Hydrocarbon productivities in different Botryococcus strains: comparative methods in product quantification

Six different strains of the green microalgae Botryococcus belonging to the A-race or B-race, accumulating alkadiene or botryococcene hydrocarbons, respectively, were compared for biomass and hydrocarbon productivities. Biomass productivity was assessed gravimetrically upon strain growth in the laboratory under defined conditions. Hydrocarbon productivities were measured by three different and independent experimental approaches, including density equilibrium of the intact cells and micro-colonies, spectrophotometric analysis of hydrocarbon extracts, and gravimetric quantitation of eluted hydrocarbons. All three hydrocarbon-quantitation methods yielded similar results for each of the strains examined. The B-race microalgae Botryococcus braunii var. Showa and Kawaguchi-1 constitutively accumulated botryococcene hydrocarbons equivalent to 30% and 20%, respectively, of their overall biomass. The A-race microalgae Botryococcus braunii, varieties Yamanaka, UTEX 2441 and UTEX LB572 constitutively accumulated alkadiene hydrocarbons ranging from 14% to 13% and 10% of their overall biomass, respectively. Botryococcus sudeticus (UTEX 2629), a morphologically different green microalga, had the lowest hydrocarbon accumulation, equal to about 3% of its overall biomass. Results validate the density equilibrium and spectrophotometric analysis methods in the quantitation of botryococcene-type hydrocarbons. These analytical advances will serve in the screening and selection of B. braunii and of other microalgae in efforts to identify those having a high hydrocarbon content for use in commercial applications

キョジュウ ケイタイ カラ ミタ ジョシ ガクセイ ノ ショクイシキ ト ショクコウドウ

居住形態別に食意識・食行動および食物摂取状況を把握するために,栄養士養成課程3年次学生を対象に,食意識と食行動に関する調査と料理単位法による食物摂取状況調査を実施した。居住形態により食事の調理担当者に違いがみられ,「家族と同居」群の場合は自分以外の家族が担当し,昼食も手作り弁当が多くなっていた。昼食に購入品が多い「一人暮らし」群に比べ,昼食においてほとんどの栄養素等摂取量が有意な高値を示し,また,1日当たりの摂取量も有意な高値を示した。1日当たり食品群別摂取量においても「家族と同居」群の方が,米類,いも類,緑黄色野菜類,その他野菜類,きのこ類,海藻類の摂取量が有意に多くなっていた。食事バランスガイドのサービング数でみると,「家族と同居」群でも摂りたい目安のサービング数に比べ主菜以外の摂取が少なく,「一人暮らし」群は,さらに少なくなっていた。「一人暮らし」群の中で食事の栄養バランスが取れていると思う者は15.4%で,「家族と同居」群に比べて低く,有意差が認められた。居住形態にかかわらず食事を改善したいという意欲はあるが,時間やお金の制約により改善できないということが明らかになった。したがって,望ましい食物摂取のためには内食に限らず,中食,外食を含めて,個々が実践できるよう食スキルの育成と食環境を整えていく必要があると考える。The purpose of this study is to determine the current state of dietary consciousness and habits and food intake in relation to living style. A survey on these three factors was administered to 165 college students enrolled in a nutrition course in Tokyo. Compared with students living alone, students living at home often brought their own lunches although they cooked less often. In addition, the intake of nutrients by students living at home was significantly higher. Students living with their family were also found to consume significantly more quantities of rice, potatoes, vegetables, mushrooms, and seaweed. In general, the students were found to consume less than the number of servings for each food group (except for main dishes) recommended in the Japanese Food Guide Spinning Top, with students living alone consuming even less. Students who were in control of their dietary habits made up 15.4% of those living alone, and this percentage was significantly lower than of those living at home. Most of the students wanted to follow ideal dietary habits, but could not afford the money and time to do so. The results suggest that the cultivation of an environment that matches participants\u27 characteristics could improve their dietary habits