Draft Genome Sequences of Type Strain Sediminibacterium salmoneum NJ-44T and Sediminibacterium sp. C3, a Novel Strain Isolated from Activated Sludge

The genus Sediminibacterium comprises species present in diverse natural and engineered environments. Here, we report for the first time the genome sequences of the type strain Sediminibacterium salmoneum NJ-44T (NBRC 103935) and the strain Sedi- minibacterium sp. strain C3 (BNM541), isolated from activated sludge, a valuable model for the study of substrate-dependent autoaggregation.Fil: Ayarza, Joaquín M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; ArgentinaFil: Figuerola, Eva Lucia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; ArgentinaFil: Erijman, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentin

Impact of the recent advances in the analysis of microbial communities on the control of the wastewater treatment process

Una de las funciones principales de la biotecnología ambiental es ocuparse del estudio de comunidades microbianas que proveen servicios esenciales para la sociedad. Más allá de las similitudes que presenta con la microbiología industrial y la agrícola, la biotecnología ambiental presenta peculiaridades, tales como los objetivos de proceso, las características de la biomasa y el tipo y modo de alimentación (sustratos), que la distinguen claramente de las otras disciplinas relacionadas. En este artículo se reseñan recientes avances en la ecología microbiana, la ecofisiología, la genómica y la ingeniería de procesos, para ilustrar cómo la integración de los nuevos conocimientos permite superar las limitaciones del análisis microbiológico clásico para entender, predecir y optimizar el funcionamiento de los procesos de tratamiento de efluentes.One of the main functions of environmental biotechnology is to address the study of microbial communities that provide essential services to society. Beyond the similarities with industrial and agricultural microbiology, the unique features exhibited by environmental biotechnology, such as process objectives, biomass characteristics and type and mode of feeding (substrates), allow a clear distinction from the other related disciplines. Recent advances in microbial ecology, ecophysiology, genomics and process engineering are herein reviewed to illustrate how the integration of the new knowledge can help overcome the shortcomings of classic microbiological analyses to understand, predict and optimize the performance of wastewater treatment.Fil: Erijman, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Figuerola, Eva Lucia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Guerrero, Leandro Demián. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Ayarza, Joaquín M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

Expression of stress-related proteins in Sediminibacterium sp. growing under planktonic conditions

Aggregation is a common trait of bacteria in natural and engineered biological systems. Microbial aggregates, such as flocs, granules, and biofilms, are spatially heterogeneous environments. It is generally observed that by growing under aggregated conditions bacteria respond and adapt to environmental stress better than free-swimming bacteria of the same species. We performed a proteomic analysis of a strain of Sediminibacterium, isolated from activated sludge, which grew planktonically in diluted culture media and in an aggregated form in media containing a high concentration of organic substrate. Auto-aggregation was also observed in the presence of pyruvate in dilute media. Expression of a number of stress-related proteins significantly increased under planktonic growth in comparison to aggregate growth. The upregulated proteins, identified by MALDI-TOF mass spectrometry, were two isoforms of a protein belonging to the universal stress family (UspA), a thioredoxin-disulfide reductase, the Campylobacter jejuni orthologue transcriptional regulator (Cj1172c), and the CocE/NonD hydrolase. We conclude that Sediminibaterium sp. C3 growth is stressed under planktonic conditions and that aggregation induced by pyruvate protects the bacteria against oxidative stress.Fil: Ayarza, Joaquín M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; ArgentinaFil: Mazzella, Maria Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; ArgentinaFil: Erijman, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentin

Nonrandom assembly of bacterial populations in activated sludge flocs

The aim of this work was to investigate the dynamics of assembly of bacterial populations in activated sludge flocs. We approached this question by following the development of active bacterial populations during floc development in four replicated lab-scale activated sludge reactors, in which solid retention time (SRT) was set at 4 days. The null hypothesis was that the similarities in community composition could be accounted for by the probability that the same organisms occur in more than one replicated reactor. Microscopic imaging showed that the size of flocs in reactors with biomass retention increased during the first few days until a steady-state size was reached. The diversity and community structure of the sludge in all reactors were analyzed during a period of up to ten SRT, using denaturing gradient gel electrophoresis (DGGE) of reverse-transcription polymerase chain reaction-amplified 16S rRNA. High rates of change in DGGE profiles from consecutive sampling points suggested a high level of dynamics in all reactors. This conclusion was confirmed by the application of the Raup and Crick probability-based similarity index (SRC) for the comparison of rRNA-based fingerprinting patterns, which indicated that bacterial communities within reactors were not significantly similar after three SRT (0.05 0.95) and became significantly dissimilar after five SRT (SRC 0.95). The fact that the patterns between replicates were more reproducible than expected by chance under highly dynamic conditions allowed us to reject the null hypothesis that activated sludge floc communities assemble randomly from the available source pool of bacteria. We suggest that communities progressively recruit from the available pool of bacterial species, each with particular ecological requirements that determine their time of emergence into the community. © 2009 Springer Science+Business Media, LLC.Fil: Ayarza, Joaquín M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Guerrero, Leandro Demián. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Erijman, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

Impacto de los recientes avances en el análisis de comunidades microbianas sobre el control del proceso de tratamiento de efluentes Impact of the recent advances in the analysis of microbial communities on the control of the wastewater treatment process

Una de las funciones principales de la biotecnología ambiental es ocuparse del estudio de comunidades microbianas que proveen servicios esenciales para la sociedad. Más allá de las similitudes que presenta con la microbiología industrial y la agrícola, la biotecnología ambiental presenta peculiaridades, tales como los objetivos de proceso, las características de la biomasa y el tipo y modo de alimentación (sustratos), que la distinguen claramente de las otras disciplinas relacionadas. En este artículo se reseñan recientes avances en la ecología microbiana, la ecofisiología, la genómica y la ingeniería de procesos, para ilustrar cómo la integración de los nuevos conocimientos permite superar las limitaciones del análisis microbiológico clásico para entender, predecir y optimizar el funcionamiento de los procesos de tratamiento de efluentes.One of the main functions of environmental biotechnology is to address the study of microbial communities that provide essential services to society. Beyond the similarities with industrial and agricultural microbiology, the unique features exhibited by environmental biotechnology, such as process objectives, biomass characteristics and type and mode of feeding (substrates), allow a clear distinction from the other related disciplines. Recent advances in microbial ecology, ecophysiology, genomics and process engineering are herein reviewed to illustrate how the integration of the new knowledge can help overcome the shortcomings of classic microbiological analyses to understand, predict and optimize the performance of wastewater treatment