Papel de Syncephalastrum racemosum como antagonista do fungo cultivado pelas formigas cortadeiras

Currently, the major method for controlling leaf-cutting ants uses toxic baits containing the insecticide sulfluramide. Such compound presents harmful effects to the environment and to human health, which drive the community’s concerns towards new strategies for controlling these insects. Previous studies showed the occurrence of Syncephalastrum racemosum in nests of the leaf-cutting ants submitted to treatments using insecticides. In order to understand the role of S. racemosum in nests of leaf-cutting ants, the present work investigated the antagonism of S. racemosum towards the leaf-cutting ant-cultivar (Leucoagaricus gongylophorus). Using in vitro essays, we co-cultivated L. gongylophorus and S. racemosum (n= 6 lineages). For comparison, we also used the same setup to test one strain of Escovopsis weberi, since this fungus is considered a specialized parasite of the leaf-cutting ant cultivar. All S. racemosum strains inhibited the growth of L. gongylophorus (ANOVA 2 way, F= 23,61, P< 0,01). The same was observed for E. weberi. There were no significant difference between S. racemosum and E. weberi inhibition (Bonferroni test, P> 0,05). In addition, we verified that all S. racemosum strains colonized and sporulated over the fungus garden up to 96 h after garden fragments without workers were inoculated with spores suspensions. Similar results were observed on gardens that were inoculated with spores of E. weberi. The results indicate that S. racemosum act as antagonist of the leaf-cutting ant cultivar. The putative possibility for using S. racemosum as biological control agent of leaf-cutting ants is discussed in the present work

Anotação de 500 ESTs da saúva Atta laevigata

Leaf-cutting ants belonging to the genus Atta occur from the tropical to subtropical regions of the Americas. These insects are considered pests because they cause serious damage in agricultural areas. Among these, stands out Atta laevigata, species which the colony requires a huge amount of leaves to grow its symbiotic fungus which is the main food source of the nest. Thus, the study of the transcriptome of these ants becomes a useful tool, because it is possible to identify proteins potentially involved with their skills as insect pests and also those related to differences between the varieties present in the nests. In the present study we described results of the partial analysis of the transcriptome of the leaf-cutting ant pest A. laevigata, from cDNA sequences previously generated in the Laboratory of Evolution and Molecular (LEM). The results may also be used for molecular, ecological, metabolic and evolutionary studies about ants, and heterologous expression of important proteins as molecular targets for the control of some leafcutting agricultural pests.

Análise morfológica de operárias de Atta sexdens rubropilosa tratadas com thiamethoxam

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Purification and properties of polygalacturonase produced by thermophilic fungus Thermoascus aurantiacus CBMAI-756 on solid-state fermentation

Polygalacturonases are enzymes involved in the degradation of pectic substances, being extensively used in food industries, textile processing, degumming of plant rough fibres, and treatment of pectic wastewaters. Polygalacturonase (PG) production by thermophilic fungus Thermoascus aurantiacus on solid-state fermentation was carried out in culture media containing sugar cane bagasse and orange bagasse in proportions of 30% and 70% (w/w) at 45°C for 4 days. PG obtained was purified by gel filtration and ion-exchange chromatography. The highest activity was found between pH 4.5 and 5.5, and the enzyme preserved more than 80% of its activity at pH values between 5.0 and 6.5. At pH values between 3.0 and 4.5, PG retained about 73% of the original activity, whereas at pH 10.0 it remained around 44%. The optimum temperature was 60–65°C. The enzyme was completely stable when incubated for 1 hour at 50°C. At 55°C and 60°C, the activity decreased 55% and 90%, respectively. The apparent molecular weight was 29.3 kDa, Km of 1.58 mg/mL and Vmax of 1553.1μmol/min/mg. The presence of Zn+2, Mn+2, and Hg+2 inhibited 59%, 77%, and 100% of enzyme activity, respectively. The hydrolysis product suggests that polygalacturonase was shown to be an endo/exoenzyme.

Feed digestion of growing Saanen goats

Pós-graduação em Zootecnia - FCAV

Cinética de crescimento do fungo termófilo Myceliophthora thermophila M. 7.7 em cultivo no estado sólido

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Structure of importin-a from a filamentous fungus in complex with a classical nuclear localization signal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mitochondrial and peroxisomal population in post-pharyngeal glands of leaf-cutting ants after lipid supplementation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Natural enemies depend on remnant habitat size in agricultural landscapes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Liming in Growing Mango Cultivar Keitt in Production

The tropical soil acidity is one of the main limiting factors for crop productivity. This study aimed to evaluate the effects of application of limestone dose to soil fertility, nutritional status of the crop, and productivity and quality of the fruits of mango, cultivar Keitt. The study was carried out at Selviria, state of Mato Grosso Sul, Brazil, in a Typic Haplustox (pH in CaCl2=4.7), cultivated with mango cultivar Keitt grafted on Coquinho pattern in the production phase (13years old). Treatments were composed of limestone doses (0, 1.55, 3.10, 4.65, and 6.20tha(-1)), arranged in blocks at random with three repetitions. The limestone was applied and incorporated in the surface layer of 0 to 5cm deep in the total area. We evaluated the chemical attributes of the soil [pH, hydrogen (H+) aluminum (Al), calcium (Ca), magnesium (Mg), potassium (K), and sum of bases and base saturation] at 16 and 28months after liming (layer 0 to 20cm deep), the nutrition of plants at 12months after liming, and quality of the fruit in two crop years. Liming promoted improvements in soil chemical attributes, reflected in the nutritional status, productivity, and quality of mango fruit. Also, there was a linear effect with the application of lime dose on the productivity of the fruit, but after the second year of evaluation.

Different true-protein sources do not modify the metabolism of crossbred Bos taurus x Bos indicus growing heifers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of starch-based supplementation level combined with oil on intake, performance, and methane emissions of growing Nellore bulls on pasture

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative study of resistance to heat in two species of leaf-cutting ants

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Contribution of different segments of the gastrointestinal tract to digestion in growing Saanen goats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)