Proteomic analysis of psychrophilic and mesophilic bacterial species
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ABSTRACT: This study, in an attempt to mimic the molecular adaptation of polar microorganisms, combines proteomic approaches with a classical microbiological analysis in several bacterial species. The comparison of the strategies employed by each bacterial species estimates the contribution of genome versus environmental variables in the adaptation to temperature. Regarding the molecular machinery used by these bacteria to face the consequences of temperature changes, chaperones have a pivoting role. They form complexes with other proteins in the response to the environment, establishing cooperation with transmembrane proteins, elongation factors, and proteins for protection against oxidative damage.
Project description:Glaciers are populated by a large number of microorganisms including bacteria, archaea and microeukaryotes. Several factors such as solar radiation, nutrient availability and water content greatly determine the diversity and abundance of these microbial populations, the type of metabolism and the biogeochemical cycles. In order to study their metabolic potentials, samples of glacial ice were taken from several glacial ecosystems. Microorganisms were analyzed by a polyphasic approach that combines a set of -omic techniques: 16S rRNA sequencing, culturomics and metaproteomics. This combination provides key information about diversity and functions of microbial populations, especially in rare habitats. Several whole essential proteins and enzymes related to metabolism and energy production, recombination and translation were found that demonstrate the existence of cellular activity at subzero temperatures.
Project description:Glaciers are populated by a large number of microorganisms including bacteria, archaea and microeukaryotes. Several factors such as solar radiation, nutrient availability and water content greatly determine the diversity and abundance of these microbial populations, the type of metabolism and the biogeochemical cycles. In order to study their metabolic potentials, samples of glacial ice were taken from several glacial ecosystems. Microorganisms were analyzed by a polyphasic approach that combines a set of -omic techniques: 16S rRNA sequencing, culturomics and metaproteomics. This combination provides key information about diversity and functions of microbial populations, especially in rare habitats. Several whole essential proteins and enzymes related to metabolism and energy production, recombination and translation were found that demonstrate the existence of cellular activity at subzero temperatures.
Project description:Glaciers are populated by a large number of microorganisms including bacteria, archaea and microeukaryotes. From an ecological point of view, three ecosystems can be differentiated in glaciers: the supraglacial ecosystem, the subglacial ecosystem and the englacial ecosystem. Several factors such as solar radiation, nutrient availability and water content greatly determine the diversity and abundance of microbial populations, the type of metabolism and the biogeochemical cycles. Firstly, the supraglacial ecosystem, sunlit and oxygenated, is predominantly populated by autotrophic microorganisms. Secondly, the subglacial ecosystem contains a majority of chemoautrotophs that are fed on the mineral salts of the rocks and basal soil. Lastly, the englacial ecosystem is the less studied and the one that contains the smallest number of microorganisms. However, these unknown englacial microorganisms establish a true trophic chain and appear to have an active metabolism. In order to study their metabolic potentials, samples of englacial ice were taken from an Antarctic glacier. The cells were harvested and their proteins were extracted and analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI/TOF/TOF). Several proteins and enzymes were found that demonstrate the existence of cellular activity at subzero temperatures. In this way it is shown that the englacial microorganisms are not quiescent, but that they maintain an active metabolism and play an important role in the glacial microbial community.
Project description:Glaciers are populated by a large number of microorganisms including bacteria, archaea and microeukaryotes. From an ecological point of view, three ecosystems can be differentiated in glaciers: the supraglacial ecosystem, the subglacial ecosystem and the englacial ecosystem. Several factors such as solar radiation, nutrient availability and water content greatly determine the diversity and abundance of microbial populations, the type of metabolism and the biogeochemical cycles. Firstly, the supraglacial ecosystem, sunlit and oxygenated, is predominantly populated by autotrophic microorganisms. Secondly, the subglacial ecosystem contains a majority of chemoautrotophs that are fed on the mineral salts of the rocks and basal soil. Lastly, the englacial ecosystem is the less studied and the one that contains the smallest number of microorganisms. However, these unknown englacial microorganisms establish a true trophic chain and appear to have an active metabolism. In order to study their metabolic potentials, samples of englacial ice were taken from an Antarctic glacier. The cells were harvested and their proteins were extracted and analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI/TOF/TOF). Several proteins and enzymes were found that demonstrate the existence of cellular activity at subzero temperatures. In this way it is shown that the englacial microorganisms are not quiescent, but that they maintain an active metabolism and play an important role in the glacial microbial community.
Project description:The species of two bacterial colonies were determined by sequencing their DNA and comparing it with databases. Their adaptation to extreme conditions (conditions similar to those found in the planet Mars) were studied by proteomics, comparing the proteome obtained from a culture under standard laboratory conditions with the proteome obtained from a culture under extreme conditions. The techniques used were 2-DE electrophoresis, Difference in gel electrophoresis (2-D DIGE) and protein analysis by mass spectrometry Matrix Assisted Laser Desorption/ Ionization – Time of Flight (MALDI-TOF).
Project description:The species of two bacterial colonies were determined by sequencing their DNA and comparing it with databases. Their adaptation to extreme conditions (conditions similar to those found in the planet Mars) were studied by proteomics, comparing the proteome obtained from a culture under standard laboratory conditions with the proteome obtained from a culture under extreme conditions. The techniques used were 2-DE electrophoresis, Difference in gel electrophoresis (2-D DIGE) and protein analysis by mass spectrometry Matrix Assisted Laser Desorption/ Ionization – Time of Flight (MALDI-TOF).
Project description:Jasmonic acid (JA) and methyl jasmonate (MeJA) regulate plant development, resistance to stress, and insect attack by inducing specific gene expression. However, little is known about the mechanism of plant defense against herbivore attack at a protein level. Using a high-resolution 2-DE gel, we identified 60 MeJA-responsive proteins and measured protein expression level changes. Among these 62 proteins, 43 proteins levels were increased while 11 proteins were decreased. We also found eight proteins uniquely expressed in response to MeJA treatment. The proteins identified in this study have important biological functions including photosynthesis and energy related proteins (38.4%), protein folding, degradation and regulated proteins (15.0%), stress and defense regulated proteins (11.7%), and redox-responsive proteins (8.3%). We found MeJA could not only induce plant defense mechanisms to insects, it also enhanced toxic protein production that potentially can be used for bio-control of Asian corn borer.
Project description:Investigation of whole genome gene expression level changes in a Salmonella enterica serovar Typhimurium UK1 delta-iacP mutant, compared to the wild-type strain. IacP is resoponsible for the secretion of virulence effector proteins via the type III secretion system, thereby contributing the virulence of S. Typhimurium. The mutants analyzed in this study are further described in Kim et al. 2011. Role of Salmonella Pathogenicity Island 1 Protein IacP in Salmonella enterica Serovar Typhimurium Pathogenesis. Infection and Immunity 79(4):1440-1450 (PMID 21263021). A chip study using total RNA recovered from two separate wild-type cultures of Salmonella enterica serovar Typhimurium UK1 and two separate cultures of a mutant strain, Salmonella enterica serovar Typhimurium UK1 delta-iacP. Each chip measures the expression level of 4,302 genes from Salmonella enterica serovar Typhimurium.
Project description:Salmonella has various mechanisms of small RNA-mediated gene regulation. In Salmonella enterica serovar Typhimurium, a novel intergenic transcript RsiM is involved in oxidative stress response which functions as one of the powerful antimicrobials in macrophage innate immunity. We note that the M-bM-^HM-^FrsiM mutant is sensitive to hydrogen peroxide (5.0mM). This finding provides insights into the function of RsiM as a regulator of oxidative stress response. UK1 wild-type and M-bM-^HM-^FrsiM strains were grown in LB medium at 37M-bM-^DM-^C to an OD600 of 0.6, and then subjected to oxidative stress (5.0 mM hydroperoxide) for 30 min. Total RNA was extracted from three biological replicates of wild-type and M-bM-^HM-^FrsiM mutant.
Project description:Chelocardin is an atypical tetracycline and its mechanism of action is discussed controversially in literature. Therefore, we analyzed the bacterial response of Bacillus subtilis to chelocardin and as a control for classical tetracyclines to tetracycline by proteomic profiling. The induced marker proteins mirror the damage in the cell due the antibiotic stress. Proteomic profiling was carried out by 2D-PAGE and spot identification by nUPLC-ESI-MS/MS. The proteomic profile of chelocardin demonstrates a dual mechanism of action with protein biosynthesis inhibition and membrane damage.