利用径向基函数神经网络通过高光谱数据估算植被生物物理参数

The radial basis function (RBF) emerged as a variant of artificial neural network. Generalized regression neural network (GRNN) is one type of RBF, and its principal advantages are that it can quickly learn and rapidly converge to the optimal regression surface with large number of data sets. Hyperspectral reffectance (350 to 2500 nm) data were recorded at two different rice sites in two experiment fields with two cultivars, three nitrogen treatments and one plant density (45 plants m^-2). Stepwise multivariable regression model (SMR) and RBF were used to compare their predictability for the leaf area index (LAI) and green leaf chlorophyll density (GLCD) of rice based on reffectance (R) and its three different transformations, the first derivative reffectance (D1), the second derivative reffectance (D2) and the log-transformed reflectance (LOG). GRNN based on D1 was the best model for the prediction of rice LAI and GLCD. The relationships between different transformations of reffectance and rice parameters could be further improved when RBF was employed. Owing to its strong capacity for nonlinear mapping and good robustness, GRNN could maximize the sensitivity to chlorophyll content using D1. It is concluded that RBF may provide a useful exploratory and predictive tool for the estimation of rice biophysical parameters.     

二氯喹啉酸·苄嘧磺隆复合污染降解菌的特性研究

A bacterial strain, designated as LS, was isolated from a contaminated soil and was found to be capable of utilizing quinclorac, bensulfuronmethyl, and a mixture of the two as carbon and energy sources for growth. Strain LS was identified as Ochrobactrum sp. based on its physiological-biochemical properties, 16S rDNA sequences, and phylogenetic analysis. The extent of degradation of quinclorac and bensulfuronmethyl at initial concentrations of 1.5 and 0.1 g L^-1 was 90% and 67%, respectively, as measured by high performance liquid chromatography （HPLC）. When a herbicide mixture of 0.34 g L^-1 quinclorac and 0.02 g L^-1 bensulfuronmethyl was applied as carbon sources, quinclorac and bensulfuronmethyl were degraded at 95.7% and 67.5%, respectively. It appears that quinclorac is utilized more easily in a mixture than in a single state. The optimal temperature for growth of strain LS was 37 ℃. Strain LS grew well at pH 6 to 9 and had the highest degradation level for quinclorac and bensulfuronmethyl at an initial pH of 7 and 8, respectively. Addition of 0.25 g L^-1 yeast extract could promote the growth and extent of degradation of quinclorac and bensulfuronmethyl by strain LS. Strain LS also showed the capability to degrade other aromatic compounds such as catechol, propisochlor, 4-chloro-2-methylphenoxyacetic acid sodium （MCPA-Na） and imazethapy. The isolate LS shows a huge potential to be used in bioremediation for treating complex herbicide residues.     

城市化对上海土壤环境质量的影响

Heavy metal contents in the soils in the Baoshan District of Shanghai were monitored to evaluate the risk of soil environmental quality degradation due to rapid urbanization and to reveal the ways of heavy metal accumulation in soil during rapid urban sprawl. It was found that the soils in this district were commonly contaminated by Pb, Zn and Cd. Evaluated with a geo-accumulation index (I_geo), the rate of Pb contamination in soils was 100% with 59% of these graded as moderate-severe or severe; Zn contamination reached 59% with 6% graded as moderate-severe or severe; and Cd contamination was over 50%, with one site graded as moderate-severe and another severe-extremely severe. Metal contamination of soils around the Shanghai metropolis was mainly attributed to trame, industrial production, wastewater irrigation and improper disposal of solid wastes. Because of continuing urbanization, the cultivated land around the metropolis should be comprehensively planned and carefully managed. Also the soil environmental quality of vegetable production bases in this area should be monitored regularly, with vegetables to be grown selected according to the degrees and types of soil contamination.     

不同N水平紫色土上不同水稻品种吸收N、K的动力学

A pot experiment was conducted to study the effect of nitrogen fertilizer on nitrogen and potassium uptake by four rice cultivars. Results showed that the quadratic parabola relationship between biomass of rice and nitrogen levels was observed, with the maximum biomass at the nitrogen level of 150 mg kg^-1. The rates of nitrogen and potassium uptake by the four rice cultivars depended on growth stage and rice cultivar with the maximum rate of N in Shanyou-63 and maximum rate of K in Kaiyou-5 (hybrid rice), respectively. The kinetics of nitrogen and potasssium uptake by rice plant could be quantitatively described by the following equations: y = a + blogt, y = ab + t^1/2 and y = ae^-bt. The b value in the equations was correlated significantly to the rates of nitrogen and potassium uptake (N_R and K_R, r = 0.901^**~0.990^**), suggesting that the b value could be used to distinguish the index of nitrogen and potassium uptake capacity of rice. The maximum values of nitrogen uptake by plant (b value) and apparent recovery of fertilizer nitrogen were observed in Shanyou-63, and the minimum value in Eryou-6078. However, the capacity of potassium uptake (b value) by Kaiyou-5 ranked first and that by Shanyou-63 second. There was a significant linear relationship between nitrogen level and nitrogen uptake by rice, but a quadratic parabola relationship was found between nitrogen level and patassium uptake by rice. The application of nitrogen fertilizer decreased the ratios of potassium to nitrogen uptake by rice plant. The greatest reduction in the ratio was observed at high nitrogen level, and the least reduction was found in Kaiyou-5 and Shanyou-63 due to their greater ability to absorb potassium.     

水盐胁迫下番茄叶片对温度、湿度的光合反应

Greenhouse tomato plants (Lycopersicon esculentum Mill cv. Capello) were grown on peat-based substrate and treated with high (4.5 mS cm^-1) and low (2.3 mS cm^-1) nutrient solution electric conductivity (EC) under high and low substrate water contents. Four weeks after the beginning of the treatments, photosynthesis (P_N) was measured under different humidity and temperatures to examine the interactive effects with rhizosphere salinity and water deficit. A rectangular hyperbolic model fitted the light-photosynthesis curve. Photosynthetic capacity (P_C) was decreased but quantum yield (Y_Q) was increased by rhizosphere salinity caused by high EC. P_N was decreased by low humidity only in high EC- and/or water-stressed plants. Under high photosynthetic photon flux (PPF), low humidity induced P_C decline in water-stressed plants and P_N oscillation in high-EC-treated plants. P_N increased steadily as the leaf temperature changed from 18 ℃ to 23 ℃ and then decreased steadily from 23 ℃ to 38 ℃. At 34 ℃, P_N decreased significantly in water-stressed plants. Dark respiration (R_D) increased in an exponential manner as the leaf temperature changed from 18 ℃ to 38 ℃ to an extent about ten times higher under 38 ℃ than under 18 ℃. Our data suggested that P_N decrease under high temperature was attributed, at least in part, to the increased R_D. R_D in high EC- and/or water-stressed plants was higher than that in the plants of control under lower temperature but lower than that in the plants of control under high temperature. The analysis of stomatal and mesophyll conductance showed that low humidity effect was mainly through stomatal response while temperature effect was mainly through biochemical functions. The result showed that environmental stresses affected P_N in an additive or synergistic manner.     

Isolation, identification, and characterization of an aluminum-tolerant bacterium Burkholderia sp. SB1 from an acidic red soil

Aluminum (Al) toxicity usually occurs in acidic soils worldwide, which is detrimental to the growth of organisms. An Al-tolerant bacterium, SB1, was isolated from an acidic red soil of Chingkang Mountain, located in Jiangxi Province of China. Polyphasic analysis, including a 16S rDNA phylogenetic tree as well as morphological and physicochemical properties, revealed that the isolate was a gramnegative, rod-shaped bacterium, which was recognized as Burkholderia sp. SB1 and had extreme acidity tolerance (pH 2.2) and excellent Al resistance (270 mg L^-1 Al³⁺). It could remove Al by up to 97.7% at a concentration of 54 mg L^-1 Al³⁺. SB1 behavior under different temperatures and antibiotics was also examined. SB1 preferred moderate temperature conditions, ranging from 25 to 37℃, and exhibited notable resistance to multiple antibiotics (including ampicillin, streptomycin, and tetracycline), except for being sensitive to chloramphenicol. Therefore, as the first reported bacterium to possess favorable Al resistance and excellent Al removal, Burkholderia sp. SB1 can potentially be used as an agent for bioremediation of Al-contaminated acidic red soils.     

一株芽孢杆菌属的苄嘧磺隆降解菌的分离鉴定和降解研究

The objectives of this study were to isolate a bensulfuron-methyl (BSM)-degrading strain of Bacillus spp. and to evaluate its effectiveness in remediation of a BSM-contaminated soil. A BSM-degrading bacterium, strain L1, was successfully isolated in this study. Strain L1 was identified as Bacillus megaterium based on its morphological, physiological, and biochemical properties, G+C content, phylogenetic similarity of 16S rDNA, and fatty acid compositions. Two experiments were used to examine BSM degradation by strain L1. When BSM was used as a sole carbon source in a mineral salt medium, the average degradation rate of BSM by strain L1 was 12.8%, which suggested that the strain was able to utilize BSM as a sole carbon and energy source. In addition, supplement of yeast extract (200 mg L-1) significantly (P ≤ 0.01) accelerated the degradation of BSM by strain L1. Almost complete degradation (97.7%) of BSM could be achieved in 84 h with addition of yeast extract. In addition, when a sterile soil was supplemented with BSM (50 mg L-l), BSM degradation rate was 94.3% in 42 d, indicating the potential of using microbes for the remediation of BSM-contaminated soils in fields.     

我国几种土壤中铁锰结核的元素组成和地球化学特点

The objective of this research was to isolate a dichlorvos （2,2-dichlorovinyl dimethyl phosphate）-degrading strain of Ochrobactrum sp., and determine its effectiveness in remediation of a dichlorvos-contaminated soil. A dichlorvos-degrading bacterium （strain DDV-1） was successfully isolated and identified as an Ochrobactrum sp. based on its 16S rDNA sequence analysis. Strain DDV-1 was able to utilize dichlorvos as a sole carbon source, and the optimal pH and temperature for its cell growth and degradation were 7.0 and 30 ℃, respectively. Also, the growth and degradation of strain DDV-1 showed the same response to dissolved oxygen. In addition, the soil degradation test indicated that in soil spiked with 100 mg L^-1 or 500 mg L^-1 dichlorvos and inoculated with 0.5% or 1.0% （v/v） strain DDV-1, complete degradation of dichlorvos could be achieved in 24 h. The present study showed that strain DDV-1 was a fast dichlorvos-degrading bacterium in soil. However, further research will be needed to clarify the degradation pathway and the properties of the key enzymes involved in its biodegradation.     

Acinetobacter sp. LMB-5对邻苯二甲脂的降解及对其中酯酶性质的研究

Phthalate esters(PAEs) are extensively applied in industry, and they migrate to environment during the process of production,employ, and treatment and are difficult to be degraded in nature. However, some microorganisms could use them as the carbon source to growth. In this study, an Acinetobacter sp. strain LMB-5, capable of utilizing PAEs, was isolated from a vegetable greenhouse soil.The degradation capability of strain LMB-5 was also investigated by incubation in mineral salt medium containing different PAEs,dimethyl phthalate(DMP), diethyl phthalate(DEP), di-n-butyl phthalate(DBP), and di-(2-ethylhexyl) phthalate(DEHP). The strain could grow well with DMP, DEP, DBP, and DEHP. When the concentration of DBP increased from 100 to 400 mg L~(-1), the half-life extended from 9.5 to 15.5 h. In the concentration range of DBP, the degradation ability of strain LMB-5 could be described by first-order kinetics. During the biodegradation of DBP, three intermediates, 1,2-benzenedicarboxylic acid,butyl methyl ester, DMP,and phthalic acid(PA) were detected, and the proposed pathway of DBP was identified. By analysis of bioinformatics, one esterase was cloned from the genome of LMB-5 and expressed in Escherichia coli. It displayed an ability to break the ester bonds of DBP. The enzyme exhibited maximal activity at pH 7.0 and 40℃ with DBP as the substrate. It was activated by Cu~(2+) and Fe~(3+) and had a high activity in the presence of low concentrations of methanol or dimethylsulfoxide(each 10%, volume:volume). The Acinetobacter sp. strain LMB-5 may make a contribution to the remediation of soils polluted by PAEs in the future.     

印度西高止和西海岸地区Arthrosphaera及相关土壤动物的分布

Seven sampling sites in each of three biomes (Western Ghats, foothills of Western Ghats and west coast) of southwestern India were investigated to study the distribution, abundance and ecology of pill millipedes (Arthrosphaera) and associated fauna in relation to edaphic features. Abundance and biomass of Arthrosphaera and other millipedes were the highest in Western Ghats, while earthworms were in foothills. Arthrosphaera magna and Arthrosphaera spp. were common in Western Ghats and foothills respectively, while no Arthrosphaera were found in the west coast. None of the sampling sites consisted of more than one species of Arthrosphaera. Biomass of Arthrosphaera, other millipedes and earthworms significantly differed in Western Ghats (P = 9.48 × 10^-7) and foothills (P = 1.35 × 10^-8), as did the biomass of species of Arthrosphaera (P = 2.76 × 10^-7) between Western Ghats and foothills. Correlation analysis revealed that biomass of Arthrosphaera was significantly (P = 0.01, r = 0.45) correlated with soil organic carbon rather than other edaphic features (pH, phosphate, calcium and magnesium). Distribution pattern, abundance, biomass and ecology of Arthrosphaera of Western Ghats in relation to soil qualities were compared with millipedes of other regions of the world.     

杀虫剂和除草剂对生防菌盾壳霉生长的影响

本研究采用FAO推荐的菌落直径法测定了8种杀虫剂、4种除草剂、3种植物生长调节剂和1种农用抗菌素对盾壳霉菌丝的毒力。研究结果表明,杀虫剂中氯氰菊酯、阿维菌素、毒死蜱和敌敌畏对盾壳霉生长的抑制作用较大,但除敌敌畏外,其他杀虫剂EC50值均高于相应的田间最大推荐使用浓度(MRAR);辛硫磷和氧乐果对盾壳霉的抑制作用次之;而吡虫啉和灭多威则对其生长几乎没有抑制作用。4种除草剂的EC50值均明显低于相应的MRAR值,对盾壳霉生长有强的抑制作用。在正常使用浓度下植物生长调节剂萘乙酸、赤霉素、云大120对盾壳霉的生长几乎没有抑制作用。链霉素对其生长有一定影响,但EC50明显高于MRAR值。因此,在使用盾壳霉防治菌核病的田中,可以合理使用较安全的植物生长调节剂及吡虫啉和灭多威等杀虫剂,而应尽量减少和避免使用吡氟乙草灵、草甘膦、百草枯等除草剂。     

Reduction of azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues in processed apples

McIntosh, Red Delicious, and Golden Delicious from two years of experimental spray programs using azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl were processed into frozen apple slices, applesauce, single-strength juice, and juice concentrate. Residue levels were expressed as micrograms per 150 g of apple or the equivalent amount of apple product to calculate the percentage change in these pesticides brought about by processing. Producing single-strength apple juice reduced azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues by 97.6, 100, 97.8, and 78.1%, respectively. Production of applesauce reduced all four compounds by >/=95%. Azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues were reduced in apple slices by 94.1, 85.7, 98.6, and 94.7%, respectively. Processing is shown to be very effective in reducing the levels of these pesticides.     

Computed and measured leaching of the insecticide methomyl from greenhouse soils into water courses

The adsorption of methomyl onto three greenhouse soils was measured and was found to be weak to moderate. The transformation rates in three greenhouse soils were reasonably high with half-lives ranging from about 3 to 14 days. These data were introduced into two computational models of pesticide behavior in simplified greenhouse systems. The computed leaching of methomyl ranged from nil to very small (0.03% of the dose), depending on the transformation rate and the amount of irrigation water. The concentrations measured by HPLC in drainage water from three greenhouses were somewhat higher than computed, although they remained below 1 gg L^?1. Various concentrations measured in water courses in an area with many greenhouses were distinctly higher than those measured in drainage water, which may be the result of discharge of surpluses of spray liquid into the water courses.     

Loss of pesticides from a litchi orchard to an adjacent stream in northern Thailand

In the hill country of northern Thailand use of agrochemicals is increasing steadily and contaminating streams and groundwater. We have measured pesticide leached from a litchi orchard to an adjacent stream and identified the flow components contributing to the pesticide transport after installing two discharge measurement stations with automatic water samplers in the stream. For 2 years, between June and September, we applied methomyl, and in 1 year additionally chlorothalonil, to the 2‐ha orchard and monitored water fluxes and pesticide concentrations in the stream water. Pesticide loads ranged from 1.6 to 3% of mass applied for chlorothalonil, a strongly sorbing fungicide, and 6.4–11.4% for the more weakly sorbing insecticide methomyl. Directly after application, pesticide transport was dominated by a fast flow component, reaching the flume before the discharge peak. Later, pesticides were transported mainly by preferential interflow, which peaked about 30 hours after a rain event. The groundwater pathway was not found to contribute to pesticide loss. Antecedent rain conditions proved to be important for the pesticide transport behaviour. While at the beginning of the rainy season large falls of rain did not lead to pesticide contamination, at the end of the season pesticide transport was induced by as little as 0.1 mm of rain. The occurrence of preferential interflow means that the hilly regions in northern Thailand are highly susceptible to contamination by pesticides used by farmers.     

广西不同地区小菜蛾对杀虫剂的敏感性研究

采用浸叶法在室内测定了广西5个菜区的小菜蛾种群对13种杀虫剂的敏感性.结果表明,这5个小菜蛾种群对印楝素和氟虫腈的敏感性最高,LC50值在0.08～0.26 mg/L之间;对苏云金杆菌、多杀菌素、溴虫腈、阿维菌素和定虫隆也具有较高的敏感性,LC50值在0.30～16.39 mg/L之间;而对辛硫磷、杀虫双、毒死蜱和敌敌畏的敏感性较低,LC50值在319.74～8 133.98 mg/L之间;对灭多威和杀螟丹的敏感性极低,已无法建立这两种杀虫剂对南宁安吉和石埠种群的毒力回归方程.不同地区小菜蛾种群对苏云金杆菌和毒死蜱的敏感性差异最大,超过6倍;其次为灭多威、杀虫双和定虫隆,种群敏感性差异达4～6倍;而不同种群对辛硫磷和溴虫腈的敏感性几乎没有差异.     

Cutinase inhibition by means of insecticidal organophosphates and carbamates. 3. Oxidation of phosphorothionates by chloroperoxidase from Caldariomyces fumago

Chloroperoxidase (CPO) from Caldariomyces fumago combined with hydrogen peroxide and chloride proved to be most efficient for the transformation of organophosphorothionate pesticides, i.e., chlorpyrifos, chlorpyrifos-methyl, parathion, and parathion-methyl, into their more potent serine esterase inhibiting oxon analogues. Following CPO pre-oxidation steps, the detection limit of a recently described spectrophotometric cutinase assay could be increased by about 2 orders of magnitude as a consequence of increased inhibition rates of the organophosphates. This type of enzymatic oxidation is easier to perform and more efficient, as compared to bromine or N-bromosuccinimide, used for acetylcholine esterase (AChE) assay in water analyses, but is insufficient for complex matrices such as plant sample extracts. The performance of a complete assay, including sample preparation, oxidation, and inhibition, takes about 3 h. Performing oxidations of organophosphorus compounds, two significant anomalies were observed. Upon CPO oxidation, chlorpyrifos-methyl showed a very strong cutinase inhibition as compared to the corresponding oxon standard, and oxidized malathion, contrarily to malaoxon, revealed cutinase inhibition, which however obeyed a reversible reaction mechanism in contrast to the usually irreversible reactions of organophosphates. Except for methomyl, no significant effects of CPO oxidation on the inhibition strength of insecticidal carbamates could be detected. The applicability of the assay was tested with fruit samples spiked with chlorpyrifos at 0.2-0.5 mg/kg, thereby regarding the role of the latter as the pesticide detected most often in fruits. Mean recoveries ranged between 30-50%. An enhanced recovery of 84% was obtained for an apple juice sample spiked with parathion-methyl (0.5 mg/L).     

Liquid chromatographic determination of N-methylcarbamate insecticides and metabolites in crops. II. Analytical characteristics and residue findings

Four laboratories obtained 177 carbamate recovery values using a liquid chromatographic method. The average recovery of 11 carbamates (aldicarb, aldicarb sulfone, bufencarb, carbaryl, carbofuran, 3-hydroxy carbofuran, 3-keto carbofuran, methiocarb, methiocarb sulfoxide, methomyl, and oxamyl) from 14 crops was 99% with a coefficient of variation of 8% (0.03-1.8 ppm fortification levels). No statistical difference in recovery was found between oxime and phenyl carbamates, or between parent and metabolite carbamates. Average recovery of aldicarb sulfoxide was 59% due to loss in the liquid-liquid partitioning because of the polarity of this compound. A fifth laboratory contributed 34 carbamate recoveries (average 99%) on table-ready food products for 4 carbamates. Bendiocarb, dioxacarb, isoprocarb, and propoxur are also quantitatively recovered through the method. Previously reported carbamate and noncarbamate recovery data are also discussed. In the Food and Drug Administration's (FDA) analysis of 319 samples (mainly crops), 86 (27%) were found to contain residues of carbamate insecticides and/or toxic carbamate metabolites. Carbaryl and methomyl were the most common carbamate residues found on the food products excluding the aldicarb sulfone and sulfoxide residues found on potatoes. In one FDA Total Diet Program "market basket", 11 of 69 table-ready food commodities contained from 0.005 to 0.094 ppm carbamate residues. Carbaryl was the most prevalent residue. Several laboratories reported adverse effects on the determinative system when inadequately purified reagents were used.     

Synthesis and biological evaluation of novel C(6) modified baicalein derivatives as antioxidative agents

Baicalein, one of the major flavones, was found to be responsible for the antioxidative activity of the traditional Chinese medicinal herb Huang-Qin ( Scutellaria baicalensis Georgi), which is widely used as an antioxidative, anti-inflammatory, and antitumor agent. The hydroxyl group of the A ring of the baicalein was alkylated at position 6 with terpenoids such as prenyl, geranyl, and farnesyl groups, and their free radical scavenging activities and glutathione (GSH) depletion capacities were examined. Their free radical scavenging activity was measured according to the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(*+)) scavenging method. Baicalein and newly synthesized baicalein derivatives were found to be good free radical scavengers. Flow cytometrical method was employed to measure the intracellular antioxidative activity and GSH depletion capacity of these derivatives in human acute monocytic leukemia cell line (THP-1). It was also found that baicalein and its derivatives could decrease the levels of exogenous cumene hydroperoxide and H2O2 in THP-1 cells. These compounds also could significantly inhibit the intracellular GSH depletion induced by cumene hydroperoxide in THP-1 cells. The production of cumene hydroperoxide-induced Bax, a pro-apoptotic related protein, could also be inhibited by baicalein and its derivatives. These results suggested that baicalein and its derivatives could be beneficial to human health.     

Determination of pesticides in apple-based infant foods using liquid chromatography electrospray ionization tandem mass spectrometry

A liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method was developed and validated to quantify and confirm trace levels of 13 pesticides including aldicarb sulfoxide, aldicarb sulfone, oxamyl, methomyl, formetanate, 3-hydroxycarbofuran, carbendazim, thiabendazole, aldicarb, propoxur, carbofuran, carbaryl, and methiocarb in apple-based infant foods such as apple sauces, apples and strawberries, apples and blueberries, and apples and plums. Data acquisition under MS/MS was achieved by applying multiple reaction monitoring of two fragment ion transitions to provide a high degree of sensitivity and selectivity for both quantification and confirmation. LC/ESI-MS/MS quantitative results were significantly affected by matrices, and thus, the standard addition was employed to compensate for the matrix effects to achieve the best accuracy of the method. Recoveries of 13 pesticides, spiked at 5.0, 25.0, and 45.0 microg/kg, were around 100% using the LC/ESI-MS/MS standard addition. The method detection limits (S/N > or = 3:1) of 13 pesticides were less than 0.2 microg/kg.     

微生物菌群JSM004对微囊藻毒素的生物降解

以太湖水华蓝藻中提取纯化的微囊藻毒素（microcystins,MCs）作为微生物生长的碳源和氮源,从富营养化的太湖水体中分离筛选到MCs高效降解菌群JSM004,24h内可以将初始浓度分别为3．64和2．62mg·L^-1的MC—RR和MC—LR完全降解。在研究关于环境因子对JSM004降解效率的影响中,发现菌群JSM004的生长受温度和pH值影响较大,而且其对MCs的降解效率也随之变化。结果表明,在接近实际水体的中性和弱碱性环境中,JSM004对MCs的降解活性最强,加入不同含碳和含氮化合物能够促进混合微生物菌群的生长,但是对MCs的降解却有明显的延滞作用。与对照组相比,MCs被完全降解的时间至少推迟24h。在实验室条件下,JSM004可在72h内完全降解太湖水中高浓度的MCs。研究结果表明微囊藻毒素降解菌群JSM004具有良好的MCs降解效果,有实际应用前景。