DHA高产菌Schizochytrium sp.FJU-512的分离及其18S rRNA基因序列比较分析

采用松花粉垂钓法分离到一株Docosahexaenoicacid(DHA)高产菌FJU 512.该菌株DHA含量高(占总脂肪酸的56. 24 % ),其它长链杂酸含量少(仅有docosapentaenoicacid, DPA),极具开发应用价值.高密度培养可获得33gL-1生物量.该菌株行二分裂生长,没有分生胞子.对其18SrRNA基因进行了克隆测序并登录GenBank(AY758384).依据18SrRNA基因建立的系统进化树表明:该菌与Schizochytriumlimacinum具有紧密的亲源关系. 图7表2参29     

水杨酸对小麦高盐毒害的缓解作用

以盐敏感品种中国春、农大８５０２１和抗盐品种冬６８、茶淀红等４个品种小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）为材料,研究盐分胁迫对小麦种子萌发和幼苗生长的影响以及水杨酸对盐害的缓解作用．结果表明,水杨酸能够相对提高盐分胁迫条件下小麦种子萌发的数量、速度和质量;提高幼苗根和叶内游离脯氨酸、可溶性糖等渗透调节物质的含量,增强其渗透调节能力,同时提高幼苗体内超氧化物歧化酶、过氧化物酶等细胞保护酶的活性,抑制膜脂过氧化作用产物丙二醛的积累,降低叶片质膜透性和盐分胁迫对细胞膜的伤害．所有这些变化都有利于缓解盐害,提高小麦抗盐性     

西南部分地区麻疯树种子油的理化性质及脂肪酸组成分析

从西南6个地区采集了麻疯树种子并分析比较了其生物学性状和种子油的理化性质及脂肪酸组成.所有样品的百粒重范围为41.80~71.39g,出仁率60.02%~81.43%,种仁含油率51.76%~57.93%,种子含油率31.07%~47.17%,不饱和脂肪酸含量74.89%~79.68%.其中永胜产麻疯树的种子品质最好,其出仁率为81.43%,种仁含油率57.93%,种子含油率47.17%,不饱和脂肪酸含量79.68%.攀枝花和宁南产麻疯树的种子品质次之.双柏和罗甸麻疯树的种子油酸值为0.81,在所有样品(0.81~9.46)中最低.对麻疯树种子及种子油性质的相关数据进行方差分析,结果表明,产地不同,麻疯树种子的生物学性质、种子油理化性质和脂肪酸组成都有一些差异.图2表3参18     

Abating whey organic load through ethanol and lactic acid production by kefir

Abstract

The extent to which selected ethanol and lactic acid production bioprocesses contribute to whey waste abatement was examined. Alcoholic fermentation of whey was carried out by kefir cells immobilized on grape stalks, delignified cellulosic materials, or brewer's spent grains. Lactic acid fermentation was also performed by free kefir cells with or without addition of brewer's spent grains as promoting material. Since whey fermentation rate is affected by the lactose uptake rate, ¹⁴C-labeled lactose was used to study the fermentation ability of kefir. The highest reductions in biochemical oxygen demand and chemical oxygen demand of whey, about 68% and 52%, respectively, were achieved by lactic acid fermentation in 6 h at 37 °C and pH 5.5, in the presence of 120 g brewer's spent grains. Additionally, at the same conditions, the highest ¹⁴C-labeled lactose uptake rate by kefir and consequently the highest alcoholic fermentation rate were also recorded. However, greater reductions in biochemical oxygen demand and chemical oxygen demand of whey are required prior to final disposal.     

珠江三角洲城市雨水的化学组成及其成因探讨

于2005—2007年间,基于降水过程监测分析了广州市和珠海市雨水的化学组成。结果表明,广州市雨水的pH值变化于3.32~7.03之间,平均值为4.35,众数约为4.15。珠海市雨水的pH值变化于3.38~6.49之间,平均值为4.51。雨水pH值随降水强度的减弱而降低,这决定于大气中水汽与酸性气体的接触时间。珠江三角洲城市雨水中所含主要离子依次是SO42-、NO3-、NH4＋、Ca2＋、Cl-。雨水的酸化与降水过程密切相关。降雨初期雨水比中后期雨水的pH值高,揭示降雨初期大气中的粉尘颗粒有效中和雨水的酸度。多天连续降水天气对大气尘埃的清洗作用明显,但是持续的SO2和NOx排放更容易使雨水酸化。滨海城市降水初期雨水的电导率上升较快（可以从小于1μS.cm-1上升到20~30μS.cm-1）,随着降水时间的延长雨水的电导率以较慢的速率上升。     

模拟酸雨条件下降尘中Cu,Pb,Zn,Cr各形态的溶出和转化研究

本文用Ｔｅｓｓｌｅｒ方法，研究了模拟酸雨条件下，降尘中Ｃｕ，Ｐｂ，Ｚｎ，Ｃｒ各形态的溶出和相互转化。试验表明：（１）降尘中Ｃｕ，Ｃｒ的溶出量随酸雨酸度的增大而增加；Ｐｂ，Ｚｎ没分别在ＰＨ＝３．５和ＰＨ＝４．５时溶出量最大，溶出的金属多源于可交换态和碳酸盐结合态，说明这两种形态的稳定性较差。（２）在模拟酸雨条件下，Ｃｕ，Ｐｂ，Ｚｎ，Ｃｒ各形态的含量发生了较大变化；Ｃｕ从其优势形态有机结合态向可交换态     

厦门近海沉积物中高分子有机质的来源初探

采用多步连续-湿法-化学方法,分离提纯了于2010年7月和12月在厦门近海采集的沉积物样品,获得3类高分子有机质,即腐殖酸（HA）、干酪根和碳黑（KB）和碳黑（BC）。以扫描电镜（SEM）作为有效的辅助手段,观察沉积物原样及高分子有机质的形貌特征,结合稳定碳同位素（δ13C）的分析,初步探讨了厦门近海沉积物中高分子有机质的来源。扫描电镜观察发现,在原样沉积物中存在多种海源物质（如钙质硅藻和圆筛藻/冠盘藻）;而在KB样品中同时发现类似于陆地植物的木质碎片以及来自海洋的藻胶鞘,暗示了其来源是海源与陆源共同作用的结果。稳定碳同位素研究表明厦门湾近海海域沉积物中有机质以陆源影响占优势,其比例在58.32%至84.45%之间;δ13C值整体上显示为夏季的贫于冬季的,这与研究区域的生态系统中陆源C3植被和海源水生植物的繁殖生长有关,同时还有排海污水及化石燃料煤燃烧后或者运煤船只洒落的碎屑的贡献。     

磷钨酸光催化降解甲基橙溶液的研究

以磷钨酸为光催化刺，在紫外灯照射下。对模拟染料废水甲基橙溶液进行光催化降解，并研究了催化剂加入量、pH值、甲基橙初始浓度和外加氧化剂H2O2对光催化降解效果的影响。结果表明，磷钨酸光催化剂加入量为300mg／100mL，pH=2．5时，甲基橙溶液的降解率明显高于其他pH值的降解率；在较低浓度下，甲基橙溶液的光催化降解反应符合一级动力学方程；外加氧化剂H2O2可提高光催化反应速率。     

Decomposition of perfluorocarboxylic acids (PFCAs) by heterogeneous photocatalysis in acidic aqueous medium

Decomposition of perfluorocarboxylic acids (PFCAs) is of prime importance since they are recognized as persistent organic pollutants and are widespread in the environment. PFCAs with longer carbon chain length are particularly of interest because of their noted recalcitrance, toxicity, and bioaccumulation. Here in this study, we demonstrate efficient decomposition of three important PFCAs such as perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) by heterogeneous photocatalysis with TiO₂ as a photocatalyst in acidic aqueous solutions. The PFCAs were decomposed into shorter carbon chain length PFCAs and fluoride ions. Photoholes of excited TiO₂ generated upon UV-irradiation are found to be the oxidation sites for PFCAs. Therefore, creation and sustenance of these photoholes in the acidic aqueous medium has enhanced the decomposition of PFCAs. Heterogeneous photocatalytic treatment achieved more than 99% decomposition and 38% complete mineralization of PFOA in 7 h. The decomposition of other PFCAs was as high as 99% with a defluorination efficiency of 38% for PFDA and 54% for PFNA. The presence of perchloric acid was found to enhance the decomposition by facilitating the ionization of PFCAs. The oxygen present in the medium served both as an oxidant and an electron acceptor. The mechanistic details of PFCA decomposition and their corresponding mineralization are elaborated.