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1.
Scanning electron microscopy was used to determine the number of flagella on the flagellates of Naegleria australiensis, N. fowleri, N. gruberi, and N. jadini. Although the majority of flagellates had 2 flagella, there was considerable variation among individual cells. The number of flagella per flagellate varied from 1-8, with 2.4 being the average number per cell. For the different species, the average number of flagella per cell ranged from 2.0 in N. jadini to 3.1 for N. australiensis. The greatest amount of variation occurred in N. australiensis, with only 43% of the cells having 2 flagella. By contrast, 92% of N. fowleri cells had 2 flagella. Naegleria jadini and N. gruberi were intermediate with 80% and 74% biflagellates, respectively. 相似文献
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V Kadlec 《Folia parasitologica》1975,22(4):317-321
The effects of various biophysical and chemical factors on the cytology of vegetative stages of Naegleria sp., Vitek strain, Acanthamoeba culbertsoni, Acanthamoeba castellanii, Neff strain and Acanthamoeba polyphaga, No. 1289, were studied. The amoebae were cultured in a liquid medium under axenic conditions. The optimum temperature was 37 degrees C for pathogenic strains of Naegleria sp. and Acanthamoeba culbertsoni and 20 degrees C for A. castellanii. No changes were observed in the growth of A. polyphaga at the temperatures 20 degrees and 37 degrees C. The strains investigated grew at pH values of 5.6 to 7.7 using Soerensen's buffer. At the limit values the growth was inhibited and the morphology of cells was markedly changed. All of the four strains grew still at pH 8.4 kept by NaHCO3. A. polyphaga grew at partial anaerobiosis. The three tested strains of the genus Acanthamoeba grew in liquid axenic medium with 0.89% NaCl. The growth of Naegleria sp., Vitek was inhibited already at 0.2% concentration of this salt. The addition of 3 X 10(-2) m KCl to the culture medium had a harmful effect on the growth and morphology of three tested strains, except A. polyphaga. In the culture medium containing 2 X 10(-3) m CaCl2 the encystment of both pathogenic strains was stimulated. The cytological changes under experimental conditions were manifested by atypical movement of trophozoits and their intracellular structure. 相似文献
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Amebae of 8 strains of Naegleria gruberi were able to destroy 10 established mammalian cell lines including lung, kidney, ovary, connective tissue, neuroblastoma, and laryngeal and cervical carcinoma cells. The strains of N. gruberi varied in their ability to produce a destructive effect (DE) in African green monkey kidney (Vero) cell cultures. However, cell line susceptibility was found to be equivalent when tested with the considerably destructive 1518/l strain of N. gruberi. The Vero cell line proved to be a useful indicator culture for assessing the destructive potential of N. gruberi strains. Other factors affecting the extent of DE produced were ameba to mammalian cell ratio and the length of time that amebae were maintained in cell culture. 相似文献
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This is a follow-up report on the viability of pathogenic Naegleria fowleri, Naegleria australiensis and Acanthamoeba castellanii isolates during 5 to 10 years of cryopreservation at -70 degrees C. The greatest decrease in viability occurred with N. fowleri and the least occurred with N. australiensis. At 10 years of cryostorage, viability was 21% for N. fowleri, 32% for A. castellanii and 51% for N. australiensis. 相似文献
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S L Chang 《Folia parasitologica》1979,26(3):195-200
In brain sections of the Naegleria-caused cases of primary amoebic meningoencephalitis, extensive demyelinization was found in the white matter, besides the severe histopathological changes and large clusters of trophozoites in the grey matter. The myelinoclasis appeared to be a result of a specific phospholipolytic effect, unlike that in post-viral encephalomyelitis, which has been attributed to vascular blockade or hemorrhages. In monkey kidney cell cultures a very early cytopathic effect was observed and traced to the cytolytic property of the seeding culture fluid. Rat brain slices inoculated with Naegleria culture exhibited amoebic growth and demyelinization in 28-52 hours incubation at 35 degrees C. In a chemically defined medium containing sphingomyelin, casein and glucose, the Naegleria produced a limited growth parallelling the clearance of the lipid turbidity during a 72 hour incubation at 35 degrees C. Chromatographic analysis of the turbidity-cleared cultures revealed decomposition of sphingomyeline with liberation of choline, sphingosine and fatty acids. It is, hence, concluded that the pathogenicity of cytopathic effect of pathogenic Naegleria can be attributed to the latter's capacity to liberate a phospholipolytic enzyme or factor during active growth, which "makes holes" in the lipid-rich cytoplasmic membrane of cells as well as demyelinizes nerve tissue. 相似文献
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Primary amoebic meningoencephalitis (PAM) was induced in mice by intranasal inoculation of Naegleria fowleri (Singh et Das, 1970) to study the role of the blood vessels and lungs in the early and later stages in this disease. Upon culturing blood and lung tissue obtained at 24-, 36-, 48-, 72-, 96-, and 120-hour time periods, it was found that amoebae grew only from blood and lung tissue obtained at the 96 and 120 hour time periods. Paraffin sections of the head revealed small foci of acute inflammation and amoebae within the olfactory bulb of the central nervous system (CNS) at 24 hours. Amoebae were not observed within blood vessels of the CNS until 96 and 120 hours. Also, amoebae were observed within the connective tissue surrounding blood vessels and sutures of the skull, bone marrow, and venous sinusoids between the skull bone tables at 96 and 120 hours. No amoebae or acute inflammatory reactions were observed in the lung sections from any time period and indirect immunofluorescence microscopy was negative for N. fowleri. This study provides evidence that neither blood vessels nor lungs provide routes for N. fowleri to the CNS during the early stages of PAM and that amoebae enter veins of the CNS and bone marrow during later stages of the disease. 相似文献
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植物青枯病生防菌株PBW1对植物青枯病的防效可高达70%以上。本文首先获得了PBW1 500 mL摇瓶培养的最佳条件:30℃、初始pH7、接种量为1%、装液量为120 mL、摇床转速为220 r/min;在最佳条件下培养48 h的菌体浓度达4.2×1012cfu/mL;同时还对500 mL摇瓶培养过程中菌体生长、还原糖、总糖及pH变化特征进行了研究。此外,本文还在6L全自动发酵罐上对PBW1培养过程中的菌体生长、还原糖、氨基氮、pH和DO的变化特征进行了研究,培养48h的菌体浓度达4.76×1012cfu/mL。 相似文献
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Abstract A bacterium designated Tr A and capable of decomposing trifluralin in the presence of glutamate, lactate, acetate and yeast extract was isolated. Optimum pH for growth of this organism was 6.5 in a glutamate medium containing 0.01% trifluralin. Maximum decomposition of the herbicide occurred at pH 7.4 A threshold concentration of 0.05% trifluralin was necessary for the growth of this organism. Ninety-five per cent of the trifluralin was decomposed within 21 days in an 0.01% trifluralin medium, but none was degraded at a concentration of 0.05%. The herbicide remained stable for 10 days in an aqueous solution at different pH levels. 相似文献
11.
Characteristics of glyphosate inhibition of growth in soybean and tobacco callus cultures 总被引：1，自引：0，他引：1
T. T. LEE 《Weed Research》1980,20(6):365-369
Callus cultures or tobacco (Nicotiana tabacum L. cv. While Gold and N. glauca-langsdorffii, a tumour-forming amphidiploid hybrid) and soybean Glycine max L., cv. Chippewa) were used lo study the effect of glyphosate [N-(phosphonnmethyl) glycine) un growth and interactions with growth hormones. Glyphosate inhibited growth both in the dark and light but showed a greater toxicity in the dark. This was contrary to its effect on chlorophyll degradation which was accelerated by light. The inhibition of growth was not reversed by simultaneous addition of aromatic amino acids to the medium. Thus the results suggest a multiple glyphosate action. The tobacco callus tissue was more sensitive to glyphosate than the soybean callus tissue, confirming a difference in tolerance between plant species. Despite the inhibitory effect of glyphosate. the treated tissue revived after being transferred to a glyphosate-free medium. The glyphosate-induced growth inhibition in soybean and tumour-forming tobacco callus cultures also was reversible by high levels of indole-3-acetic acid (IAA), which itself was inhibitory Theglyphosate-IAA interaction in the tissues which were sensitive to IAA suggests that the inhibition of growth by glyphosate was related to auxin levels in these tissues. 相似文献
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从安徽省宣城市麻姑山林场采集到自然罹病的德国小蠊僵虫，通过分离纯化获得一株绿僵菌RCEF6416，采用显微形态和分子生物学相结合方法将该菌株鉴定为贵州绿僵菌。本试验研究了在不同培养基、盐浓度、pH以及高温胁迫等条件下，该菌株的培养特征及产孢能力，以期为世界性卫生害虫德国小蠊的生物防治提供种质资源和理论依据。结果表明：该菌株在PPDA培养基上的生长速度较快，菌落直径平均日增量为4.94 mm/d，但在PDA培养基上产孢量最大，为5.1×107孢子/cm2；在一定范围内，随着盐浓度增加菌落直径日增量增加，但是产孢量逐渐下降，且菌落逐渐产生白色菌丝圈；当pH为8时，菌株生长速度最快，产孢量最大；高温对菌株孢子萌发率影响很大，当水浴温度为45℃处理4 h后，其孢子萌发率仅为2.6%。 相似文献
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The mechanism of action of the phenylsulphonyl carbamate herbicide (asulam) was examined in celery tissue cultures to see whether the mechanism involved an inhibition of folic acid synthesis. When asulam was included in the nutrient medium, growth of the celery cultures was reduced but not entirely inhibited even at a concentration of 250 μm . Growth was also reduced if a phenylcarbamate herbicide (barban), or sulphanilamide were included in the medium. The addition of folic acid, or 4-amino benzoic acid, which is a precursor of folic acid, almost totally reversed the inhibitory effect of the asulam and sulphanilamide, but not of barban, whereas the addition of thymidine, methionine, serine or adenine, all of which are formed from folic acid, did not reverse the inhibitory effect of asulam, sulphanilamide or barban. Nevertheless the removal of the growth inhibition of asulam by folic acid or 4ABA suggested the mechanism of action of asulam was similar to that of a sulphanilamide. This mechanism of action in celery cell cultures appears to be similar to that found for asulam in intact plants of a range of species. 相似文献
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核盘菌重寄生菌链孢粘帚霉HL-1-1菌株的生物学特性研究 总被引：5，自引：0，他引：5
对植物真菌病害优良生防菌株链孢粘帚霉(Gliocladium catenulatum) HL-1-1的生物学特性进行了研究。结果表明,以核盘菌菌核粉为唯一碳源的培养基最适合HL-1-1的菌丝生长,PDA最适合产孢;蔗糖作为碳源、硝酸钾作为氮源、2530℃、pH值5及黑暗等条件适合HL-1-1的菌丝生长;可溶性淀粉作为碳源、牛肉膏作为氮源、25℃、pH值6及光照等条件适合产孢;菌核浸出液对HL-1-1的分生孢子萌发有促进作用,葡萄糖对分生孢子萌发有抑制作用;2530℃及黑暗条件适合孢子萌发,温度低于5℃或高于40℃,孢子不能萌发;孢子致死温度为52℃。 相似文献
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砖红镰孢生物学特性研究 总被引：6，自引：0，他引：6
砖红镰孢(Fusarium lateritium)在10种不同固体和液体培养基上均能生长。固体培养基以燕麦片培养基上生长最好,水琼脂上生长较差,菌丝也最稀疏;液体培养基中以查氏酵母浸膏培养基上生长量最大,无菌水最差。砖红镰孢在10~30℃均能生长,最适温度25℃,低于5℃或高于35℃时不生长。在pH 4.98~9.18的范围内都能生长,最适pH 7.38。荧光下生长最好,菌丝干重也最多,紫外灯照射对砖红镰孢生长有不利影响。该菌能利用多种单糖、多糖及醇类作碳源和L-丙氨酸等有机氮和硝酸钠等无机氮作氮源。病菌致死温度为50℃ 10 min。大型分生孢子在10~30℃、相对湿度90%~100%和pH 4.98~9.18的范围内均能萌发,其中最适温度为25℃、最适pH为7.38和相对湿度100%中的萌发率最高 相似文献
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交枝顶孢霉杀柑橘全爪螨活性及其生物学特性研究 总被引：2，自引：0，他引：2
为了明确交枝顶孢霉Acremonium implicatum CQBBW8的杀螨活性及其生物学特性,采用触杀毒力法检测CQBBW8菌株对柑橘全爪螨的致死率,通过单因素试验测试不同培养基、碳源、氮源、温度、pH及紫外线对CQBBW8菌株生长、产孢及其分生孢子萌发的影响。结果表明,CQBBW8菌株对柑橘全爪螨Panonychus citri(McGregor)的校正致死率为54.42%,LC_(50)为1.2×10~6个/mL,LT_(50)值为5.175 9d。最佳生长和产孢培养基分别为PDA和SEA;菌丝生长最适碳源和氮源为甘露醇和蛋白胨,产孢最适碳源和氮源为可溶性淀粉和氯化铵;最适生长温度为25℃,最适产孢和分生孢子萌发温度为30℃;最适生长和产孢pH为6.0,最适萌发pH为7.0;紫外线对菌丝生长影响不明显,对产孢影响较大,紫外线照射时间越长,孢子萌发率越高。综上,CQBBW8菌株对柑橘全爪螨有较强的毒力,对营养需求不高,环境适应性较强,具有开发为杀螨真菌制剂的潜力。 相似文献
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为明确一株高致病力赭绿青霉Penicillium ochrochloron Q-1的生防潜力,室内测试了不同营养、环境因素及常见杀菌剂、杀虫剂对菌株Q-1的影响,并采用室内毒力测定方法研究菌株Q-1对不同昆虫的毒力。结果表明：菌株Q-1对营养要求较低,最适生长和产孢培养基分别为淀粉琼脂培养基（SYA）和马铃薯葡萄糖琼脂培养基（PDA）,最适生长碳源为麦芽糖,最适产孢碳源为葡萄糖,最适生长和产孢氮源均为蛋白胨,最适生长及产孢温度为28℃,最适pH为6.0,同时菌株Q-1的孢子对紫外线具有一定的耐受力;化学农药中四螨嗪等杀虫剂对菌株Q-1生长影响较小,多菌灵、咪鲜胺等杀菌剂明显抑制菌株Q-1生长;在1×107孢子/mL浓度下,菌株Q-1对棉铃虫幼虫、家蚕幼虫及柑橘全爪螨雌成螨的LT50分别为4.08、21.37和28.43 h。综上,菌株Q-1生长快、产孢量高,对棉铃虫幼虫、家蚕幼虫及柑橘全爪螨雌成螨致病力高,本研究为赭绿青霉进一步开发利用提供理论依据。 相似文献
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马唐生防真菌弯孢霉(Curvularia sp.)菌株QZ-200的生物学特性研究 总被引：7，自引：1，他引：7
本文主要研究影响马唐生防菌弯孢霉(curvularia sp.)菌株QZ-200营养生长、孢子萌发及孢子形成的因子。该菌在SCS(黄豆粉-玉米粉-蔗糖)培养基上生长最好;生长温度为10~40℃,最适为28℃;pH为2~11,最适pH为6;在以葡萄糖为碳源、以磷酸氢二铵为N源的Czapek培养基上生长良好。分生孢子萌发的温度为10~45℃,最适为28~30℃,失活温度为52℃10min;pH为2~11,适宜为5~8;以自由水或饱和湿度条件下萌发率最高;1%蛋白胨、1%牛肉浸膏、0.1%的TW-80、1%马唐煎汁和0.2%的菜籽油溶液明显提高萌发速度。该菌孢子形成的温度为15~35℃,最适为28℃;连续光照比光暗12h交替处理更有利于产孢,黑光灯为最佳光源。 相似文献
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苹果黑星病菌中国菌株生物学特性研究 总被引：14，自引：0，他引：14
苹果黑星病菌(Venturia inaequalis(Cooke) Wint.)适合生长的培养基有苹果叶汁、苹果果汁、麦芽浸渍物、PSA、PDA、V8和马铃薯麦芽糖;适合产孢的培养基有苹果叶汁、V8和PSA。菌落生长和产孢适宜的pH值为5.0~6.5,温度为15~20℃。在碳源和氮源中,蔗糖、葡萄糖、果糖、麦芽糖、酵母提取物、硝酸钠和牛肉膏有利于病菌生长和产孢,硫酸铵抑制产孢,草酸铵抑制菌落的生长和产孢。20℃时,光周期为12 h,光照强度为600 lx条件下有利于病菌在PSA培养基上生长和产孢,其产孢量约为黑暗条件下的13倍。病菌分生孢子在水滴中萌发的适宜温度为20~25℃,最适pH值为5.0~6.5 相似文献