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Produção de ácido indol acético in vitro por Torulaspora globosa
(Universidade Federal de São Carlos, 2017-05-02) Albertini, Jéssica; Rosa-Magri, Márcia Maria; https://lattes.cnpq.br/4166319985147604; https://lattes.cnpq.br/7803960030368793
The indole acetic acid (IAA) is a phytohormone capable of providing fast responses to plant development such as cell elongation and differentiation and division of cells. It is known that exist in the rhizosphere there are yeasts capable of assisting the plant development by the IAA production. In this study, the objective was isolate yeasts of the rhizosphere and select lineages capable of producing IAA; the selected lineage was evaluated for the influence of temperature, pH, agitation, carbon and nitrogen on the production of IAA. For isolation, corn rhizosphere and sugarcane were sampled from the campus area of UFSCar, Araras/SP. The samples were plated on YEPD medium, Sabouraud and BDA. The lineages were selected using colorimetric methodology, with Salkowsky reagent. The best results were evaluated for the influence of factors in the production of AIA, through experimental planning with multivariate analysis. Six yeast strains were isolated; the strain 6S01, identified as Torulaspora globosa, was selected. The results of the multivariate analysis show that among the studied factors, which significantly affected the production of IAA were pH, agitation and nitrogen. The pH showed the greatest influence on production, because it affected significantly at all times evaluated; the highest recorded production values were obtained in the treatment in which the initial pH of the medium was adjusted to 9,0. The highest yields occurred between 24 and 48 hours of incubation, and the maximum production was 217,73 μg/mL. It was observed that, in the tests in which there was no addition of nitrogen source in the culture medium, the production was higher; probably tryptophan provided as a precursor molecule of AIA synthesis was used by tthe yeast as a nitrogen source and was better absorbed in the absence of other sources of the nutrient. It is concluded that the yeast T. globosa (6S01), isolated from maize rhizosphere presents capacity of high production of IAA, with potential for large scale production; the best conditions for the production are in the absence of nitrogen source and in alkaline medium.
Solubilização in vitro de fosfato por Torulaspora globosa
(Universidade Federal de São Carlos, 2017-05-02) Rocha, Renata Kühl; Rosa-Magri, Márcia Maria; ; https://lattes.cnpq.br/3962441453324220
Soil is an environment with great microbial diversity. Filamentous fungi and bacteria have been known for decades for the ability to stimulate plant development. Recently, studies have shown that yeasts are also capable of benefiting plants, for example, through the solubilization of inorganic phosphates. This work aims at a better understanding of the ability of rhizospheric yeasts in the solubilization of tricalcium phosphate. It also aims to study the influence of factors (pH, temperature and agitation) in the process. Initially, isolates of corn and sugarcane rhizosphere yeasts were made. The isolates were evaluated for the ability to solubilize tricalcium phosphate in solid medium BDYA. The isolate with the highest solubilization capacity was identified and evaluated for the solubilization capacity of tricalcium phosphate in NBRIP liquid medium at different temperature levels (20, 25 and 30 ° C), initial pH (3, 5 and 7) and agitation (0, 100, 150 and 200 rpm). Solubilization evaluations were also performed at 24-hour intervals, ranging from 1 to 7 days. Six isolates were obtained. All presented a positive result for solubilization. The yeast 6S01 (Torulaspora globosa) had the highest solubilization capacity. After five days, T. globosa solubilized 26 to 35% of the total phosphorus in the NBRIP culture medium. There was no significant difference for any of the environmental parameters tested. Assays performed in periods of 1 to 7 days showed that the yeast solubilized a maximum amount of phosphorus in 48 hours (42%). This makes it interesting for industrial and agricultural applications, since it has a fast solubilization process and can be used in a wide range of conditions. It was possible to understand that a higher cell growth is not related to the efficiency in the solubilization, and that acidification of the medium may be one of the main mechanisms used by yeast in the in vitro solubilization of tricalcium phosphate.
Coloração de Arestas em Grafos Split-Comparabilidade
(Universidade Federal de São Carlos, 2017-05-02) Cruz, Jadder Bismarck de Sousa; Almeida, Sheila Morais de; https://lattes.cnpq.br/9151881548763857; Silva, Cândida Nunes da; https://lattes.cnpq.br/6019111128413167; https://lattes.cnpq.br/2157434731256503
Let G = (V, E) be a simple and undirected graph. An edge-coloring is an assignment of colors to the edges of the graph such that any two adjacent edges receive different colors. The chromatic index of a graph G is the smallest number of colors such that G has an edge-coloring. Clearly, a lower bound for the chromatic index is the degree of the vertex of higher degree, denoted by ?(G). In 1964, Vizing proved that chromatic index is ?(G) or ?(G) + 1. The Classification Problem is to determine if the chromatic index is ?(G) (Class 1 ) or if it is ?(G) + 1 (Class 2 ). Let n be number of vertices of a graph G and let m be its number of edges. We say G is overfull if m > (n-1) 2 ?(G). Every overfull graph is Class 2. A graph is subgraph-overfull if it has a subgraph with same maximum degree and it is overfull. It is well-known that every overfull and subgraph-overfull graph is Class 2. The Overfull Conjecture asserts that every graph with ?(G) > n 3 is Class 2 if and only if it is subgraph-overfull. In this work we prove the Overfull Conjecture to a particular class of graphs, known as split-comparability graphs. The Overfull Conjecture was open to this class.
Capacidade de locomoção de Ololygon Alcatraz (Anura:Hylidae): subsídios para a conservação Ex Situ
(Universidade Federal de São Carlos, 2017-05-02) Lisboa, Cybele Sabino; Brasileiro, Cinthia Aguirre; https://lattes.cnpq.br/2415614509705858; Cruz, João Batista da; https://lattes.cnpq.br/6711198385217623; https://lattes.cnpq.br/3503075011196526
The current global amphibian situation requires the implementation of efficient conservation measures to minimize or stabilize declines and extinctions rates. Ex situ conservation is a complementary strategy to in situ conservation and is mainly used in captive breeding and maintenance of endangered species for possible reintroductions. It is known that certain abilities can be lost after multiple generations in captivity, generating individuals more adapted to the captive environment. Locomotor function is a fundamental trait to survival, therefore, for an ex situ conservation program it is important to know whether the locomotion and metabolic capacities of captive born and wild animals are similar. Thereby, the present study evaluated the locomotor and metabolic capacities of ex situ and in situ populations of Ololygon alcatraz. This species is bromeligenous, endemic to the Ilha dos Alcatrazes (Brazil) and is threatened, categorized as Critically Endangered on the IUCN and Brazilian red lists. The locomotor performance was measured by manual stimulation of the individuals in an arena and the metabolic capacity was estimated by measuring the maximum activity of enzymes responsible for the production of energy for the locomotion activity. Captives born presented greater resistance to exercise when compared to the wild ones, traveling greater distances, jumping more times and spending more time in exercise, besides presenting higher activity of the enzyme citrate synthase. Wild animals had the potential to perform longer jumps and presented greater activity of the enzyme lactate dehydrogenase, which supports this type of exercise. These differences seems to be explained by phenotypic plasticity, arising from the environment in which individuals were created during ontogenetic development. This study evidenced the need to implement some measures to avoid that such differences are fixed in captives born Ololygon alcatraz and do not compromise their survival if they are translocated to the wild, thus subsidizing the species ex situ conservation program.