Naoto Hirose

Okinawa Prefectural Fisheries and Ocean Research Center, Okinawa, Okinawa, Japan

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Publications (10)7.13 Total impact

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    ABSTRACT: Forty-three fungal producers for glycolipid biosurfactants, mannosylerythritol lipids (MELs), were isolated from leaves and smuts of sugarcane plants. These isolates produced MELs with sugarcane juice as nutrient source. The strains were taxonomically categorized into the genera Pseudozyma and Ustilago on the basis of partial sequences of the ribosomal RNA gene.
    No preview · Article · Sep 2012 · Bioscience Biotechnology and Biochemistry
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    ABSTRACT: Sugarcane (Saccharum officinarum L.) wax that contains policosanol (a mixture of long-chain alcohols), is widely known to have beneficial effects on human health. In order to investigate differences in the composition and content of sugarcane wax in different sugarcane cultivars, the wax, policosanol, and long-chain aldehyde composition of eight sugarcane cultivars were examined. The wax composition of sugarcane was analyzed using HPLC coupled with an evaporative light scattering detector (ELSD). Sugarcane waxes were comprised of 55–60% aldehyde and sterol esters, 32–40% alcohol, and small amounts of TAG, acid, and plant sterols. Additionally, the composition of policosanol and long-chain aldehydes was determined using GC-FID and their mass fragment compounds were identified using GC-MS. The highest content of policosanol and long-chain aldehyde compounds (500 mg and 600 mg/100 g rind, respectively), was found in the hand-peeled rind of the Ni 22 sugarcane cultivar. The content of these compounds increased up to 72% during sugarcane maturation from October to January. This study indicated that the composition and content of wax, policosanol, and long-chain aldehydes may vary depending on the cultivar of the sugarcane and the specific part of the sugarcane analyzed, as well as on the degree of sugarcane maturity. Practical applications: Different sugarcane cultivars have been evaluated in terms of their usefulness as a source of policosanol, which is a valuable wax component that may have beneficial effects on human health. Policosanol is the common name that refers to a group of long-chain (C20–C30) aliphatic primary alcohols that are of great interest since their effects include reduction of platelet aggregation, reduction of low-density lipoprotein levels in blood, inhibition of cholesterol synthesis, and prevention of atherosclerosis development, and which also display ergogenic properties. The present study detailed the wax composition, including that of policosanol and long-chain aldehydes, of sugarcanes of different cultivars. The results of this study could provide a basis for selection of sugarcane cultivars in agricultural areas for wax or policosanol production.
    Full-text · Article · May 2012 · European Journal of Lipid Science and Technology

  • No preview · Article · Jan 2012 · Horticultural Research (Japan)
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    ABSTRACT: Mannosylerythritol lipids (MELs) are glycolipid biosurfactants excreted by fungal strains. They show not only excellent surface-active properties but also versatile biochemical actions. Ustilago scitaminea NBRC 32730 has been reported mainly to produce a mono-acetylated and di-acylated MEL, MEL-B, from sucrose as sole carbon source. In order to make biosurfactant production more efficient, we focused our attention on the use of sugarcane juice, one of the most economical resources. The fungal strain produced MEL-B at the yield of 12.7 g/L from only sugarcane juice containing 22.4% w/w sugars. Supplementation with organic (yeast extract, peptone, and urea) and inorganic (sodium nitrate and ammonium nitrate) nitrogen sources markedly enhanced the production yield. Of the nitrogen sources, urea gave the best yield. Under optimum conditions, the strain produced 25.1 g/L of MEL-B from the juice (19.3% sugars) supplemented with 1 g/L of urea in a jar fermenter at 25 °C over 7 d. The critical micelle concentration (CMC) and the surface-tension at the CMC for the present MEL-B were 3.7×10(-6) M and 25.2 mN/m respectively. On water-penetration scan, the biosurfactant efficiently formed the lamella phase (L(α)) and myelins over a wide range of concentrations, indicating excellent surface-active and self-assembling properties. More significantly, the biosurfactant showed a ceramide-like skin-care property in a three-dimensional cultured human skin model. Thus, sugarcane juice is likely to be effective in glycolipid production by U. scitaminea NBRC 32730, and should facilitate the application of MELs.
    No preview · Article · Jul 2011 · Bioscience Biotechnology and Biochemistry
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    ABSTRACT: An ustilaginomycetous anamorphic yeast species isolated from the leaves of Saccharum officinarum (sugarcane) in Okinawa, Japan, was identified as a novel Pseudozyma species based on morphological and physiological aspects and molecular taxonomic analysis using the D1/D2 domains of the large subunit (26S) rRNA gene and the internal transcribed spacer 1 (ITS1)-5.8S-ITS2 regions. The name Pseudozyma churashimaensis sp. nov. was proposed for the novel species, with JCM 16988(T) as the type strain. Interestingly, P. churashimaensis was found to produce glycolipid biosurfactants, a mixture of mannosylerythritol lipids (MELs), including a novel tri-acetylated derivative (MEL-A2), from glucose. The observed critical micelle concentration (CMC) and the surface tension at CMC of MEL-A2 were 1.7 × 10⁻⁶ M and 29.2 mN/m, respectively. Moreover, on a water-penetration scan, MEL-A2 efficiently formed different lyotropic liquid crystalline phases, including the lamella phase at a wide range of concentrations, indicating its excellent surface-active and self-assembling properties. The novel strain of the genus Pseudozyma should thus facilitate the application of glycolipid biosurfactants in combination with other MEL producers.
    No preview · Article · May 2011 · Journal of Bioscience and Bioengineering
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    ABSTRACT: Biosurfactants (BS) are produced by a variety of microorganisms from renewable resources, and have unique properties compared to chemical surfactants. In order to attain efficient production of BS from low-cost materials, we focused our attention on the use of sugarcane molasses. Fifteen yeast strains that are known as BS producers were examined for BS productivity from a culture medium consisting of only molasses and water. Among the strains tested, only Starmerella bombicola NBRC 10243 produced sophorolipids (SL), which are glycolipid BS. The culture conditions for the yeast were then investigated in a shake-flask culture. SL production was significantly affected by the pH of the medium and was highly accelerated at pH 6. Under the optimum conditions, the amount of SL reached 14.4 g/L after 120 h from a medium containing 150 g/L of total sugars. We tried to improve the production of SL further by feeding the molasses using a jar fermentor. Interestingly, the amount of SL increased up to 22.8 g/L after 120 h; the production rate was 1.6-fold higher than that in the shake-flask culture. These results suggest that the present yeast should have great potential for the low-cost production of SL, and facilitate the application of BS in various fields.
    No preview · Article · Jan 2011 · Journal of oleo science
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    ABSTRACT: The effects of the roller material used in mill and liming treatments on the color tone, nutritional and functional components and sensory characteristics of non-centrifugal sugar were investigated. The iron roller in mill and liming treatments was responsible for the dark color in commercially available non-centrifugal sugar, suggesting an acceleration in the amino-carbonyl reaction by iron during the liming treatment. Use of the stainless-steel roller in mill but not liming treatment depressed the amino-carbonyl reaction, resulting in a light tone non-centrifugal sugar. The light tone non-centrifugal sugar had lower iron and calcium contents than that obtained using the iron roller for the same treatment. No difference in potassium and magnesium content, amino acid components, sucrose content, and polyphenolic content was observed between the light tone and dark tone non-centrifugal sugar when the iron roller was used in the combined mill and liming treatment. Moreover, the light tone non-centrifugal sugar was superior to the dark tone using the iron roller in the combined treatment on the sensory evaluation.
    No preview · Article · Jan 2009 · Nippon Shokuhin Kagaku Kogaku Kaishi

  • No preview · Article · Jan 2008
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    ABSTRACT: Sugar cane-fermented lactic acid beverage including functional nutritional components, such as γ-aminobutyric acid (GABA), was developed from the perspective of the development of sugar cane as a resource for fermented lactic acid beverages. Based on a screening of lactic acid bacteria, Lactococcus lactis was selected for GABA productivity to an index in skim milk medium containing sugar cane juice. The optimum conditions for GABA productivity were as follows : sugar cane juice content, 30% ; skim milk content, 10% ; fermentation temperature, higher than 30°C ; and fermentation time, 48 to 72 hrs. The quantity of the starter culture of Lc. lactis did not influence GABA content in lactic fermentation beverage. GABA increased with increased sugar cane juice content, and decreased with lowered skim milk content. GABA productivity was not shown for fermentation at temperatures less than 20°C. The GABA content of the sugar cane differed with breed or crop season. However, these differences did not influence GABA content of the lactic fermentation beverage. Sugar cane fermented lactic acid beverage included a high level of minerals, such as potassium and magnesium, and polyphenolics. DPPH-radical scavenging activity increased in reflection of the high content of polyphenolics. In addition, antimutagenic activity of lactic fermentation beverage was increased by using sugar cane.
    No preview · Article · Jan 2008 · Nippon Shokuhin Kagaku Kogaku Kaishi
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    ABSTRACT: We previously demonstrated that Hosobawadan was an effective anti-oxidative vegetable that contained anti-oxidative constituents such as D(+)-chicoric acid (ChA), chlorogenic acid (ChgA), caffeic acid (CA), luteolin 7-0-β-D-glucuronide (LU-gluc) and luteolin 7-O-β-D-glucopyranoside (LU-glc). In the present study, we first examined anti-LDL oxidative activity of Hosobawadan and found that the strength of anti-oxidative activity for LDL was dependent upon ChA, LU-gluc and LU-glc. This was due to ChA, which exhibited moderate activity and was abundant in Hosobawadan, with LU-gluc and LU-glc also exhibiting strong activity. We then examined the levels of these polyphenol compounds in rat plasma after oral administration of Hosobawadan extract (ChA 200 mg/kg body weight). ChA was detected at the highest concentrations (2.9±1.6 μg/mL) in the rat plasma 15min after oral administration. Conversely, luteolin (LU) was detected in rat plasma treated with glucuronidase/sulfatase, suggesting that LU in plasma existed as LU conjugates.
    No preview · Article · Jan 2006 · Nippon Shokuhin Kagaku Kogaku Kaishi