RESUMO
In recent years, there has been an increase in the number of diseases caused by bacterial, fungal, and viral infections. Infections affect plants at different stages of agricultural production. Depending on weather conditions and the phytosanitary condition of crops, the prevalence of diseases can reach 70-80% of the total plant population, and the yield can decrease in some cases down to 80-98%. Plants have innate cellular immunity, but specific phytopathogens have an ability to evade that immunity. This article examined phytopathogens of viral, fungal, and bacterial nature and explored the concepts of modern plant protection, methods of chemical, biological, and agrotechnical control, as well as modern methods used for identifying phytopathogens.
RESUMO
Using chromatography on different matrixes, three beta-glucosidases (120, 116, and 70 kDa) were isolated from enzymatic complexes of the mycelial fungi Aspergillus japonicus, Penicillium verruculosum, and Trichoderma reesei, respectively. The enzymes were identified by MALDI-TOF mass-spectrometry. Substrate specificity, kinetic parameters for hydrolysis of specific substrates, ability to catalyze the transglucosidation reaction, dependence of the enzymatic activity on pH and temperature, stability of the enzymes at different temperatures, adsorption ability on insoluble cellulose, and the influence of glucose on catalytic properties of the enzymes were investigated. According to the substrate specificity, the enzymes were shown to belong to two groups: i) beta-glucosidase of A. japonicus exhibiting high specific activity to the low molecular weight substrates cellobiose and pNPG (the specific activity towards cellobiose was higher than towards pNPG) and low activity towards polysaccharide substrates (beta-glucan from barley and laminarin); ii) beta-glucosidases from P. verruculosum and T. reesei exhibiting relatively high activity to polysaccharide substrates and lower activity to low molecular weight substrates (activity to cellobiose was lower than to pNPG).
Assuntos
Proteínas Fúngicas/química , Proteínas Fúngicas/isolamento & purificação , Fungos/enzimologia , beta-Glucosidase/química , beta-Glucosidase/isolamento & purificação , Estabilidade Enzimática , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fungos/química , Fungos/genética , Hidrólise , Cinética , Especificidade por Substrato , beta-Glucosidase/genética , beta-Glucosidase/metabolismoRESUMO
Two alpha-galactosidases were purified to homogeneity from the enzymatic complex of the mycelial fungus Penicillium canescens using chromatography on different sorbents. Substrate specificity, pH- and temperature optima of activity, stability under different pH and temperature conditions, and the influence of effectors on the catalytic properties of both enzymes were investigated. Genes aglA and aglC encoding alpha-galactosidases from P. canescens were isolated, and amino acid sequences of the proteins were predicted. In vitro feed testing (with soybean meal and soybean byproducts enriched with galactooligosaccharides as substrates) demonstrated that both alpha-galactosidases from P. canescens could be successfully used as feed additives. alpha-Galactosidase A belonging to the 27th glycosyl hydrolase family hydrolyzed galactopolysaccharides (galactomannans) and alpha-galactosidase C belonging to the 36th glycosyl hydrolase family hydrolyzed galactooligosaccharides (stachyose, raffinose, etc.) of soybean with good efficiency, thus improving the digestibility of fodder.
Assuntos
Proteínas Fúngicas/química , Penicillium/enzimologia , alfa-Galactosidase/química , Ração Animal , Animais , Cátions Bivalentes/química , Estabilidade Enzimática , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/metabolismo , Galactose/química , Concentração de Íons de Hidrogênio , Cinética , Metais/química , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Temperatura , alfa-Galactosidase/isolamento & purificação , alfa-Galactosidase/metabolismoRESUMO
Pectin lyase A (molecular weight 38 kD by SDS-PAGE, pI 6.7) was purified to homogeneity from culture broth of the mycelial fungus Penicillium canescens using chromatographic techniques. During genomic library screening, the gene encoding pectin lyase A from P. canescens (pelA) was isolated and sequenced, and the amino acid sequence was generated by applying the multiple alignment procedure (360 residues). A theoretical model for the three dimensional structure of the protein molecule was also proposed. Different properties of pectin lyase A were investigated: substrate specificity, pH- and temperature optimum of activity, stability under different pH and temperature conditions, and the effect of Ca2+ on enzyme activity. In the course of the laboratory trials, it was demonstrated that pectin lyase A from P. canescens could be successfully applied to production and clarification of juice.
Assuntos
Espaço Extracelular/enzimologia , Proteínas Fúngicas/química , Penicillium/enzimologia , Polissacarídeo-Liases/isolamento & purificação , Polissacarídeo-Liases/metabolismo , Sequência de Aminoácidos , Bebidas , Cálcio/farmacologia , Cromatografia por Troca Iônica , DNA Fúngico/química , DNA Fúngico/genética , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Frutas/enzimologia , Frutas/metabolismo , Proteínas Fúngicas/genética , Concentração de Íons de Hidrogênio , Hidrólise/efeitos dos fármacos , Focalização Isoelétrica , Dados de Sequência Molecular , Pectinas/metabolismo , Penicillium/genética , Polissacarídeo-Liases/genética , Conformação Proteica , Alinhamento de Sequência , Análise de Sequência de DNA , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , TemperaturaRESUMO
A new enzyme preparation of fungal pectin lyase (EC 4.2.2.10) was shown to be useful for the production of cranberry juice and clarification of apple juice in the food industry. A comparative study showed that the preparation of pectin lyase is competitive with commercial pectinase products. The molecular weight of homogeneous pectin lyase was 38 kDa. Properties of the homogeneous enzyme were studied. This enzyme was most efficient in removing highly esterified pectin.
Assuntos
Bebidas , Proteínas Fúngicas/química , Penicillium/enzimologia , Polissacarídeo-Liases/química , Biotecnologia/métodos , Indústria de Processamento de Alimentos , Proteínas Fúngicas/isolamento & purificação , Malus/química , Polissacarídeo-Liases/isolamento & purificação , Vaccinium macrocarpon/químicaRESUMO
A fragment of Penicillium canescens genomic DNA carrying the xlnR gene coding for a translational activator of xylanolytic genes was isolated. It was demonstrated that a loss of this function in genetically modified transformants resulted in a drastic decrease in the production of P. canescens major xylanases and had a negative effect on the syntheses of several other extracellular xylanases. An increase in the dose of the xlnR gene elevated the xylanolytic activity as well as the activities of a number of other auxiliary enzymes involved in xylan degradation. The activities of two P. canescens major secreted enzymes--beta-galactosidase and alpha-L-arabinofuranosidase-appeared weakly dependent on the translational activator xlnR.
Assuntos
Regulação Enzimológica da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Penicillium/enzimologia , Transativadores/fisiologia , Xilosidases/biossíntese , Sequência de Aminoácidos , Sequência de Bases , Deleção de Genes , Dosagem de Genes , Genes Fúngicos , Genoma Fúngico , Glicosídeo Hidrolases/biossíntese , Glicosídeo Hidrolases/genética , Dados de Sequência Molecular , Penicillium/genética , Transativadores/genética , Transformação Genética , Xilanos/metabolismo , Xilosidases/genéticaRESUMO
Specialist gynecology care practice development in a center of consultation and diagnosis with more than 15,000 women beneficiaries in its books and 26 military clinics for consultation services.