カサンカスイソ カラ ハッセイ スル ヒドロキシルラジカル ノ カッセイ ヲ カシカ シタ リカジッケン キョウザイ カイハツ ト ソノ キョウイク コウカ

本研究は，酵素の単元で学習した過酸化水素分解反応に関わる酵素の存在意義について，進化的側面からその重要性について再考察させることを目的とした。そして，本研究教材をバイオテクノロジーの探究活動として位置づけ，酵素とバイオテクノロジーの単元で学習する知識と実験技術を融合した発展的教材として，過酸化水素と2価鉄から生じる最も酸化力の高いヒドロキシルラジカルのDNAに対する酸化力の強さを可視化するための最適実験条件を電気泳動法により明らかにした。また，中学・高校生を対象とした教育実践から，本教材の教育効果の検証および高等学校生物への発展的導入について考察を行った。教育実践の事前・事後アンケートの比較の結果，本教材は，酸素を利用する生物にとって過酸化水素の無毒な水への分解反応が，いかに生物学的に重要な反応であるかを生徒に気付かせることに有効であることが明らかとなった。そして，過酸化水素分解反応が，エネルギー生産に酸素を利用する生物が進化の過程で獲得した過酸化水素の毒性に対する防御機構として重要な反応であることを，進化的側面と結び付けて理解させる効果的な教材であることが明らかとなった。よって，高等学校生物への発展的教材として，今後の導入が期待された。This study aims to reorient a foundation of the existing teaching material toward putting greater focus on the importance of the evolutionarily preserved implication of the meaningfulness of the reaction to hydrogen peroxide decomposition. The study material is placed as an exploratory activity of biotechnology and considered as a developmental learning tool backed up by techniques of experiment and knowledge taught through unit learning of enzyme and biology.An experiment was designed to discover an optimum condition by electrophoresis that visualizes the DNA decomposition from hydroxyl radicals (reactive oxygen species) derived from hydrogen peroxide and ferrous iron. In addition to the educational practice conducted for junior high and high school students, the study considered the validation of educational effectiveness of the teaching material together with a view to ushering in a developmental approach to high school biology class.As the result of the pre- and post-survey, the teaching material was found to be an effective means for students to associate the biological importance with reaction to hydrogen peroxide decomposition and put an emphasis on the significance of the reaction that is an important discovery of mankind to learn the course of evolution as an organism acquires its defense mechanism against the toxicity of hydrogen peroxide while using oxygen as a source of energy. Thus, the experimental teaching material is encouraged to be introduced to high school biology class as part of progressive educational material

ショクブツ シキソ アントシアニン ノ ヒドロキシルラジカル ショウキョカッセイ ヲ カシカ シタ リカジッケン キョウザイ カイハツ ト ソノ キョウイク コウカ

本研究は，植物色素が光合成のみならず酸素毒性から細胞や種を守る抗酸化物質としても働いてきたことを，進化的側面から植物色素の存在意義について再考察させるための実験開発と教材開発を行った。実験開発では，過酸化水素と2価鉄から生じる最も酸化力の高いヒドロキシルラジカルによるDNA分解が，植物色素であるアントシアニンにより防ぐことができることを可視化するための最適実験条件を明らかにした。また，高校生を対象とした授業実践から，本実験教材を用いた授業の教育効果を検証し，高等学校生物への発展的導入について考察を行った。授業実践の事前・事後アンケートの比較の結果，本教材のアントシアニンによる抗酸化能を可視化した実験により，植物色素の抗酸化能について理解しやすい教材であることが明らかとなった。また，授業解説と実験を行うことで，植物色素の抗酸化能が，紫外線や光合成から生じる活性酸素の毒性に対する防御機構として，植物の細胞機能の維持に重要な働きをしていることを，進化的側面から理解させることのできる効果的な教材であることも明らかとなった。よって本研究は，光合成以外の働きとして重要な植物色素の抗酸化能に着目した新たな実験としてだけでなく，光合成とバイオテクノロジーで学ぶ知識と実験技術を融合したバイオテクノロジーの発展的教材として，生徒に生命進化の観点から植物色素を多面的に理解させるための探究活動として，高校生物への今後の導入が期待された。This study aims to reorient a foundation of the existing teaching material and experiment in school education toward putting more focus on the evolutionarily preserved implication that plant pigments function not only as photosynthesis but also as anti-oxidant to protect living cells and plant seeds from oxidative toxicity. A developed experiment was designed for high school students to visualize the anti-oxidant potential of anthocyanin preventing DNA decomposition from hydroxyl radicals (ROS) derived from hydrogen peroxide and ferrous iron through electrophoresis as showing the indicative optimum condition. In addition, to the educational practice conducted for high school students, the study considered the validation of educational effectiveness of the teaching material together with a view to ushering in a developmental approach to high school biology class.It is also indicative that the posteriori survey revealed that students clearly understand the anti-oxidant ability of plant pigments, and it is effective for students to associate the biological importance of plant pigments in the course of evolution by teaching this function as anti-oxidant material of plant pigments for species preservation against ROS toxicity resulting from ultraviolet rays and photosynthesis. The study suggests that hands on experimental teaching material elicits students’ multifaceted understanding of plant pigments and the evolutionary implication, in high school education. Furthermore, the study material could be utilized as an exploratory activity to fulfill the requirement of biotechnology class, which is supported by techniques of scientific experiment and knowledge taught through unit learning of photosynthesis and biotechnology. Thus, the experimental teaching material is encouraged to be introduced to high school biology class as part of progressive educational material

オウヨウセイブツカガクブ1ネンセイ ヲ タイショウ トシタ ショクイクトライアル ノ ジッシ ト ヒョウカ ジュギョウサンカシャ ヘノ アンケート ニヨル ケントウ

応用生物科学部1年生を対象に,食育トライアル授業として,食の生産,安全管理,健康管理などに関する10回の講義と2回の農業体験(種まき,収穫作業等)を実施し,学生の授業への出席状況及び授業前後のアンケートによって,プログラムの内容および学生の食育に対する知識,意欲等の変化を評価した。応用生物科学部全学科の学生に授業への参加を呼びかけた結果,授業の出席者は27名であり,栄養科学科の学生が20名と最も多く,参加学生の学科構成に偏りがみられた。授業の初回に行ったアンケートの回答者は24名,最終回に行ったアンケートの回答者は11名であった。授業後のアンケートでは,「食育活動への興味は深まったか」「知りたい情報は得られたか」「参加後,農業と食の関連に対する考えが変わったか」「授業として開講された場合受講するか」という問いに対し,それぞれ73～91%が「はい」と回答し,「授業への総合的な満足度」についても73%が「(非常に)満足である」と回答した。「農業」に原点をおいた食育トライアル授業によって,食べ物の成長を通した気づきと感動,生産者への感謝の気持ち,環境への配慮,栄養と健康との関連知識の習得等に寄与することができたと考えられる。今後は授業への参加者数を増やし,結果の一般化可能性について検討するとともに,授業の実現に向けた人的・物的資源の問題について検討する必要がある。We aimed to evaluate changes in both knowledge of dietary education (Shokuiku) and in motivation, in first-year students of the Faculty of Applied Biosciences who attended a voluntary Shokuiku program in 2008. The program comprised 10 lectures on food production, safety management, and health management, as well as 2 farming practicum classes (seed sowing, harvesting, etc.). Twenty of the 27 students who attended the courses belonged to the Department of Nutritional Sciences. We received responses from 24 and 11 students to questionnaires administered before and after the program, respectively. We obtained a "yes" answer 73-91% of the time in response to the following questions : 1) Was your interest in dietary education activities enhanced? 2) Were you able to obtain the information you sought? 3) After attending these courses, did your understanding of the relationship between farming and diet change? and 4) Would you take this course if it were officially offered as a class? Seventy-three percent of students replied that they were very satisfied with the courses. By placing "farming" as the central principle, these courses contributed to food awareness and appreciation, feelings of gratitude toward producers, consideration for the environment, and knowledge acquisition about the relationship between nutrition and health. Future studies should address the generalizability by examining a larger pool of participants. In addition, other issues such as human and material resources should be considered in realization of the Shokuiku program curriculum

Identification of O2-induced peptides in an obligatory anaerobe, Clostridium acetobutylicum

AbstractClostridium acetobutylicum DSM792 (=ATCC824), a solvent producing obligate anaerobe, grew well after a shift in growth conditions from anoxic to microoxic at the mid exponential phase. In two-dimensional gel electrophoresis, a spot migrating at 45 kDa and three spots at 23 kDa accumulated after 30 min of flushing with 5% O2/95% N2. Based on peptide mass fingerprints, the 45 kDa polypeptide was determined to be NP_347663 (A-type flavoprotein homologue) and the 23 kDa polypeptides were determined to be NP_350180 or NP_350181 (novel type rubrerythrin homologue). Northern blot analysis indicated that the expressions of these peptide transcripts were upregulated within 10 min after flushing with 5% O2/95% N2

b-Type Dihydroorotate Dehydrogenase Is Purified as a H2O2-Forming NADH Oxidase from Bifidobacterium bifidum▿ †

Our previous report showed the existence of microaerophilic Bifidobacterium species that can grow well under aerobic conditions rather than anoxic conditions in a liquid shaking culture. The difference in the aerobic growth properties between the O2-sensitive and microaerophilic species is due to the existence of a system to produce H2O2 in the growth medium. In this study, we purified and characterized the NADH oxidase that is considered to be a key enzyme in the production of H2O2. Bifidobacterium bifidum, an O2-sensitive bacterium and the type species of the genus Bifidobacterium, possessed one dominant active fraction of NADH oxidase and a minor active fraction of NAD(P)H oxidase activity detected in the first step of column chromatography for purification of the enzyme. The dominant active fraction was further purified and determined from its N-terminal sequence to be a homologue of b-type dihydroorotate dehydrogenase (DHOD), composed of PyrK (31 kDa) and PyrDb (34 kDa) subunits. The genes that encode PyrK and PryDb are tandemly located within an operon structure. The purified enzyme was found to be a heterotetramer showing the typical spectrum of a flavoprotein, and flavin mononucleotide and flavin adenine dinucleotide were identified as cofactors. The purified enzyme was characterized as the enzyme that catalyzes the DHOD reaction and also catalyzes a H2O2-forming NADH oxidase reaction in the presence of O2. The kinetic parameters suggested that the enzyme could be involved in H2O2 production in highly aerated environments

Response of the Microaerophilic Bifidobacterium Species, B. boum and B. thermophilum, to Oxygen

We investigated the effects of O(2) on Bifidobacterium species using liquid shaking cultures under various O(2) concentrations. Although most of the Bifidobacterium species we selected showed O(2) sensitivity, two species, B. boum and B. thermophilum, demonstrated microaerophilic profiles. The growth of B. bifidum and B. longum was inhibited under high-O(2) conditions accompanied by the accumulation of H(2)O(2) in the medium, and growth was restored by adding catalase to the medium. B. boum and B. thermophilum grew well even under 20% O(2) conditions without H(2)O(2) accumulation, and growth was stimulated compared to anoxic growth. H(2)O-forming NADH oxidase activities were detected dominantly in cell extracts of B. boum and B. thermophilum under acidic reaction conditions (pH 5.0 to 6.0)