一株抗铜细菌的分离及其生物学特性的初步研究

[目的]从受铜污染的土壤中分离抗铜细菌。[方法]采集玉林市受铜污染的土壤9份,在培养基中加入不同浓度的Cu^2＋,经过不断的分离和驯化筛选耐铜细菌,根据其形态特征和生理生化特征进行初步鉴定,并对其生物学特性进行了初步研究,包括生长曲线的测定、pH值和渗透压对其生长的影响;采用原子吸收分光光度法检测培养时间和pH值对该菌株去除Cu^2＋能力的影响。[结果]在玉林市德兴造纸厂排污口附近的土壤中筛选出一株耐铜细菌。编号为RCBl,其耐Cu^2＋水平迭500mg／L;根据其形态和生理生化特征初步鉴定该菌为生丝微菌属Hyphomicrobium;该茵在pH4～8生长良好,其中最适生长pH为6．0—7．2,在1％NaCI下生长良好。该菌株在培养24h、pH为7时,Cu^2＋去除率达到76％。[结论]不仅丰富了抗铜微生物方面的研究,也为铜污染水、土壤修复等工业化生产提供了重要菌株。     

Effects of ethylene,abscisic acid and auxin on fruit abscission in water dropwort (Oenanthe stolonifera DC.)

Fruit abscission in water dropwort (Oenanthe stolonifera DC.) was investigated by measuring fruit removal force (FRF) affected by fruit ages and plant hormones. FRF decreased rapidly 30 days after anthesis (DAA). Ethylene evolution increased rapidly at 35 DAA and ABA concentration increased gradually after 20 DAA. ACC and ethephon decreased the FRF of fruit explants and the promoting effect of ACC was delayed by silver thiosulphate and cycloheximide, but not by norbornadiene and actinomycin D. ABA enhanced fruit abscission without increasing ethylene evolution. However, the observation that CoCl₂ delayed abscission induced by ABA indicates possible involvement of ethylene in the ABA effect. Treatment with NAA, fenoprop and IAA had no effect on 30 DAA fruit explants, but IAA delayed abscission of 25 DAA explants. This suggests that the effect of auxins may differ with fruit age when used as control agents.     

Straw management and optimal N fertilization in seed production of timothy (Phleum Pratense L.) and Meadow Fescue (Festuca Pratensis Huds.)

The market for herbage seed straw has diminished in many seed-production areas due to less livestock. Seed growers are therefore looking for alternatives to straw removal, which up to now has been the most common practice. During 2000–2006, different alternative straw chopping methods, both at the back of the combiner and with a tractor-mounted flail-chopper, and field burning strategies were evaluated in seed crops of timothy (Phleum pratense) and meadow fescue (Festuca pratensis) in southeast Norway. The requirement for an extra N input in autumn (30–40?kg ha^-1) when practising straw chopping was also examined. Compared to straw removal, straw chopping at the back of the combiner during seed harvest did not reduce seed yield in the following year as long as stubble height was low (<10?cm in timothy) and the straw spread uniformly in the field. On average, seed yield was 1–4% and 1–9% higher compared to straw removal in timothy and meadow fescue, respectively. If the chopped straw was spread unevenly, or long stubble was left at combining, it is recommended to use a tractor-mounted flail-chopper after harvest. The experiments did not provide any support for an extra input of nitrogen in autumn, either in timothy or meadow fescue, when the straw was chopped rather than removed. Burning of stubble and straw soon after seed harvest was another efficient clean-up method after harvest, which increased seed yield 9–15% and 17–20% compared to straw removal in the two species, respectively. However, as the burning method is risky and causes smoke emissions, it is normally not recommended. It is concluded that for most seed growers, the most effective, least laborious and most environment-friendly alternative to straw removal will be to chop the straw at the back of the combiner during seed harvest.     

膜式氧合器不同解吸方式对水产养殖水体中氨氮去除效果的影响

研究了膜式氧合器3种不同解吸方式，即：O2对流法、真空抽取法和酸吸收法去除水产养殖水体中氨氮的影响因素，并比较对其氨氮的去除效果。结果表明，氨氮初始浓度和pH是氨氮去除率的主要影响因素；当pH＞9时，O2对流法和真空抽取法对氨氮去除效果比pH＜9时要高，而酸吸收法不论pH高低时比其它2种方法都能获得较高的氨氮去除率。     

乳制品厂污水中螺旋藻的生长及其对氮磷去除作用研究

利用自制实验装置模拟开放跑道池式培养方式,采用预处理过的乳制品厂污水为培养基,在流动状态下,研究了不同培养液含量和不同流速条件下对螺旋藻养殖的影响。结果表明,乳制品厂污水经过简单的处理可以用于螺旋藻的培养,在污水稀释率为1d的情况下,螺旋藻可以良好的生长并可以获得一定的产量。最高密度达到3.0g·L-1(湿重),氮的去除率在85%左右,磷的去除率在50%以上。污水养殖螺旋藻的品质基本达到国家标准。     

木棉花加工中护色与脱除茸毛工艺研究

[目的]解决木棉花花脯产品护色和表面粗糙、入口有轻微毛感的问题。[方法]对木棉花加工中护色和脱除表面毛的工艺进行研究。[结果]采用3.0%柠檬酸溶液浸泡20 min或1.0%氯化钙溶液浸泡15 min控制褐变效果明显,干花产品贮存3个月无褐变现象。纤维素酶脱除木棉花表面茸毛的效果比果胶酶效果好,30℃下,0.5%纤维素酶处理木棉花60 min,脱除表面茸毛效果最好。[结论]氯化钙和纤维素酶是一种较好的护色和脱除茸毛的药剂。     

无机碳源对零价铁介导的自养脱氮序批式反应器处理高氨氮废水的影响

无机碳源作为自养微生物的能量来源,是影响自养脱氮细菌富集的重要因素。文章通过添加不同量的KHCO3作为ZVI介导的自养脱氮体系中无机碳源,研究反应体系的脱氮效果影响趋势以及适宜的无机碳源添加量。结果如下:1)KHCO3作为无机碳源可以显著提高NH^+4-N去除率,KHCO3添加量越多,其NH^+4-N去除率越高。KHCO3添加量分别为2 g,1 g,0.5 g的SBR反应器R2,R1,R0.5的NH^+4-N去除率分别为98.39%,65.18%,44.56%,相较不添加KHCO3的R0分别提高86.5%,53.29%,32.67%。ZVI的添加会降低KHCO3对NH^+4-N氧化的促进作用。2)KHCO3可明显提高TIN去除效果,促进总氮脱除的高低顺序是R1>R0.5>R2,SBR反应器R2,R1,R0.5的平均TIN去除率分别为19.01%,32.04%,27.62%,相较于空白组R0分别提高了10.60%,23.63%,19.21%。3)KHCO3可中和硝化反应产生的H^+,对反应体系具有缓冲作用,可使微生物处于较适宜的酸碱环境中,更有利于反应器的稳定运行。4)适量的无机碳源KHCO3可以促进氨氧化细菌和厌氧氨氧化细菌的活性。该研究探讨了无机碳源在零价铁脱氮体系中的影响趋势,为铁型脱氮技术提供了理论支撑。     

序批式生物膜法处理水产养殖废水的研究

目前我国水产养殖废水直接排放的现象较多, 使受纳水体富营养化和生物多样性降低; 同时养殖水体中残饵、水生生物排泄物容易引起水体溶解氧下降、病原体增加并产生有害物质如氨氮、亚硝酸盐等, 引起养殖对象发病甚至死亡。提出采用以组合填料为载体的序批式生物膜反应器处理水产养殖废水。通过试验确定了最佳运行模式: 水力停留时间12 h, 其中瞬时进水y 厌氧( 3 h) y 曝气( 5 h) y 添加原水(添加比1B 3) y 缺氧( 3 h) y 曝气( 1 h) y 沉淀( 0. 5 h) y 排水( 0. 5 h), 并考察了试验对污染物的去除特性。试验结果表明了序批式生物膜法处理水产养殖废水的可行性, 对有机物、氨氮、TN、TP的平均去除率分别为91. 1%、85. 1%、751 8%、89. 5%, 处理后出水可回用于水产养殖。     

甘薯茎尖脱毒与快速繁殖技术研究

甘薯茎尖分生组织脱毒培养与茎段快速繁殖,对培养条件和几种主要培养因子的反应十分敏感,以MS为基本培养基对甘薯茎尖分生组织与茎段进行不同激素种类种类和浓度试验,结果表明,IAA：6－BA为1：5－20诱导效果好,最佳诱导分化培养基为：MS＋6－BA1mg/L IAA0.1-0.2mg/L GA3 0.1mg/L;试管苗株系经指示植物,NCM－ELISA法检测,获得了6个品种的脱毒苗,脱毒苗茎段试快速繁殖时,不同品种之间有差异,单独使用IAA或与GA3结合使用,在28℃,光照12h/d,液体培养效果好。     

日粮蛋白质水平对4岁马鹿产茸性能的影响

为探讨马鹿日粮蛋白质水平和蛋白质 /代谢能比值对其产茸性能的影响 ,采用 3个蛋白质水平 (分别为Ⅰ :7 60 % ,Ⅱ :1 1 60 % ,Ⅲ :1 5 60 % )日粮的单因子设计 ,将选出的 2 0头健康和上年产茸量相近的 4岁马鹿随机分配到 3个日粮处理组中 (Ⅰ组为 8头 ,其他两组各为 6头 ) ,进行饲养试验。试验结果表明 ,蛋白质水平及蛋白质 /代谢能比值分别为 1 1 60 %、1 3 74g/MJ的日粮处理对产茸性能 (茸重、茸日增重、料茸比等 )的影响效果较好 ,但各组间差异不显著 (P >0 0 5 )。