Mirna Januária Leal Godinho

Dipeptide metabolites from the marine derived bacterium Streptomyces acrymicini

The chemical investigation of the crude extract obtained from the growth media of the marine-derived actinomycete Streptomyces acrimycini isolated from marine sediments led to the isolation of two new dipeptide derivatives: 8-amino-[ 1,4] diazonane-2,5-dione (1) and leucyl-4-hydroxyproline (3). The dipeptides were isolated from the growth media by a series of chromatographic steps, and identified by analysis of spectroscopic data. The macrocyclic carbon backbone of 8-amino-[ 1,4] diazonane-2,5-dione has been previously reported only once in marinobactins, siderophores isolated from the marine bacterium Marinobacter sp.

Seasonal and spatial distribution of Bacterioplankton in a fluvial-lagunar system of a tropical region: density, biomass, cellular volume and morphologic variation

ABSTRACT The temporal and spatial fluctuations of Bacterioplankton in a fluvial-lagunar system of a tropical region (Pitimbu River and Jiqui Lake, RN) were studied during the dry and the rainy periods. The bacterial abundance varied from 2.67 to 5.1 Cells10 7 mL -1 and did not show a typical temporal variation, presenting only small oscillations between the rainy and the dry periods. The bacterial biomass varied from 123 µgC L -1 to 269 µgC L -1 in the sampling sites and the average cellular volume varied from 0.12 to 0.54µm 3 , showing a predominance of the rods. The temperature showed a positive correlation with the cellular volume of the rods (R=0.55; p=0.02) and vibrio (R=0.53; p=0.03). Significant spatial differences of biomass (Mann Whitney: p=0.01) and cellular volume of the morphotypes (Mann Whitney: p=0.003) were found between the sampling sites. The strong positive correlations of the water temperature and oxygen with bacterioplankton showed a probable high bacterial activity in this system.

Evaluation of the water quality of tidal creeks of Pontal do Paraná, Paraná, Brazil

Foi objetivo da presente pesquisa, avaliar a qualidade da agua de quatro gamboas do Parana, Brasil, que sofrem influencias antropicas distintas. Em cinco coletas trimestrais, foram obtidas, as seguintes variaveis em aguas superficiais: temperatura, salinidade, pH, alcalinidade, dioxido de carbono, oxigenio dissolvido, nitrito, nitrato, N-amoniacal, fosfato, silicato, material particulado em suspensao, substâncias humicas, clorofila total, coliformes totais e coliformes termotolerantes. Os resultados mostraram que a temperatura da agua apresentou caracteristicas tipicamente subtropicais com valores significativamente menores no inverno em todas as estacoes. A salinidade (7 - 25‰) e o pH (7,08 - 7,91) mais elevados, registrados na Gamboa Pereque, indicaram que somente este curso d´agua e influenciado pelo mar adjacente. As quantidades baixas de oxigenio dissolvido, chegando a anoxia, altas de fosfato (8,11 - 208,11 µM), N-amoniacal (0,90 - 75,33 µM), coliformes totais (<200 - 160.000 NMP 100 mL-1) e coliformes termotolerantes (<200 - 50.000 NMP 100 mL-1) observadas na Gamboa Olho d´Agua indicam que esta apresenta caracteristicas tipicas de eutrofizacao, principalmente no verao, epoca de maior pluviosidade e maior fluxo de turistas na regiao. As gamboas Pereque, Penedo e Barranco podem ser caracterizadas como gamboas meso- e oligotroficas.

Bacteria and protozoa populations in groundwater in landfill area in São Carlos, SP

The microbial populations of groundwaters were analyzed in a region under the influence of a landfill (piezometer L12) in the town of Sao Carlos, Sao Paulo, Brazil, and in an area not influenced by the landfill (piezometer L5). Heterotrophic bacteria were counted by spread plate method and the number of protozoa was estimated by the most probable number method. There was a larger number of organisms in well L12, with a mean value of 15.76 x 104 CFU/ml for bacteria and 9.7 MPN/ml for protozoa, whereas the mean values for piezometer L5 were 2.88 x 104 CFU/ml for bacteria and 3.4 MPN/ml for protozoa. The greater abundance detected in piezometer L12 may be related to the influence of the leachate through the landfill on the microbial populations, also demonstrated by deoxygenation and by the high conductivity values (3530 µS/cm) compared to piezometer L5 (2.47 mg/L dissolved oxygen and 42 µS/cm conductivity). The most commonly detected protozoa were amoebae and flagellates. The density of flagellate protozoa determined under microaerophilic conditions was 10 times higher than that determined under aerobic conditions.

Checklist dos "protozoários" de água doce do Estado de São Paulo, Brasil

Species checklists are important to know the local biodiversity, its ecology and scale its biotechnological and economic exploration and conservation. In this work the protozoan data (ciliates, naked amoebas, tecamoebas, heliozoans and heterotrophic flagellates) from Sao Paulo State have been listed. From 75 environments analized to this moment, 471 different protozoan taxa were recorded, distributed in 218 genera and 304 species. From the protozoan groups analyzed, the most representative was the ciliate with 160 genera and 219 species. Among the ciliates, two were new records: Neobursaridium gigas Balech, 1941 to Brazil and Loxodes rex Dragesco, 1970 to South America

Gordonia polyisoprenivorans from groundwater contaminated with landfill leachate in a subtropical area: characterization of the isolate and exopolysaccharide production

Uma linahgem de Gordonia sp. (linhagem Lc), proveniente de aguas subterrâneas contaminadas por chorume, foi caracterizada por taxonomia polifasica e estudada quanto a producao de exopolissacarideos (EPS). As celulas, bastonetes agregados, isolados ou aos pares em formato de V, tipico de bacterias corineformes, apresentaram reacao Gram positiva, catalase positiva, oxidase negativa, nao apresentaram motilidade. O organismo cresceu em aerobiose e em ambiente anoxico na presenca de NaNO3. A linhagem apresentou caracteristicas morfologicas, bioquimicas e propriedades quimiotaxonomicas tipicas do genero Gordonia e perfil de acidos micolicos e acidos graxos correspondentes aos de G. polyisoprenivorans DSM44302T. A analise do sequenciamento dos primeiros 500 pares de bases do rDNA16S da linhagem mostrou 100% de similaridade com Gordonia polyisoprenivorans DSM44302T. Experimentos conduzidos em condicoes anaerobias em meio E com sacarose ou glicose como principal fonte de carbono, mostraram que a linhagem nao cresceu quando cultivada com sacarose. Entretanto, utilizando-se glicose, a velocidade especifica maxima de crescimento foi 0,17h-1, o tempo de geracao de aproximadamente 4 horas e o maximo de producao de EPS total ocorreu durante a fase exponencial (126,17 ± 15,63 g l-1). A producao de EPS livre excedeu a de capsular e a relacao EPS livre/EPS capsular aumentou de 1,9, durante a fase exponencial para 7,8 durante a fase estacionaria. Ate entao, foram isoladas seis linhagens de G. polyisoprenivorans de diferentes ambientes. A linhagem Lc e a sexta linhagem de G. polyisoprenivorans descrita, a segunda detectada nas aguas subterrâneas em questao e a primeira cuja producao de EPS esta sendo estudada.

Protozooplankton and its relationship with environmental conditions in 13 water bodies of the Mogi-Guaçu basin - SP, Brazil

Protozooplankton is an important component of the aquatic microbial food webs and its composition, density, and distribution reflect the chemical, physical, and biological aspects of the environment. Considering the scarce literature on freshwater protozoans in Brazil and on protozoan ecology in subtropical environments, we listed the ciliates and amoebae taxa found in 13 water bodies in Sao Paulo State and analyzed their abundance in relation to the environmental variables. We collected two samples in each environment, fixed immediately with mercuric chloride and stained with bromophenol blue. After microscopical analysis, 74 protozoan genera were identified and the Ciliophora were dominant in the majority of the environments. The Stichotrichia, represented mostly by the genus Halteria, occurred in all environments, and was the dominant subclass in five of them. The canonic correspondence analysis of the most frequent genera and the environmental variables showed that nitrite and nitrate were the variables that better explained the distribution of Limnostrombidium, Urotricha, and Vorticella. The densities of the genera Halteria, Coleps, and of the species Cinetochilum margaritaceum were positively affected by increasing concentrations of dissolved oxygen, particulate phosphate, conductivity, and temperature. C. margaritaceum were also negatively affected by increasing concentrations of nitrite and nitrate. Considering that we made only one sampling in each environment, the richness was high compared to the mean diversity of lakes in the Sao Paulo State. The Diogo Lake, located in an ecological reserve, was the richest one, confirming the need of more research on the biodiversity of more preserved environments.

Use of Starved Cells of a Klebsiella Pneumoniae Strain Isolated from a Brazilian Oil Reservoir in a Transport and Plugging Experiment in a Sandstone Core

Abstract: Microbial biomass can be used as a plugging agent in high-permeability zones in applications of microbial enhanced oil recover (MEOR) technology to oil-bearing strata. Laboratory tests have shown that bacterial cells, reduced in size by starvation, can penetrate more deeply when injected into a porous medium and also grow therein after nutrient is added. Transport and growth of Klebsiella pneumoniae starved cells through a Rio Bonito sandstone core (440 mD of permeability) were tested, to verify application to oil recovery. The injection of starved cells followed by nutrient medium at a flow rate of 1.8 mL/h, promoted cell growth in the core, which raised the inner pressure from 0.016 to 13.7 psi, resulting in a 99.9% reduction in the permeability of the core. The biobarrier formed persisted during the injection of 4 pore volumes of brine into the core at a flow rate of 1.8 mL/h, keeping the permeability reduced to 99.7%.