Entomopathogenic fungal activity against pupae and adult Haematobia irritans (Diptera: Muscidae)

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

Molecular Identification and Characterization of Ileal and Cecal Fungus Communities in Broilers Given Probiotics, Specific Essential Oil Blends, and Under Mixed Eimeria Infection

Broiler digestive tract fungal communities have gained far less scrutiny than that given corresponding bacterial communities. Attention given poultry-associated fungi have focused primarily on feed-associated toxin-producers, yeast, and yeast products. The current project focused on the use of pyrosequencing and denaturing gradient gel electrophoresis (DGGE) to identify and monitor broiler digestive fungal communities. Eight different treatments were included. Four controls were an Uninfected-Unmedicated Control, an Unmedicated-Infected Control, the antibiotic bacitracin methylene disalicylate plus the ionophore monensin as Positive Control, and the ionophore monensin alone as a Negative Control. Four treatments were two probiotics (BC-30 and Calsporin) and two specific essential oil blends (Crina Poultry Plus and Crina Poultry AF). All chickens except the Unmedicated-Uninfected Control were given, at 15 days of age, a standard oral Eimeria inoculum of sporulated oocysts. Ileal and cecal digesta were collected at pre-Eimeria infection at 14 days of age and at 7 days post-Eimeria infection at 22 days of age. Extracted cecal DNA was analyzed by pyrosequencing to examine the impact of diet supplements and Eimeria infection on individual constituents in the fungal community, while DGGE was used to compare more qualitative changes in ileal and cecal communities. Pyrosequencing identified three phyla, seven classes, eight orders, 13 families, 17 genera, and 23 fungal species. Ileal and cecal DGGE patterns showed fungal communities were clustered mainly into pre- and post-infection patterns. Post-infection Unmedicated-Uninfected patterns were clustered with pre-infection groups demonstrating a strong effect of Eimeria infection on digestive fungal populations. These combined techniques offered added versatility towards unraveling the effects of enteropathogen infection and performance enhancing feed additives on broiler digestive microflora.

Production of polysaccharidases in different carbon sources by Leucoagaricus gongylophorus Moller (Singer), the symbiotic fungus of the leaf-cutting ant Atta sexdens linnaeus

Leucoagaricus gongylophorus, the fungus cultured by the leaf-cutting ant Atta sexdens, produces polysaccharidases that degrade leaf components by generating nutrients believed to be essential for ant nutrition. We evaluated pectinase, amylase, xylanase, and cellulase production by L. gongylophorus in laboratory cultures and found that polysaccharidases are produced during fungal growth on pectin, starch, cellulose, xylan, or glucose but not cellulase, whose production is inhibited during fungal growth on xylan. Pectin was the carbon source that best stimulated the production of enzymes, which showed that pectinase had the highest production activity of all of the carbon sources tested, indicating that the presence of pectin and the production of pectinase are key features for symbiotic nutrition on plant material. During growth on starch and cellulose, polysaccharidase production level was intermediate, although during growth on xylan and glucose, enzyme production was very low. We propose a possible profile of polysaccharide degradation inside the nest, where the fungus is cultured on the foliar substrate.

Susceptibility of the ant-cultivated fungus Leucoagaricus gongylophorus (Agaricales : Basidiomycota) towards microfungi

The aim of this study was to select virulent strains of microfungi against Leucoagaricus gongylophorus, a symbiotic fungus cultivated by leaf-cutting ants. The results from in vitro assays showed that microfungal strains had a variable and significant impact on the colony development of L. gongylophorus. Specifically, Trichoderma harzianum, Escovopsis weberi CBS 810.71 and E. weberi A088 were more effective, inhibiting the L. gongylophorus colonies by 75, 68 and 67%, respectively (P < 0.05) after 15 days. Strain E. weberi A086 and Acremonium kiliense were less effective: 43 and 26%, respectively (P < 0.05). In spite of the current negative perspective of a microbiological control approach for these ants, the present work discusses the possibility of using mycopathogenic fungi for the control of these insects, and points out the importance of encouraging more studies in this area.

Yeasts isolated from a fungus-growing ant nest, including the description of Trichosporon chiarellii sp nov., an anamorphic basidiomycetous yeast

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relationship Between Population Size and Symbiont Fungus Culture Volume in Colonies of Acromyrmex balzani (Hymenoptera: Formicidae)

In order to quantify the population of Acromyrmex balzani Emery, 1890 nests and to verify whether the population dynamic of the colony is correlated with the symbiont fungus volume, the principal energy source of the colony, five nests located in grassland areas were evaluated. The nests were sprayed with neutral talcum powder to improve visualization and digging. The symbiont fungus and the entire population existent in the chambers were collected. The mean fungus volume and total nest population in excavated nests were, respectively, 74.76 ml and 1,095 individuals. Simple linear correlation analysis verified that the fungus volume grew proportionally to the number of individuals. Despite the correlation between fungus volume and population dynamic of colonies, the factors that determine this relationship are little known since other microorganisms live in association with the colony.

Growth of the Symbiotic Fungus of the Grass-cutting Ant Atta capiguara (Hymenoptera: Formicidae): Effect of Grass Extracts

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

Growth of populations and the fungus garden of Atta sexdens rubropilosa (Hymenoptera, Formicidae) response to foraged substrates

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

Application technology for the entomopathogenic nematodes Heterorhabditis indica and Steinernema sp. (Rhabditida: Heterorhabditidae and Steinernematidae) to control Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) in corn

O efeito de diversas tecnologias de aplicação foi avaliado sobre a concentração, viabilidade e eficácia dos juvenis infectantes dos nematóides Heterorhabditis indica Poinar, Karunakar & David (IBCB-n5) e Steinernema sp. (IBCB-n6) no controle da lagarta-do-cartucho Spodoptera frugiperda Smith na cultura do milho. Para o controle da lagarta-do-cartucho no terceiro estádio em placas de Petri foram necessários 280 juvenis infectantes de Steinernema sp., enquanto que 400 juvenis infectantes de H. indica controlaram apenas 75% das lagartas. Podem-se pulverizar os entomopatógenos, sem que haja perda significativa na sua concentração e viabilidade, com equipamentos que forneçam carga elétrica à calda, ponta centrífuga e pontas hidráulicas. Entretanto, o emprego de pulverizadores com pontas que requerem elementos filtrantes com malha igual a 100 resultou em decréscimo na concentração de juvenis infectantes de H. indica e Steinernema sp., de 28% e 53%, respectivamente. Os tensoativos organosiliconado e etoxilados não afetaram a viabilidade dos juvenis infectantes de Steinernema sp. Nos experimentos de pulverização em plantas de milho (V6) com Steinernema sp., doses equivalentes a até 288 milhões de juvenis infectantes por hectare, diluídos em volume de calda de até 800 L ha-1 com 0,01 % do tensoativo etoxilado, ou nesse volume seguido de exposição a chuva artificial (lâmina de água de 6 mm), não foram suficientes para o controle de S. frugiperda em casa-de-vegetação.

Structural characterization of Botryosphaeran: a (1 -> 3;1 -> 6)-beta-D-glucan produced by the ascomyceteous fungus, Botryosphaeria sp.

The exopolysaccharide, Botryosphaeran, produced by the ligninolytic, ascomycetcous fungus Botryosphaeria sp., was isolated from the extracellular fluid by precipitation with ethanol, and purified by gel permeation chromatography to yield a carbohydrate-rich fraction (96%) composed mainly of glucose (98%). Infra-red and C-13 NMR spectroscopy showed that all the glucosidic linkages were in the beta-configuration. Data from methylation analysis and Smith degradation indicated that Botryosphaeran was a (1 --> 3)-beta-(D)-glucan with approx 22% side branching at C-6. The products obtained from partial acid hydrolysis demonstrated that the side branches consisted of single (1 --> 6)-beta-linked glucosyl, and (1 --> 6)-beta-linked gentiobiosyl residues.[GRAPHICS](C) 2003 Elsevier Ltd. All rights reserved.

Comparison of Botryosphaeran production by the ascomyceteous fungus Botryosphaeria sp., grown on different carbohydrate carbon sources, and their partial structural features

The influence of glucose concentration and other carbohydrates (monosaccharides: fructose, galactose, mannose; polyols: mannitol and sorbitol; disaccharides: lactose, sucrose and commercial sucrose; and industrial sugarcane molasses) were compared as sole carbon sources for the production of Botryosphaeran, an exopolysaccharide (EPS) produced by Botryosphaeria sp. The optimum glucose concentration for EPS production was 50 g 1(-1). With the exception of mannitol, the fungus produced EPS on all carbon sources studied, with highest yields occurring with sucrose followed by glucose. All EPS showed exclusively glucose after acid hydrolysis and monosaccharide analysis. FTIR spectroscopy demonstrated the presence of beta-anomers indicating that all the EPS produced by Botryosphaeria sp. on the different carbon sources were essentially of the beta-D-glucan type.

Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

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

The adaptive potential of a plant pathogenic fungus, Rhizoctonia solani AG-3, under heat and fungicide stress

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of TLR-2 in the immune response in the infection induced by fungus Sporothrix schenckii

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

Microscopic evidence supports the hypothesis of high cellulose degradation capacity by the symbiotic fungus of leaf-cutting ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)