氨氮降解菌最佳培养条件及降解动力学研究＊

从污水处理厂活性污泥中筛选分离得到一株高效氨氮降解菌AD-5,研究了温度、pH值、摇床转速以及接种量对降解菌AD-5的影响。实验结果表明:降解菌AD-5最适生长温度为35℃,最适宜培养基pH为7,最适宜摇床转速为120r/min,100mLLB液体培养基,最适宜的接种量为6.0mL。在最佳培养条件下菌株AD-5具有更高的活性。菌种AD-5对氨氮的降解动力学实验结果表明:氨氮的残留浓度Y与时间X符合方程Y=73.3836e(-0.07722)X。     

高效纤维素分解菌复合系的构建及其环境适应性研究

以纤维素培养基和纤维素刚果红培养基为初筛和复筛培养基,从采集的样品中分离得到具有纤维素分解能力的菌株20株。选择其中具有较高纤维素酶活力的12个菌株与2株自生固氮菌和EM菌进行正交实验,得到3个组合表现出协同降解纤维素的作用,对滤纸降解效果为组合12〉组合8〉组合5。选用组合12进行了一系列的环境适应性研究,结果表明,碳源为微晶纤维素＋CMC-Na时CMC酶活最高,最适氮源为蛋白胨＋酵母膏,最适pH6．5,最适培养温度为30℃。培养第6天CMC酶活最高。     

生态条件和瘤胃菌丛密度与纤维分解的关系

在自行设计装配的人工模拟瘤胃发酵装置内，用90523-1瘤胃菌丛进行瘤胃体外发酵试验，结果表明纤维素的分解与瘤胃细菌的密度及其类群变化有着密切关系，都受生态环境条件的制约。在发酵温度40℃，搅拌速度为60～70r／min的条件下搅动20min／h，C／N为10：1的生态条件环境中的细菌密度和纤维素分解率都高于相同生态条件的其它梯度组。     

砷超富集植物蜈蚣草的离体培养及植株再生

探讨了蜈蚣草组织培养的最佳孢子萌发培养基、初代培养基、最佳继代培养基、生根培养基。结果表明,蜈蚣草孢子在1/2MS孢子萌发培养基上萌发效果最好,经初代培养后最佳继代培养基为1/2 MS+6-BA 0.5mg/L+NAA 0.2mg/L,经生根培养后炼苗移栽成活,因此通过孢子组织培养成为蜈蚣草幼苗快速繁殖的最佳途径。     

Enzymatic degradation of low-rank coals by a cell-free enzymatic system from Coriolus versicolor

An extracellular fraction from the lignin degrading white-rot fungus, Coriolus versicolor, can biosolubilize leonardite and pretreated lignites in vitro. Leonardite is often found as an overburden to lignite deposits, and is related to humic acid, and is more oxidized than lignites. Extracts from certain fungi such as C. versicolor solubilize leonardite. The biosolubilization activity is at least in part enzymatic in nature. A protein which is at least partly responsible for the solubilization effect has been substantially purified and concentrated by ultrafiltration and ion-exchange chromatography from the broth of an agitated submerged culture of C. versicolor grown in a defined medium. An in vitro coal biosolubilization assay was used to establish the effects of various physical and chemical factors affecting enzyme activity, including temperature and the salt and buffer composition of the reaction mixture. Some initial studies on the mechanism of the enzymatic leonardite biosolubilization reaction are described.     

Decolorization and Complete Degradation of Methyl Red by a Mixed Culture

Synthetic dyes, azo dyes in particular, are widely found in the effluents from textile industries. The persistence and toxicity of these compounds cause adverse impacts in the receiving streams. A mixed culture isolated from a domestic wastewater treatment plant was found to remove the colour of the azo dye, methyl red, efficiently. Total decolorization and degradation occurred within 18 h. The mixed culture could degrade 700 mgl^–1 of methyl red efficiently in the presence of 200 mgl^–1 of glucose, whereas in the absence of glucose it could degrade only 100 mgl^–1 of methyl red. The mixed culture, when suspended in phosphate buffer along with methyl red at 100 mgl^–1 concentration could degrade methyl red efficiently within 2 h of incubation. The pH of the medium decreased continuously during degradation. After the complete removal of initial methyl red, another 100 mgl^–1 was added to the culture filtrate and incubated further. The mixed microbial cultures could degrade methyl red efficiently through three cycles but further degradation was not possible as the pH of the medium decreased to 3.5.     

Cellulose-based anion exchanger with tertiary amine functionality for the extraction of arsenic(V) from aqueous media

A novel cellulose-based anion exchanger (Cell-AE) with tertiary amine functionality was synthesized by graft polymerization reaction of cellulose and glycidyl methacrylate using N,N′-methylene-bis-acrylamide as a crosslinker and benzoyl peroxide as an initiator, followed by dimethylamine (amination) and acid (HCl) treatment. The chemical modification was confirmed by infrared spectroscopy and CHN analysis. The anion exchanger was used in batch processes to study AS(V) adsorption in solutions. The operating variables studied were pH, contact time, initial As(V) concentration, sorbent mass, and ionic strength. The process was affected by solution pH with an optimum adsorption occurring at pH 6.0. Adsorption equilibrium was achieved within 1 h. Increasing ionic strength of solution negatively affected the arsenic uptake. The adsorption process performed more than 99.0% of As(V) removal from an initial concentration of 25.0 mg/L. The process of adsorption followed pseudo-second-order kinetics. The adsorption equilibrium isotherm data were analyzed using the Langmuir, Freundlich, Redlich–Peterson and Langmuir–Freundlich equations. The Langmuir–Freundlich isotherm described the adsorption data over the concentration range 25–400 mg/L. The adsorption mechanism appears to be a ligand-exchange process. A simulated groundwater sample was treated with Cell-AE to demonstrate its efficiency in removing As(V). The adsorbed As(V) ions were desorbed effectively by a 0.1 M NaOH solution.     

Biodegradation and bioconversion of cellulose wastes using bacterial and fungal cells immobilized in radiopolymerized hydrogels

Annually, great amounts of cellulose wastes, which could be measured in many billions of tons, are produced worldwide as residues from agricultural activities and industrial food processing. Consequently, the use of microorganisms in order to remove, reduce or ameliorate these potential polluting materials is a real environmental challenge, which could be solved by a focused research concerning efficient methods applied in biological degradation processes. In this respect, the scope of this chapter is to present the state of the art concerning the biodegradation of redundant cellulose wastes from agriculture and food processing by continuous enzymatic activities of immobilized bacterial and fungal cells as improved biotechnological tools and, also, to report on our recent research concerning cellulose wastes biocomposting to produce natural organic fertilizers and, respectively, cellulose bioconversion into useful products, such as: ‘single-cell protein’ (SCP) or ‘protein-rich feed’ (PRF). In addition, there are shown some new methods to immobilize microorganisms on polymeric hydrogels such as: poly-acrylamide (PAA), collagen-poly-acrylamide (CPAA), elastin-poly-acrylamide (EPAA), gelatin-poly-acrylamide (GPAA), and poly-hydroxy-ethyl-methacrylate (PHEMA), which were achieved by gamma polymerization techniques. Unlike many other biodegradation processes, these methods were performed to preserve the whole viability of fungal and bacterial cells during long term bioprocesses and their efficiency of metabolic activities. The immobilization methods of viable microorganisms were achieved by cellular adherence mechanisms inside hydrogels used as immobilization matrices which control cellular growth by: reticulation size, porosity degree, hydration rate in different colloidal solutions, organic and inorganic compounds, etc. The preparative procedures applied to immobilize bacterial and fungal viable cells in or on radiopolymerized hydrogels and, also, their use in cellulose wastes biodegradation are discussed in detail. In all such performed experiments were used pure cell cultures of the following cellulolytic microorganisms: Bacillus subtilis and Bacillus licheniformis from bacteria, and Pleurotus ostreatus, Pleurotus florida, and Trichoderma viride from fungi. These species of microorganisms were isolated from natural habitats, then purified by microbiological methods, and finally, tested for their cellulolytic potential. The cellulose biodegradation, induced especially by fungal cultures, used as immobilized cells in continuous systems, was investigated by enzymatic assays and the bioconversion into protein-rich biomass was determined by mycelial protein content, during such long time processes. The specific changes in cellular development of immobilized bacterial and fungal cells in PAA hydrogels emphasize the importance of physical structure and chemical properties of such polymeric matrices used for efficient preservation of their metabolic activity, especially to perform in situ environmental applications involving cellulose biodegradation by using immobilized microorganisms as long-term viable biocatalysts.     

球壳孢菌和胶孢炭疽菌的液体培养特性研究

对银杏叶内生真菌球壳孢科菌株A114和胶孢炭疽菌菌株05—27的液体培养特性的初步研究得出：两种菌株均在马铃薯葡萄糖液体培养基中生长最好、菌丝产量最高，在pH4．0-8．5的马丁氏液体培养基中均能生长。A114菌株和05—27菌株的最佳氮、碳源分别为酵母粉和葡萄糖，A114菌株最适pH为6．6，05—27菌株最适pH为6．9。     

固定化真菌漆酶对分散兰-2BLN的脱色和降解

采用改良壳聚糖固定化的真菌漆酶对染料分散兰-2BLN进行脱色和降解条件的研究,探索了固定化漆酶活力、处理时间、染料浓度、温度和pH对其降解效果的影响。结果表明,固定化漆酶脱色降解分散兰-2BLN的适宜条件为：固定化漆酶活力18.2U／mL,染料浓度100mg／L,温度40℃,pH4.6,在上述条件下降解1.5h,分散兰-2BLN脱色率能达到87.68％。重复分批使用固定化漆酶处理2BLN兰,在使用6批次后,脱色率仍能保持在55％以上,其催化效率得到了较大提高。     

Effect of nonylphenol surfactants on fungi following the application of sewage sludge on agricultural soils

The effect of nonylphenol on fungi following the application of contaminated sewage sludge on agricultural soil was studied in laboratory experiments. Nonylphenol bioavailability and adsorption were determined in the soil alone and soil-sludge mixtures. Mixing the soil with sludge made it possible to measure the nonylphenol concentration in the soil solution, which comprised between 6.6 x 10(-6) and 3.8 x 10(-7) M, according to the sludge. We then examined the dose-response relationship between nonylphenol concentration in the culture medium and both biomass production and germination rate of the spores from several strains of filamentous fungi. When applied in this range of concentration, nonylphenol was without noticeable short-term effect on these endpoints. Long-term exposure of fungi to nonylphenol was also assessed. The most intensive effect was a strong stimulation of spore production and germination in Fusarium oxysporum Schlechtendahl. Biomass production by the Fusarium strains also increased. Finally, nonylphenol was shown to induce laccase production in Trametes versicolor. We conclude that the potential of nonylphenol to adversely affect several soil fungi remains low.     

探析武术教学对民族传统文化的传承简

采用文献资料法、访谈调查法和综合分析法就以武术为媒介传承民族文化精神作出探索并分析，求证武术与传统文化的密切联系，发现了武术教学在传承民族文化时存在被竞技体育形式化，武德教育缺失，良好传统被扭曲等尴尬之处，并指出武术教学改革应重点把握武术基础理论、武德、习武的精神要义、功法原理等，可以利用各种传媒，利用多种特色鲜明的技术内容，利用传统招法名称教学等方法进行民族传统文化的传承。     

冻干壳聚糖微球固定化纤维素酶的研究

分别以冻干壳聚糖微球和湿壳聚糖微球为载体,戊二醛为交联剂进行纤维素酶的固定化研究,并对2种固定化酶的热稳定性、米氏常数、重复利用次数、pH值加以对比分析。确定酶固定化的适宜条件为：0．03g冻干壳聚糖微球与10mL4g/L戊二醛交联4h后,加入10mg酶固定2h,酶活力回收率为96．3％;0．1g湿壳聚糖微球与10mL 2g／L戊二醛交联2h后,加入6mg酶固定4h,酶活力回收率为62．4％。与游离酶相比,2种固定化酶的米氏常数均降低;具有很好的热稳定性;最适酶解温度分别为60℃,50℃;酶解反应适宜pH范围3．0—4．0,最适pH值均向酸性方向移动。冻干载体更易与酶分子结合,酶活力回收率高于湿载体固定化酶。     

Ecological limitations and appropriation of ecosystem support by shrimp farming in Colombia

Shrimp farming in mangrove areas has grown dramatically in Asia and Latin America over the past decade. As a result, demand for resources required for farming, such as feed, seed, and clean water, has increased substantially. This study focuses on semiintensive shrimp culture as practiced on the Caribbean coast of Colombia. We estimated the spatial ecosystem support that is required to produce the food inputs, nursery areas, and clean water to the shrimp farms, as well as to process wastes. We also made an estimate of the natural and human-made resources necessary to run a typical semiintensive shrimp farm. The results show that a semiintensive shrimp farm needs a spatial ecosystem support—the ecological footprint—that is 35–190 times larger than the surface area of the farm. A typical such shrimp farm appropriates about 295 J of ecological work for each joule of edible shrimp protein produced. The corresponding figure for industrial energy is 40:1. More than 80% of the ecological primary production required to feed the shrimps is derived from external ecosystems. In 1990 an area of 874–2300 km² of mangrove was required to supply shrimp postlarvae to the farms in Colombia, corresponding to a total area equivalent to about 20–50% of the country’s total mangrove area. The results were compared with similar estimates for other food production systems, particularly aquacultural ones. The comparison indicates that shrimp farming ranks as one of the most resource-intensive food production systems, characterizing it as an ecologically unsustainable throughput system. Based on the results, we discuss local, national, and regional appropriation of ecological support by the semiintensive shrimp farms. Suggestions are made for how shrimp farming could be transformed into a food production system that is less environmentally degrading and less dependent on external support areas.     

Methane fermentation of dung from litter-free reared domestic animals — an optimisation study

Data on the quantity (27 453 tons from litter-free reared animals in Bulgaria, only) and the chemical and energy characteristics of dung produced in intensive management farms for domestic animals suggests that technologies combining biogenic elements recycling with energy utilistation and dung decontamination are expedient to be applied on these types of farms. To this effect a fermenter was designed and a mathematical model (a Chen-Hashimoto model based computer programme) was applied, as a result of which the optimum methane fermentation parameters were determined. The technological methane output (Y_v) — indicator of biogas production efficiency (output/dm³ fermentor volume) showed an optimum at temperature 55°C and period of exchange 6 days. The methane output per unit mineralised organic matter in the substrate (B) — assumed as an indicator of ecological efficiency (maximum organic matter degradation) exhibited an optimum at 33°C for 15 days period of exchange.     

Potential environmental fate of elsinochrome A,a perylenequinone toxin produced in culture by bindweed biocontrol fungus Stagonospora convolvuli LA39

The photosensitizing perylenequinone toxin elsinochrome A (EA) is produced in culture by the bindweed biocontrol fungus Stagonospora convolvuli LA39 where it apparently plays a pathogenicity related role. We investigated the fate of EA with reference to its stability under different temperature and light conditions. EA remained stable when boiled in water at 100^∘C for 2 h. Similarly, exposing EA to 3–27^∘C in the dark for up to 16 weeks did not affect its stability either in dry or in aqueous form. However, results from irradiation experiments indicate that direct photolysis may be a significant degradation pathway for EA in the environment. EA either in dry form or dissolved in water was degraded by different irradiation wavelengths and intensities, with degradation plots fitting a first order rate kinetics. EA degraded faster if exposed in aqueous form, and at higher quantum flux density (μmol s⁻¹ m⁻²). Sunlight was more effective in degrading EA than artificial white light and ultraviolet radiations (UV-A or UV-B). Exposing EA to natural sunlight, particularly, during the intense sunshine (1,420– 1,640 μmol s⁻¹ m⁻²) days of 30 July to 5 August 2004 in Zurich caused the substance to degrade rapidly with half-life under such condition only 14 h. This implies that should EA gets into the environment, particularly on exposed environmental niches, such as on plant surfaces through biocontrol product spray, or released from shed diseased leaves, it may have no chance of accumulating to ‘level of concern’. Furthermore, a toxicity assay using Trichoderma atroviride P1 as biosensor showed that photo-degraded EA was not toxic, indicating that no stable toxic by-products were left.     

The frequency-dependent effect of extremely low-frequency electromagnetic field and mechanical vibration at infrasound frequency on the growth, division and motility of Escherichia coli K-12

The aim of this work was to investigate the frequency-dependent effects of extremely low-frequency electromagnetic field (ELF-EMF) and mechanical vibration at infrasound frequency (MV at IS frequency or MV) on growth and development of Escherichia coli K-12, by using classical microbiological (counting colony forming units), isotopic, spectrophotometric and electronmicroscopic methods. The frequency-dependent effects of MV and ELF-EMF were shown that they could either stimulate or inhibit the growth and the division of microbes depending on the periods following exposure. However, the mechanism through which the MV and ELF-EMF effects affect the bacteria cell is not clear yet. It was suggested that the aqua medium could serve a target through which the biological effect of MV and ELF-EMF on microbes could be realized. To check this hypothesis, the frequency-dependent effects (2, 4, 6, 8, 10 Hz) of both MV and ELF-EMF on the bacterial growth, division and their motility in cases of exposure, the preliminary treated microbes-free medium and microbes containing medium were studied. Both MV and ELF-EMF effect on microbes have frequency and post-exposure period duration-dependent characters. The [ ³ H]-thymidine involving experiments shown that EMF at 4 Hz exposure has pronounced stimulation effect on cell proliferation while 4 Hz MV has inhibition effect. But at 8–10 Hz, the both EMF and MV have inhibitory effects on cell proliferation. It is suggested that 4 and 8 Hz EMF have different biological effects on microbes.     

石油污染土壤原位生物修复的强化实验研究

为研究添加营养物质和高效降解石油微生物对油污土壤生物修复的作用,通过分层土柱的方法,连续监测了不同条件下不同土层的含水率、石油烃含量、细菌数量及脱氢酶活性。结果表明:添加营养物质同时接种高效微生物可使降解效果明显改善,降解率比在自然条件下提高近50%,而单纯添加营养物质不接种高效微生物可使降解率比在自然条件下提高约25%。降解初期,上层土壤降解效果较好,而到中后期,中下层降解效果好于上层。微生物数量和脱氢酶活性与石油降解率之间存在良好的相关性,脱氢酶活性比微生物数量更能反映修复过程中微生物的存活状态。添加营养物质和高效降解石油微生物对油污土壤原位生物修复具有强化作用。     

Transesterification of Pistacia chinensis seed oil using a porous cellulose-based magnetic heterogeneous catalyst

In the present work, a novel cellulose-based porous heterogeneous solid acid catalyst encapsulation of ferriferous oxide (Fe₃O₄) and sulfonated graphene (GO-SO₃H) into cellulose to form composite porous microspheres catalyst (GO-SO₃H/CM@Fe₃O₄)was synthesized and evaluated for biodiesel production from Pistacia chinensis seed oil. The SEM, EDS and FTIR analysis revealed that the catalyst GO-SO₃H/CM@Fe₃O₄ owned stronger active sites and GO-SO₃H dispersed well in porous surface and inside of cellulose support. Under the optimum conditions, microwave-assisted transesterification process was carried out with the best catalyst amount, i.e. 5 wt% GO-SO₃H/CM@Fe₃O₄ (weight ratio of GO-SO₃H/cellulose), and conversion yield reached 94%. The prepared catalyst could be easily separated from reaction solution by extra magnetic field and reclaimed at least five runs.