Microwave assisted solvent-free synthesis and biological activities of novel imines (Schiff bases)

Twelve new ortho-Hydroxyketimines were synthesized by conventional as well as microwave method and evaluated for their antinemic activity against Meloidogyne incognita [(Kofoid and White) Chitwood]. Conventional methods for synthesis of Schiff bases require refluxing at 140°C of the reactants in different solvents for at least 24 h or more, where as the microwave-assisted synthesis has brought down the reaction time from 24 h to 1 minute. The procedure reported is simple as it does not require any organic solvents and the time has been reduced to only 1 minute. Comparative yields of all compounds by different methods revealed that the yield was low in conventional method (79–87%) as compared to microwave assisted synthesis (94–97%). The bioassay revealed that all the test compounds exhibited promising nematicidal activity; N-propyl-2-hydroxypropiophenonimine being the most effective with LC₅₀ value of 74.46 mgL^?1 followed by N-hexyl-2-hydroxyacetophenonimine with LC₅₀ value of 99.60 mgL^?1 after 72 h of exposure. The results obtained from bioassay indicated that this class of compounds has not only given a lead with regard to potential of Schiff bases in pest control, but has suggested that a carbon chain length of 6 atoms in the side chain is optimum on the basis of structure activity relationship (SAR).     

北京市某城市污水处理厂微生物气溶胶污染特性研究

以北京市某城市污水处理厂的格栅间、曝气池、污泥浓缩池和污泥脱水间为对象,研究不同功能区的空气微生物浓度、粒径分布及微生物组成.结果表明:(1)该污水处理厂4个功能区空气异养细菌浓度平均值为3.3×104cfu/m3,范围为1.0×102～4.3×105cfu/m3;真菌浓度平均值为6.1×103cfu/m3,范围为7.5×10～7.6×104cfu/m3.异养细菌和真菌浓度存在显著性差异,尤以曝气池上空最高,其次是污泥脱水间,浓度最低的区域为格栅间和污泥浓缩池.各功能区均存在不同程度的异养细菌和真菌污染.(2)该污水处理厂不同功能区逸散出的异养细菌分布比例最高的为第2～5级,真菌主要分布在第3～5级.4个功能区空气中粒径为2.10～4.70μm(第3、4级)的异养细菌和真菌粒子分别占到了总数的37％～40％和46％～56％,而粒径为0.65～2.10μm(第5、6级)的异养细菌和真菌粒子则分别占到了总数的30％～33％和31％～37％,说明该污水处理厂不同功能区内的空气微生物存在一定的健康风险,可能对人呼吸道构成感染威胁.(3)假单孢菌(Pseudomonas)为该污水处理厂不同功能区均检出的优势异养细菌,而优势真菌种属为毛霉(Mucor)和曲霉(Aspergillus).     

氯氰菊酯的酶促降解研究

从氯氰菊酯高效降解真菌镰孢霉属（Fusarium）菌株TS-203中提取了降解酶,研究了降解酶对氯氰菊酯的降解特性。结果表明,胞内酶对氯氰菊酯的降解率高达59．8％,细胞碎片对氯氰菊酯的降解率为47．6％,而由（NH。）：sO。沉淀法提取到的胞外酶对氯氰菊酯的降解率仅为10．3％,由此确定菌株TS-203产生的降解酶为胞内酶。以牛血清白蛋白为标准蛋白测得胞内粗酶液中可溶性蛋白质含量为3．24mg／mL;该酶对氯氰菊酯酶促降解的最适pH为7．0,最适温度为30℃,降解酶的米氏常数K。为6．8120×10^-4mmol／mL,最大反应速度Vmax为1．1799×10^-4mmol／min。研究结果表明,该酶具有较好的热稳定性和pH稳定性,对热和pH均具有较好的耐受力,对氯氰菊酯降解效果较好。     

The effect of air pollution and other environmental stressors on leaf fluctuating asymmetry and specific leaf area of Salix alba L

We aimed at evaluating the effect of low-level air pollution on leaf area fluctuating asymmetry (FAA) and specific leaf area (SLA) of Salix alba L., taking into account other environmental factors. Cuttings were grown in standardized conditions in the near vicinity of air quality measuring stations in Belgium. Variability of SLA and FAA between measuring stations explained 83% and 7.26%, respectively, of the total variability. FAA was not influenced by air pollution or environmental factors such as shading, herbivory, air temperature and humidity. SLA was increased by an increase in shadow, while NO_x and O₃ concentrations had only a marginal influence. The influence of SO₂ concentration was negligible. Although our data analysis suggests a relationship between SLA and NO_x/O₃ concentration, the absence of a straightforward relationship between FAA and SLA and air pollution still questions the usefulness of these bio-indicators for monitoring air pollution.     

Evaluation of fungal potentiality for bioconversion of domestic wastewater sludge

This study was undertaken to screen the filamentous fungi isolated from its relevant habitats (wastewater, sewage sludge and sludge cake) for the bioconversion of domestic wastewater sludge. A total of 35 fungal strains were tested against wastewater sludge (total suspended solids, TSS 1%-5% w/w) to evaluate its potentiality for enhancing the biodegradability and dewaterability using liquid state bioconversion(LSB) process. The strains were divided into five groups i. e. Penicillium, Aspergillus, Trichoderma, Basidiomycete and Miscellaneous, respectively. The strains WWZP1003, SCahmA103, SCahmT105 and PC-9 among their respective groups of Penicillium,Aspergillus, Trichoderma and Basidiomycete played potential roles in terms of separation (formation of pellets/flocs/filaments),biodegradation(removal of COD) and filtration(filterability) of treated domestic wastewater sludge. The Miscellaneous group was not considered due to its unsatisfactory results as compared to the other groups. The pH value was also influenced by the microbial treatment during fermentation process. The filterability of treated sludge was improved by fungal treatment, and lowest filtration time was recorded for the strain WWZP1003 and SCahmA103 of Penicillium and Aspergillus groups respectively compared with other strains.     

真菌煤炭脱硫的试验因素与规律研究

用真菌在常温常压下对煤炭脱硫效率的主要影响因素:pH值、温度、煤浆度、煤粒度因素进行了试验和降解规律研究,实验结果表明:温度在45℃、pH为6、煤浆浓度为10%、煤粒度为100目条件下,真菌2d内最高可脱除煤中43.75%的全硫和54.84%的无机硫,且随着时间的延长,降解效果提高。     

Sexual selection, feather breakage and parasites: the importance of white spots in the tail of the barn swallow (Hirundo rustica)

The long outermost tail feathers of barn swallows Hirundo rustica have white spots that are larger in males than in females and in adults than in juveniles. Spot size increases with age among adults and is positively correlated with tail length. We tested the functional significance of these white spots by randomly assigning males to either of three groups during spring: (1) subjected to a considerable reduction in the size of all spots using a black permanent pen; (2) subjected to a small reduction in the size of all spots; or (3) a control group with no reduction. Experimental treatment significantly affected the total number of offspring produced per season: breeding tended to be delayed and second broods were less frequent after a considerable reduction in the size of the males' tail feather spots. White parts of feathers lacking melanin were more often found to be the site of feather breakage than the melanised parts of similar width. Furthermore, white tail spots were the preferred feeding site of feather-eating Mallophaga and, since long-tailed males have fewer Mallophaga than short-tailed males, long-tailed males may pay a lower cost for their large white tail spots than short-tailed males. Hence, the cost of increased risk of feather breakage at white tail spots and the non-random distribution of feather lice among individuals will render tail spots a reliable signal of phenotypic quality. Received: 25 May 1998 / Accepted after revision: 4 January 1998     

Biodegradation of Chitosan-Gellan and Poly(L-lysine)-Gellan Polyion Complex Fibers by Pure Cultures of Soil Filamentous Fungi

The degradation of two kinds of polyion complex (PIC) fibers, chitosan-gellan (CGF), and poly(L-lysine)-gellan (LGF) fibers, by seven species of soil filamentous fungi has been investigated. All of the pure-line soil filamentous fungi, Aspergillus oryzae, Penicillium caseicolum, P. citrinum, Mucor sp., Rhizopus sp., Curvularia sp., and Cladosporium sp. grew on the two fiber materials. Microscopic observation of the biodegradation processes revealed that P. caseicolum on the CGF and LGF grew, along with the accompanying collapse of the fiber matrices. In the biochemical oxygen-demand (BOD) test, the biodegradation of the LGF by P. caseicolum and Curvularia sp. exceeded 97% carbon dioxide generation and the biodegradation of the CGF by A. oryzae was 59%. These results might offer some clues to the applications of the PIC fibers as environmentally biodegradable materials.     

应用白腐真菌技术处理难降解有机物的研究进展

本文综述了白腐真菌的生物学特性及其在清洁生产、各种难降解有机物处理中的应用和应用基础研究方面的进展 ,探讨了白腐真菌应用的趋势。     

Composition of the Saprotrophic Fungi in Calluna Heathland Soil and the Influence of Ammonium Nitrate Application

The composition of saprotrophic soil fungi in the mor layerof a Calluna-dominated, Danish heathland wasinvestigated after two years of fertilization with ammoniumnitrate (0, 35, 50 and 70 kg N ha^1- yr^-1) using asoil washing technique. The most frequently isolated generafrom the soil particles plated were Penicillium, Trichoderma, Mortierella and Mucor. Eightspecies of Penicillium were identified and Penicillium spinulosum was the most frequently isolated.The occurrence of dark, sterile fungi on the soil particleswas low. There were no measurable changes in the specificcomposition of the saprotrophic soil fungal groups due tothe nitrogen treatments, beside from an increasedoccurrence of Absidia californica. I conclude that adirect impact on the composition of the saprotrophic fungiin heathland soil is unlikely under enhanced nitrogen input.