Fungos melanizados associados a formigas cortadeiras (Formicidae: Tribo Attini)

Leafcutter ants are considered pests in agriculture for their impact in human crops, as they behave utilizing foliar fragments to raise their simbiont fungi (Agaricales: Lepiotaceae) inside their nest. Recent studies have noticed that other fungi may be associated to ants inside their nests, for instance, fungi with melanized wall, known by “dematiaceous”. Historically, many black fungi have been noticed as fitopathogens of many plant cultures with economic importance, highlighting dematiaceous ecological behavior importance in this study. This investigation had the purpose of amplifying ecological knowledge of this fungi, isolating and identificating dematiaceous fungi found in Attini nests, having the intention of understanding plant pathogens dispersion by ants. In this work, 66 isolates were characterized in the following genus: Aspergillus, Penicillium, Paecilomyces, Oxyporus, Rhodotorula, Bipolaris, Curvularia, Fusarium, Giberella, Paraphaeosphaeria, and Cladosporium. The genus Bipolaris, Curvularia, Fusarium and Giberella are known for their opportunistic behaviour, with some published human infections in literature. Fusarium is a notorious fitopathogen, with wide number of descriptions and studies involving pathogenicity development, biochemistry and genetics. The isolates outline is of phyto – associated (phytopathogens, endophytic or epiphitic), fulfilling this work intention in alarming fungi capacity of dispersal by ants. The comprehension of phytopathogenical processes may be clarified based on the knowledge of oportunistics fungi that may utilize ants bodies for their own dispersal. The identification of isolates with capacity of infecting humans brings out public health issues.

Microalgas na Produção de Biodiesel: Extração e Composição Lipídica

The uninterrupted rise in emission of greenhouse gases open way to the use of biofuels, due to politics that focus on fuel safe, clean and renewable. The use of microalgae for biodiesel production has been described as one of the most promising sources of biomass for biofuels. The aim of this study was to evaluate the extraction and lipid profile of the microalgae Dunaliella tertiolecta, Isochrysis galbana and Tetraselsim gracilis. The extractions were performed with solvents chloroform /methanol and petroleum ether. The lipid profile was analyzed by gas chromatography after transesterification.The petroleum ether showed more efficiency in the extraction, the best result obtained was in the microalgae D. tertiolecta with 19.52% of lipid. The lipid profile analysis indicated a biodiesel stable to oxidation and elevated viscosity

Cryptococcus: isolamento ambiental e caracterização bioquimica

Pós-graduação em Ciência Animal - FMVA

Growth and development time of subtropical Cladocera Diaphanosoma birgei Korinek, 1981 fed with different microalgal diets

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

Potential use of bioagents in the control of postharvest rot in melon

Rot caused by Fusarium pallidoroseum has had a severely negative impact on the export of melons from Brazil. Uncertainty regarding the health of the fruit due to the quiescent infection of the pathogen has led producers to use fungicides in the postharvest treatment of the fruit, thereby causing contamination and risking the health of consumers. Consequently, there is a demand for clean and safe natural technologies for the postharvest treatment of melons, including biological control. The present study aimed at evaluating bioagents for use in controlling Fusarium rot in 'Galia'melon. The following bioagents were evaluated: two isolates of Bacillus subtilis, B. licheniformis and a mixture of B. subtilis and B. licheniformis, as well as the yeasts Sporidiobolus pararoseus, Pichia spp., Pichia membranifaciens, P. guilliermondii, Sporobolomyces roseus, Debaryomyces hansenii and Rhodotorula mucilagenosa. Treatment with imazalil and water were used as controls. Two experiments were conducted in a completely randomised design with 10 replicates per treatment with four fruit per replicate; the disease incidence was evaluated in the first experiment, and the disease severity was evaluated in the second. Similarity analysis of the temporal evolution profiles of rot incidence caused by F. pallidoroseum allowed the evaluated treatments to be clustered into four groups. In the first experiment, the yeasts P. membranifaciens and D. hansenii produced results similar to that of the fungicide imazalil. The second experiment highlighted the yeasts P. guilliermondii and R. mucilaginosa. Electron microscopy studies confirmed that once applied to the fruit, the yeasts colonised the skin and damaged the pathogen mycelium; the action of the yeasts affected the mycelium of F. pallidoroseum, which had infected wounds on the fruit's surface. Bacillus spp. did not provide good disease control. These results demonstrated that yeasts have the potential to control postharvest rot caused by F. pallidoroseum in 'Galia'melon.

Cryptococcus: isolamento ambiental e caracterização bioquímica

Cryptococcosis is an opportunistic fungal infection caused by Cryptococcus yeasts, especially C. neoformans and Cryptococcus gattii. The fungus is found in substrates of animal and vegetable origin, and infection occurs through inhalation and seedlings present in the environment. The present study aimed to investigate the existence of microfocus Cryptococcus sp. from the environmental samples of Araçatuba city, São Paulo, featuring new niches, by decoupling the direct relationship between fungus and host in order to minimize the risk of contamination of man and animals, understanding the ecoepidemiology of Cryptococcus. Fifty samples from hollows and tree trunks were harvested (Cassia sp., Ficus sp., Caesalpinea peltophorides) from ten representatives in the urban perimeter. The samples were immediately sent to the Laboratory of Bacteriology and Mycology, Faculty of Veterinary Medicine Araçatuba - Unesp where they were processed and plated on Petri dishes containing agar seed Niger and Sabouraud dextrose agar with chloramphenicol, incubated at 30ºC for a period of no less than 5 days. Afterwards they were subimitted to biochemical tests: urease production, thermotolerance at 37°C and quimiotipagem in CGB agar (L- Canavanine-Glycine-Bromothymol blue). The results showed that 17 (34%) cultures were positive for Cryptococcus, 9 (18%) for Cryptococcus gattii and 8 (16%) for Cryptococcus neoformans. Other yeast correlated as Rhodotorula sp. and Candida sp. were isolated. We conclude that the infectious propagules of Cryptococcus are dispersed in nature and constitute an environmental microfocus, not necessarily being bound to a single host.

Eficácia e ecotoxicidade do diquat em mistura com fontes de cobre para controle de Ceratophyllum demersum e alga unicelular e filamentosa

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Leveduras patogênicas em fezes de aves de cativeiro: relação fenotípica e genotípica entre os isolados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eficácia biológica e feitos tóxicos de fontes de cobre e diquat para organismos aquáticos

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Ocorrência de fungos negros em ambientes domésticos

Black fungi are able to adapt to extreme environmental conditions, such as: high temperatures, the presence of toxic chemical substances and lack of nutrients. Besides, they are also potential pathogens to humans. The natural environment of many black fungi is still unknown and some studies are being conducted to evaluate the biodiversity of this group and their different habitats. This study aimed to isolate black fungi in domestic environments and facilities, such as toothbrushes, fridge sealing rubbers, bathroom strainers and divisions, windows, wall tiles and bath sponge. For the collection, material surfaces were scratched with a scalpel and the resulting fragments were sewed in Mycosel agar (DifcoTM), supplemented with actidione to inhibit the growth of highly-sporulating fungi. Plates were incubated at 25ºC for three weeks. The 46 isolated fungi were maintained on MA2% slants at 8ºC and cryopreserved at -80ºC. Fungal identification was performed through the analysis of macro and microscopic features and ITS rDNA sequencing. The following black fungi taxa were found: Ascomycota sp., Cladosporium spp., Dothideomycete sp., Exophiala alcalophila, Ochroconis mirabilis and Rhinocladiella atrovirens. Non-melanized fungi were also found, such as Geosmithia sp., Penicillium sp. and Rhodotorula mucilaginosa. The temperature tests showed that isolated black fungi were not able to grow at 37°C, however, this temperature proved to be fungistatic to 43% of them. According to literature, all black fungi isolated in this study are opportunistic pathogens and additional studies are necessary to evaluate the risk that these micro-organisms offer to health, once they were isolated from domestic environments

Population histories of right whales (Cetacea: Eubalaena) Inferred from Mitochondrial Sequence Diversities and Divergences of Their Whale Lice (Amphipoda: Cyamus)

Right whales carry large populations of three ‘whale lice’ (Cyamus ovalis, Cyamus gracilis, Cyamus erraticus) that have no other hosts. We used sequence variation in the mitochondrial COI gene to ask (i) whether cyamid population structures might reveal associations among right whale individuals and subpopulations, (ii) whether the divergences of the three nominally conspecific cyamid species on North Atlantic, North Pacific, and southern right whales (Eubalaena glacialis, Eubalaena japonica, Eubalaena australis) might indicate their times of separation, and (iii) whether the shapes of cyamid gene trees might contain information about changes in the population sizes of right whales. We found high levels of nucleotide diversity but almost no population structure within oceans, indicating large effective population sizes and high rates of transfer between whales and subpopulations. North Atlantic and Southern Ocean populations of all three species are reciprocally monophyletic, and North Pacific C. erraticus is well separated from North Atlantic and southern C. erraticus. Mitochondrial clock calibrations suggest that these divergences occurred around 6 million years ago (Ma), and that the Eubalaena mitochondrial clock is very slow. North Pacific C. ovalis forms a clade inside the southern C. ovalis gene tree, implying that at least one right whale has crossed the equator in the Pacific Ocean within the last 1–2 million years (Myr). Low-frequency polymorphisms are more common than expected under neutrality for populations of constant size, but there is no obvious signal of rapid, interspecifically congruent expansion of the kind that would be expected if North Atlantic or southern right whales had experienced a prolonged population bottleneck within the last 0.5 Myr.

Ocorrência de fungos negros em ambientes domésticos

Black fungi are able to adapt to extreme environmental conditions, such as: high temperatures, the presence of toxic chemical substances and lack of nutrients. Besides, they are also potential pathogens to humans. The natural environment of many black fungi is still unknown and some studies are being conducted to evaluate the biodiversity of this group and their different habitats. This study aimed to isolate black fungi in domestic environments and facilities, such as toothbrushes, fridge sealing rubbers, bathroom strainers and divisions, windows, wall tiles and bath sponge. For the collection, material surfaces were scratched with a scalpel and the resulting fragments were sewed in Mycosel agar (DifcoTM), supplemented with actidione to inhibit the growth of highly-sporulating fungi. Plates were incubated at 25ºC for three weeks. The 46 isolated fungi were maintained on MA2% slants at 8ºC and cryopreserved at -80ºC. Fungal identification was performed through the analysis of macro and microscopic features and ITS rDNA sequencing. The following black fungi taxa were found: Ascomycota sp., Cladosporium spp., Dothideomycete sp., Exophiala alcalophila, Ochroconis mirabilis and Rhinocladiella atrovirens. Non-melanized fungi were also found, such as Geosmithia sp., Penicillium sp. and Rhodotorula mucilaginosa. The temperature tests showed that isolated black fungi were not able to grow at 37°C, however, this temperature proved to be fungistatic to 43% of them. According to literature, all black fungi isolated in this study are opportunistic pathogens and additional studies are necessary to evaluate the risk that these micro-organisms offer to health, once they were isolated from domestic environments

Length-weight relationship for seven freshwater fish species from Brazil

The present study reports length-weight relationships for seven native freshwater fish species (Triportheus angulatus, Psectrogaster rhomboides, Prochilodus brevis, Leporinus piau, Cichlasoma orientale, Crenicichla menezesi, and Pimelodella gracilis) captured in a semiarid Brazilian reservoir located in the state of Rio Grande do Norte.

Study of photorespiration in marine microalgae through the determination of glycolic acid using hydrophilic interaction liquid chromatography

Determination of organic acids in intracellular extracts and in the cultivation media of marine microalgae aid investigations about metabolic routes related to assimilation of atmospheric carbon by these organisms, which are known by their role in the carbon dioxide sink. The separation of these acids was investigated by hydrophilic interaction liquid chromatography (HILIC) using isocratic elution with a mobile phase composed of 70: 30 v/v acetonitrile/20 mmol/L ammonium acetate buffer (pH 6.8) and detection at 220 nm. HILIC allowed the determinations of glycolic acid, the most important metabolite for the evaluation of the photorespiration process in algae, to be made with better selectivity than that achieved by reversed phase liquid chromatography, but with less detectability. The concentration of glycolic acid was determined in the cultivation media and in intracellular extracts of the algae Tetraselmis gracilis and Phaeodactylum tricornutum submitted to different conditions of aeration: (i) without forced aeration, (ii) aeration with atmospheric air, and (iii) bubbling with N(2). The concentration of glycolic acid had a higher increase as the cultures were aerated with nitrogen, showing higher photorespiratory flux than that occurring in the cultures aerated with atmospheric air.

Intracellular biosynthesis and removal of copper nanoparticles by dead biomass of yeast isolated from the wastewater of a mine in the brazilian Amazonia

In this study was developed a natural process using a biological system for the biosynthesis of nanoparticles (NPs) and possible removal of copper from wastewater by dead biomass of the yeast Rhodotorula mucilaginosa. Dead and live biomass of Rhodotorula mucilaginosa was used to analyze the equilibrium and kinetics of copper biosorption by the yeast in function of the initial metal concentration, contact time, pH, temperature, agitation and inoculum volume. Dead biomass exhibited the highest biosorption capacity of copper, 26.2 mg g(-1), which was achieved within 60 min of contact, at pH 5.0, temperature of 30°C, and agitation speed of 150 rpm. The equilibrium data were best described by the Langmuir isotherm and Kinetic analysis indicated a pseudo-second-order model. The average size, morphology and location of NPs biosynthesized by the yeast were determined by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). The shape of the intracellularly synthesized NPs was mainly spherical, with an average size of 10.5 nm. The X-ray photoelectron spectroscopy (XPS) analysis of the copper NPs confirmed the formation of metallic copper. The dead biomass of Rhodotorula mucilaginosa may be considered an efficiently bioprocess, being fast and low-cost to production of copper nanoparticles and also a probably nano-adsorbent of this metal ion in wastewater in bioremediation process