植物激素对平菇茵丝生长及酶活性的影响

采用固体平板和液体摇瓶培养方法,研究了赤霉素、2,4-D、吲哚乙酸和萘乙酸4种激素对平菇- 126菌丝生长及酶活性的影响.结果表明,吲哚乙酸虽然能提高发酵液胞外蛋白的含量和过氧化物酶活性,但对菌丝的生长起抑制作用,这与吲哚乙酸能引起平菇菌丝裂解和细胞膜渗漏有关;萘乙酸、低浓度2,4-D能促进菌丝的伸长;萘乙酸、赤霉素在低浓度下也能促进菌丝的分枝,对菌丝的生长整体上起促进作用.除吲哚乙酸外,其他3种激素对平菇菌丝生长影响都有两重性:低浓度下能促进菌丝的生长,浓度过高则会对菌丝生长产生毒害作用.     

千层塔扦插繁殖研究

通过扦插试验,采用不同浓度水平的吲哚丁酸、萘乙酸、生根粉和吲哚丁酸＋萘乙酸等药剂处理千层塔插条,研究对插条的生根量、生根率、成活率等的影响和插条萌芽状况及扦插基质对插条生根的影响,为千层塔资源快速再生提供有效的繁殖途径。     

葛藤茎叶栽培平菇研究

通过对葛藤茎叶栽培平菇试验的观察和研究表明，葛藤茎叶中丰富的果胶质经高温处理产生的降解产物——单糖及衍生物能刺激菌丝的生长；经石灰水浸渍和未浸渍的试验组，菌丝满袋分别为26d和33d；生物学效率分别为188％-176％，比稻草对照组生物学效率提高44％-56％。葛藤茎叶是一种非常适合栽培平菇的好原料。     

微量元素对双孢蘑菇菌丝生长的影响

聋用固体平板和液体摇瓶培养试验方法,研究了Zn2+、Cu2+、Co2+、Mo(VI)、Mn2+等5种微量元素对双孢蘑菇2796菌丝生长的影响。通过测定各处理组的菌丝干重、胞内多糖、过氧化物酶活和菌丝生长势等生长参数表明,双孢蘑菇在添加上述5种浓度为20—40mg/L的微量元素时,对菌丝生长势、胞内多糖量和胞外蛋白量等都有促进作用,加入的浓度不同其促进程度也不同。加入Mn2+促进菌丝生长的效果最明显,使菌丝干重达最高值(200mg/100ml),胞内多糖量高达23mg/100ml,分别比对照组增加200%和400%,但添加高浓度的微量元素则会抑制菌丝的生长。     

几种激素对光合细菌生长的影响

提出在培养基中添加一定浓度的动物或植物生长激素可促进光合细茵的生长。泼尼松、地塞米松、三十烷醇、α-萘乙酸的最适添加浓度分别为0．5mg／L，1mg/L，0．5mg/L和0．5mg/L。混和激素促生效果好于单一激素。指出在生产性培养中，添加某些激素促进光合细茵的生长是可行的。     

钝顶螺旋藻在有机污水处理方面的应用初探

以钝顶螺旋藻(Spirulina Platenis)A9、A9L(藻体长直型)2种藻株为实验材料,研究了不同浓度苯酚(Phenol)对2种藻株生长的影响。结果显示:①低浓度苯酚能促进实验藻株生长;②不同藻株对苯酚浓度敏感性和忍受力有差异;③钝顶螺旋藻A9、A9L藻株可用于含低浓度苯酚的有机污水处理。     

植物生长调节剂对格药柃硬枝扦插繁殖的影响

研究了NAA、IBA对格药柃硬枝扦插繁殖的影响.结果表明,选择适当浓度的外源植物生长调节物质可显著提高格药柃硬枝扦插繁殖效果.其中用1000mg/L质量浓度的吲哚丁酸溶液速浸5min插穗,其生根率可达76.67%.     

几种能在夏季栽培的食用菌

1.草菇:孢子萌发的适宜温度为40℃,菌丝在15—45℃范围内均能生长,其最适温度为32℃,幼龄期生长的适温为35℃;气温低于15℃或高于45℃时,均不利于草菇生长。草菇的培养料可分别采用棉籽壳、废花、稻草、麦草等,适当加入麦麸、牛粪辅料配成。一般每50kg料可产鲜菇5—7.5kg,最高可产20kg左右。 2.pH-1(平菇高温种):该品种菌丝能在10—30℃内生长,最适温度为25—30℃;子实体形成的适温为25—28℃,喜偏碱性,培养料pH为7—8较适宜。     

多主枝孢粗毒素提取及抑菌活性研究

采用生长速率法和孢子萌发法研究多主枝孢毒素粗提物TIC和TOC对小麦赤霉病菌、番茄早疫病菌菌丝生长和孢子萌发的抑制作用.结果表明,TIC和TOC对两种供试病菌菌丝生长和孢子萌发都有一定的抑制作用,且对菌丝生长抑制作用的强度与毒素浓度呈正相关.TOC对番茄早疫病菌菌丝生长的抑制作用强于对小麦赤霉病菌的抑制作用,而TIC在较高浓度下对番茄早疫病菌菌丝生长的抑制作用较强.TIC和TOC对番茄早疫病菌孢子萌发的抑制作用均强于小麦赤霉病菌.     

不同因素对黄山贡菊叶中过氧化氢酶活性的影响

以黄山贡菊离体叶片中过氧化氢酶为研究对象，采用室内模拟方法，研究不同因素处理对黄山贡菊离体叶片中过氧化氢酶活力的影响。结果表明，在30℃时酶活力较高，高温或低温时酶活力均减小；低浓度的K^＋和Ca^2＋对过氧化氢酶有激活作用，高浓度的K^＋和Ca^2＋对过氧化氢酶有抑制作用；Mg^2＋、Pb^2＋、Cu^2＋对过氧化氢酶均具有抑制作用，生长素和赤霉素对过氧化氢酶活性的影响不明显。     

Differentiating nonpoint sources of deisopropylatrazine in surface water using discrimination diagrams

Pesticide degradates account for a significant portion of the pesticide load in surface water. Because pesticides with similar structures may degrade to the same degradate, it is important to distinguish between different sources of parent compounds that have different regulatory and environmental implications. A discrimination diagram, which is a sample plot of chemical data that differentiates between different parent compounds, was used for the first time to distinguish whether sources other than atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) contributed the chlorinated degradate, deisopropylatrazine (DIA; 6-chloro-N-ethyl-1,3,5-triazine-2,4-diamine) to the Iroquois and Delaware Rivers. The concentration ratio of deisopropylatrazine to deethylatrazine [6-chloro-N-(1-methylethyl)1,3,5-triazine-2,4-diamine], called the D2R, was used to discriminate atrazine as a source of DIA from other parent sources, such as cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile) and simazine (6-chloro-N,N'-diethyl-1,3,5-triazine-2,4diamine). The ratio of atrazine to cyanazine (ACR) used in conjunction with the D2R showed that after atrazine, cyanazine was the main contributor of DIA in surface water. The D2R also showed that cyanazine, and to a much lesser extent simazine, contributed a considerable amount (approximately 40%) of the DIA that was transported during the flood of the Mississippi River in 1993. The D2R may continue to be a useful discriminator in determining changes in the nonpoint sources of DIA in surface water as cyanazine is currently being removed from the market.     

Soil sorption of acidic pesticides: modeling pH effects

A model of acidic pesticide sorption in soils was developed from theoretical modeling and experimental data, which initially considered a combination of a strongly acidic pesticide and a variable-charge soil with high clay content. Contribution of 2,4-D [(2,4-dichlorophenoxy) acetic acid] anionic-form sorption was small when compared with molecular sorption. Dissociation of 2,4-D was not sufficient to explain the variation in Kd as a function of pH. Accessibility of soil organic functional groups able to interact with the pesticide (conformational changes) as a function of organic matter dissociation was proposed to explain the observed differences in sorption. Experimental 2,4-D sorption data and K(oc) values from literature for flumetsulam [N-(2,6-difluorophenyl)-5-methyl [1,2,4] triazolo [1,5-a] pyrimidine-2-sulfonamide] and sulfentrazone [N-[2,4-dichloro-5-[4-(difluromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl] phenyl] methanesulfonamide] in several soils fit the model.     

Treatment of 2,4-dichlorophenol polluted soil with free and immobilized laccase

Enzyme treatment is currently considered for remediation of terrestrial systems polluted with organic compounds. In this study, two soils from Pennsylvania with 2.8 or 7.4% organic matter contents (Soils 1 and 2, respectively) were amended with 14C-labeled 2,4-dichlorophenol (2,4-DCP) and incubated with a laccase from Trametes villosa (free or immobilized on montmorillonite). 2,4-DCP was either transformed to methanol-soluble polymeric products (11-32%) or covalently bound to soil organic matter (53-85%); unaltered 2,4-DCP could be recovered from soil by methanol extraction (0-38%) at the completion of a 14-d incubation period. In Soil 1, both free and immobilized laccase removed 100% of 2,4-DCP without regard for moisture conditions. In Soil 2, immobilized laccase removed more 2,4-DCP (about 95%, regardless of moisture conditions) than free enzyme (55, 75, and 90% at 30, 55, and 100% of maximum water-holding capacity, respectively). Binding of 2,4-DCP in the humin fraction was nearly the same for free and immobilized laccase. More 2,4-DCP, however, was bound to humic and fulvic acids in the presence of immobilized laccase than in the presence of free laccase. In general, immobilized laccase performed better than free laccase. However, for practical applications, the higher activity of immobilized laccase is offset by a 23% loss in enzyme activity during immobilization, which approximates the 30% increase in free laccase needed to achieve the same level of remediation. Furthermore, immobilized laccase is more costly than free T. villosa laccase.     

外源激素对白花龙插条生根的影响

研究不同种类和浓度的外源激素对白花龙生根能力的影响.结果表明,选择适当种类的外源激素和适宜浓度的外源激素可显著提高白花龙的扦插繁殖效果.其中,用250mg/L萘乙酸溶液浸泡插穗5min,其生根率最高,可达61.67%.     

Effect of sequentially combining methanol and acetic acid on the performance of biological nitrogen and phosphorus removal

A sequentially combined carbon (SCC) source using methanol and acetic acid was investigated for biological nitrogen and phosphorus removal in a wastewater treatment process consisting of an anoxic zone, an oxic zone and a final settling tank. The anoxic zone was divided into two separate anoxic zones to feed methanol in the first anoxic zone and acetic acid in the second anoxic zone. Methanol and acetic acid, each as the sole carbon source, were also tested for comparison. The use of SCC was superior in nitrogen removal with all combined COD ratios of methanol/acetic acid tested, yielding 95.8-97% efficiency (less than 1 mg N/l in the final effluent). The highest phosphorus removal of above 92% (final effluent concentration of 0.12 mg P/l) was achieved when only acetic acid was used at a quantity equivalent to 50 mg COD/l. However, when SCC was used, the acetic acid dosage of 50 mg COD/l could be reduced down to 20 mg COD/l when 30 mg COD/l was replaced by methanol; this resulted in a final effluent phosphorus concentration of 0.6 mg P/l. Additional benefits of SCC included the excellent sludge settling properties compared to the use of methanol or acetic acid alone.     

Kinetic of carbonaceous substrate in an upflow anaerobic sludge sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP)

The performance of an upflow anaerobic sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP) was evaluated at different hydraulic retention times (HRTs) using synthetic wastewater in order to obtain the growth substrate (glucose-COD) and 2,4 DCP removal kinetics. Treatment efficiencies of the UASB reactor were investigated at different hydraulic retention times (2-20 h) corresponding to a food to mass (F/M) ratio of 1.2-1.92 g-COD g(-1) VSS day(-1). A total of 65-83% COD removal efficiencies were obtained at HRTs of 2-20 h. In all, 83% and 99% 2,4 DCP removals were achieved at the same HRTs in the UASB reactor. Conventional Monod, Grau Second-order and Modified Stover-Kincannon models were applied to determine the substrate removal kinetics of the UASB reactor. The experimental data obtained from the kinetic models showed that the Monod kinetic model is more appropriate for correlating the substrate removals compared to the other models for the UASB reactor. The maximum specific substrate utilization rate (k) (mg-COD mg(-1) SS day(-1)), half-velocity concentration (K(s)) (mg COD l(-1)), growth yield coefficient (Y) (mg mg(-1)) and bacterial decay coefficient (b) (day(-1)) were 0.954 mg-COD mg(-1) SS day(-1), 560.29 mg-COD l(-1), 0.78 mg-SS g(-1)-COD, 0.093 day(-1) in the Conventional Monod kinetic model. The second-order kinetic coefficient (k(2)) was calculated as 0.26 day(-1) in the Grau reaction kinetic model. The maximum COD removal rate constant (U(max)) and saturation value (K(B)) were calculated as 7.502 mg CODl(-1)day(-1) and 34.56 mg l(-1)day(-1) in the Modified Stover-Kincannon Model. The (k)(mg-2,4 DCP mg(-1) SS day(-1)), (K(s)) (mg 2,4 DCPl(-1)), (Y) (mg SS mg(-1) 2,4 DCP) and (k(d)) (day(-1)) were 0.0041 mg-2,4 DCP mg(-1) SS day(-1), 2.06 mg-COD l(-1), 0.0017 mg-SS mg(-1) 2,4 DCP and 3.1 x 10(-5) day(-1) in the Conventional Monod kinetic model for 2,4 DCP degradation. The second-order kinetic coefficient (k(2)) was calculated as 0.30 day(-1) in the Grau reaction kinetic model. The maximum 2,4 DCP removal rate constant (U(max)) and saturation value (K(B)) were calculated as 0.01 mg COD l(-1) day(-1) and 9.8 x 10(-3) mg l(-1) day(-1) in the Modified Stover-Kincannon model.