Avermectin
Mostrando 1-12 de 25 artigos, teses e dissertações.
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1. Avermectins residues in milk produced in the state of Pernambuco
Abstract Milk is a food widely consumed by the population, so it is important that it has adequate hygienic conditions and is free of chemical contaminants from various sources. This study aimed to evaluate the occurrence of avermectin residues in milk produced in the state of Pernambuco. The collections were performed in the dry and rainy season, being coll
Food Sci. Technol. Publicado em: 2020-12
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2. Efeitos letais e subletais de inseticidas sobre Tamarixia radiata (Waterston, 1922) (Hymenoptera:Eulophidae) / Lethal and sublethal effects of insecticides on Tamarixia radiata (Waterston, 1922) (Hymenoptera: Eulophidae)
Tamarixia radiata (Waterston, 1922) is one of the major biological control agents of Diaphorina citri Kuwayama, vector of huanglongbing, in Brazil. This parasitoid has been very effective due to the high parasitism rates, high dispersal ability and high establishment and adaptation rates in the field. However, the efficiency of T. radiata may be affected by
Publicado em: 2009
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3. Efeito de alguns inseticidas sobre a mariposa Plutella xylostella (L., 1758) (Lepidoptera, Plutellidae) por meio de iscas esterilizantes. / Inseticide effects on the diamondback moth Plutella xylostella (L., 1758) (Lepidoptera, Plutellidae) by using sterilizing baits.
Plutella xylostella (L., 1758) (Lepidoptera, Plutellidae), commonly known as diamondback moth, is an important pest of Brassicaceae in Brazil and several other countries. Its control is usually done with frequent applications of conventional insecticides. However, this approach is sometimes ineffective, besides some drawbacks such as environmental contaminat
Publicado em: 2008
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4. Parasitoses dos bovinos: atitudes de pecuaristas em Minas Gerais, Brasil
The objective of this work was to characterize animal management under conditioning factors of parasitosis control ways in cattle herds in the State of Minas Gerais, Brazil. From a total of 2500 interviews, 1289 were selected, relative to 555 municipalities of the 66 microregions of the State. Data were submitted to descriptive analysis and correspondence an
Publicado em: 2006
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5. Estudo do processo de eletrodegradação do ivermectin / Study of the electrodegradation of ivermectin
Ivermectin is widely used as an antiparasitic agent against endo and ectoparasites of animaIs and humans; it has a broad spectrum of activity at low dosage levels. Commercial products (Ivomec@, Eqvalan@, Cardomec@~ Mectizan~ usually contain 1% of Ivermectin in glycerol formulation. Ivermectin is a rnixture oftwo homologs containing more than 80% Avermectin B
Publicado em: 2004
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6. Avermectin B2 O-methyltransferase activity in "Streptomyces avermitilis" mutants that produce increased amounts of the avermectins.
The level of activity of avermectin B O-methyltransferase, the enzyme which catalyzes the conversion of avermectin B components to avermectin A components, was analyzed in a series of "Streptomyces avermitilis" mutants selected for increased production of the avermectins. In all of the mutants, increased avermectin production was accompanied by increased ave
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7. Genetic studies of avermectin biosynthesis in Streptomyces avermitilis.
A genetic recombination study of an industrial strain of Streptomyces avermitilis which produces avermectin is described. A genetic map has been constructed by analysis of haploid recombinants and linkage relationships of 16 marker loci. Fifteen avermectin-nonproducing mutants, produced by mutagenesis, were classified into two phenotypically different groups
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8. Involvement of glucose catabolism in avermectin production by Streptomyces avermitilis.
The addition of glucose in the early stage of fermentation suppressed not only avermectin production but also the activity of 6-phosphogluconate dehydrogenase in the pentose phosphate pathway. On the other hand, when glucose was added at the late stage of fermentation, suppression of avermectin formation and 6-phosphogluconate dehydrogenase activity was not
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9. Organization of the biosynthetic gene cluster for the polyketide anthelmintic macrolide avermectin in Streptomyces avermitilis
Analysis of the gene cluster from Streptomyces avermitilis that governs the biosynthesis of the polyketide anthelmintic avermectin revealed that it contains four large ORFs encoding giant multifunctional polypeptides of the avermectin polyketide synthase (AVES 1, AVES 2, AVES 3, and AVES 4). These clustered polyketide synthase genes responsible for avermecti
The National Academy of Sciences.
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10. Cloning and Analysis of a DNA Fragment Stimulating Avermectin Production in Various Streptomyces avermitilis Strains
To isolate a gene for stimulating avermectin production, a genomic library of Streptomyces avermitilis ATCC 31267 was constructed in Streptomyces lividans TK21 as the host strain. An 8.0-kb DNA fragment that significantly stimulated actinorhodin and undecylprodigiosin production was isolated. When wild-type S. avermitilis was transformed with the cloned frag
American Society for Microbiology.
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11. Avermectin B1a irreversibly blocks postsynaptic potentials at the lobster neuromuscular junction by reducing muscle membrane resistance.
Avermectin B1a, a macrocyclic lactone with broad spectrum anthelmintic activity, affects neuromuscular transmission in the lobster stretcher muscle. Perfusion of the muscle with 1-10 microgram of the drug per ml eliminates inhibitory postsynaptic potentials within a few minutes. Intracellularly recorded excitatory postsynaptic potentials are gradually reduce
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12. Methylation of demethylavermectins.
Demethylavermectins, which lack methyl groups on the oleandrose moiety, were fed to wild-type "Streptomyces avermitilis," which produces the normal avermectin components, and the bioconversion products were identified. The oleandrose units of the demethylavermectins were not methylated by the wild-type strain, but the C-5 of the macrolide ring was methylated