苏云金杆菌H3-111菌株对蓑蛾的毒效

通过苏云金杆菌H3- 1 1 1菌株摇瓶培养液对蓑蛾进行室内毒力测定 ,4 8h毒力回归方程为y=4 1 94 0 +3 31 85x ,r =0 95 31 ,LC5 0 =0 0 0 0 0 2 5 7,与标准品比较其生物效价为 4 86 2 93IU·mg- 1 ,有较高的毒效 ;同时经大田试验表明BtH3- 1 1 1菌株防治蓑蛾高峰期在药后 72～ 96h ,稀释 5 0 0～1 0 0 0倍的防效达 92 4 6 %～ 95 1 5 % ,超过化学农药DDVP的最高防效 (85 0 7% ) 。

Bt生物农药发酵研究进展

对近年来Bt生物农药的发酵工艺进行了综述,主要包括Bt发酵中的原料、pH值、温度、氧气、发酵时间。

Screening on Synergist of Bacillus thuringiensis Wettable Powder

[Objective] This study aimed to screen the best synergistic material for Bt wettable powder and evaluate their synergistic effect. [Method] The synergism of six different kinds of additives for Bacillus thuringiensis wettable powder （Bt WP） on the 2^nd instar larvae of Plutella xylostella was tested by method of leaf dipping in labora- tory. [Result] The mixtures of Bt with 0.1% ZnCl2, 0.5% ZnCl2, 1.0% ZnCl2, 1.0% MgCI2, 0.5% boric acid, 1.0% boric acid, 0.5% citric acid or 1.0% citric acid all ex- hibited synergistic effect, in which the synergistic effect of mixture containing 0.5% boric acid was the highest, with 17.2 synergistic ratio; followed by the mixture containing 1.0% ZnCl2, with 15.6 synergistic ratio. Moreover, addition of 0.5% boric acid could shorten the median lethal time of Bt wettable powder by about 10 h. After the mixtures of Bt with 0.5% boracic acid or 1.0% ZnCl2 was stored for 15 d at room temperature, toxicities of the two mixtures did not change significantly. [Conclusion] Boracic acid as the synergist of Bt wettable powder could not only increase insecti- cidal effect of Bt, but also accelerate its insecticidal rate. So, boracic acid could improve the disadvantages of Bt wettable powder such as poor insecticidal effect and slow insecticidal speed in a certain degree.

无公害蔬菜的生产技术措施

1无公害蔬菜的概念不含农药、化肥、工业废水、废气、废渣及其它有害微生物污染的蔬菜。2无公害蔬菜基地的建设为了避免一切人为的环境污染,菜地要无污染。

Isolation and Biological Determination of Bacillus thuringiensis with High Toxicity in Soil of Changbai Mountain Area

[Objective] This study was conducted to isolate and screen new Bacillus thuringiensis （Bt） strains against Lepidoptera insecticides. [Method] Bt strains were isolated from soil of Changbai Mountain area by temperature screening method, and highly-toxic Bt stains were then selected by biological determination and toxicity de- termination. [Result] From 150 soil samples, 18 Bt isolates were isolated, with an average isolation rate of 12.0%. Specifically, the isolation rate from mountain field was 8.5 %, and the isolation rate from farmland was 16.2%. The results of activity determination showed that there were17, 5 and 4 strains showing lethality rate over 90% against Plutel/a xylosrel/a, Spodoptera litura and Spodptera exigua, respectively, and among them, strain YNI-1 exhibited high activity against all the 3 kinds of in- sects. The results of toxicity determination showed that strain YNl-lhad the best fast-acting property against S.litura and S. exigua; strains with high toxicity against S. exigua were YN6-2〉YN1-1〉YN4-2〉YN2-6 sequentially; and toxicity of strains against S. /itura was in order of YN4-4〉YN1-1 〉YN6-1 〉YN4-1 〉YN2-1. [Conclusion] According to activity determination and toxicity determination, strain YN1-1 was screened as the target strain with wide spectrum, fast-acting property and high toxi- city.

Evidence for Positive Darwinian Selection of Vip Gene in Bacillus thuringiensis

Vegetative insecticidal proteins （VIPs）, produced during the vegetative stage of their growth in Bacillus thuringiensis, are a group of insecticidal proteins and represent the second generation of insecticidal trans-genes that will complement the novel δendotoxins in future. Fewer structural and functional relationships of Vip proteins are known in comparison with those of δ-endotoxins. In this study, both the maximum-likelihood methods and the maximum parsimony based sliding window analysis were used to evaluate the molecular evolution of Vip proteins. As a result, strong evidence was found that Vip proteins are subject to the high rates of positive selection, and 16 sites are identified to be under positive selection using the Bayes Empirical Bayesian method. Interestingly, all these positively selected sites are located from site-705 to site-809 in the C-terminus of the Vip proteins. Most of these sites are exposed and clustered in the loop regions when mapped onto its computational predicted secondary tertiary and a part of the tertiary structure. It has been postulated that the high divergence in the C-terminal of Vip proteins may not result from the lack of functional constraints, but rather from the rapid mutation to adapt their targeted insects, driven by positive selection. The potential positive selection pressures may be an attempt to adapt for the ＂arm race＂ between Vip proteins and the targeted insects, or to enlarge their target＇s host range. Sites identified to be under positive selection may be related to the insect host range, which may shed a light on the investigation of the Vip proteins＇ structural and functional relationships.

Protein Characteristics and Field Efficacy of YN1-1, a Highly Virulent Strain of Bacillus thuringiensis

[Objective] This study aimed to investigate the biological characteristics of a Bacillus thuringiensis strain YNI-1, which has high virulence to Lepidoptera spp. [Method] The crystal protein of YNI-1 was analyzed by SDS-PAGE, and its indoor and field efficacy for Lepidoptera spp. was investigated. [Result] The parasporal crystal of YNI-1 has a diamond-like structure. The molecular weight of the original toxin protein is 136 kDa. After trypsin treatment, the original toxin protein was hy- drolyzed into active toxin protein with molecular weight of 63 kDa. For Plutella xy- Iostella and Pieris rapae, the indoor efficacy of B. thuringiensis was better than that of commercial B. thuringiensis （WP）. In view of field efficacy, rate of YNI-1 strain was higher than that of commercial B [Conelusion] YNI-1 strain has excellent development potential. the insects reduced thuringiensis （WP）.

Isolation of an acid producing Bacillus sp. EEEL02: Potential for bauxite residue neutralization

Bauxite residue deposit area(BRDA)is a typical abandoned mining wasteland representing extreme hostile environment with increased alkalinity.Microbially-driven neutralization of bauxite residue,based on the microbial acid producing metabolisms,is a novel strategy for achieving rapid pH neutralization and thus improving its environmental outcomes.The hypothesis was that these extreme conditions promote microbial communities which are capable of novel ecologically relevant functions.Several alkaliphilic acid producing bacteria were isolated in this study.One strain was selected for its superior growth pattern and acid metabolism(termed EEEL02).Based on the phylogenetic analysis,this strain was identified as Bacillus thuringiensis.The optimized fermentation conditions were as follows:pH 10;NaCl concentration 5%;temperature 25℃;EEEL02 preferred glucose and peptone as carbon and nitrogen sources,respectively.Based on optimal fermentation conditions,EEEL02 induced a significant pH reduction from 10.26 to 5.62 in 5-day incubation test.Acetic acid,propionic acid and CO2(g)were the major acid metabolites of fermentation,suggesting that the pH reduction in bauxite residue may be caused by acid neutralization derived from microbial metabolism.This finding provided the basis of a novel strategy for achieving rapid pH neutralization of bauxite residue.

The use of Bacillus thuringiensis on Forest Integrated Pest Management

Bacillus thuringiensis is a major microbial insecticide and a source of genes encoding several proteins toxic to insects. In this paper the authors g ive a brief summary of Bacillus thuringiensis used on the integrated pest manage ment in forestry. The derivatives of Bt strain HD1 subsp kurstaki have been wide ly used to control the forest pests such as the gypsy moth (Lymantria dispar), s pruce budworm (Choristoneura fumiferana), the pine processionary moth (Thaumetop oea pityocampa), the European pine shoot moth (Rhyacionia buoliana) and the nun moth (Lymantria monacha). Some progresses of transferring and expressing Bt toxi n gene in forest trees are offered with a discussion on the limits and future pr ospects of using Bt products in forestry.

Plant biotechnology:a case study of Bacillus thuringiensis(Bt) and its application to the future of genetic engineered trees

Agricultural productivity may be raised in a sustainable way by many different technologies such as biological fertilizers, soil and water conservation, biodiversity conservation, improved pest control, and changes in land ownership and distribution. Of these measures, biotechnology applications probably hold the most promise in augmenting conventional agricultural productivity, because biotechnology applications give not only the need to increase production, but also protect the environment and conserving natural resources for future generations. Biotechnology applications will have the possibilities to increase productivity and food availability through better agronomic performance of new varieties, including resistance to pests; rapid multiplication of disease-free plants; ability to obtain natural plant products using tissue culture; diagnosis of diseases of plants and livestock; manipulation of reproduction methods increasing the efficiency of breeding; and the provision of incentives for greater participation by the private sector through investments. Insect resistance through the transfer of a gene for resistance fromBacillus thuringiensis (Bt) is one of the most advanced biotechnology applications already being commercialized in many parts of the world. This paper reviews the development and the status ofBt technology and application ofBt transgenic plants in current agriculture, and discusses specific issues related to the transfer of the technology to the future of genetic engineered trees with emphasis on conifers. Key words Agricultural productivity - Bacillus thuringiensis - Genetic engineering - Insect resistance - Trees CLC number Q812 - S763.306 Document code A Biography: Tang Wei (1964-), male, Ph. Doctor, Research associate, Department of Biology, Howell Science Complex, East Carelina University, Greenville, NC 27858-4353, USA.Responsible editor: Chal Ruihai

Ecological Consequences of Elevated CO2 and Bt Cotton on Soil Collembola

Transgenic cotton was modified to express a gene derived from the bacterium Bacillus thuringiensis （Bt） to combat agriculturally important Lepidopteran pests. Elevated CO2 is expected to further alter the chemical composition of the plant, and this change may affect the role soil fauna plays in decomposition of Bt plants. A 3 months litterbag field study, consisting of four treatments using leaves from Bt cotton and near-isolines of non-Bt cotton grown under ambient and elevated CO2 levels, was conducted to investigate the abundance and community structure of soil Collembola that developed on the decaying leaf material. A total of 4,884 collembolans, including 13 genera of five families, were extracted in the present study. These results suggest that collembolan distribution was relatively uniform among the Bt cotton, elevated concentration of CO2 and control treatments, except for a significant difference in the densities of Onychiurus and Folsomides. No significant effects were detected in the decomposition rate between the two cotton varieties and two CO2 treatments. These findings indicated that transgenic Bt cotton plants and elevated CO2 do not have any adverse effect on the soil collembolans through the decomposition way in soil ecosystem.

Properties study and phylogenetic analysis of a bacterial strain with high de-emulsification efficiency

For further practical application, the phylogenetic analysis and de-emulsification properties study of strain XH1 with high de-emulsification efficiency isolated from crude oil contaminated soil in Daqing oil field were conducted with a surfactant-stabilized water-kerosene model emulsion. The factors influencing the de-emulsification efficiency and the generation site of de-emulsification active component of the strain were also investigated. The similarity of 16SrDNA sequences between strain XH1 and Bacillus mojavensis （DQ993678）was 99%. According to the physiological biochemical test, strain XH1 was preliminarily identified as Bacillus mojavensis. The logarithmic growth, stable phase and decline phase of strain XHI were determined as 14, 18 and 28 h, respectively. The best de-emulsification activity emerged after cultivating for 18h, and the complete de-emulsification was achieved at 24 h. The most favorable incubation conditions for de-emulsification occurred with pH of 6. 0 at 30 ℃. The de-emulsification capability of strain XH1 was mainly resulted from extracellular metabolites. The above results indicate that strain XH1 has high de-emulsification efficiency and is potential as a commercial de-emulsifier.

General Evaluation of Biocide （Bt-ASF-1） Produced from Iraqi Isolate of Bacillus thuringiensis

General evaluation of isolate Bacillus thuringiensis （Bt-ASF-1） used as biocide in meddle scale application was conducted. Some morphological and confirmation tests were achieved. The sensitivity tests had been accomplished by diffusion and dilution techniques to determine the response of isolate against the antibiotics. The results of diffusion tests showed to the sensitivity of bacteria to antibiotics of cefixime, erythromycin, gentamicin and tetracycline respectively. It was resistant to trimethoprim sulfonamide （TMP）, bacitracin, penicillin and all its generations, and moderate resistance to nalidixic acid. Minimum Inhibitory Concentration （MIC） for amoxicillin was ranged between 30-40 pg/mL and these results are an approximation of the universal findings. Curing experiments showed the effective role of sodium dodecyl sulfate （SDS） （1.5%） comparing with temperature. The bacterial cells became sensitive to amoxicillin and TMP. The curing by temperature did not differ significantly from control treatment in plasmid pattern or antibiotics response. Plasmid profile referring that curing by SDS has been caused disturbance in beta -lactamase genes through the sensitivity to amoxicillin and remaining resistance to ampicillin. Curing isolate by SDS also became more sensitive to nalidixic acid, erythromycin and tetracycline respectively. It was found from the curing treatments the complexity distribution of r-genes between different plasmid size and chromosome but not effect on their insecticidal ability.

A New Strain of Entomopathogenic Bacillus of the Tea Pest, Eterusia magnifica （Butl.） （Zyganiidae： Lepidoptera） from Darjeeling Foothill Region of India

An entomopathogenic strain of Bacillus sp. was isolated from diseased red slug caterpillars of the leaf-feediug pest of tea, Eterusia magnifica, from the Darjeeling foothill region. Analysis of the bacterimn based on polyphasic approach such as growth phase, biochemical tests, whole body＂ protein, crystal protein profiles along with bioassay （i.e. LC50 and LT50 values） established it as a different strain but close to Bacillus thuringiensis kurstaki （Btk）, the commercial microbial pesticides of lepidopterans. Among biochemical parameters differences were noted between the new strain and Btk in ONPG, lysine decarboxylase, omithin decarboxylase, urease, nitrate reduction, V-P and glucose utilization tests. PAGE analysis of the whole body protein for the new strain recorded a 34 kDa band which was absent in Btk （used as reference）. Crystal protein profile of the newly isolated bacterial strain showed 53 and 49 kDa bands whereas in Btk only 52 kDa band was evident. Although the LC50 values of the new strain and Btk were close, their LT50 values were much different, the new strain showing a lower value than Btk. In light of the above differences and in absence of any report of entomopathogenic bacterial strain of E. magnifica, the isolated strain of Bacillus appeared to be new to science and hence was designated as RS01. The new strain opens up the possibility of its futttre use as microbial pesticide after standardizing its formulation and checking its safety aspects.

Alkalibacillus halophilus subsp. hitensis subsp. nov.:A new subspecies of moderately halophilic bacterium isolated from a chemical plant in China

In order to develop halophilic microorganism resources to improve environment, a Gram-positive, strictly aerobic and moderately halophilic bacterial strain JSA1 was obtained from the waste water sample collected from Jinhong Chemical Plant at Weihai city, by the methods of quick isolation and screening of halophilie bacteria. Systematic studies on it were carried out. Results show that the strain JSA1 is bacillus. The temperature range most suitable for its growth is 29 - 35 ℃ and the most suitable pH is 6. 5 - 9. 0. It can grow well at the salt mass concentration of 30 - 150 g/L. The C ＋ G mole fraction of its DNA is 37.5%. The analytical result of 16S rRNA gene sequence reveals that this strain has the closest relationship with Alkalibacillus halophilus （DQ359731） of Alkalibacillts. Their similarities are as high as 99%. However, they have obvious differences in aspects of whole-cell main fatty acid components, cell size, cell morphology, motility, oxidase, gelatine liquefication, NaCl tolerance range, pH tolerance range, G ＋ C mole fraction, sole carbon source, sole nitrogen source, antibiotic sensitivity and strain source. Comparing with other species of the same genus, differences of this strain are even more obvious. In view of muhiple identification results, we believe this strain is a new subspecies ofAlkalibacillus halophilus and name it Alkalibacillus halophilus subsp, hitensis subsp, nov.

The Impact of Beauveria bassiana, Bacillus thuringiensis （Bt） Spray, Trichogramma pretiosum and Spinosad on the Lepidoptera： Crambidae, European Corn Borer （Ostrinia nubilalis）

The research cxamined the effects of microbial and novel insecticidal control strategies and also Irichogramma pretiosum on the I,epidoptera： Crambidae, the European corn borer （ECB）, （Ostrinia nubilalis）. The treatments included ~ino^d, from bacteria the entomopathogenic fungus Beauveria bassiana, the egg parasitoid Trichogramma pretiosum, and foliar applied Bt spray, and t^vo combinations Bearveria bassiana plus Bt spray and Trichogramma pretiosum and spinosad. The infestations by the European corn borer larvae on stalks of corn were very＂ severe in all the control treatments both 2006 and 2007. The microbial treatments caused various levels of European corn borer mortality. In all the parameters there was a significant difference between the control and other treatments with a P 〈 0.00 l. In this research, treatment with spinosad emerged as the most effective biological agent in the control of the European corn borer. The treatments had no significant effects on the relative abundance and composition of non-target arthropods （P 〉 0.05）. This research is relevant in boosting underutilized control strategies and increasing stakeholder adoption of integrated pest management practices and thereby＇ reducing the use of conventional insecticides especially for orgamc thrmers. This is very important especially in certain countries where the commumities are skeptical about consuming transgenic crops.

Efficacy of Trichogramma evanescens and Bacillus thuringiensis kurstaki to Control Lesser Date Moth Batrachedra amydraula Merck

Efficacy of the egg parasitoid, Trichogramma evanescens and the bio-pesticide bacteria, Bacillus thuringiensis kurstaki （Btk） in reduction of lesser date moth, Batrachedra amydraula infestations were studied during seasons of 2011 and 2012. The result of 2011 showed that the release of egg parasitoid by rate of 500 and 1,000 parasitoids/palm tree achieved 55.06% and 67.45% reduction in infestation percentage, respectively. Meanwhile high reduction in infestation was achieved by Btk （78.65%） at dose rate of 6 g Btk powder/kg talc powder. The result of 2012 showed that the highest control efficacy （58.78%） was achieved at the first time of the control process, using Btk at dose rate of 6 g/kg talc powder. This result was not different significantly from the release of egg parasitoid by rate of 1,000 parasitoids/palm tree which achieved 53% reduction in infestation percentage. At the second time （after one week from the first application）, the efficacy of Btk at dose rate of 6g/kg talc powder was increased to 78.78%, which differ significantly with the release of egg parasitoid by the same rate of 1,000 parasitoids/palm tree, having 61.79% efficacy. Reapplication of the control method achieved an increase in efficacy of the control agents, such increase was significant for both the release of the parasitoid at rate of 1,000/palm tree and for Btk at a dose of 6 g/kg talc powder.

Sex-Related Larval Susceptibility of Diamondback Moth, Plutella xylostella （Lepidoptera：Plutellidae） to some Reduced-Risk Insecticides

Five reduced-risk insecticides were compared for their toxicities to male and female third instar larvae of diamondback moth （DBM）, Plutella xylostella L. （Lepidoptera：Plutellidae） obtained from a laboratory colony. Leaf-dip bioassays were used to assess larval mortality at different insecticides rates （ranging from 0.01 mg AI/L to 100 mg A1/L） and exposure times （24, 48 and 72 h after treatment）. Toxicity of the insecticides generally increased with rate and exposure time. At 72 h after treatment, median lethal concentrations （LCs0s） of methoxyfenozide, spinosad, novaluron, indoxacarb and Bacillus thuringiensis （Bt） against the male third instar larvae of P, xylostella were 0.0524, 0.1117, 0.9149, 1.1939 and 4.4983 mg AI/L, respectively, and were 0.1008, 0.2583, 1.0649, 0.2850 and 5.3053 mg AI/L against female third instar larvae, respectively. At 0.1% of the approximate recommended field rates, methoxyfenozide （60%-75%） and spinosad （53%-57%） were the most toxic, while Bt （30%-45% mortality） was the least toxic to male and female P. xylostella larvae. Spinosad was the fastest acting and the only insecticide that caused significant larval mortality （17%） at 24 h after exposure. Significant sexual differences were recorded in the susceptibility of P. xylostella larvae to two of the insecticides： spinosad and indoxacarb. Male larvae were two-fold more susceptible to spinosad but 10-fold more tolerant to indoxacarb than female larvae.

Toxicity of Bacillus thuringiensis Crystal Toxins to Field Populations of Rice Leaf Folder, Cnaphalocrocis medinalis （Guenee） and Establishment of Baseline Susceptibility to Cry1Ab

Eight insecticidal crystal proteins of Bacillus thuringiensis, CrylAa, CrylAb, CrylAc, CrylB, Cry2Aa, CrylC, CrylDa and Cry 1Ea were assessed for toxicity against 1 st instar larvae of rice leaf folder, Cnaphalocrocis medinalis （Guenee） at 48 HAT and 72 HAT. Bioassay results depicted CrylAa was the most toxic （LCso 2.35 ppm） followed by CrylBa （LCso 8,50 ppm） and CrylAb （LCso 8.73 ppm） at 48 HAT, whereas, at 72 HAT CrylAb proved to be highly toxic （LC50 0.50 ppm） followed by CrylAa （LCso 4.07 ppm）, CrylAc （LCso 4,84 ppm） and CrylBa （LCso 6.42 ppm）. Toxins Cry2Aa, CrylCa, CrylDa and CrylEa did not resulted in any mortality at 48 HAT and 72 HAT, respectively. Baseline estimates for CrylAb against 1st instar larvae of C. medinalis sampled from seven geographical locations revealed variation in LC50＇s from 0.37 ppm to LC50 16.25 ppm at 48 HAT and LC50 0.50 ppm to LC50 6.49 ppm 72 HAT, respectively with relative resistance ratios of 44-fold and 13-fold at 48 HAT and 72 HAT over the susceptible population.

Economic and Environmental Impact Transgenically Modified Cotton Comparative with Synthetic Chemicals for Insect Control

This article combines both a review of the literature and original data from our research. The comparative efficacy of Bacillus thuringiensis （Berliner） traits Bollgard, Bollgard II, WideStrike, and non-Bt expressing cotton, Gossypium hirsutum L., for control of the noctuid complex of bollworm, Helicoverpa zea （Boddie）; fall armyworm, Spodopterafrugiperda （J.E. Smith）; beet armyworm, Spodoptera exigua （Htibner）; and cabbage looper, Trichoplusia ni （Hiibner）, were evaluated in the Lower Rio Grande Valley of Texas during 2005-2009. Noctuid larval survival and damage to leaves on non-Bt cotton were 3.6-fold greater than on Bollgard II or WideStrike cotton and 1.5-fold greater than on cotton varieties with the Bollgard trait. Transgenic cotton has reduced the need for conventional insecticides with benefits to human health and the environment. The revenue differences between Bt and conventional cotton for last four years in LRGV of Texas was 214.35/ha and profit about 94.95/ha. We also analyzed cotton noctuid losses between Bt and conventionally grown cotton in the USA summary of all states and Texas summary of all regions.