Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “biopesticide”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2004

Influence of the stabilisation of organic materials on their biopesticide effect in soils.

Some organic materials have shown a suppressive effect on several diseases induced by soilborne plant pathogens. We have carried out a laboratory experiment (microcosm) to ascertain the influence of the stabilisation process of sewage sludge on it biopesticide effect when Pythium ultimum or Phytophthora sp. were introduced to soil as pathogens for pea or pepper. When P. ultimum was introduced there was a 63.8% reduction in the weight of the stems grown in the control, 47.6% in the presence of sewage sludge, but only 24.7% with compost. The same biopesticide effect was evident from the weight of the roots. The biopesticide effect was also strong when compost was used as organic amendment in the presence of Phytophthora, as could be seen from stem and shoot weight and length. The data showed that the degree of stabilisation of the organic material (compost) had a positive influence on it biopesticide effect. The changes undergone by a soil after the addition of organic materials helped to explain the biopesticide effect of the amendment. The organic treatments reduced P. ultimum and Phytophthora sp. populations.

Analysis of Variance↗
PubMed1997

Insect chitinases: molecular biology and potential use as biopesticides.

Chitin, an insoluble structural polysaccharide that occurs in the exoskeletal and gut linings of insects, is a metabolic target of selective pest control agents. One potential biopesticide is the insect molting enzyme, chitinase, which degrades chitin to low molecular weight, soluble and insoluble oligosaccharides. For several years, our laboratories have been characterizing this enzyme and its gene. Most recently, we have been developing chitinase for use as a biopesticide to control insect and also fungal pests. Chitinases have been isolated from the tobacco hornworm, Manduca sexta, and several other insect species, and some of their chemical, physical, and kinetic properties have been determined. Also, cDNA and genomic clones for the chitinase from the hornworm have been isolated and characterized. Transgenic plants that express hornworm chitinase constitutively have been generated and found to exhibit host plant resistance. A transformed entomopathogenic virus that produces the enzyme displayed enhanced insecticidal activity. Chitinase also potentiated the efficacy of the toxin from the microbial insecticide, Bacillus thuringiensis. Insect chitinase and its gene are now available for biopesticidal applications in integrated pest management programs. Current knowledge regarding the molecular biology and biopesticidal action of insect and several other types of chitinases is described in this mini-review.

Amino Acid Sequence↗
PubMed2004

IgE sensitization to bacterial and fungal biopesticides in a cohort of Danish greenhouse workers: the BIOGART study.

BACKGROUND: The use of biopesticides in agriculture may implicate new risks of work-related allergic reactions. METHODS: Sera were tested from the BIOGART project, a longitudinal respiratory health study among >300 Danish greenhouse workers. IgE was measured by enzyme immunoassay (EIA) with extracts of biopesticide products containing Bacillus thuringiensis (BT) or Verticillium lecanii (Vert). RESULTS: Many sera had detectable IgE to BT (23-29%) or Vert (9-21%). IgE titers from the 2- and 3-year follow-up (n=230) were highly correlated, with discordant results in <15%. IgE titers to different BT, or to different Verticillium products were also significantly correlated (both r >0.70), whereas IgE anti-BT and anti-Verticillium showed no correlation at all. CONCLUSIONS: Exposure to these microbial biopesticides may confer a risk of IgE-mediated sensitization. In future research there is a need to identify allergenic components in the preparations, perform studies on non-exposed controls and analyze the relation between sensitization and health parameters.

Adult↗
PubMed2005

Baculoviruses-- re-emerging biopesticides.

Biological control of agricultural pests has gained importance in recent years due to increased pressure to reduce the use of agrochemicals and their residues in the environment and food. Viruses of a few families are known to infect insects but only those belonging to the highly specialized family Baculoviridae have been used as biopesticides. They are safe to people and wildlife, their specificity is very narrow. Their application as bioinsecticides was limited until recently because of their slow killing action and technical difficulties for in vitro commercial production. Two approaches for the wider application of baculoviruses as biopesticides will be implemented in future. In countries where use of genetically modified organisms is restricted, the improvements will be mainly at the level of diagnostics, in vitro production and changes in biopesticide formulations. In the second approach, the killing activity of baculoviruses may be augmented by genetic modifications of the baculovirus genome with genes of another natural pathogen. It is expected that the baculoviruses improved by genetic modifications will be gradually introduced in countries which have fewer concerns towards genetically modified organisms.

Animals↗
PubMed2005

Biopesticide effect of green compost against fusarium wilt on melon plants.

AIMS: The biopesticide effect of four green composts against fusarium wilt in melon plants and the effect of soil quality in soils amended with composts were assayed. METHODS AND RESULTS: The composts consisted of pruning wastes, with or without addition of coffee wastes (3/1 and 4/1, dry wt/dry wt) or urea (1000/1, dry wt/dry wt). In vitro experiments suggested the biopesticide effect of the composts against Fusarium oxysporum, while only the compost of pine bark and urea (1000/1dry wt/dry wt) had an abiotic effect. Melon plant growth with composts and F. oxysporum was one to four times greater than in the non-amended soil, although there was no significant decrease in the level of the F. oxysporum in the soil. The addition of composts to the soil also improved its biological quality, as assessed by microbiological and biochemical parameters: ATP and hydrolases involved in the P (phosphatase), C (beta-glucosidase) and N (urease) cycles. CONCLUSIONS: Green composts had greater beneficial characteristics, improved plant growth and controlled fusarium wilt in melon plants. These composts improve the soil quality of semi-arid agricultural soils. SIGNIFICANCE AND IMPACT OF THE STUDY: Biotic and abiotic factors from composts have been tested as responsible of their biopesticide activity against fusarium wilt.

Coffea↗
PubMed2002

Simultaneous production of biopesticide and alkaline proteases by Bacillus thuringiensis using sewage sludge as a raw material.

The simultaneous production of Bacillus thuringiensis (Bt) based biopesticide and proteases was studied using synthetic medium and wastewater sludge as a raw material. The studies were conducted in shake flask and computer controlled 15-L capacity fermentors. Measuring viable cell and spore counts, entomotoxicity and protease activity monitored the progress of the biopesticide production process. A higher viable cell count and spore count was observed in synthetic Soya medium, however, higher entomotoxicity and protease activity were observed in wastewater sludge medium. Thus, the wastewater sludge is a better raw material than commercial Soya medium for the biopesticides and enzyme production. The maximum entomotoxicity and protease activity observed in the fermentor was 9,332 IU/microL and 4.58 IU/mL, respectively. The proteases produced by Bt were also characterised. Two types of proteases were detected; neutral proteases with pH optimum 7.0 and alkaline proteases with pH optimum 10-11. Further, two types of alkaline proteases were detected; one having a pH and temperature optimum at 10 and 50 degrees C while the other at 11 and 70 degrees C. The protease thermal stability was found to increase in the presence of CaCl2, indicating the proteases were metalloproteases.

Animals↗
PubMed2004

Esterase-mediated tolerance to a formulation of the organophosphate insecticide monocrotophos in the entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuill: a promising biopesticide.

The use of biopesticides compatible with chemical pesticides is recommended in pest management as an effective and ecologically sound strategy. The entomopathogenic fungus Beauveria bassiana (Balsamo) Vuill, which is used as a biopesticide, was found to exhibit and lose tolerance to two organophosphorus insecticides widely used in Indian fields. The pattern of response is similar to the esterase-mediated organophosphate tolerance in aphids achieved through esterase gene duplication. Therefore the role of esterase in the tolerance exhibited by isolates of B. bassiana to the organophosphate, monocrotophos, was studied. Both the total soluble protein content and esterase activity were found to increase significantly in B. bassiana cultures that were able to grow in the presence of monocrotophos. With the hitherto established linkage between esterase overproduction and organophosphate tolerance in insects and the observed similarity in response of the insects and B. bassiana to the chemical, it is concluded that tolerance to monocrotophos in B. bassiana may be due to a mechanism similar to that operating in insects. Habituation of the fungus to monocrotophos to initiate expression of esterase gene may help in achieving compatibility between the two.

Adaptation, Physiological↗
PubMed2006

Genetic engineering of Periplaneta fuliginosa densovirus as an improved biopesticide.

The smoky-brown cockroach (Periplaneta fuliginosa) densovirus (PfDNV) has previously shown potential in urban pest control. To improve its efficacy as a biopesticide, the genome of PfDNV was engineered by inserting the insect-specific toxin gene BmKIT1 in the open reading frame encoding the major structural proteins. A green fluorescent protein (GFP) marker was tagged to the BmKIT1 at its C-terminus for in vivo imaging using Confocal laser scanning microscopy (CFSM). Using a virion rescue strategy, the genomes of recombinant and wild-type (wt) PfDNV were then cotransfected in P. fuliginosa nymphs. Reverse transcription PCR (RT-PCR) showed that the inserted BmkIT1 genes were expressed in the P. fuliginosa nymphs 48 h after cotransfection. CFSM and transmission electron microscopy also confirmed the generation of virus particles and expression of BmKIT1-GFP fusion protein in the cotransfected nymphs. The recombinant viruses remained infective to P. fuliginosa nymphs in feeding tests. Using the LT(50) bioassay method, the coninfection of the recombinant and wt PfDNV killed the P. fuliginosa nymphs approximate 32% faster than wt PfDNV only. This is the first report showing the improvement of engineered densovirus for the potential application of biopesticide.

Animals↗
PubMed2005

Bioconversion of industrial wastewater and wastewater sludge into Bacillus thuringiensis based biopesticides in pilot fermentor.

Starch industry wastewater (SWW), slaughterhouse wastewater (SHWW) and secondary sludges from three different wastewater treatment plants (Jonquière--JQS, Communauté Urbaine de Québec--CUQS and Black lake-BLS) were used as raw materials for the production of Bacillus thuringiensis (Bt) based biopesticides in a pilot scale fermentor (100 L working volume). The slaughterhouse wastewater exhibited the lowest Bt growth and entomotoxcity (Tx) potential (measured against spruce budworm) due to low availability of carbon, nitrogen and other nutrients. Performance variation (growth, sporulation, proteolytic activity and Tx potential) within the three types of sludges was directly related to the availability of nitrogen and carbohydrates, which could change with sludge origin and methods employed for its generation. The Tx potential of Bt obtained in different secondary sludges (JQS: 12 x 10(9) SBU/L; CUQS: 13 x 10(9) SBU/L and BLS: 16 x 10(9) SBU/L) and SWW (18 x 10(9) SBU/L) was higher than the soybean based synthetic medium (10 x 10(9) SBU/L). The maximum protease activity was obtained in CUQ secondary sludge (4.1 IU/mL) due to its high complex protein concentration. Nevertheless, high carbohydrate concentration in SWW repressed enzyme production. The secondary sludges and SWW were found to be suitable raw materials for high potency Bt biopesticide production.

Agriculture↗
PubMed2005

Synergistic interaction between Beauveria bassiana- and Bacillus thuringiensis tenebrionis-based biopesticides applied against field populations of Colorado potato beetle larvae.

Commercial biopesticides based on the fungal pathogen Beauveria bassiana strain GHA and the bacterial pathogen Bacillus thuringiensis tenebrionis were applied alone and in combination (tank mixed) against larval populations of the Colorado potato beetle, Leptinotarsa decemlineata, in small plots of potatoes over three field seasons. Interactions between the two products were evaluated in terms of pest-control efficacy. B. bassiana (formulated as Mycotrol) was applied at low and medium label rates of 1.25 and 2.5 x 10(13) conidia/ha, and B. thuringienis (formulated as Novodor) was applied at low and high label rates of 40.3 and 120.8 x 10(6) Leptinotarsa units/ha. Two weekly applications of the bacterial pesticide alone provided 50-85% control of beetle larvae within 14 days after the initial application, while applications of the mycopesticide alone produced no greater than 25% control. Maximum control, in nearly all tests, was produced by the combination of the two products. The combined treatments produced a statistically significant 6-35% greater reduction in larval populations than would have been predicted had the two biopesticides acted independently. This low-level synergistic interaction was observed during all field seasons and resulted from combinations at all rates, including, in one of two tests, the low rates of each product. These results indicate that B. thuringiensis and B. bassiana have strong potential for integrated biologically based management of Colorado potato beetle.

Animals↗
PubMed2005

Sludge based Bacillus thuringiensis biopesticides: viscosity impacts.

Viscosity studies were performed on raw, pre-treated (sterilised and thermal alkaline hydrolysed or both types of treatment) and Bacillus thuringiensis (Bt) fermented sludges at different solids concentration (10-40 g/L) for production of biopesticides. Correlations were established among rheological parameter (viscosity), solids (total and dissolved) concentration and entomotoxicity (Tx) of Bt fermented sludges. Exponential and power laws were preferentially followed by hydrolysed fermented compared to raw fermented sludge. Soluble chemical oxygen demand variation corroborated with increase in dissolved solids concentration on pre-treatments, contributing to changes in viscosity. Moreover, Tx was higher for hydrolysed fermented sludge in comparison to raw fermented sludge owing to increased availability of nutrients and lower viscosity that improved oxygen transfer. The shake flask results were reproducible in fermenter. This study will have major impact on selecting fermentation, harvesting and formulation techniques of Bt fermented sludges for biopesticide production.

Animals↗
PubMed2003

Biopesticides.

The term 'biopesticide' encompasses a broad array of microbial pesticides, biochemicals derived from micro-organisms and other natural sources, and processes involving the genetic incorporation of DNA into agricultural commodities that confer protection against pest damage (plant-incorporated protectants). Some microbial pesticides, such as Bacillus thuringiensis, have a long history of safe and effective use as a biological insecticide. More recent developments in microbial pest control include the utilisation of other bacterial and fungal species that may competitively inhibit the growth of pathogenic and toxigenic micro-organisms on important agricultural commodities. The use of microbes and their gene products introduces additional considerations to the toxicological dose-response relationship, including a need to determine the plausibility of infectious and immunological effects in association with human exposure to these biopesticides in food or the environment. Studies of substantial equivalence suggest that foods currently derived from plant-incorporated protectants are not likely to differ from conventional foods. However, there is general consensus that the scientific methods to assess risks from genetically modified foods and micro-organisms will continue to evolve in the future.

Agriculture↗
PubMed2001

Effect of surface active agents on the production of biopesticides using wastewater sludge as a raw material.

Effect of surface active agents on the production of Bacillus thuringiensis based biopesticides using secondary wastewater sludge as a raw material was studied. The experiments were conducted in a shake flask and nine different commercial surface active agents were used at a concentration of 0.2% (v/v). The sludge samples after addition of surface active agents were sterilised at 121 degrees C for 30 min. The progress of biopesticide production was monitored by measuring viable cells and viable spores counts. The entomotoxicity was determined through bioassay against 3rd instar larvae of spruce budworm. ATPLUS 522, Tween 80 and Tween 85 increased the entomotoxicity potential in comparison to the control. The highest increase of 24% in entomotoxicity was observed when sludge was fortified with Tween 80.

Animals↗
PubMed2003

Production of biopesticides using wastewater sludge as a raw material--effect of process parameters.

Production of Bacillus thuringiensis (Bt) based biopesticide was studied using hydrolysed or raw wastewater sludge as a raw material. The sludge hydrolysis was carried out at different pH (2, 4 and 6). The sludge after hydrolysis was sterilised at 121 degrees C for 30 minutes. The effect of temperature, pH and agitation speed on growth and toxin production was also investigated. The pH in the shake flask was controlled by adding 0.1 M TRIS buffer. The progress of the biopesticide production process was monitored by measuring viable cell count (VC), spore count (SC) and entomotoxicity (Tx). The entomotoxicity was measured against spruce budworm. Control of pH substantially increased the entomotoxicity of the final product. Increased agitation speed resulted in higher VC, SC and Tx values.

Animals↗
PubMed2026

Evaluation of the effects of domestic tomato processing on biopesticide residue using natural deep eutectic solvents (NADES) extractions.

The present study evaluated the fate of fourteen botanical biopesticides in processed tomato samples. Various processing methods were employed, including washing, dehydration, and the preparation of juice and sauce. The extraction was performed using more sustainable techniques, aimed at minimizing the environmental impact of conventional organic solvents by substituting them with natural deep eutectic solvents (NADES). Solid-liquid extraction (SLE) and dispersive liquid-liquid microextraction with solidification of floating organic drop (DLLME-SFOD) were utilized for solid and liquid tomato samples, respectively. The NADES used was choline chloride:2,3-butanediol (ChClBt) at a 1:4&#xa0;molar ratio for both techniques, resulting in recovery values ranging from 69.2 to 106.2% for SLE, and extraction efficiencies reaching up to 46.2% for DLLME-SFOD. The impact of these processes was evaluated employing the processing factor (PF), yielding PF values of less than 1 in all cases. Compounds as pyrethrins, azadirachtin, and rotenone persisted after processing, posing a potential consumer risk.

Solanum lycopersicum↗
PubMed1995

An examination of the potential "genotoxic" carcinogenicity of a biopesticide derived from the neem tree.

Structural analyses of azadirachtin, a promising biopesticide recently introduced into the United States, indicates that this natural product has the potential for acting as a "genotoxic" carcinogen. In view of the fact that genotoxic carcinogens are regarded as presenting a potential carcinogenic risk to humans, the present finding suggests that the possible metabolism of azadirachtin to DNA-reactive products be evaluated experimentally.

Animals↗
PubMed2004

Scale-up of biopesticide production processes using wastewater sludge as a raw material.

Studies were conducted on the production of Bacillus thuringiensis (Bt)-based biopesticides to ascertain the performance of the process in shake flasks, and in two geometrically similar fermentors (15 and 150 l) utilizing wastewater sludge as a raw material. The results showed that it was possible to achieve better oxygen transfer in the larger capacity fermentor. Viable cell counts increased by 38-55% in the bioreactor compared to shake flasks. As for spore counts, an increase of 25% was observed when changing from shake flask to fermentor experiments. Spore counts were unchanged in bench (15 l) and pilot scale (5.3-5.5 e(+08) cfu/ml; 150 l). An improvement of 30% in the entomotoxicity potential was obtained at pilot scale. Protease activity increased by two to four times at bench and pilot scale, respectively, compared to the maximum activity obtained in shake flasks. The maximum protease activity (4.1 IU/ml) was obtained in pilot scale due to better oxygen transfer. The Bt fermentation process using sludge as raw material was successfully scaled up and resulted in high productivity for toxin protein yield and a high protease activity.

Animals↗
PubMed2005

Effect of biopesticides on the lactate dehydrogenase (LDH) of the rice leaffolder, Cnaphalocrocis medinalis (Guenée) (Insecta: Lepidoptera: Pyralidae).

The effects of bacterial toxins (Bacillus thuringiensis) and botanical insecticides (Azadirachta indica and Vitex negundo) on lactate dehydrogenase (LDH) activity in Cnaphalocrocis medinalis (Guenée) (the rice leaffolder) were evaluated. Bacterial toxins and botanical insecticides affected the LDH activity individually and in combination. When they were combined, the effect was more severe at low concentration. There was a decrease in enzyme activity over controls at all concentrations tested. The combined effect of the three biopesticides resulted in a considerable decrease in enzyme activity, indicating strong enzyme inhibition. Clear dose-response relationships were established with respect to enzyme activity.

Animals↗