ABSTRACT Fungi are ubiquitous components of soil microbial communities, generally comprise the largest proportion of soil biomass. They can occur as filamentous forms or unicellular yeasts, in both, as free-living or symbionts. Next generation sequencing has allowed greater depth of the access to soil fungal diversity complementing culture-dependent results. In Brazil, the state of Minas Gerais is recognized for its mining activity, which modifies the vegetation cover and consequently the soil microbial communities. To describe the fungal community (total fungi and yeast) in a post-mining area, comparing natural and modified ecosystems, we used environmental metabarcoding of ITS2 region. We assessed four ecosystems, with different vegetation and levels of impact, ranging from none to high impact (Atlantic forest, Iron outcrops, Eucalyptus, and Grass). Sequence data were compared with culture data obtained from previous studies. The fungal communities (total fungi and yeast) were more similar between Eucalyptus and Atlantic Forest, while Grass and Iron outcrops ecosystems showed greater dissimilarity. Despite its modified state, Grass ecosystem presented the highest alpha diversity values. Yeasts represented a proportion of fungal communities ranging from 1.7 to 17 % of fungal sequences in soil. The Ascomycota:Basidiomycota ratio was higher for the total fungi analysis, while a greater proportion of Basidiomycota was observed with the yeast analysis. Grass ecosystem was the only exception, where a higher proportion of ascomycetous yeasts was detected. The yeast communities responded to the environmental stress caused by the mining activity, resulting in changes in the composition, mainly increasing the abundance of black yeasts. Saitozyma podzolica relative abundance obtained with ITS sequencing was coherent with the findings obtained with culture data. Despite greater diversity depth obtained by metabarcoding, sequence and culture data were complementary tools in describing the fungal soil community. This study contributes significantly to the inventory of yeast species in tropical and subtropical soils.

Nove fêmeas bovinas canuladas no rúmen alimentadas com diferentes fontes energéticas foram utilizadas para avaliar um preparado de anticorpos policlonais aviário contra bactérias ruminais específicas e monensina na diversidade da comunidade microbiana. O design experimental foi três quadrados latinos 3 x 3 distintos pela principal fonte energética na dieta [milho seco e moído, silagem de grão úmido de milho ou polpa cítrica]. Dentro de cada quadrado latino, os animais receberam um dos aditivos alimentares [controle, monensina ou preparado de anticorpos policlonais]. Cada período teve duração de 21 dias onde 20 dias foram utilizados para adaptação aos tratamentos e o último dia para colheita das amostras. A diversidade microbiana foi avaliada pela contagem de protozoários e pela técnica da eletroforese em gel com gradiente desnaturante. Anticorpos policlonais adicionado a polpa cítrica na dieta resultou em um aumento na contagem relativa de Isotricha o que pode indicar um efeito sobre esta população de ciliado ruminal. Em linhas gerais, no presente estudo, não foi possível determinar um padrão nas estruturas de amplificação das comunidades Bacteria e Archaea do conteúdo ruminal. A imunização passiva oral é uma tecnologia que surge como alternativa eficiente para a produção de aditivos alimentares. Novas pesquisas são ainda necessárias para melhor compreender seu mecanismo de ação.

Nine ruminally cannulated cows fed different energy sources were used to evaluate an avianderived polyclonal antibody preparation against specific ruminal bacteria and monensin on microbial community diversity. The experimental design was three Latin squares 3 x 3 distinguished by the main energy source in the diet [dry-ground corn grain, high moisture corn silage or citrus pulp]. Inside each Latin square, animals received one of the feed additives per period [control, monensin or polyclonal antibody preparation]. Each period lasted 21 days where 20 were used for treatments adaptation and the last one for sampling collection. Microbial diversity was evaluated by protozoa counts and denaturing gradient gel electrophoresis. Polyclonal antibodies plus citrus pulp (CiPu) addition in the diet resulted in an increase of relative counting of Isotricha protozoa that indicates a possible effect on this ruminal ciliate population. In general lines, in the present experiment, it was not possible to assign that there was a pattern in the structures of amplification of Bacteria and Archaea communities of the ruminal content. Oral passive immunization is a technology that arises as an effective alternative for feed additive production. Further research is still necessary to better understand its mechanisms of action.

Em 211 machos da raça Nelore, PO, foi estudada a associação entre os polimorfismos do gene do hormônio de crescimento bovino (bGH) e características reprodutivas. Para o estudo foram realizadas medições mensais da circunferência escrotal e concentração de testosterona dos 10 aos 16 meses de idade e, ainda foi calculada a taxa de crescimento testicular. O DNA foi amplificado por PCR e digerido com as enzimas de restrição Msp I e Hae III. Cada um dos polimorfismos obtidos apresentou dois alelos. Os aleleo D (0,85) e F (0,98) predominaram na população estudada. Não foram encontrados animais portadores do genótipo EE do polimorfismo bGH/Hae III. Houve associação significativa (P<0,05) entre o polimorfismo bGH/Msp I, a circunferência escrotal e o crescimento testicular após a puberdade e, ainda, entre o polimorfismo do bGH/Hae III e a concentração da testosterona na puberdade. Os resultados sugerem que os polimorfismos bGH/Msp I e bGH/Hae III poderiam ser considerados marcadores do desenvolvimento testicular e o aparecimento da puberdade. Pela importância das observações, em função do reduzido tamanho da amostra, os estudos devem prosseguir.

The polymorphism of the bovine growth hormone gene (bGH) was studied in 211 Nellore pure breed males for association with reproductive traits. Scrotal circumference and testosterone concentrations were collected monthly from 10 until 16 months of age. Additionally, testicular growth rates were calculated. DNA was amplified by PCR and digested using Msp I and Hae III restriction enzymes. Every polymorphism presented two alleles. The predominant alleles were D (0.85) and F (0.98), respectively, and genotype EE - bGH/Hae III was missing. Significant association (P<0.05) between bGH/Msp I polymorphism, scrotal circumference and testicular growth after puberty, as well as between bGH/Hae III and testosterone concentrations at puberty were detected. The results suggested that these association could be useful for selection, since bGH/Msp I and bGH/Hae III polymorphisms could be considered as markers for testicular development after puberty and onset of puberty, respectively.

O polimorfismo do gene do hormônio de crescimento bovino (bGH) foi estudado em 211 bovinos machos da raça Nelore, puros de origem (PO), a fim de observar as freqüências genotípicas e alélicas, e a possível associação com a característica peso. Para alcançar este objetivo, foram considerados os pesos ao nascer, à desmama e mensais dos 10 aos 16 meses de idade, e calculados os ganhos de peso do nascimento à desmama e da desmama aos 16 meses. Foi coletado sangue para extração do DNA e análise dos sítios polimórficos (RFLP) oriundos da digestão com as endonucleases Msp I (bGH/Msp I, 891 pb), Hae III (bGH/Hae III, 441 pb) e Alu I (bGH/Alu I, 427 pb). Para cada polimorfismo foram encontrados dois alelos, ocorrendo predominância dos alelos D, F e A, respectivamente. Foi observado o efeito do genótipo AA do bGH/Alu I sobre o ganho de peso da desmama até 15 meses de idade e do genótipo DD do bGH/Msp I sobre os ganhos de peso da desmama aos 14 e 15 meses. Os resultados sugerem que os polimorfismos bGH/Alu I e bGH/Msp I constituem marcadores, em potencial, da característica ganho de peso em animais jovens.

The polymorphism of the growth hormone gene (bGH) was studied in 211 Nellore pure breed bovine males to estimate the genotype and allelic frequencies and possible associations of the gene with weight traits. For this study, body weight data were collected at birth, weaning and monthly from 10 to 16 months of age. Additionally, weight gains from birth to weaning and weaning to 16 months of age were calculated. DNA was extracted from blood samples and the animals genotyped for Msp I (bGH/Msp I, 891 bp), Hae III (bGH/Hae III, 441 bp) and Alu I (bGH/Alu I, 427 bp) polymorphic sites. Every polymorphism presented two alleles. The predominant alleles were D, F and A, respectively. The effect of the bGH/Alu I AA genotype was observed on the weight gain from weaning to 15 months of age, and of the bGH/Msp I DD genotype from weaning to 14 and 15 months. The results suggest that bGH/Alu I and bGH/Msp I polymorphisms may be potential markers for the weight gain trait in young bulls.