Neste trabalho avaliou-se a influência de fontes de carbono (FC) e composições de meio definido no crescimento celular e na produção do polissacarídeo PS14. Em batelada, testou-se como FC glicose, sacarose e frutose em diferentes concentrações. Testou-se também meios com ausência dos aminoácidos asparagina, ácido aspártico, fenilalanina, serina, alanina, treonina, triptofano, lisina e tirosina, das vitaminas/cofatores ácido fólico, piridoxamina, ácido p-aminobenzóico, <font face=\"Symbol\">b-NAD e riboflavina, além bem como da adição de maiores concentrações de aminoácidos identificados como importantes. Em cultivo contínuo foram avaliadas vazões específicas de alimentação (D) de 0,1h-1a 0,5h-1 e a influência das bases nitrogenadas. O meio com sacarose como FC, retirada dos aminoácidos e vitaminas citados e adição do dobro de glicina isoleucina, leucina, valina e o triplo de glutamina levou à maior produção de PS14 (441mg/L). Obteve-se a maior produtividade com D=0,4h-1e a maior quantidade de PS14 com adenina na concentração original no meio de cultura. / In this work we assessed the influence of different carbon sources (CS) and defined medium compositions on cell growth and polysaccharide PS14 production. In bath, glucose, sucrose and fructose were tested at different concentrations. Also, media were tested with absence of the amino acids: asparagine, aspartic acid, phenylalanine, serine, alanine, threonine, tryptophan, lysine, and tyrosine, and vitamins/cofactors: folic acid, pyridoxamine, p-aminobenzoic acid, riboflavin and <font face=\"Symbol\">b-NAD, besides the addition of higher concentration of amino acids identified as important. In continuous cultivation, dilution rates (D) from 0.1 h-1 to 0.5 h-1 were evaluated as well as the influence of nitrogenous bases. The medium containing sucrose as CS, absence of amino acids and vitamins and addition of twice glycine isoleucine, leucine, valine, and triple glutamine led to higher production of PS14 (441mg/L). D of 0.4 h-1 showed higher productivity and adenine in standard concentration produced greater amounts of PS14.

MSCAGR (Animal Science) / Department of Animal Science / The use of in vitro culture media and assisted hatching techniques remain a challenging obstacle to hatching of blastocyst-stage embryos. Mechanical, chemical, enzymatic thinning and laser assisted techniques have been used previously, but there is still a lack of information on its application and implication in livestock. The aim of this study was to compare the effect of two in vitro culture media ((Ham’s F10 and Tissue Culture Medium 199 (TCM-199)) and four assisted hatching techniques (mechanical, chemical, enzymatic and laser) on blastocyst formation and hatching rate using murine embryos as a model. The C57BL/6 and BALB/c mouse breeds were bred and raised until they reach maturity and then bred naturally to produce a hybrid F1 generation. The light in the breeder house was controlled at 14 hours light and 10 hours darkness. Feed and water were provided ad libitum for the mice. Mature female mice were super-ovulated using equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG). A total of 400 blastocysts were collected from the F1 generation and these were allocated equally for the four assisted hatching techniques (laser, mechanical, chemical and enzymatic) as well as a non-treated control group. The blastocysts were paired into a group of 10 and replicated 4-four times for each assisted hatching techniques and control group. The embryos were then cultured for 24 hours and the hatching of the embryos were observed. Hatched embryos were stained for blastomere counting. The general linear model (GLM) of statistical analysis software (SAS) version 9.4 was used to analyze the data. Assisted hatching techniques (laser, mechanical, enzymatic and chemical) yielded 46.86±37.12; 51.07±40.19; 39.05±35.83 and 33.32±37.50% of hatching, respectively under in vitro culture in Ham’s F10. There was a significant difference (p<0.05) observed between assisted hatching techniques using Ham’s F10 as culture medium. In the TCM-199, laser, mechanical, enzymatic and chemical assisted hatching techniques yielded 56.25±43.30; 52.55±35.50; 49.16±37.50 and 33.85±35.50%, respectively, with significant differences (p<0.05). However, the hatching rate of embryos for all techniques was higher when in vitro cultured in TCM-199 compared to those cultured in Ham’s F10, and statistically higher than the control group. In conclusion, laser assisted hatching technique is the best of the techniques to use to assist the hatching of murine embryos and TCM-199 is the best of the two in vitro culture media for the hatching percentage.

No description available.

The study of the aging process is the investigation as to how the passage of time affects cells, organs, and organisms. Aging is a very complex and incompletely understood phenomenon. This is reflected by the number of theories attributing aging to a variety of causative factors such as: (1) the somatic mutations occurring spontaneously or produced by ionizing radiation, which are thought to have some effect on again but are not responsible for the normal process; (2) the alteration of macromolecules as the cells of an organism age forming neoantigens and functioning in the autoimmune reactions; the Cross-linkage theory which maintains that large molecules necessary for life processes, such as deoxyribonucleic acid (DNA) and collagen are progressively immobilized in all cells and tissues by cross-linkage. Aging has also been studied in relation to the self-destructive “programmed death” characteristic of some parts of embryological development. Moreover, senescent changes involve different kinds of cells and tissues in the organism and therefore various mechanisms must occur. For example, the aging of postmitotic cells, such as neurons and cardiac cells probably proceeds by a different mechanism than the proliferating tissues, such as the skin, the gut lining, and the blood forming elements. It is apparent that there is probably no single aging process, but a series of aging processes which natural selection would tend to synchronize even if the causes were physiologically independent.

The purpose of this research was to examine the colonization process and relationship of physico-chemical parameters to diatom and protozoan communities colonizing polyurethane foam (PF) artificial substrates in lentic habitats. This was the first study to utilize multivariate techniques for comparison of protozoan and diatom communities The following hypotheses were examined in this study: 1. diatom and protozoan species accrual is similar because the organisms are approximately the same size and share similar ecological conditions, 2. protozoan assemblages are influenced by the physicochemical parameters of their environment, and 3. diatoms and photosynthetic protozoans are more closely related to the physico-chemical parameters of their environment than are the protozoans of all trophic groups. PF substrates were placed in the littoral zone of lentic habitats. Substrates were sampled through a time series and examined for their diatom and protozoan species' presence-absences. The first hypothesis was tested by using the MacArthur-Wilson equilibrium model and by fitting the data to the model by non·linear least squares regression. Protozoan species accrual fit the model in most cases, while diatom species accrual did not. The second part of the research dealt with five lentic habitats in northern lower Michigan which were sampled as described above and concurrent with organismal sampling several physico-chemical parameters were sampled. These environmental parameters included pH, alkalinity, conductivity, temperature, and concentrations of dissolved oxygen, chloride, silica, ammonia, and total and ortho-phosphate. Protozoan communities were examined using reciprocal averaging ordination. It was found that the bog and marsh had distinct communities, while the three lakes did not. Several physicochemical parameters and factors correlated significantly with axes generated by samples in species space. The final section tested the degree of relationship among diatoms, autotrophic protozoans, and protozoans to the physicochemical parameters and factors. pH had the highest correlations with the first axes for each group. Diatom communities had the greatest degree of relationship to the physico-chemical parameters, evidence for this is provided by the greatest number of correlations between ordination axes and the physico-chemical parameters and factors. / Ph. D. / incomplete_metadata

Emergent infectious diseases are a major driver of the accelerated rates of biodiversity loss that are being documented around the world. Global losses of amphibians provide evidence of this, especially those associated with chytridiomycosis, a lethal skin disease caused by the fungus Batrachochytrium dendrobatidis (Bd). Amphibian skin can harbor diverse bacterial communities that, in some cases, can inhibit the growth of Bd. Thus, there is interest in using skin bacteria as probiotics to mitigate Bd infections in amphibians. However, experiments testing this conservation approach have yielded mixed results, suggesting a lack of understanding about the ecology of these microbial communities. My dissertation research aimed to assess basic ecological questions in microbial ecology and to contribute to the development of probiotics using amphibian skin bacteria. First, to assess whether environmental conditions influence the function of amphibian skin bacterial communities, I conducted a field survey across low and high elevation populations of an amphibian host to assess their skin bacterial communities and metabolite profiles. I found that similar bacterial communities produced different metabolites at different locations, implying a potential functional plasticity. Second, since culturing is critical for characterizing bacteria, I aimed to identify the culture media (low vs high nutrient concentration) that recovers the most representative fraction of the amphibian skin bacterial community. I found that media with low nutrient concentrations cultured a higher diversity and recovered a more representative fraction of the diversity occurring on amphibian skin. I also determined that sampling more individuals is critical to maximize culture collections. Third, I assessed the diversity of the amphibian skin fungal community in relation to Bd infection across eight amphibian species. I determined that amphibian species was the most important predictor of fungal diversity and community structure, and that Bd infection did not have a strong impact. My dissertation highlights the importance of environmental conditions in the function of amphibian skin bacteria, expands our knowledge of the understudied fungal component of the amphibian skin microbiome, and complements current efforts in amphibian conservation. / Ph. D. / In light of the global losses of amphibian diversity due to, in part, the skin disease chytridiomycosis (caused by the fungus Batrachochytrium dendrobatidis [Bd]); the discovery that some amphibian-skin bacteria can inhibit Bd growth provides hope for amphibian conservation via their use as probiotics to control Bd infections. However, experiments testing these bacteria have yielded inconsistent results, suggesting a limited understanding about the factors influencing the diversity of amphibian-skin microbes and their ability to inhibit Bd. Also, efforts to identify effective candidates for probiotic therapy are still premature. Thus, my dissertation had an ecological emphasis and focused on complementing conservation efforts focused on probiotics. First, I assessed whether environmental conditions influence bacteriallyproduced products, which can have antifungal properties. Specifically, I surveyed low and highelevation populations of an amphibian species to assess the skin-bacteria and their products. I determined that, while skin bacterial communities were similar across an environmental gradient, their products differed, suggesting potential different antifungal properties. Second, I assessed the ability of different culture media types (low vs high nutrient concentrations) to grow a high portion and most representative fraction of the amphibian-skin bacteria. I found that culture media with low nutrient concentrations allowed the growth of a higher diversity of the bacteria occurring on the amphibian-skin, including the abundant members, and also determined that including a large number of amphibians is the best way to improve culture collections. Third, I assessed the fungal diversity occurring in the skin of different amphibian species and how it might response to Bd infections, and examined whether skin-fungi interact with co-occurring bacteria. I found that the amphibian species was the most important driver of the fungal diversity, and that Bd infection did not influence the diversity of these communities. Moreover, I identified the most diverse fungal phyla occurring in the amphibian-skin and determined that these fungi might interact with co-occurring bacteria. My dissertation contributes to our understanding about the influence of the environmental conditions in the amphibian-skin bacteria, expands our limited knowledge on the amphibian-skin fungi, and complement current amphibian conservation efforts.

The ability of mammary tissue from prepubertal bulls and heifers of beef and dairy breeds to respond to hormonal stimuli through synthesis and secretion of milk proteins was studied. Experimental animals were six to eight month old Angus and Holstein cattle. All subjects were injected with estradiol and progesterone for seven days and slaughtered on day 15. Mammary tissue was explanted and cultured for 96 h in basal medium (B) which contained hormones necessary for maintenance, or stimulatory medium (P), further supplemented with prolactin. Selected cultures were incubated for 24 h in B or P medium containing 3H-amino acids. Concentrations of non-labeled alpha-lactalbumin (Alac), 3H-Alac, and 3H-total protein (TP) were determined in media and in explant homogenates. Among cultures of bull mammary tissue, Angus explants secreted greater overall quantities of 3 H-TP and 3H-Alac than Holstein explants (p<.05). Secretion of Alac was also greater in Angus cultures at two of eight treatment periods (p<.01). Concentrations of all three protein fractions were likewise enhanced in homogenates of Angus explants for at least three of four treatment periods (p≤.05). Presence of prolactin in medium stimulated secretion of Alac (p<.005), and accumulation of all three fractions in explants (p<.10). Holstein heifer explants secreted more Alac at three of eight treatment periods than Angus explants (p<.0005). Overall secretion of ³H-TP and ³H-Alac also was elevated in Holstein over Angus females (p<.10), as were concentrations of all three fractions in homogenates (p≤.01). Presence of prolactin had no direct effect on any protein parameters in female tissue. I conclude that mammary tissue of immature bulls and heifers can be hormonally induced to express it's genetic merit for milk production (based on breed differences), through synthesis and secretion of milk proteins. Prolactin stimulated protein production in bulls but not in heifers. These findings indicate that similar methods of stimulating mammary tissue to produce milk proteins may be adaptable for commercial evaluation of genetic potential for milk production, especially in young bulls. / M.S.

Little is known concerning the production and significance of bacterial pigments. There is seemingly an open field for studying the effects produced by varying the nutritive content of culture media upon which organisms are grown. This has led to an especial interest in, and the purpose of this investigation.

A cana-de-açúcar (S. officinarum) é uma gramínea perene de grande importância na economia brasileira. Devido a isto, estudos relativos ao aprimoramento das condições de cultivo são de grande interesse, podendo ser uma destas bases um melhor conhecimento sobre as comunidades microbianas associadas à cana-de-açúcar. Sabe-se que a rizosfera é um ambiente de íntima interação entre as plantas e seus respectivos microbiomas, sendo esta relação intermediada pela exsudação radicular. Este estudo teve como objetivo realizar o cultivo de bactérias da rizosfera e do solo de cana-de-açúcar, sendo os isolados obtidos posteriormente caracterizados genética (BOX-PCR e sequenciamento parcial do gene 16S rRNA) e metabolicamente (BIOLOG®). Os resultados demonstraram que o número de bactérias cultiváveis na rizosfera é maior comparado ao solo, sendo que dentre os isolados destaca-se a maior afiliação taxonômica ao filo Proteobacteria (principalmente as classes &gamma;-proteobacteria e &beta;- proteobacteria). A análise de BOX-PCR mostrou uma grande diversidade genética, mesmo quando comparados isolados obtidos a partir do mesmo meio de cultivo, ou pertencentes ao mesmo grupo taxonômico. Em contrapartida, a análise de sequenciamento parcial do gene 16S rRNA mostrou que muitos isolados preservam grande similaridade do gene ribossomal analisado. A análise de perfil metabólico corroborou com os dados de BOX-PCR, onde isolados com afiliação taxonômica bastante correlata apresentaram capacidades distintas de utilizar as diversas fontes de carbono avaliadas. Por fim, esta diversidade metabólica se traduziu na obtenção de respostas distintas de isolados pertencentes aos mesmos gêneros bacterianos, isolados do solo ou da rizosfera, quando estes foram cultivados na presença de exsudatos radiculares. De maneira geral, este estudo demonstrou que as plantas de cana-de-açúcar podem influenciar o comportamento das comunidades bacterianas presentes no solo, e indicaram que existe uma grande diversificação dos organismos presentes na rizosfera, sendo a resposta a este ambiente diferenciada de forma independente da afiliação taxonômica dos isolados. / The sugarcane plant (S. officinarum) is a perennial gamineous with a great importance for the Brazilian economy. Due to this, studies related to the improvement of cultivation conditions are of great importance, indicating that one of these bases must contribute with the better knowledge about the microbial communities associated with sugarcane. It is known that the rhizosphere is an environment that hosts an intimate interaction between plants and their respective microbiomes, being it mediated by the roots exudates. This study aimed to cultivate bacterial isolates from soil and rhizosphere of sugarcane, followed by the genetic (BOX-PCR and partial sequencing of the 16S rRNA gene) and metabolic (BIOLOG&reg;) characterization of them. Results demonstrated higher numbers of cultivable bacteria in rhizosphere when compared to soil samples, with the prevalent affiliation of the isolates to the phylum Proteobacteria (specially with the classes &gamma;-proteobacteria and &beta;- proteobacteria). The BOX-PCR results showed a great genetic diversity, even when isolates obtained in the same culture medium or affiliated to the same taxa are compared. In counterpart, the analysis of the 16S rRNA gene sequence indicated that several isolates preserve high similarities in the ribosomal gene. The metabolic profiling results corroborated with the BOX-PCR data, which isolates highly correlated in the taxonomical analyses presented distinct capacities to use the carbon sources that were tested. At the end, this metabolic diversity was evidenced by the distinct behavior of isolates belonging to the same genera, isolated from soils or rhizosphere samples as well, when cultivated in the presence of roots exudates. In general, this study demonstrated that sugarcane plants can influence the behavior of bacterial communities present in soils, and indicated a great diversification of organisms present in the rhizosphere being the response to this environment very particular, regardless of the taxonomical affiliation of the isolates.

Considerando que os meios de cultura e as condições de incubação são os principais fatores para o sucesso do primo isolamento, além do método de descontaminação, quatro meios de cultura e três condições de incubação foram investigados. Noventa e sete amostras de lesões granulomatosas foram submetidas ao método de descontaminação com cloreto de 1-hexadecilpiridinio (HPC) a 1,5%, e semeadas em dois meios a base de ovo, Stonebrink e Löwenstein-Jensen com piruvato de sódio, e em dois meios a base de ágar, B83 e Middlebrook 7H11. Cada meio foi incubado a 37ºC por 90 dias em três condições de incubação, atmosfera com 10% de CO2, atmosfera normal e atmosfera com suposta tensão de CO2 obtida pela queima do algodão hidrófobo e fechamento do tubo com rolha de cortiça. O tipo de condição de incubação utilizado teve influência nos meios a base de ovo apenas no inicio da incubação (30 dias), mas nenhuma nos meios a base de ágar. A incubação em atmosfera com 10% de CO2 diminuiu o tempo de aparecimento da primeira colônia e aumentou o número de UFC. O meio B83 foi mais rápido no aparecimento das colônias e teve o maior sucesso de isolamento aos 30 dias, mas não houve diferença com os meios Stonebrink e Löwenstein-Jensen com piruvato, no sucesso de isolamento e número de UFC aos 60 e 90 dias. De acordo com os dados, em sete oportunidades houve isolamento de M. bovis apenas no meio de Stonebrink e em quatro apenas no B83, assim, sugere-se a utilização desses dois meios de cultura em paralelo, incubados em atmosfera com acréscimo de CO2 / Considering that the culture media and the incubation conditions are the main factors for the success of primary isolation, besides the decontamination procedure, four culture media and three incubation conditions were investigated. Ninety-seven samples of granulommatous lesions were submitted to the decontamination procedure by 1-hexadecylpyridinium chloride at 1,5% w/v, and inoculated on two egg-based media, Stonebrink and Löwenstein-Jensen with sodium pyruvate, and two agar-based media, B83 and Middlebrook 7H11. Each medium was incubated at 37ºC for 90 days in three incubation conditions, in air containing 10% CO2, in air, and in air with a supposed higher CO2 tension created by burning the hydrophobic cotton used to close the tubes and subsequently closing with a cork. The type of incubation condition used had influence on the egg-based media only at the beginning of incubation (30 days), but none on the agar-based media. The incubation in air containing 10% CO2 decreased the time to first appearance of colonies and increased the number of colonies. B83 medium showed a faster growth and detected more isolates at 30 days of incubation. However, there was no difference between B83, Stonebrink and Löwenstein-Jensen with pyruvate at 60 and 90 days of incubation. According to the data, seven M. bovis isolates grew only on Stonebrink and four only on B83, therefore, the use of both media, in parallel, incubated in air containing CO2 is suggested.