固定化枝孢霉吸附Cu2+的研究

通过比较包埋法和载体结合法对枝孢霉的固定化性能，确定海藻酸钠一明胶包埋法为最佳固定方法，并利用正交试验得到固定化菌体制备的最优操作条件．探讨了不同环境因素如接触反应时间、溶液pH、温度对生物吸附Cu^2＋的影响．实验结果表明，固定化菌的吸附作用是先快后慢的过程，在3h达到生物吸附平衡，最佳pH为4．5，在15—45℃温度范围内，吸附量随温度升高有略微增加．在30～400mg L^-1范围内，吸附量随Cu^2＋的初始浓度的增加而增加，整个吸附过程较好地符合Langmuir和Freundlich吸附模型，在浓度为0．5mol L^-1的多种解吸剂中，HCl的解吸效果最好，解吸率达到99．96％，图3表5参12     

铅对大鼠海马神经元瞬间外向钾电流和延迟整流钾电流的影响

利用全细胞膜片钳技术研究了铅对大鼠海马CA1区神经元瞬间外向钾电流(IA)和延迟整流(IK)的影响．结果表明，铅可浓度依赖地抑制IA和IK，半数抑制浓度分别为37μmol L^-1和30μmol L^-1．此外还与电压呈依赖关系．50μmol L^-1的Pb(Ac)2可非常显著地影响IA和IK的激活过程，还非常显著地影响IA的失活过程，使激活和失活曲线均右移．铅可抑制大鼠海马神经元的IA和IK，并改变IA和IK的激活和失活过程．这可能是铅损伤海马神经元的作用机制之一．图5参16     

小麦铝抗性和敏感品系对铝胁迫的生理生化反应

研究了冬小麦Triticum aestivvum L.铝抗性品系T202和铝敏感品系T105幼苗经0，50μmol L^-1，75μmol L^-1，100μmol L^-1和150μmol L^-1铝处理后根部的生理生化变化．结果表明：小麦根生长被严重抑制；酸性磷酸酶活性增强，磷代谢激活；硝酸还原酶受到一定程度的抑制；葡萄糖-6-磷酸脱氢酶对铝浓度极其敏感；葡萄糖含量下降；而膜脂过氧化产物丙二醛(MDA)含量上升，超氧化物歧化酶(SOD)的活性升高和还原型谷胱甘肽(GSH)的含量下降．证实：铝胁迫造成了氧化伤害，激活了植物体内的抗氧化系统．分析还表明，T202耐铝的各项指标优于T105，前者的代谢酶活性对铝胁迫的反应更为迅捷，并有良好的能量储备和调动机制来抵御铝胁迫及由此产生的胁迫．图8参14     

树状多节孢原生质体的制备和再生

研究了酶系组成、酶解时间、酶解温度、渗透压稳定剂、PH值,培养基成分、培养方式,预处理、保护剂等因素对紫杉醇产生菌树状多孔孢原生质体制备和再生的影响。结果表明：将树状多节孢在PDA液体培养其中静止培养2－3d,离心收集菌体,用PH5．5－6．0的0．7mol/L的NaCl配制成的含有3％纤维素酶、2％蜗牛酶和1％溶菌酶的复合酶,30℃恒温酶解9h,原生质体制备率最高。但是考虑到原生质体的再生,参酶解7h左右为宜,获得的原生质体经过纯化,用0.7mol/LNaCl配制的PDA再生培养基进行双层平板培养法再生,原生质体的再生率最高。本研究为以后通过原生质体诱变、转化、融合构建紫杉醇工程菌株奠定了基础,图3表9参16     

沼泽红假单胞菌的番茄红素含量

研究了沼泽红假单胞菌适宜培养条件下番茄红素的含量．结果发现，在厌氧、30℃条件下，培养基中加入Fe^3 0．01g L^-1，有利于提高番茄红素的含量；培养基中Mg^2 浓度对其产量影响不显著；当光照强度为20001x时培养的菌体中番茄红素的含量最高，处于生长稳定初期(6d)，沼泽红假单胞菌中番茄红素的积累量可达53．7μgmg^-1．图3表1参11     

挂膜生长的白腐真菌处理草浆造纸黑液废水

比较了几株白腐真菌在造纸黑液废水中的挂膜生长状况及其对黑液废水的处理效果．结果表明，在pH6．0的废水中添加葡萄糖1．0g／L，酒石酸铵0．2g／L及适量无机盐时，黄孢原毛平革菌(Phanerochaete chrysosporium)和侧耳菌(Pleurotus ostieatus)以及本实验室自选的白腐真菌S22的挂膜状况和对黑液废水的处理效果最好．废水中添加的葡萄糖和酒石酸铵的浓度分别为1．0g／L和0．2g／L时，侧耳菌的挂膜和对黑液废水的处理效果最佳．S22菌在pH10．0时其木质素降解率和COD去除率最高，分别可达84％和69％．黄孢原毛平革菌、侧耳菌和S22菌能够在碱性较强的废水中生长挂膜并显著降解木质素，表现出对废水很强的适应能力．生物膜对黑液废水的半连续化处理结果表明了生物膜法的优越性．图8表1参14     

真菌对铜离子生物吸附的研究

从电镀废水污泥中分离、纯化获一高抗铜菌株，经鉴定为枝孢霉菌(Cladasporium sp.)，并采用不同的化学试剂对枝孢霉菌进行预处理。考察了不同因素如溶液的pH、摇床转速、接触反应时间对未处理菌和预处理菌的吸附能力的影响。结果表明：经0．2mol／LNaOH预处理的菌体具有最佳吸附效果。pH、摇床转速对菌体的吸附具有较显著影响。未处理菌吸附的最佳pH值为4.0，摇床转速为100r/min，预处理菌吸附的最佳pH为5．0，格床转速为100r/min。在一定的浓度范围内(10-150mg/L)菌对铜离子的吸附较好地符合Langmuir模型。生物吸附过程中pH变化呈一定的规律。     

皮氏罗尔斯通氏菌株DX-T3-01的耐镉性能及镉富集机理

从江西德兴铜矿土壤中分离筛选到一株具有较强耐镉(Cd)能力的细菌DX-T3-01,经生理生态及16S rRNA分析进行鉴定,研究其对不同浓度Cd2+的耐受特性及对重金属Zn2+、Cu2+、Ni2+的耐受性,进一步利用扫描电镜-能谱仪(SEM-EDX)和红外光谱(FTIR)探讨菌株对Cd2+累积去除的机理.经鉴定,耐镉细菌DX-T3-01为皮氏罗尔斯通氏菌(Ralstonia pickettii);Cd2+最高耐受浓度(MTC)为16 mmol L-1,最低抑制浓度(MIC)为4 mmol L-1,并可耐受一定浓度的Zn2+、Cu2+;菌体积累Cd2+后细胞表面有沉淀物附着并有镉元素检出,对Cd2+的累积主要依靠细胞壁上—PO43-、胺基中的—C—N—、—M—O(O—M—O)、C=O和酰胺基(—CO—NH—)基团.图5参16     

五氯酚对鱼鳃丝组织结构及电解质元素的影响

利用场发射扫描电镜观察了罗非鱼在0．05mg L^-1和0．10mg L^-1五氯酚(PCP)中暴露3d，7d和10d后鳃丝上皮组织结构的变化，以及扫描电镜／X-射线能谱联用仪定量分析鳃丝中主要电解质元素Na，Ca和Cl的变化．与CK比较，随着暴露时问的延长和暴露浓度的增加，泌氯细胞出现的密度增加，部分泌氯细胞个体的面积也增大，扁平上皮细胞的微脊碎片数量增加，排列散乱，细胞受损现象明显；鳃丝中Na，Ca和Cl元素的含量总体上呈下降的趋势，在一定程度上说明与Ca^2 、Na^ 和Cl^-运转有关的酶的活性受到抑制．图2参14     

氢化可的松高转化菌株的选育及其发酵条件

利用酮康唑抗性突变选育氢化可的松高转化菌株，即将经过紫外线诱变处理的新月弯孢霉原生质体倾注于含有酮康唑最小抑制浓度(10μmoL／L)的培养基平板上，获得了136株酮康唑抗性突变株，氢化可的松转化率高于出发菌株的有14株．其中抗性突变株KA-91，其氢化可的松转化率为出发菌株的1．42倍，达到68．05％．研究了菌株的发酵性能，优化了培养基组成和发酵工艺条件，氢化可的松转化率达到73．6％．图7表3参5     

Al~（3＋）对绿豆根生长和根类细胞核仁的影响

研究了不同浓度铝离子［ｃ（Ａｌ３＿）＝１０１，１０－２，１０－３，１０－４和平共处０－５ｍｏｌ／Ｌ）］对绿豆（ＰｈａｓｅｏｌｕｓｒａｄｉａｔｕｓＬ．）根生长及根尖细胞核仁的影响．结果表明：ｃ（Ａｌ３＋）在１０－３ｍｏｌ／Ｌ以上时对根生长和根尖细胞核仁都有着抑制作用．该仁受毒害后．核仁物质外溢细胞质内，严重时核仁物质几乎占据整个细胞质．该现象在分生组织细胞和根冠细胞中都可以观察到．     

Impact of cadmium and lead on Catharanthus roseus--a phytoremediation study

The Madagascar Periwinkle, Catharanthus roseus (L.) G. Don (a valued medicinal plant) was exposed to different concentrations ofheavymetals like, CdCl, and PbCl, with a view to observe their bioaccumulation efficiency. Germination was inhibited by both the heavy metals in the seeds previously imbibed in GA, and KNO, for 24 hr. EC50 (the effective concentration which inhibits root length by 50%) was recorded as 180 microM for CdCl2, and 50 microM for PbCl2. Both alpha-amylase and protease activity were reduced substantially on treatment of seeds with increasing concentrations of CdCl2, and PbCl2. Malondialdehyde (MDA) a product of lipoxigenase (LOX) activity also increased due to the treatment of both CdCl, and PbCl2. When two-months-old plants grown in normal soil were transferred to soils containing increasing amounts of these two heavy metals, senescence of lower leaves and extensive chlorosis were noticed after four days of transfer However, plants gradually acclimatized and after 20 days the chlorophyll content was almost comparable to normal. Plants receiving CdCl2 treatment (250 microg g(-1) and less) became acclimatized after two weeks and started normal growth. But PbCl2 of 432 microg g(-1) and less could not affect the plant growth throughout, after a preliminary shock was erased. In case of CdCl2 treatment, a stunted growth with reduced leaf area, reduced biomass and sterility were recorded after six months, while plants show normal growth and flowering in case of PbCl2 treatment. Total alkaloid was also found to be decreased in the roots of CdCl2 treated plants. No change was observed in case of PbCl2. GA3 treatments to the CdCl2 treated plants show internode elongation and increase in leaf area with relatively elongated leaves and thinning of stem diameter AAS analyses of leaves of treated plants exhibited 5-10% accumulation of cadmium, but there was no accumulation of lead at all.     

Response in germination and seedling growth in Phaseolus mungo under salt and drought stress

The effect of salt and drought stress at the water potentials of-2, -4,-6and -8 bars induced by NaCl and PEG 6000 (Polyethylene glycol 6000) each, on germination and early seedling growth, were investigated for two varieties (PU-19 and Type-9). Electrical conductivity (EC) value of the NaCl solutions were 4.5, 8.8, 12.7 and 16.3 dS m(-1). Germination percentage, root and shoot length, and seedling fresh and dry weight were measured in the study. The objective was to determine genotypic differences among P. mungo varieties in terms of salt and drought stress and to determine factors (salt toxicity or osmotic stress due to PEG) inhibiting seed germination. The germination results revealed that the genotypes significantly differed for salt and drought stress. PU-19 appeared to be more tolerant to salt and drought stress comparable to var Type-9. Both NaCl and PEG inhibited germination and seedling growth in both the varieties, but the effects of NaCI compared to PEG was less on germination and seedling growth. All varieties were able to germinate at all NaCl levels without significant decrease in germination, while a drastic decrease in germination was recorded at -6 and -8 bars of PEG. It was concluded that inhibition in germination at equivalent water potential of NaCl and PEG was mainly due to an osmotic effect rather than salt toxicity.     

乙烯消减盐抑制苜蓿种子萌发的机理研究

0．25mol/L的NaCl胁迫下的苜蓿种子转变1－氨基环丙烷－1－羧酸（ACC）和乙烯利为乙烯的能力明显降低。加入外源乙烯能引发受NaCl胁迫48h的苜蓿种子迅速萌发,但对种子内的Na^ 含量无明显影响。在种子吸涨过程中,外源乙烯对受NaCl胁迫的种子的水分吸收也无影响。外源乙烯能显著地提高NaCl胁迫下种子的呼吸速率和ATP含量。对乙烯消减盐抑制苜蓿种子萌发的作用机理进行了讨论。图6表1参21     

Effect of cadmium on germination, coleoptile and root growth of barley seeds in the presence of gibberellic acid and kinetin

Effect of cadmium on barley seeds treated with kinetin and gibberellic acid was investigated. As usual, cadmium has inhibited seed germination, and showed important inhibitory effects on roots and coleoptile growth after germination. In general, increase in cadmium concentration caused a greater inhibition of germination, root and coleoptile growth. The adverse effect of cadmium on root and coleoptile growth was more pronounced than that on germination. While testa was pierced by radicle (an indication of germination), no root or coleoptile development was observed above at concentration of 3-9.5 mM CdCl2xH2O. Low concentrations of cadmium have inhibited the root growth more than it did on coleoptile growth. Treatment of seeds with gibberellic acid and kinetin did not show any significant difference on the effect of cadmium in germination. However, inhibition of coleoptile elongation by cadmium has decreased a very much after kinetin application. The same result, although with lower rates when compared to kinetin, has been obtained for GA3 as well. In addition, the inhibitory effect of cadmium on root growth increased even more after kinetin application. The results have been found statistically significant through the least significant different (LSD) test at levels ofp < 0.05 and p < 0.01.     

ABA对米槠和格氏栲种子发育的影响

采用酶联免疫分析法（ＥＬＩＳＡ） 提取和测定米槠和格氏栲发育过程中果实内ＡＢＡ含量,并用不同浓度ＡＢＡ喂养,测定果实不同发育期对外源ＡＢＡ的敏感性．用放射性同位素法测定ＡＢＡ对贮藏蛋白质的积累作用,结果表明：在米槠和格氏栲种子发育过程中内源ＡＢＡ 含量逐渐上升,两者均在１０ 月５ 日达到峰值,米槠为１６４８ ｎｇｇ,格氏栲为１ ４６８ ｎｇｇ,随后ＡＢＡ含量均逐渐下降．果实成熟采收时,ｃ（ＡＢＡ） 仅为高峰时的１９．随着果实的发育对外加ＡＢＡ的敏感性逐渐变小,ｃ（ＡＢＡ）＝１０－４ ｍｏｌＬ－１ 可以完全抑制１０ 月２５ 日（ 米槠） 和１０ 月１５ 日（ 格氏栲） 前种子发芽,但对完全成熟的种子ｃ（ＡＢＡ）＝１０－２ ｍｏｌＬ－１ 亦不能抑制发芽．ＡＢＡ 对成熟前期胚的贮藏蛋白质合成无影响,但能促进成熟中后期胚的贮藏蛋白质的积累作用,ＡＢＡ维持米槠和格氏栲贮藏蛋白质合成和积累作用表现在转录水平上．     

Impact of rhizobacteria on growth and chromium accumulation in Scirpus lacustris L. grown under chromium supplementation

Four chromate tolerant rhizobacterial strains viz., RZB-01, RZB-02, RZB-03 and RZB-04 were isolated from rhizosphere of Scirpus lacustris collected from Cr-contaminated area. These strains characterized at morphological and biochemical levels. The most efficient chromate tolerant strain RZB-03 was inoculated to fresh plant of S. lacustris and grown in 2 microg ml(-1) and 5 microg ml(-1) of Cr+6 supplemented nutrient solution under controlled laboratory condition. The effects of rhizobacterial inoculation on growth and chromium accumulation in S. lacustris were evaluated. The inoculation of rhizobacteria increased biomass by 59 and 104%, while total chlorophyll content by 1.76 and 15.3% and protein content increased by 23 and 138% under 2 microg ml(-1) and 5 microg ml(-1) concentrations of Cr+6, respectively after 14 d as compared to non-inoculated plant. Similarly, the Cr accumulation also increased by 97 and 75% in shoot and 114 and 68% in root of inoculated plants as compared to non inoculated plants at 2 microg ml(-1) and 5 microg ml(-1) Cr+6 concentrations, respectively after 14 d. The chromate tolerant rhizobacteria which play an important role in chromium uptake and growth promotion in plant may be useful in development of microbes assisted phytoremediation system for decontamination of chromium polluted sites.     

接种Glomus versiforme对红三叶草利用有机磷的影响

以红三叶草为材料,利用三室隔网培养方法,研究接种菌根真菌Glmous versiforme对土壤有机磷及外加有机磷化合物植酸钠（Na-Phytate)、核糖核酸（RNA）和卵磷脂（Lecithin)的利用效率,植株生长7wk后收获测定植标干物重、含磷量和根系菌根侵染率,结果表明：接种菌根真菌能明显增加植株干物重、含磷量和吸磷总量,与各有机磷处理相比,无机磷（KH2PO4）处理生长效应最好,施用有机磷化合物各处理与CK相比均明显促进了植株生长,但不同有机磷处理之间没有显著差异,在植株吸磷量上,各接种处理均为相应CK处理的2倍以上,其中磷酸二氢钾处理吸磷量最高,菌根对照植物的根外菌丝虽然被限制在有限的空间内,但其吸磷量也达到不施磷的CK－M处理的2倍多,这说明由于菌根的形成植物能利用土壤因有的有机磷来满足自身生长的需要,表3参10     

百喜草茎叶发酵前后甲醇溶提物对离体条件下AM真菌的生长效应

发酵前后百喜草（Paspalum notatum Fl     

Studies on seed germination and growth in weed species of rice field under salinity stress

An investigation was made to see the salt tolerance of 10 weed species of rice. Properly dried and treated seeds of weed species were placed on 9 cm diameter petridishes lined with Whatman No. 1 filter paper under 6 salinity regimes, viz. 0 (control), 4, 8, 16, 24 and 32 dS m(-1). The petri dishes were then kept in germinator at 25 +/- 1.0 degrees C and 12 hr light. The number of germinated seeds were recorded daily. The final germination percentage, germination index (GI), seedling vigour index, mean germination time and time for 50% germination were estimated. Root and shoot lengths of the weed seedlings were measured at 20 days after salt application and relative growth values were calculated. Results revealed that salinity decreased final germination percentage, seed of germination as measured by GI, and shoot and root length in all the species. Germination of most of the weed seeds was completely arrested (0) at 32 dS m(-1) salinity except in E. colona (12%) and C. iria (13.9%). The species C. iria, E. colona, J. linifolia and E. crusgalli showed better germination (above 30%) upto 24 dS m(-1) salinity level and were regarded as salt-tolerant weed species. J. linifolia, F. miliacea, L. chinensis and O. sativa L. (weedy rice) were graded as moderately tolerant and S. zeylanica, S. grosus and C. difformis were regarded as least tolerant weed species.