Rosana Vazoller - Academia.edu (original) (raw)
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Papers by Rosana Vazoller
Specific methanogenic activity measurements and scanning electron microscopy (SEM) were used as i... more Specific methanogenic activity measurements and scanning electron microscopy (SEM) were used as indirect tools to study the microbial population and structure of biofilms formed on sand grains. The biofilms were developed in an anaerobic fluidized bed reactor (diameter 0.08m; height 0.9m) fed with synthetic sewage wastewater. Biofilm thickness increased from 10 to 70 um after 510 days of reactor operation. Reactor bed stratification was observed http://www.bioline.org.br/request?bf98003 (1 of 14) [8/1/2002 10:25:52 AM] http://www.bioline.org.br/request?bf98003 after one year of operation, and agglomeration of various biofilms resulted in aggregates (2.0 to 5.0 mm). Microbial activities were determined through methane production from acetate, butyrate, propionate and sucrose. Samples were taken from two different points in the reactor, and the largest aggregates were found nearer the reactor base. These had 0.01 mmol CH4/gSSV.h of acetoclastic activity. Bacterial aggregates from the upper part of the reactor presented greater acetoclastic activity, 0.03 mmol CH4/gSSV.h. Microscopical observations of both samples revealed the predominant presence of methanogenic bacteria similar to Methanothrix, as well as hydrogenotrophic methanogen species and Desulfovibrio-like bacteria.
Environmental Technology, Jun 1, 2004
Fluorescent in situ hybridization (FISH) with domain and group specific probes that target intrac... more Fluorescent in situ hybridization (FISH) with domain and group specific probes that target intracellular 16S rRNA were used to investigate microbial composition of anaerobic biofilms developed on polypropylene (hydrophobic) and glass (hydrophilic) surfaces fitted inside a Modified Robbins Device (MRD). Crushed anaerobic granular sludge was used as inoculum for biofilm development in the MRD. The inoculum and biofilms formed showed nearly the same microbial composition, both were dominated by hydrogenotrophic methanogenic Archaea related to the Methanobacteriaceae as detected by the specific probe (MB1174). This group accounted for 44 to 90% of the DAPI-stained cells. Cells which hybridized to the Bacteria specific probe (EUB338) accounted for 3-18% of the DAPI-stained cells. After the first day of the biofilm formation experiment, a larger number of cells, 4.6 x 10 4 cells mm-2 , could be seen colonizing the polypropylene coupon compared to the glass, 8.2 x 10 3 cells mm-2. However, after 9 days these numbers were very similar, i.e. 6.3 x 10 5 cells mm-2 and 7.2 x 10 5 cells mm-2 , for the glass and polypropylene coupons, respectively. Our data suggest that the hydrophobicity of the support material did not influence the initial development and the microbial composition of anaerobic biofilms developed in the MRD.
Brazilian Archives of Biology and Technology, 2006
Neste trabalho investigou-se o desenvo lvimento de biofilmes anaeróbios em um sistema ele laborat... more Neste trabalho investigou-se o desenvo lvimento de biofilmes anaeróbios em um sistema ele laboratório chamado ele "modified robbins device" (MRD). O objetivo XIII
Rev Microbiol, Mar 1, 1992
Specific methanogenic activity measurements and scanning electron microscopy (SEM) were used as i... more Specific methanogenic activity measurements and scanning electron microscopy (SEM) were used as indirect tools to study the microbial population and structure of biofilms formed on sand grains. The biofilms were developed in an anaerobic fluidized bed reactor (diameter 0.08m; height 0.9m) fed with synthetic sewage wastewater. Biofilm thickness increased from 10 to 70 um after 510 days of reactor operation. Reactor bed stratification was observed http://www.bioline.org.br/request?bf98003 (1 of 14) [8/1/2002 10:25:52 AM] http://www.bioline.org.br/request?bf98003 after one year of operation, and agglomeration of various biofilms resulted in aggregates (2.0 to 5.0 mm). Microbial activities were determined through methane production from acetate, butyrate, propionate and sucrose. Samples were taken from two different points in the reactor, and the largest aggregates were found nearer the reactor base. These had 0.01 mmol CH4/gSSV.h of acetoclastic activity. Bacterial aggregates from the upper part of the reactor presented greater acetoclastic activity, 0.03 mmol CH4/gSSV.h. Microscopical observations of both samples revealed the predominant presence of methanogenic bacteria similar to Methanothrix, as well as hydrogenotrophic methanogen species and Desulfovibrio-like bacteria.
Minerals Engineering, 2005
One of the most serious environment problems created by the mining industry is acid mine drainage... more One of the most serious environment problems created by the mining industry is acid mine drainage. In one plant of Nuclear Industries of Brazil-INB, this problem is a matter of concern. The presence of iron sulfites, such as pyrite, generates water with acidity above the levels allowed by the legislation and therefore, inappropriate for releasing straight into the environment. The industry maintain a high cost treatment in acid water from mines and waste disposal which consists in neutralizing and precipitating heavy metals. The treatment of acid water using sulfate-reducing bacteria (SRB) has been used in other countries with quite good technical results as well as economical advantages and thus, the object of this research. A seasonal study was carried out on the sulfate-reducing bacteria present in the liquid effluent discharged from two wastes disposal of the uranium mine, in phase of decommission, in Poços de Caldas. This study shows the presence of SRB in the analyzed environmental, as well as some factors that are related with the amount of SRB presents, such as: dissolved oxygen, pH and organic matter.
Applied Microbiology and Biotechnology, 1995
Recent studies have shown the importance of viruses as potential sources of plankton mortality, w... more Recent studies have shown the importance of viruses as potential sources of plankton mortality, which affect primary production and biogeochemical functions of their hosts. Here, we report basic characteristics of a novel virus (Stephanopyxis palmeriana virus: SpalV) that causes lysis of a culture of the diatom S. palmeriana, which was isolated in Jaran Bay, Korea, in August 2008. SpalV is a round-shaped viral particle ~25-30 nm in diameter that propagates in its host's cytoplasm. In addition, it shows species-specific infectivity among the tested diatom species. The burst size and latent period are estimated to be roughly 92 infectious units cell-1 and <80 h, respectively.
Specific methanogenic activity measurements and scanning electron microscopy (SEM) were used as i... more Specific methanogenic activity measurements and scanning electron microscopy (SEM) were used as indirect tools to study the microbial population and structure of biofilms formed on sand grains. The biofilms were developed in an anaerobic fluidized bed reactor (diameter 0.08m; height 0.9m) fed with synthetic sewage wastewater. Biofilm thickness increased from 10 to 70 um after 510 days of reactor operation. Reactor bed stratification was observed http://www.bioline.org.br/request?bf98003 (1 of 14) [8/1/2002 10:25:52 AM] http://www.bioline.org.br/request?bf98003 after one year of operation, and agglomeration of various biofilms resulted in aggregates (2.0 to 5.0 mm). Microbial activities were determined through methane production from acetate, butyrate, propionate and sucrose. Samples were taken from two different points in the reactor, and the largest aggregates were found nearer the reactor base. These had 0.01 mmol CH4/gSSV.h of acetoclastic activity. Bacterial aggregates from the upper part of the reactor presented greater acetoclastic activity, 0.03 mmol CH4/gSSV.h. Microscopical observations of both samples revealed the predominant presence of methanogenic bacteria similar to Methanothrix, as well as hydrogenotrophic methanogen species and Desulfovibrio-like bacteria.
Environmental Technology, Jun 1, 2004
Fluorescent in situ hybridization (FISH) with domain and group specific probes that target intrac... more Fluorescent in situ hybridization (FISH) with domain and group specific probes that target intracellular 16S rRNA were used to investigate microbial composition of anaerobic biofilms developed on polypropylene (hydrophobic) and glass (hydrophilic) surfaces fitted inside a Modified Robbins Device (MRD). Crushed anaerobic granular sludge was used as inoculum for biofilm development in the MRD. The inoculum and biofilms formed showed nearly the same microbial composition, both were dominated by hydrogenotrophic methanogenic Archaea related to the Methanobacteriaceae as detected by the specific probe (MB1174). This group accounted for 44 to 90% of the DAPI-stained cells. Cells which hybridized to the Bacteria specific probe (EUB338) accounted for 3-18% of the DAPI-stained cells. After the first day of the biofilm formation experiment, a larger number of cells, 4.6 x 10 4 cells mm-2 , could be seen colonizing the polypropylene coupon compared to the glass, 8.2 x 10 3 cells mm-2. However, after 9 days these numbers were very similar, i.e. 6.3 x 10 5 cells mm-2 and 7.2 x 10 5 cells mm-2 , for the glass and polypropylene coupons, respectively. Our data suggest that the hydrophobicity of the support material did not influence the initial development and the microbial composition of anaerobic biofilms developed in the MRD.
Brazilian Archives of Biology and Technology, 2006
Neste trabalho investigou-se o desenvo lvimento de biofilmes anaeróbios em um sistema ele laborat... more Neste trabalho investigou-se o desenvo lvimento de biofilmes anaeróbios em um sistema ele laboratório chamado ele "modified robbins device" (MRD). O objetivo XIII
Rev Microbiol, Mar 1, 1992
Specific methanogenic activity measurements and scanning electron microscopy (SEM) were used as i... more Specific methanogenic activity measurements and scanning electron microscopy (SEM) were used as indirect tools to study the microbial population and structure of biofilms formed on sand grains. The biofilms were developed in an anaerobic fluidized bed reactor (diameter 0.08m; height 0.9m) fed with synthetic sewage wastewater. Biofilm thickness increased from 10 to 70 um after 510 days of reactor operation. Reactor bed stratification was observed http://www.bioline.org.br/request?bf98003 (1 of 14) [8/1/2002 10:25:52 AM] http://www.bioline.org.br/request?bf98003 after one year of operation, and agglomeration of various biofilms resulted in aggregates (2.0 to 5.0 mm). Microbial activities were determined through methane production from acetate, butyrate, propionate and sucrose. Samples were taken from two different points in the reactor, and the largest aggregates were found nearer the reactor base. These had 0.01 mmol CH4/gSSV.h of acetoclastic activity. Bacterial aggregates from the upper part of the reactor presented greater acetoclastic activity, 0.03 mmol CH4/gSSV.h. Microscopical observations of both samples revealed the predominant presence of methanogenic bacteria similar to Methanothrix, as well as hydrogenotrophic methanogen species and Desulfovibrio-like bacteria.
Minerals Engineering, 2005
One of the most serious environment problems created by the mining industry is acid mine drainage... more One of the most serious environment problems created by the mining industry is acid mine drainage. In one plant of Nuclear Industries of Brazil-INB, this problem is a matter of concern. The presence of iron sulfites, such as pyrite, generates water with acidity above the levels allowed by the legislation and therefore, inappropriate for releasing straight into the environment. The industry maintain a high cost treatment in acid water from mines and waste disposal which consists in neutralizing and precipitating heavy metals. The treatment of acid water using sulfate-reducing bacteria (SRB) has been used in other countries with quite good technical results as well as economical advantages and thus, the object of this research. A seasonal study was carried out on the sulfate-reducing bacteria present in the liquid effluent discharged from two wastes disposal of the uranium mine, in phase of decommission, in Poços de Caldas. This study shows the presence of SRB in the analyzed environmental, as well as some factors that are related with the amount of SRB presents, such as: dissolved oxygen, pH and organic matter.
Applied Microbiology and Biotechnology, 1995
Recent studies have shown the importance of viruses as potential sources of plankton mortality, w... more Recent studies have shown the importance of viruses as potential sources of plankton mortality, which affect primary production and biogeochemical functions of their hosts. Here, we report basic characteristics of a novel virus (Stephanopyxis palmeriana virus: SpalV) that causes lysis of a culture of the diatom S. palmeriana, which was isolated in Jaran Bay, Korea, in August 2008. SpalV is a round-shaped viral particle ~25-30 nm in diameter that propagates in its host's cytoplasm. In addition, it shows species-specific infectivity among the tested diatom species. The burst size and latent period are estimated to be roughly 92 infectious units cell-1 and <80 h, respectively.