共查询到20条相似文献,搜索用时 15 毫秒
1.
Grapevine trunk pathogens (GTPs) cause serious damage to grapevines and have significant economic impacts. There is no effective protection against grapevine trunk diseases. Newly designed AgSe nanoparticles (NPs) and CuSe NPs, single-element Ag NPs, Cu NPs, Se NPs and selected chemicals or chemical agents such as sodium arsenite, 8-hydroxyquinoline, silver nitrate, colloidal silver, Altron Silver fertilizer and silver thiosulfate complex (NH 4) 3/Ag(S 2O 3) 2 were tested in vitro against two serious GTPs Diaporthe eres, Eutypa lata and Diplodia seriata isolated from walnut. The most significant inhibition of fungal growth was observed for silver nitrate and AgSe NPs, which showed the highest level of half the maximum effective EC 50 concentration with the lowest concentrations. In the case of silver nitrate at a concentration of 1000 mg L −1, 79% inhibition of mycelial growth was observed for the pathogen E. lata, 48% for D. seriata and 54% for D. eres. AgSe NPs, in which the concentration of silver is 2588 mg L −1 and that of selenium is 902 mg L −1, showed 68% inhibition of mycelial growth in the pathogen E. lata, 54% in D. seriata and 58% in D. eres. 相似文献
2.
以2年生金银花为试验材料,采用叶面喷施法,研究不同浓度的苯丙氨酸(Phe)、酪氨酸(Lyr)以及锌(Zn2+)、铜(Cu2+)对金银花生长发育和质量的影响。结果显示:(1)喷施不同浓度的Phe、Lyr以及Zn2+、Cu2+对叶面积无明显影响;不同处理的叶绿素含量随喷施次数的增加而出现不同程度的下降,喷施浓度适宜则有助于叶绿素的合成;喷施一定浓度的Phe、Lyr以及Zn2+、Cu2+可增加花蕾重量,如经1 000mg/g Phe处理后的花蕾鲜重与干重较对照增加了20.1%和51.4%。(2)不同浓度的Phe、Lyr可显著影响碳代谢,但对氮代谢影响不明显;Zn2+、Cu2+对碳氮代谢产物影响较明显,如喷施10mg/L的CuSO4及ZnSO4可提高可溶性糖及淀粉含量。(3)除Zn2+处理后的花蕾类黄酮含量显著低于对照外,其他处理较CK无显著差异;花蕾总黄酮含量均显著低于对照,但绿原酸含量均高于对照。(4)叶片中离子含量受喷施次数及浓度影响较明显,除30mg/L CuSO4处理外,其它处理的花蕾中Zn2+、Cu2+、Fe2+含量均显著低于对照。研究表明,在金银花的第一茬花抽枝初期喷施适宜浓度的Phe、Lyr(如1 000mg/g Phe、2 000mg/g Lyr)以及Zn2+、Cu2+(如50mg/L ZnSO4、10mg/L CuSO4)可改善金银花的生长发育,并提高产量和质量。 相似文献
3.
Optimum conditions for the growth of Pseudomonas arvilla, a hydrocarbon utiliser, have been studied. The microorganism produced economic cell yield at pH 5.7 and 4% kerosene concentration.
C 10-C 16 hydrocarbons were utilised by the strain. The growth was maximum on n-decane. Supplementation of the hydrocarbon medium with
0.5% glucose stimulated the growth. Glutamic acid 16.0 mg; leucine 9.0 mg; valine 10.0 mg; methionine 2.5 mg; arginine 2.5
mg; histidine 1.0 mg were present in 100 ml of the broth. Cell protein contained leucine 13.69%, isoleucine 4.9%, histidine
4.37%, tryptophan 2.33%, methionine 1.8% and arginine 2.70%. 相似文献
4.
Cladophora glomerata grown in continuous-flow culture was found to have optimal specific growth rate (μ) at, or near, 20°C. Specific growth rate increased linearly with increased duration of illumination per day up to 24h, and increased light intensity up to 6000 lx. Undissociated ammoniacal nitrogen (0·185 mg 1 -1) reduced μ to 50% of that at 0·010 mg 1 -1: 0·077–1·057 mg NO 2-N1 -1 and 7·2–15·2 mg NO 3-N1 -1 had no significant effect on μ. At 4·9 mg PO 4-P1 -1, μ was 48% of that at 1·9 mg1 -1. The critical medium PO 4-P concentration was less than 0·098 mg1 -1. Specific growth rate was reduced to 50% of that in the based medium by 0·036 mg Cu1 -1, 0·070 mg Zn1 -1 and 1·03 mg Pb1 -1. Results are discussed in the context of the natural distribution of the alga in the field situation. 相似文献
5.
The effect of three different nitrogen sources on the growth of external ectomycorrhizal mycelium was studied in Perspex micorocosms. Nonsterile peat was used as substrate. Five different fungal isolates growing in symbiosis with pine seedlings were investigated: two isolates of Paxillus involutus, one of Suillus bovinus and two unidentified ectomycorrhizal fungi isolated from ectomycorrhizal root tips. Three different nitrogen sources were used: ammonium as (NH 4) 2SO 4, nitrate as NaNO 3 and a complete nutrient solution (Ingestad 1979), and three different nitrogen concentrations, 1, 2 or 4 mg N/g dry wt. of peat. The mycelial growth of all fungi was found to be negatively affected by the nitrogen amendments, although the sensitivity to nitrogen varied between the isolates. One of the unidentified isolates was extremely sensitive and growth was completely inhibited by all nitrogen treatments. In contrast, the growth of one of the P. involutus isolates was only slightly reduced by the nitrogen amendments. The different nitrogen sources all reduced growth, and since no significant difference was found between the nitrogen sources or between the different nitrogen concentrations the results were pooled to give one value that summarized the effect of nitrogen on mycelial growth. Thus, the mycelial growth of one of the two P. involutus isolates was reduced to approximately 80% of the growth in the control, the other P. involutus and one of the unidentified fungi, vgk 2 89.10, were reduced to 40–50% of the control growth, S. bovinus to 30% of the control and the most sensitive fungus, the unidentified isolate vg 1 87.10, was reduced to 3% of the growth in the control treatment. In all experiments, the shoot to root ratio generally increased, mainly as a result of increased shoot growth. 相似文献
6.
The effects of three heavy metal cations, mercury (II), copper (II), and chromium (VI), on the growth of the rumen ciliate
Entodinium caudatum in vitro culture was studied. The E. caudatum culture was challenged by HgCl 2, CuCl 2, and K 2Cr 2O 7 for a period of 4 days. The tested concentrations of mercury (II) and copper (II) were 1, 5, 10, 20, 50 mg/L and 2, 10, 20,
40 mg/L for chromium (VI) at single dose with either untreated or inhibited bacterial co-culture population. Effective metal
concentrations required to reduce ciliate growth by 50% (EC 50) for mercury (II), copper (II), and chromium (VI) either with untreated or inhibited bacterial co-culture population after
24 h of metal application were 24, 20, and 21 or 15, 20, and 19 mg/L, respectively. After 4 days of metal application, corresponding
EC 50 values for mercury (II), copper (II), and chromium (VI) were 16, 20, and 17 (with untreated bacterial population) or not
determinable, 20, and 15 mg/L, respectively (with inhibited bacterial population). Increased sensitivity of E. caudatum to tested heavy metals with inhibited bacterial co-culture population indicate that the ciliate resistance to the heavy metal
tested depends on detoxification abilities of rumen bacterial population. 相似文献
7.
蛹虫草是一种药食两用真菌,具有与冬虫夏草相似的功能,且富硒能力较强。本研究通过大量的人工栽培试验,旨在探究不同浓度Na_2SeO_4对新疆本地蛹虫草子实体生长的影响。试验表明,质量浓度为20 mg/L的Na_2SeO_4对蛹虫草的生长不产生显著影响,但蛹虫草各项生物学指标均随着培养基中外源Na_2SeO_4浓度的增加而呈下降趋势,说明随着外源Na_2SeO_4浓度的增加会对蛹虫草的生长产生抑制效应,当外源Na_2SeO_4质量浓度达到200 mg/L时,生产的蛹虫草已不具备商品价值。由此可见,20 mg/L的质量浓度是以Na_2SeO_4为硒源进行蛹虫草富硒研究的安全浓度。该研究为富硒产品开发寻找新的硒源开辟了新思路,为新疆地区进一步大规模栽培富硒蛹虫草提供一定的参考,但是对以Na_2SeO_4为硒源的最佳富硒浓度还有待于进一步研究。 相似文献
8.
Summary The effect of addition of varying concentrations of certain inorganic compounds in selected media upon growth and pigment elaboration of Eidamella deflexa ( Berk.) Benjamin was studied in submerged culture. Preliminary experiments were performed to establish approximate optimum ranges of certain inorganic compounds. Further investigations in a glycine-sucrose basal medium indicated that the following range of concentrations stimulated growth to the greatest extent: 0.2% MgSO 4·7H 2O, 0.2% K 2HPO 4, 0.25 mg% CuSO 4·5H 2O, 0,0% ZnSO 4·7H 2O and 10.0 mg % FeSO 4·7H 2O. The degree of pigment production did not seem to be affected by different concentrations of these compounds.The effects of additional molybdenum and zinc upon growth and pigmentation were studied in the following media: lactose-peptone, lactose-glycine, maltose-peptone and maltose-glycine. Molybdenum increased pigmentation slightly in maltose-glycine and maltose-peptone media, but inhibited the amount of growth. Molybdenum decreased both growth and pigmentation in the two lactose media. Zinc had little affect on either growth or pigment elaboration in the two maltose media. However, in the lactose-glycine medium, zinc decreased both growth and pigmentation while in lactose-peptone media zinc slightly increased growth and pigmentation. 相似文献
9.
Aim of this study was to investigate the nature of dormancy in black henbane ( Hyoscyamus niger) seeds which have low germination rate under normal laboratory conditions. To do this, before placing the seeds in Petri
dishes, they were soaked in 5,10 and 15 mg/L GA; 1,2 and 3% H 2SO 4, 15 mg/L GA + 1% H 2SO 4, 0.01 M KNO 3 solutions, tap water, 40, 50 and 60°C hot water for 30 min. The study was performed under both continuous illumination and
darkness in growth chambers to evaluate the effect of light on germination rate. The results showed that H 2SO 4 and GA treatments were the most important factors affecting seed germination and their germination enhancing effects were
more evident in darkness. The results also suggested that black henbane seeds exhibit double dormancy involving a hard seed
coat and a partially dormant embryo and have a partial dark requirement to germinate. 相似文献
10.
The determination of growth constant of Aspergillus niger were obtained for semisolid cultures on cassava flour, Manihot esculenta, as a sole carbon source. As a consequence, a technique was developed that consisted of the use of a packed-bed microfermentor with a working volume of 16 cm 3. The bed consisted of gelatinized and granulated cassava flour containing mineral nutrients and mold spores. The carbon dioxide produced during the respiration was drawn off with a current of air and then absorbed in a solution of sodium hydroxide. The absorption of CO 2, P, was correlated with the specific growth rate μ, by means of the equation P= Keμt, where t is time and K is a constant. Ammonium nitrogen was used as a limiting substrate and its concentration was varied from 0.039 to 2.5% in dry base. The maximum growth rate, μ max, and the saturation constant, Ks, were 0.31 hr ?1 and 0.065 mmol (NH 4) 2SO 4/g total dry solids. Substrate inhibition was presented and the constant ki gave a value of 1.5 mmol (NH 4) 2SO 4/g total dry solids. The proposed method is highly recommended for the evaluation of the semisolid fermentation of molds and for strictly aerobic bacteria and yeasts. It can be used especially in the evaluation of the growth of microorganisms on peanut shells, coffee residues, sugar cane bagasse, and other agricultural wastes. 相似文献
11.
Summary The fundamental nutritional requirements of one strain of Gymnoascus reessii were established. Growth was measured on a dry weight basis. The optimum medium for growth consisted of 5% maltose, 2% KNO 3, 0.2% K 2HPO 4, 0.2% MgSO 4.7H 2O, 1 mg% adenine, 1 mg% uracil, 1 mg% guanine, 5 mg% xanthine, 0.8 mg% biotin and 0.2 mg% pyridoxine. An initial Ph range of 5.0–8.0 was found to permit optimum growth.
Zusammenfassung Die Grunderfordernisse der Ernährung eines Stammes vonGymnoascus reessii sind festgestellt worden. Das Wachstum war an der trockenen Gewichtsgrundlage gemessen. Der optimale Nährboden für das Wachstum bestand in 5% Maltose, 2% KNO3, 0.2% K2HPO4, 0.2% MgSO4. 7HO2, 1 mg% Adenine, 1 mg% Uracil, 1 mg% Guanine, 5 mg% Xanthine, 0.8 mg% Biotin und 0.2 mg% Pyridoxine. Eine Anfangsbreite der Ph von 5.0–8.0 erlaubte ein optimales Wachstum. 相似文献
12.
To evaluate the role of exogenous application of a phytochelating agent glutathione in increasing resistance against different
heavy metals stress, nodal explants excised from 28-day-old in vitro seedlings of Spilanthes calva L. were cultured on Murashige and Skoog’s medium supplemented with 10 μM benzyl adenine and five different concentrations
(1, 5, 50, 100, or 200 mg/l) of four heavy metals: As 2O 3, CuSO 4, ZnSO 4, or Pb(NO 3) 2. Data were recorded for percent survival, shoot number, and shoot length after 28 d of heavy metal treatment. All four heavy
metals severely inhibited growth and morphogenesis. Pb proved most inhibitory whereas Zn was least effective. Pb was further
selected to study the reversal effect of glutathione on morphogenesis. The addition of different concentrations (1, 5, 10,
or 25 mg/l) of glutathione to media containing the Pb resulted in a significant improvement in almost all growth parameters.
Inclusion of glutathione at 10 mg/l was optimum for maximum reversal of the negative effects of heavy metals on morphogenesis. 相似文献
13.
Cell material from different phases of growth for the green alga Selenastrum capricornutum Printz was analysed for major elements and chlorophyll a content. The ranges in percentage of the dry weight were 50–80%, 4.4–8.8%, 0.24–3.0%, and 0.20–3.23% for C, N, P and chlorophyll a, respectively. The dry weight per cell varied 2.3 times between different growth phases. A N/P-quotient of about 10 (by weight) was found to be a critical level for Selenastrum when these elements were the most limiting nutrients for growth. 31 different organic N-compounds were tested as single N sources in growth experiments with Selenastrum. At least 19 of them could be utilized to varying extent for algal growth. Three organic P-compounds of six tested, were utilized for algal growth. Yield coefficients (mm 3 cell volume/mg limiting nutrient element) for Selenastrum were determined with NO 3, -N (y N= 134). NH 4-N (Y N= 111) and PO 4-P (Y P= 2580). 相似文献
14.
Microbial fermentation of citrinin-free Monascus pigments is in favor in the development of food industry. This study investigated the influences of carbon source, nitrogen source, and mineral salts on the cell growth, monascin (MS), and citrinin (CT) production in Monascus M9. A culture medium composition was established for maximizing the production of citrinin-free MS in submerged culture, as follows: 50?g/L Japonica rice powder, 20?g/L NH 4NO 3, 3?g/L NaNO 3, 1.5?g/L KH 2PO 4, 1?g/L MgSO 4?·?7H 2O, 0.2?g/L MnSO 4. Under these conditions, no CT was detectable by high performance liquid chromatography. The yield of MS reached 14.11?mg/g, improving approximately 30% compared with before optimization. 相似文献
15.
【目的】通过考察Mn 2+对A/O-BAF系统处理效能及微生物群落多样性的影响,研究了15℃下不同浓度Mn 2+对A/O-BAF系统处理效能的影响,并通过高通量测序考察了细菌群落多样性的变化情况。【方法】在温度15°C、水力负荷0.50 m 3/(m 2·h)、气水比10:1的条件下,在进水中投加Mn 2+,考察反应器处理效能的变化情况,并通过高通量测序对BAF生物膜样品进行分析。【结果】2.0 mg/L Mn 2+作用下A/O-BAF系统的COD、NH 4+-N、TN、TP去除率分别提高3.51%、2.21%、6.26%和12.13%;4.0 mg/L Mn 2+作用下COD、NH 4+-N、TN、TP去除率分别提高了4.24%、1.92%、7.75%和10.73%;Mn 2+作用下A/O-BAF系统内反硝化细菌和亚硝酸菌的数量明显增加,硝酸菌... 相似文献
16.
【目的】从内蒙古种植葵花的盐碱地中筛选高效溶磷真菌,为盐碱地增产节肥开发生物肥料提供溶磷菌种资源。【方法】利用ITS r DNA序列鉴定菌株、固体培养基测定耐盐性,液体摇床培养与盆栽试验结合分析菌株溶磷能力,盆栽和田间试验明确菌株M1促进作物生长和增产作用;LC-MS技术测定菌株M1在液体培养基中分泌有机酸和植物激素含量,明确菌株M1的溶磷和促生机理。【结果】溶磷菌株M1鉴定为日本曲霉(Aspergillus japonicus)。液体培养基接种菌株M1培养6 d,以Ca_3(PO_4)_2为磷源时上清液有效磷达1020.89 mg/L,溶解率为63.30%;以AlPO_4为磷源时有效磷达995.69 mg/L,溶解率为48.59%;以贵州开阳磷矿粉、江苏锦屏磷矿粉、云南晋宁磷矿粉、河北钒山磷矿粉和云南昆阳磷矿粉为磷源接种菌株M1,从晋宁磷矿粉释放的有效磷浓度最高,达到363.64 mg/L。菌株M1可耐受10%NaCl。将M1制备的菌剂分别接种于施用Ca_3(PO_4)_2、AlPO_4和开阳磷矿粉3种磷源的4种盆栽试验土壤包括北京石灰性潮土、安徽黏性潮土、安徽水稻土和山东沿海盐潮土。结果显示,菌株M1对玉米植株促生效果显著,玉米植株鲜重比对照提高2.14%–90.91%、干重增加22.15%–268.28%;土壤有效磷提高21.81–24.27 mg/kg。菌株M1与4种土壤的适配性均高于对照菌株DSM 821。田间小区花生产量结果显示,接种溶磷菌剂M1增产效果最好,花生果实产量达4.46 t/hm~2,比不接种菌剂的对照处理增加0.81 t/hm~2,增产22.19%。菌株M1在含有磷酸三钙、磷酸铝和开阳磷矿粉3种难溶磷培养液中经过6 d培养,均产生7种有机酸,其中草酸和柠檬酸含量最高,分别为616.16 mg/L和413.69 mg/L;培养液均能检测到吲哚乙酸(IAA)和玉米素,IAA含量为15.45–77.58 mg/L,玉米素浓度为0.06–0.11 mg/L。【结论】获得了一株高效溶解多种难溶磷的日本曲霉菌M1,它能显著增加土壤有效磷、促进玉米生长和花生增产,与4种典型土壤适配性好,具有良好的农业应用前景。 相似文献
17.
Screening was carried out to obtain microorganisms which produced the enzyme to reduce the disulfide bond, from our type cultures of yeast. Among many strains of yeast showing activity to reduce the disulfide bond, Candida claussenii, Candida brumptii and Candida rugosa were selected to have the highest activity. The enzyme activity was detected in the cell free extracts, but not in culture broth.The highest enzyme formation occured during the exponential growth phase, and rapid decrease of activity was observed in the stationary phase. Pantothenate and boron ion contributed to enzyme formation, and biotin and zinc ion to growth. The maximum enzyme activity was obtained in the following synthetic medium: 10% sucrose, 0.3% (NH 4) 2SO 4, 0.5% KH 2PO 4, 0.15% MgCl 2·6HO 2 0.05% CaCl 2, 0.015% MnCl 2, 0.001% pantothenate, 0.0001% biotin, 0.0001% H 3BO 3, 0.00004% FeCl 3·6H 2O and 0.00008% ZnCl 2. In addition, 30°C of the cultural temperature and vigorous aeration showed good results for enzyme formation. 相似文献
18.
Muds from 12 types of soils were used as the only source of phosphorus in cultures of Scenedesmus dimorphus. Some muds supported as much algal growth as was obtained with 0.075 to 0.5 mg/1 of phosphorus, while little or no growth occurred in cultures which contained other muds as a source of phosphorus. Algal growth was correlated with the fractions of soil phosphorus which were extracted with the following solutions; I — the phosphorus — free nutrient solution, II — 0.05N HCl plus 0.025N H2SO4, III — 0.002N H2SO4 plus 3 g/l of K2SO4, and IV — 0.1N HCl plus 0.03N/NH4F. Additions of phosphorus to the soils prior to their use as muds increased the suitability of some as sources of phosphorus, but for others the added phosphorus was so tightly bound to the soil that little or none was available to S. dimorphus. The findings indicate that the type of soil in a pond will likely have a large influence on the efficiency of fertilization with phosphate fertilizers. 相似文献
19.
The capacity of Elodea nuttallii (Planch.) St. John and Elodea canadensis Michx. to remove nitrogen from water was evaluated in laboratory experiment. The growth rate of plants and their effect on the nitrogen level of hypertrophic Lake Zwemlust (the Netherlands) as well as on lake water enriched with nitrogen were investigated. The plants grew best in water enriched with up to 2 mg NH 4-Nl –1 and 2 mg NH 4-Nl –1 plus 2 mg NO 3 Nl –1. During a 14 day experiment, plants absorbed from 75% to 90% of nitrogen. Higher nitrogen concentration than 4 mg l –1 had a negative effect on growth of both species. Elodea nuttallii and E. canadensis prefer NOinf4/ p+ over NOinf4/ p– when both ions were present in water in equal concentrations. 相似文献
20.
Cell growth and accumulation of polyhydroxybutyric acid, P(3HB), from CO 2 in autotrophic condition of a newly isolated hydrogen-oxidizing bacterium, the strain O-1, was investigated. The bacterium,
which was deposited in the Japan Collection of Microorganisms as JCM17105, autotrophically grows by assimilating H 2, O 2, and CO 2 as substrate. 16S rRNA gene sequence of the bacterium was the closest to Ideonella dechloratans (99%). Specific growth rate of the strain O-1 was faster than a hydrogen-oxidizing bacterium, Ralstonia eutropha, which is well-known P(3HB)-producing microorganism. The strain O-1 is tolerant to high O 2 concentration and it can grow above 30% ( v/ v) O 2, while the growth of R. eutropha and Alcaligenes latus was seriously inhibited. In culture medium containing 1 g/L (NH 4) 2SO 4, cell concentration of the strain O-1 and P(3HB) increased to 6.75 and 5.26 g/L, respectively. The content of P(3HB) in the
cells was 77.9% ( w/ w). The strain O-1 was very tolerant to carbon monoxide (CO) and it grew even at 70% ( v/ v) CO, while the growth of R. eutropha and A. latus were seriously inhibited at 5% ( v/ v) CO. From these results, it is expected that the strain O-1 will be useful in the manufacture of P(3HB) because the industrial
exhaust gas containing CO 2, H 2, and CO can be directly used as the substrate in the fermentation process. 相似文献
|