas hydrophila ATCC 7966(T) could utilize the xenosiderophore desferrioxamine B (DFOB) for growth by inducing the expression of its own outer membrane receptor. Two consecutive genes, desR and desA, were selected as candidates involved in DFOB utilization. The presence of the ferric-uptake regulator boxes in their promoters suggested that these genes are under iron-dependent regulation. Mutation of desA, a gene that encodes the outer membrane receptor of ferrioxamine B, disrupted the growth of the amonabactin-deficient mutant in the presence of DFOB. β-Galactosidase reporter assays and reverse transcriptase-quantitative PCR demonstrated that desR, a gene that encodes an AraC-like regulator homolog is required for the induction of desA transcription in the presence of DFOB and under iron-limiting conditions. The functions of desA and desR were analyzed using complementation experiments. Our data provided evidence that DesA is powered primarily by the TonB2 system.
- Production of a pharmaceutical intermediate via biohydroxylation using whole cells of Rhodococcus rubropertinctus N82. [Journal Article]
- Biosci Biotechnol Biochem 2014 Oct; 78(10):1772-6.
Rhodococcus rubropertinctus N82 possesses unique regiospecific hydroxylation activity in biotransformation of compounds. In this study, the ability of whole cells of the strain R. rubropertinctus N82 in biotransformation was studied. The hydroxylation activity resulted in transforming 6,7-dihydro-4H-thieno[3,2-c]-pyridine-5-carboxylic acid tert-butyl ester (LS1) into 2-hydroxy-6,7-dihydro-4H-thieno[3,2-c]-pyridine-5-carboxylic acid tert-butyl ester (LP1), a pharmaceutical intermediate. By optimizing conditions for the hydroxylating biotransformation using whole cells of R. rubropertinctus N82 as biocatalyst, 3.3 mM LP1 was successfully produced from 4 mM LS1 with a molar yield of 83%. Thus, effective method was newly developed to produce LP1, which is a synthetic intermediate of a platelet inhibitor active pharmaceutical ingredient drug, prasugrel.
- Urine 3-hydroxykynurenine is higher during the postovulatory phase than in the preovulatory phase indicating a higher vitamin B6 requirement. [Journal Article]
- Biosci Biotechnol Biochem 2014 Oct; 78(10):1757-60.
The relationship between l-tryptophan to nicotinamide metabolism and the menstrual cycle of Japanese women was investigated. Nine metabolism intermediates from urine samples collected during the preovulatory and postovulatory phases were measured. Only urine 3-hydroxykynurenine was higher in the postovulatory phase than in the preovulatory phase. This increase in 3-hydroxykynurenine suggests a decreased reaction of 3-hydroxykynurenine → 3-hydroxyanthranilic acid catalyzed by kynureninase, a vitamin B6 enzyme.