摘要：
Laboratory batch experiments were conducted to study arsenic （As） removal from a naturally contaminated soil using phosphoric acid （H_3PO_4） and potassium dihydrogen phosphate （KHEPO_4）. Both H_3PO_4 and KHEPO_4 proved to reduce toxicity of the soil in terms of soil As content, attaining more than 20% As removal at a concentration of 200 mmol/L. At the same time, acidification of soil and dissolution of soil components （Ca, Mg, and Si） resulted from using these two extractants, especially H_3PO_4. The effectiveness of these two extractants could be attributed to the replacement of As by phosphate ions （PO~(3-)_4）. The function of H_3PO_4 as an acid to dissolve soil components had little effects on As removal. KH_2PO_4 almost removed as much As as H_3PO_4, but it did not result in serious damage to soils, indicating that it was a more promising extractant. The results of a kinetic study showed that As removal reached equilibrium after incubation for 360 rain, but dissolution of soil components, especially Mg and Ca, was very rapid. Therefore dissolution of soil components would be inevitable if As was further removed. Elovich model best described the kinetic data of As removal among the four models used in the kinetic study.
作者机构：
湖南农业大学,生物科学技术学院,湖南,长沙,410128;英国萨里大学,生物医学与分子科学学院,食品营养与安全研究中心,吉尔福德,萨里郡,CU2 7XH;[CLIFFORD Michael N.] 萨里大学;[WANG Zheng] 湖南农业大学
通讯机构：
College of Bioscience and Biotechnology, Hunan Agricultural University, China
关键词：
LC-MSn
摘要：
To investigate the chlorogenic acids resources in Eucommia ulmoides Olive leaves, Lonicera japonica Thunb. leaves and Houttuynla cordata Thunb. leaves, methanolic extracts of these three materials have been analysed qualitatively for chlorogenic acids and their derivatives by structure-diagnostic LC-MSn. Three monocaffeoylquinic acids (3-CQA, 4-CQA, 5-CQA) were detected. 5-CQA dominated this subgroup in Eucommia ulmoides Olive and Lonicera japonica Thunb. leaves, but 3-CQA and 4-CQA dominated this subgroup of chlorogenic acids in the leaves of Houttuynla cordata Thunb. Caffeoylquinic acid-glycosides were detected for the first time from Eucommia ulmoides leaves. 5-FQA was found in Lonicera japonica Thunb. leaves, and 3-FQA and 4-pCoQA have been identified in Houttuynla cordata Thunb. This is the first report of the chlorogenic acid profile in Houttuynla cordata Thunb. The comparatively unusual profile of caffeoylquinic acids in Houttuynla cordata Thunb. makes it a convenient source of 3-CQA and 4-CQA that are not commercially available.
摘要：
从土壤及霉变淀粉质材料等样品中分离获得到产糖化酶活性较高的菌株L-3,经鉴定为一种紫红曲霉;通过紫外线和硫酸二乙酯分别进行诱变,得到4株性能良好的糖化酶变异株,其中菌株7性能最好,命名为M.F7。对该菌株进行发酵性能测试,结果表明该菌株糖化酶活力比原菌株提高了20.8%;经过继代培养,证明其性状能稳定遗传。通过正交试验,确定菌株7最佳培养温度为30℃,最适pH值为5.5～6.0,最适培养时间为5 d.
摘要：
用含质粒载体pCAMBIA1301的根癌农杆菌EHA105转化贡蕉(Musa A A Pisang Mas cv. Mas)品种的胚性悬浮细胞,通过测定GUS基因瞬时表达率,对转化初期的主要影响因素进行了研究。结果表明,取处于对数期的胚性悬浮细胞和D_(600nm)为0.2的菌液混合,在室温、8000r/min离心5min,然后在110r/min的旋转摇床上摇5min,在体细胞胚诱导培养基上共培养8d,瞬时表达率达到最高值25.30%。
