Changes in the charged metabolite and sugar profiles of pasteurized and unpasteurized Japanese sake with storage

Japanese sake (rice wine) is commonly heat treated (pasteurized) to maintain its quality. In this study, temporal changes in the metabolite profiles of pasteurized and unpasteurized sake were investigated during storage. Metabolomic analyses were conducted for eight sets of pasteurized and unpasteurized sake obtained from single process batches stored at 8 or 20 °C for 0, 1, 2, or 4 months. Capillary electrophoresis time-of-flight mass spectrometry and liquid chromatography tandem mass spectrometry were used to obtain charged metabolite and sugar profiles, respectively. The total amino acid concentration decreased with storage, and the decrease was faster in pasteurized sake than in unpasteurized. The organic acid concentrations were relatively constant in both types of sake. Peptide and glucose concentrations increased and polysaccharide concentrations decreased in unpasteurized sake, while they were relatively constant in pasteurized sake. Rather than stabilizing the sake metabolite profile during storage, pasteurization results in characteristic changes compared to unpasteurized sake.     

Long-term fluctuations in mollusk populations before and after the appearance of the alien predator <Emphasis Type="Italic">Euspira fortunei</Emphasis> on the Tona coast,Miyagi Prefecture,northern Japan

The impact of Euspira fortunei as an alien predator on fluctuations in population densities of prey mollusks between 2001 and 2010 on the Tona coast, northern Japan, was investigated. This species increased dramatically from 2002 to 2004. In contrast, prey species such as Ruditapes philippinarum and Macoma incongrua decreased rapidly from 2001 to 2004, whereas Pillucina pisidium and Batillaria cumingii did not show a significant decrease during this period. Using a laboratory experiment, we were able to show that these decreases in the population densities of some species of mollusks but not other species were the result of species-selective predation by E. fortunei, as the experiment revealed that E. fortunei preferred to attack R. philippinarum and M. incongrua rather than P. pisidium, although the predator did expand its diet to include P. pisidium after it had consumed 16 of the 20 preferred prey available (i.e., R. philippinarum and M. incongrua). This case study suggests that invasive naticid predators have the potential to affect the population density and community structure of prey mollusks in recipient coastal ecosystems through predation.     

Current trends in conservation education in Japan

Conservation education (CE) is an important component of environmental education. Its goal is to teach the theory and practice of preservation and restoration of biodiversity affected by human activities so that people can increase their awareness of conservation issues and change their attitudes and behavior to promote environmental conservation.This paper describes two successful case studies to highlight trends in CE in Japan. One case is a project implemented to create “agricultural wetlands” that resulted in the establishment of a Ramsar Convention site comprised of a restored wetland and its adjacent rice paddy in a rural area near Sendai City in northern Japan. Rice paddy fields are a major component of Satoyama, which are traditional agricultural ecosystems in Japan and occupy 40% of the undeveloped landscape in Japan (Ministry of the Environment Government of Japan, 2007. Third National Biodiversity Strategy of Japan. Ministry of the Environment Government of Japan, Tokyo). Restoration of Satoyama and wetlands by local citizens is a key component of CE practices in Japan, where practical, hands-on, community-based learning is important. The second CE project, geared toward university students and citizens in Yokohama, restored degraded dragonfly ponds and created butterfly biotope in the second largest city in Japan. Restoration of habitat that is centered around highly visible, popular species such as dragonflies and butterflies also benefits other, less prominent species that share these habitats, yet allows residents to easily monitor the benefits of the project.     

Composition and Regiodistribution of Fatty Acids in Triacylglycerols and Phospholipids from Red and Black Rices

Regiospecific profiles of fatty acids (FA) of triacylglycerols (TAG) and phospholipids (PL) isolated from red and black rices were investigated. The lipids extracted from red and black rices were separated by thin‐layer chromatography (TLC) into eight subfractions, respectively. With a few exceptions, the major lipid components were TAG (76.4–80.5%), free FA (7.2–9.8%), and phospholipids (3.5–3.6%), while hydrocarbons, steryl esters, diacylglycerols (1,3‐DAG and 1,2‐DAG), and monoacylglycerols were present in minor proportions (0.1–4.1%). The PL components isolated from the two cultivars were phosphatidyl choline (52.3–53.7%), phosphatidyl ethanolamine (22.3–23.1%), phosphatidyl inositol (20.6–21.3%), and others (<3.4%). No significant differences (P < 0.05) in FA distribution were found when these cultivars were compared. The principal characteristics of the FA distribution in the TAG and PL were evident in the rices between the two cultivars: unsaturated FA were predominantly located at the sn‐2 position (77.3–96.8%), while saturated FA primary occupied the sn‐1 or the sn‐3 position (35.0–78.7%) in these lipids. The results of this study could provide useful information to both consumers and producers during manufacture of traditional rice foods in Japan.     

Directed evolution of yeast ferric reductase to produce plants with tolerance to iron deficiency in alkaline soils

One of the most serious problems in agriculture worldwide is low iron (Fe) availability, due to high soil pH. About 30% of arable land is too alkaline for optimal crop production. Non-graminaceous and dicot plants, which use a reduction strategy to uptake Fe, suffer from Fe deficiency under these conditions, because the ferric chalets reductase in the root plasma membrane functions inefficiently at high pH. The refrel (reconstructed yeast ferric reductase) gene was subjected to random mutagenesis to obtain variants with high activity under high pH conditions. A mutant library was screened using a yeast in vivo assay system, and screens at pH 8.0 and 8.5 produced 10 candidates. In vivo ferric reductase activity was analyzed quantitatively. Yeast cells carrying the variant with the highest ferric reductase activity showed 6.0, 8.7, and 38 times greater activity at pH 8.0, 8.5, and 9.0, respectively, than did cells containing the original refrel gene. An amino acid substitution at position 312 was common to most of the high-activity variants. This substitution is believed to play an important role in the increased reductase activity at high pH. Interestingly, this mutation is near a hams-coordinating histidine co on, and the corresponding residue is probably located in the intramembranous region close to the cytoplasm. The variant gene with the highest reductase activity was introduced into tobacco, and transgenic tobacco carrying the gene showed enhanced tolerance to low Fe availability. This result should be useful in the engineering of non-graminaceous and dicot plants tolerant to Fe deficiency in alkaline soils.     

Effect of microbubbles in deep flow hydroponic culture on Spinach growth

Microbubbled air may be efficiently supplied to the culture solution, since microbubbles are more efficiently dissolved in water than millibubbles. To establish an enhanced air supply method in the hydroponic culture of vegetables, microbubbles were applied using the deep flow technique to a hydroponic culture system of spinach. Spinach was cultivated in culture solution treated microbubbles for 21 days, then harvested and measured growth and concentrations of inorganic components and chlorophyll in the leaf blade. The results showed that microbubbles applied to the culture solution promoted the growth of spinach more than that by millibubbles. Using microbubbles, cultivars maintained a high concentration of dissolved oxygen at the middle growth stage, during which the dissolved oxygen concentration in the culture solution was reduced by the active root respiration. This result suggests that microbubbles are more effective than millibubbles in the hydroponic culture of vegetables.     

Microinsemination with first-wave round spermatids from immature male mice

In several mammalian species, including mice, round spermatids have been used to produce normal offspring by means of microinsemination techniques. In this study, we examined whether mouse round spermatids retrieved from immature testes undergoing the first wave of spermatogenesis had acquired fertilizing ability comparable to cells from mature adults. Microinsemination with round spermatids was performed by direct injection into preactivated oocytes, as previously reported. About 60-85% of the successfully injected oocytes developed to the morula/blastocyst stage after 72 h in culture, irrespective of the age of the males (17-25 days old). After embryo transfer, normal pups were obtained from all age groups, including the day-17 group, the stage at which the first round spermatids appeared. A high correlation (r=0.90) was found between the birth rate and male age (P<0.01, Spearman rank correlation), indicating that the efficiency of producing offspring was dependent on the age of the donor males. Imprinted genes (H19, Igf2, Meg3, and Igf2r) were expressed from the correct parental alleles (maternal, paternal, maternal, and maternal, respectively) in all (n=12) day-9.5 fetuses derived from day-20 spermatids. These results clearly indicate that at least some first-wave spermatogenic cells have a normal haploid genome with the correct paternal imprint and are capable of supporting full-term embryo development, as do mature spermatozoa from adults. The use of male germ cells from immature animals may save time in the production of inbred/congenic strains and rescue male-factor infertility of early onset.