Effects of diverse environmental factors on the growth rate ( od4oo ) and nitrogenase activity ( ara ) of the strain w12 hi nitrogen - free culture were investigated in our experiments. the results implied that the strain w12 could easily adapt to different cultural conditions : it could use various carbon sources ( especially glucose, sucrose, malic acid, mannitol ), propagate quickly and fix nitrogen at a temperature range of 15 ? to 40 ? and at 25 - 35 ? for optimum, at a ph range of 4 to 8. 5, at a saline concentration range of 0. 01 % to 1. 5 % ; low nlv " concentration had little effect on its nitrogenase activity. ara could also be detected when it grow in the culture media with 5mmol / l ntv "
W12菌株對環境因子的適應性研究:無氮培養條件下,測定溫度、碳源、酸堿度、滲透壓對w12生長及固氮能力的影響,結果表明,在15 - 40下均能生長並表達固氮酶活性,其最適生長及固氮的溫度為25 - 35 ;能利用葡萄糖、
蔗糖、蘋果酸、甘露醇等多種碳源生長並固氮,當培養基中同時存在
蔗糖和蘋果酸時,細菌生長和固氮活性最強;在偏酸和偏堿的條件下( ph4 . 5 - 8 . 5 )均能保持較強的生長勢和較高的固氮酶活性,並能通過調
節自身代謝平衡並適應環境的酸、堿性變化,使培養液趨于中性:能耐受較高的滲透壓,培養液中卜、 5 naci濃度對其生長和固氮酶活性影響不大,當naci濃度升至2時,菌株的生長勢及固氮酶活性才有所下降:低濃度的鉸對其固氮酶活性影響不大,在0
In this study, systems of rapid propagation of the cultivars such as d. zingiberensis, d. panthaica and d. composite were setup to find the best way to meet the need of producing, and to establish the base of introduction, breeding and cultivar improvement of foreign dioscorea with high diosgenin ; in addition, there are two strategies to obtain polyploids combining with chromosome engineering : screeding natural mutations and mutation breeding were carred out on d. zmgiberensis. exploratively studies were done on rapid propagation of the three dioscorea plants. the result showed : explants of d. pathaica obtained the appreciate propagation efficency on ms + ba1. 0mg / l + naa0. 1mg / l, ms basic medium containing 6. 0mg - 1 ba, l. 0mg - 1 kt and sucrose at 30gl - 1 or 60g1 - 1 was the appreciate medium for microtuberization
三種薯蕷屬植物離體再生體系培養條件的探索試驗結果表明:黃山藥外植體適宜的增殖培養基為ms + ba1 . 0mg / l + naa0 . 1mg / l ,微型塊莖誘導為ms + ba6 . 0mg / l + kt1 . 0mg / l + 3
蔗糖,高濃度的
蔗糖含量( 6 )能提高微型薯蕷的誘導率,但對其誘導起關鍵作用的還是ba的濃度;菊葉薯蕷增殖效果較好的培養基為ms + ba1 . 0mg / l ,以ms培養基為誘導微型薯蕷的最佳選擇,誘導率可達50 ;盾葉薯蕷最適宜的增殖培養基為ms + ba2 . 0mg / l ,在誘導微型薯蕷的實驗中發現,當ba濃度為6 . 0mg / l和8 . 0mg / l時, 15d左右
節間處膨大形成綠色圓球狀小塊,但繼續培養其上則開始分化芽。
After sitting down for a rest beneath a big tree, we went back to work, aiming for another big tree about one to two hundred meters ahead. when we reached this second target, we sat down again and ate some of the sugarcane that we had brought with us
我取出兩
節帶來的甘
蔗,和師姊坐下來吃,吃完后,再以前方一兩百公尺遠的一棵樹為目標,繼續推進,到了以後,同樣停下來,取出甘
蔗邊吃邊休息。
A snail exposed to the smell of pear drops and then food sucrose, which they love, for example, will respond weeks later to the smell of pear drops by rhythmically moving its mouth parts in anticipation of food, even when none is provided
例如,先讓蝸牛聞一下梨汁的氣味,然後再給以食物(例如蝸牛喜歡的
蔗糖) ,一個星期後,當蝸牛聞到梨汁的氣味后,就會有
節奏地張開嘴巴來等待食物,即使是什麼也不給它。
It is strange enough that most strict diets recommend artificial sweeteners to take the place of sugar and other natural sweeteners
說來也真奇怪,那些最嚴格的節食的食譜推薦用人造的甜味劑來代替蔗糖和其他天然的甜食品。