降解甲基对硫磷真菌的分离及降解特性

利用富集培养基从农药厂的活性污泥中分离到 3株能以甲基对硫磷为碳源和能源而生长的真菌 ,分别编号为 Hw- 3、Hw- 6和 Hw- 7,并进行了降解条件的研究。结果表明 ,pH7.0、温度 2 8℃是 3株真菌降解甲基对硫磷的最佳条件。同时对底物浓度对降解率的影响及菌株的共代谢作用进行了探讨。     

一硫代磷酸酯类杀虫剂的微生物降解

在纯培养条件下测定了分离株 YF0 5对对硫磷等一硫代磷酸酯类杀虫剂的降解作用。在接种量 (OD4 15nm)为 0.2、pH7.0、30℃条件下 ,测得 10、25、50、100、200、500 mg/L对硫磷的降解符合一级动力学特征 ,其降解速率常数分别为 0.077、0.123、0.128、0.119、0.084、0 .013,高浓度对硫磷对 YF05菌有抑制作用 ;分离株 YF05在不同温度及 pH下对对硫磷的降解作用为 40℃ >30℃ >20℃ ,pH8.0 >pH7.0 >pH6 .0。同样条件下 ,YF05对杀螟硫磷和甲基对硫磷也有较好的降解作用 ,对甲基对硫磷的降解速率常数与对硫磷相仿 ,对杀螟硫磷的降解速率常数略高于对硫磷。     

土壤中降解涕灭威菌株的分离鉴定及降解特性

为探明土壤微生物对涕灭威的降解能力,用富集培养法分离驯化土壤中涕灭威的优势降解菌,初步筛选出了对涕灭威具有较高降解能力的菌株TB26和100-8。经过生理生化鉴定和16S rDNA序列同源性分析,将菌株TB26初步鉴定为克雷伯杆菌属(Klebsiella sp.),菌株100-8初步鉴定为枯草芽孢杆菌属(Bacillus sp.)。TB26和100-8生长的最适碳源分别为麦芽糖、D-果糖,最适氮源分别为蛋白胨、脲。基础无机盐培养基和缺氮培养基对两种菌的生长情况及降解率的影响不同,外加氮源能够提高100-8的降解率,而缺氮培养基中TB26的降解率较高。     

烟嘧磺隆降解菌株的筛选及其降解特性初探

为得到烟嘧磺隆的高效降解菌株,并了解其降解特性,从烟嘧磺隆生产厂家污水处理池中筛选得到1株可高效降解烟嘧磺隆的菌株ND1,经形态学观察及生理生化、16S rDNA鉴定,该菌株为枯草芽孢杆菌Bacillus subtilis。在30℃、150 r/min条件下,该菌株3 d内可将200 mg/L的烟嘧磺隆降解98%以上;进一步通过高效液相色谱-串联质谱仪(HPLC-MS/MS)检测其降解产物,发现该菌株可作用于烟嘧磺隆的磺酰脲键,使其桥键发生断裂而产生降解产物2-氨基-4,6-二甲氧基嘧啶和磺酰胺。     

除草剂莠去津降解菌SFAD3的分离鉴定及其土壤修复潜力

为获得能够修复除草剂莠去津污染土壤的高效降解菌,采用摇瓶富集法、平板分离法从莠去津过量使用的土壤中分离得到降解菌SFAD3,通过形态学、生理生化特征观察以及16S rDNA和ITS序列分析进行种类鉴定,测定获得菌株的最适降解条件,并通过土壤接种和盆栽试验验证菌株对莠去津污染土壤的修复作用。结果表明,菌株SFAD3最终被鉴定为门多萨假单胞菌Pseudomonas mendocina,该菌株培养30 d时对污染土壤中50 mg/kg莠去津的降解率可达72.6%;菌株SFAD3在MM液体培养基中最适降解条件为温度37℃、pH 7、莠去津初始浓度6.25 mg/L、接种量2%,对莠去津降的降解率为50.0%～72.2%;与仅有莠去津的处理相比,添加有SFAD3发酵液的处理20 d后芝麻的株高、根长、湿重和干重能够显著恢复,并且该菌对芝麻还具有一定的促生作用。表明降解菌SFAD3在修复莠去津污染土壤方面具有潜在的应用价值。     

咪唑乙烟酸高效降解菌降解性能的研究

研究了丙酸杆菌属（Propionibacterium）、海球菌属（Marinococcus）和酸单胞杆菌属（Acidomonas）单一菌株和混合菌株对咪唑烟酸的降解能力及环境条件对降解活性的影响。结果表明,混合菌株处理的咪唑乙烟酸,在第90天时的降解率高达87.20％,明显优于单一菌株。此外,外界环境条件对降解菌的活性也有显著的影响,在培养温度为25～30 ℃,土壤湿度为田间最大持水量的50%,咪唑乙烟酸残留浓度为100 μg/kg,最佳接菌量为5 mL/kg时,3株降解菌的降解活性最强,对咪唑乙烟酸的降解率最高。     

化学发光酶联免疫分析法同时检测3种有机磷农药残留

利用能同时识别对硫磷、甲基对硫磷和杀螟硫磷的宽谱特异性单克隆抗体,建立了同时测定这3种有机磷农药残留的化学发光酶联免疫分析方法（chemiluminescence enzyme immunoassay,CLEIA）,比较了间接竞争（ic-CLEIA）和直接竞争（dc-CLEIA）2种反应模式,优化了相关理化参数,确立了最适反应条件。结果表明:间接竞争CLEIA法检测对硫磷、甲基对硫磷和杀螟硫磷的抑制中浓度（IC₅₀）分别为5.57、2.30和2.62 μg/kg,检测线性范围分别为0.39~100、0.39~25和0.39~25 μg/kg;直接竞争CLEIA法检测对硫磷、甲基对硫磷和杀螟硫磷的抑制中浓度（IC₅₀）分别为5.43、1.34和1.24 μg/kg,检测线性范围分别为0.39~100、0.10~25和0.10~25 μg/kg。所建立的CLEIA方法基本能满足对硫磷、甲基对硫磷和杀螟硫磷在谷物和果蔬中最大残留限量的检测要求,为研制有机磷农药多残留检测试剂盒提供了技术依据。     

粪产碱杆菌ZWS11菌株对烟嘧磺隆的酶促降解特性

为明确粪产碱杆菌Alcaligenes faecalis ZWS11菌株对烟嘧磺隆的酶促降解特性,采用丙酮沉淀、超声波破碎和高速离心等方法,提取制备了ZWS11菌株的胞外和胞内粗酶液以及菌体碎片悬浮液,并分别测定了其酶活力。结果表明:当V（菌体发酵液）:V（丙酮）=1:3时提取到的胞外粗酶液具有较高的酶活力;胞外粗酶液、胞内粗酶液和菌体碎片悬浮液对24.9 μmol/L烟嘧磺隆的平均降解率分别为87.4%、16.9%和17.4%,胞外粗酶液的降解能力与胞内粗酶液或菌体碎片悬浮液相比差异显著（P<0.05）,由此确定对烟嘧磺隆起降解作用的酶属于胞外酶。最适降解条件研究表明:该降解酶的酶促反应适宜温度为35℃,较适pH值为6.0,反应时间为30 min,在此条件下其对烟嘧磺隆的降解率在80%以上。此外,该降解酶在35～70℃、pH值4.0～9.0范围内均能够保持较高的酶活力,对烟嘧磺隆的降解率均在60%以上,表明该降解酶具有较好的热稳定性和酸碱稳定性。加入不同浓度十二烷基硫酸钠（SDS）和苯甲基磺酰氟（PMSF）,对该降解酶的活力表现出了不同程度的抑制作用。研究结果可为烟嘧磺隆降解酶制剂的规模化生产及被烟嘧磺隆污染土壤的生物修复提供科学依据。     

咪唑乙烟酸降解菌的分离、鉴定及降解特性研究

采用高压富集方法,从生产咪唑乙烟酸农药厂排污口污泥中分离得到1株咪唑乙烟酸高效降解菌P14,根据菌株形态、生理生化特性及16S rDNA分析,鉴定该菌株为哈夫尼希瓦氏菌Shewanella hafniensis。初步研究了其在不同条件下对咪唑乙烟酸的降解性能。结果表明:在以咪唑乙烟酸为唯一碳源的无机盐培养基中,当咪唑乙烟酸初始质量浓度为100 mg/L、培养温度为30 ℃、pH值6.0、接种量7%时,菌株P14对咪唑乙烟酸的降解效果最佳,3 d内的降解率可达92%,因而可以此作为菌株P14降解咪唑乙烟酸的最佳条件。外加不同碳源时,P14菌株对咪唑乙烟酸的降解率呈现不同程度下降,其中柠檬酸钠对P14菌株降解效果影响较小。     

防治桃小食心虫越冬幼虫的有效药剂及其降解动态

研究树下土表施药防治桃小食心虫越冬幼虫的取代药剂。用毒土法测定了分属4类的13种药剂对桃小食心虫越冬幼虫的触杀毒力,其结果以毒死蜱、三唑磷、高效氯氟氰菊酯、甲基对硫磷和辛硫磷毒力较高,LC_(90)值依次为18．38、22．48、35．95、47．63及49．57 mg·kg~(-1),甲氰菊酯、丙溴磷、阿维菌素、甲胺基阿维菌素、氰戊菊酯、马拉硫磷、丙硫克百威和丁硫克百威LC_(90)值处于77．11～205．86mg·kg~(-1)之间。用高效液相色谱法测定了毒力较高的毒死蜱、三唑磷、高效氯氟氰菊酯以及阿维菌素在土壤中的降解动态,半衰期分别为8．28、11．37、10．17及19．70天。欲达30天的有效控制期,按LC_(90)值计算,这4种药剂在土壤中的初施浓度应分别为226．36、139．90、278．03及346．81mg·kg~(-1)。从药剂毒力、降解速率、相同控制期所需剂量及应用成本综合评价,毒死蜱、三唑磷具有较高的应用价值。     

苍白杆菌B2对甲基对硫磷降解途径研究

采用薄层层析、紫外吸收光谱以及气谱-质谱联用的方法分析了苍白杆菌Ochrobacterum sp. B2降解甲基对硫磷的中间产物。结果表明,B2水解甲基对硫磷产生对硝基苯酚(PNP),PNP通过产生4-硝基邻苯二酚(4-nitrocatechol,4-NC)和1,2,4-苯三酚(1,2,4-benzenetriol) 的途径进一步代谢。苍白杆菌B2可以以PNP和4-NC为碳源生长,在菌的初始OD600值为0.02时,B2可在48 h内将50 mg/L的PNP完全降解, 在60 h内,将30 mg/L的4-NC完全降解。     

Effect of paraoxon-methyl and parathion-methyl on DNA in human lymphocytes and protective action of vitamin C

The molecular basis of the genotoxicity of the commonly used organophosphorus insecticide, parathion-methyl is poorly understood and there is a lack of information on the possible effects of its metabolic conversion products. In the present work the action of parathion-methyl and its immediate metabolite paraoxon-methyl on DNA in human lymphocytes was compared using the comet assay. Parathion-methyl at 25 and 75 µM did not cause any significant changes but at 200 µM a significant increase in the tail moment was observed as compared with the control. Paraoxon-methyl at 25, 75 and 200 µM evoked dose-dependent DNA damage measured as a significant increase in comet tail moment of lymphocytes. The change evoked by paraoxon-methyl at 200 µM was much more pronounced than that by parathion-methyl at the same concentration. To search for the mechanism underlying the observed effect, the action of a well-known antioxidant, vitamin C, along with parathion-methyl and paraoxon-methyl was studied. The vitamin at 10 and 50 µM reduced the DNA-damaging activity of paraoxon-methyl at all its concentrations. The results indicate that the reported genotoxic effects of parathion-methyl could be mainly attributed to its metabolite paraoxon-methyl. The protective action of vitamin C suggests that paraoxon-methyl may cause oxidative DNA damage. © 1999 Society of Chemical Industry     

3株木霉(Trichoderma spp.)对华山松疱锈病菌锈孢子的破坏作用

从不同来源的茶藨生柱锈锈孢子堆和疱锈病枝干上分离获得3株木霉,室内生测结果表明,3株木霉的菌丝和培养滤液对锈孢子壁有较强的破坏作用;菌株TR2和TR3在锈孢子堆上生长速度快,锈孢子死亡率随孢子壁破坏率的增加而升高,锈孢子壁对孢壁降解酶有强烈诱导作用;TR1对锈孢子壁的破坏作用弱于TR2和TR3,但在PD培养液中有较强的产毒能力,锈孢子壁能抑制TR1菌株产毒。     

Bioconversion of dieldrin by wood‐rotting fungi and metabolite detection

BACKGROUND: Dieldrin is one of the most persistent organochlorine pesticides, listed as one of the 12 persistent organic pollutants in the Stockholm Convention. Although microbial degradation is an effective way to remediate environmental pollutants, reports on aerobic microbial degradation of dieldrin are limited. Wood‐rotting fungi can degrade a wide spectrum of recalcitrant organopollutants, and an attempt has been made to select wood‐rotting fungi that can degrade dieldrin, and to identify the metabolite. RESULTS: Thirty‐four isolates of wood‐rotting fungi were investigated for their ability to degrade dieldrin. Strain YK543 degraded 39.1 ± 8.8% of dieldrin during 30 days of incubation. Phylogenetic analysis demonstrated that strain YK543 was closely related to the fungus Phlebia brevispora Nakasone TMIC33929, which has been reported as a fungus that can degrade chlorinated dioxins and polychlorinated biphenyls. 9‐Hydroxydieldrin was detected as a metabolite in the cultures of strain YK543. CONCLUSION: It is important to select the microorganisms that degrade organic pollutants, and to identify the metabolic pathway for the development of bioremediation methods. Strain YK543 was selected as a fungus capable of degrading dieldrin. The metabolic pathway includes 9‐hydroxylation reported in rat's metabolism catalysed by liver microsomal monooxygenase. This is the first report of transformation of dieldrin to 9‐hydroxydieldrin by a microorganism. Copyright © 2010 Society of Chemical Industry     

一株内生拮抗细菌的分离鉴定及其抗菌机理研究

本研究通过平板稀释法、平板对峙法从核桃根部皮层筛选出一株对核桃根腐病有拮抗作用的内生菌株1A,通过形态特征测定、理化特性分析和16SrDNA序列分析鉴定该菌为芽胞杆菌(Bacillus sp.),GenBank序列登录号为KJ865856;其抑菌特性研究结果表明:该拮抗菌对核桃根腐病菌有显著的抑制效果,抑菌率达63.33%;此外,该菌对板栗疫病菌等几种不同的林木病原菌均有较强的抑制作用。抗生机理研究结果表明,该菌株通过分泌蛋白酶和纤维素酶降解真菌细胞壁中蛋白质和纤维素,破坏病菌菌丝,病菌生长受到抑制。该拮抗菌能够显著抑制核桃根腐病菌菌丝生长和孢子萌发,孢子萌发抑制率达74.89%,病菌菌丝表现为菌丝扭曲、断裂,分支增多并缠绕,菌丝颜色加深等。盆栽生防效果研究显示,该拮抗菌对各组核桃根腐病具有显著的防治效果,采用该拮抗菌预处理具有相对较好的生防效果。     

In vitro inhibition of the carbonic anhydrase from saanen goat (Capra hircus) with pesticides

This study was conducted to determine the in vitro effects of four commonly used pesticides (Nuarimol™, Fenarimol™, Parathion-methyl™ and 2,4-D™) on erythrocyte carbonic anhydrase (CA) activity from Saanen goats (SG). The enzyme was 262.57-fold purified by affinity chromatography and the purity was confirmed by SDS-PAGE. Inhibitory effect of the pesticides on the purified enzyme was determined using the CO₂-hydratase activity method. IC₅₀ values of the pesticides that caused inhibition were determined by means of activity percentage diagrams. The concentrations of Nuarimol™, Fenarimol™, and 2,4-D™ that inhibited 50% of the enzymatic activity were 0.352, 0.924 and 2.04 mM, respectively. Conversely, the enzyme activity was increased by parathion-methyl.     

棉花黄萎病拮抗细菌H14的筛选鉴定及其拮抗机理分析

为筛选对大丽轮枝菌Verticillium dahliae Kleb.具有拮抗活性的根际细菌,以大丽轮枝菌为靶菌,分离获得棉花根际细菌,利用平板对峙法和琼脂扩散法筛选具有较高拮抗活性的菌株,采用室内盆栽法测定筛选所得菌株对棉花黄萎病的防效,并通过形态特征、生理生化特性和16S r DNA基因序列分析确立其分类地位,采用底物降解法和抗菌肽基因克隆法检测其产生水解酶和抗菌肽的能力。结果显示,试验共分离获得182株棉花根际细菌,筛选得到3株对大丽轮枝菌抑菌率大于50.00%且抑菌圈直径大于15 mm的菌株,其中菌株H14的抑菌率和抑菌圈直径最大,分别为54.25%和18.10 mm。该菌能在0～9%NaCl和pH 4.5～9.0的NB培养基上生长;经形态特征观察、生理生化试验及16S rDNA基因序列分析,最终将其鉴定为莫哈韦芽胞杆菌Bacillus mojavensis;菌株H14对大丽轮枝菌孢子萌发的抑制率和对棉花黄萎病的盆栽防效分别为89.55%和74.57%;菌株H14能合成蛋白酶,含有srfAA、fenD、bacA脂肽类抗生素合成基因。表明莫哈韦芽胞杆菌菌株H14能够合成蛋白酶和脂肽类拮抗物质,具有良好的抑菌和防病能力。     

内生细菌B504的鉴定及对黄瓜枯萎病的生防作用

B504是从黄瓜植株中分离到的内生细菌。平板对峙试验表明,该菌株对黄瓜枯萎病菌等10种植物病原真菌具有拮抗作用,对黄瓜枯萎病菌的生长抑制率达44.1%。该菌株造成黄瓜枯萎病菌的分生孢子畸形,形成泡状物,尔后细胞壁消解,引起细胞内含物外溢,明显影响孢子萌发。用B504对黄瓜种子进行催芽处理,对黄瓜苗期、成株期枯萎病的防治效果分别为54.0%和41.7%。B504的16S rDNA序列与枯草芽胞杆菌具有高度相似性。根据菌体形态、培养性状、生理生化特性及16S rDNA序列分析等指标,确定B504为枯草芽胞杆菌（Bacillus subtilis）。     

Comparative sensitivity of barley (Hordeum vulgare L.) to insecticide and fungicide on different stages of cell cycle

In this study, the comparison of cytogenetic effects of insecticide and fungicide in different phases of cell cycle was investigated in the root tip cells of barley (Hordeum vulgare L.). The seeds of H. vulgare L. Var. Karan 16 were treated with different concentrations (0.05%, 0.1% and 0.5%) of insecticide Profenophos (PF) and fungicide Mancozeb (MZ) for 6 h after presoaking durations of 7, 17 and 27 h.The different presoaking durations were used to bring the cells in various phases of cell cycle. Negative control was run parallel in distilled water. Cytogenetic examinations of root meristems exposed to the PF and MZ showed significant inhibition of mitotic index (MI) as well as significant increase in chromosomal aberrations (CAs). These parameters were dependent on the concentrations of insecticide and fungicide. The present study shows that PF and MZ both caused more damage in S phase of cell cycle which indicates that S phase is more sensitive in comparison to other phases.     

连续施药及室内药剂驯化对番茄灰葡萄孢对咯菌腈敏感性的影响

为了解连续施药对番茄灰葡萄孢对咯菌腈敏感性的影响,在温室条件下,从灰霉病发生初期开始,按推荐剂量(有效成分67.5 g/hm2)定期向番茄苗喷施咯菌腈,通过菌丝生长速率法检测灰葡萄孢对咯菌腈的敏感性。结果表明,在番茄1个生长季节中连续施药7次后,病菌对咯菌腈仍表现敏感,其EC50值在0.004 7～0.046 2 μg/mL之间。在含咯菌腈的PDA培养基上对30个灰葡萄孢敏感菌株进行药剂驯化7代后,共产生2个抗药性突变体(Rg-12和Rdz-28),其中Rg-12对咯菌腈的EC50值是其亲本菌株g-12的46倍,Rdz-28的EC50值大于500 μg/mL,2个抗性突变体在菌丝生长速率、产孢量和产菌核能力方面均显著低于其亲本菌株。推测灰葡萄孢可能不易对咯菌腈产生抗性,咯菌腈可作为防治番茄灰霉病的理想候选药剂。