Environmental fluctuations require rapid adjustment of the physiology of bacteria. Anoxygenic phototrophic purple sulfur bacteria, like Allochromatium vinosum, thrive in environments that are characterized by steep gradients of important nutrients for these organisms, i.e., reduced sulfur compounds, light, oxygen and carbon sources. Changing conditions necessitate changes on every level of the underlying cellular and molecular network. Thus far, two global analyses of A. vinosum responses to changes of nutritional conditions have been performed and these focused on gene expression and protein levels. Here, we provide a study on metabolite composition and relate it with transcriptional and proteomic profiling data to provide a more comprehensive insight on the systems level adjustment to available nutrients. We identified 131 individual metabolites and compared availability and concentration under four different growth conditions (sulfide, thiosulfate, elemental sulfur, and malate) and on sulfide for a ΔdsrJ mutant strain. During growth on malate, cysteine was identified to be the least abundant amino acid. Concentrations of the metabolite classes "amino acids" and "organic acids" (i.e., pyruvate and its derivatives) were higher on malate than on reduced sulfur compounds by at least 20 and 50 %, respectively. Similar observations were made for metabolites assigned to anabolism of glucose. Growth on sulfur compounds led to enhanced concentrations of sulfur containing metabolites, while other cell constituents remained unaffected or decreased. Incapability of sulfur globule oxidation of the mutant strain was reflected by a low energy level of the cell and consequently reduced levels of amino acids (40 %) and sugars (65 %).
Allochromatium vinosum formerly Chromatium vinosum is a mesophilic purple sulfur bacterium belonging to the family Chromatiaceae in the bacterial class Gammaproteobacteria. The genus Allochromatium contains currently five species. All members were isolated from freshwater, brackish water or marine habitats and are predominately obligate phototrophs. Here we describe the features of the organism, together with the complete genome sequence and annotation. This is the first completed genome sequence of a member of the Chromatiaceae within the purple sulfur bacteria thriving in globally occurring habitats. The 3,669,074 bp genome with its 3,302 protein-coding and 64 RNA genes was sequenced within the Joint Genome Institute Community Sequencing Program.
Activities in the field of automated driving have produced a variety of development tools and methodologies over the past decades. The requirements the systems have to fulfil and thus also the development guidelines are often documented in different kinds of catalogues (use‐case catalogues, situation catalogues, scenario catalogues etc.). These catalogues cannot be directly applied for the development of partially and highly automated vehicle guidance concepts like conduct‐by‐wire (CbW) or H‐mode. One reason is that up to now, no consistent terminology known to the authors yet exists for vehicle automation within the community. Moreover, as the aim of the two project groups CbW and H‐mode is to make a comprehensive feasibility assessment of cooperative vehicle guidance, all interacting components of the overall system as well as all potential driving conditions a cooperative vehicle guidance system might have to cope with have to be analysed. This article focuses on two aspects. The first is a metaphor‐based terminology discussion leading to a proposal for a fundamental ontology. The second aspect is an outlook on the different catalogues that use the new terminology and that have been developed. The methodology introduced here is a fundamental contribution towards simplifying communication and the exchange of findings.
In this study, we investigated if the driver’s ability to take over vehicle control when being engaged in a secondary task (Surrogate Reference Task) can be predicted by a subject’s multitasking ability and reaction time. 23 participants performed a multitasking test and a simple response task and then drove for about 38 min highly automated on a highway and encountered five take-over situations. Data analysis revealed significant correlations between the multitasking performance and take-over time as well as gaze distributions for Situations 1 and 2, even when reaction time was controlled. This correlation diminished beginning with Situation 3, but a stable difference between the worst multitaskers and the best multitaskers persisted. Reaction time was not a significant predictor in any situation. The results can be seen as evidence for stable individual differences in dual task situations regarding automated driving, but they also highlight effects associated with the experience of a take-over situation.
ABSTRACT In the present study, we compared the proteome response of Allochromatium vinosum when growing photoautotrophically in the presence of sulfide, thiosulfate, and elemental sulfur with the proteome response when the organism was growing photoheterotrophically on malate. Applying tandem mass tag analysis as well as two-dimensional (2D) PAGE, we detected 1,955 of the 3,302 predicted proteins by identification of at least two peptides (59.2%) and quantified 1,848 of the identified proteins. Altered relative protein amounts (≥1.5-fold) were observed for 385 proteins, corresponding to 20.8% of the quantified A. vinosum proteome. A significant number of the proteins exhibiting strongly enhanced relative protein levels in the presence of reduced sulfur compounds are well documented essential players during oxidative sulfur metabolism, e.g., the dissimilatory sulfite reductase DsrAB. Changes in protein levels generally matched those observed for the respective relative mRNA levels in a previous study and allowed identification of new genes/proteins participating in oxidative sulfur metabolism. One gene cluster ( hyd ; Alvin_2036-Alvin_2040) and one hypothetical protein (Alvin_2107) exhibiting strong responses on both the transcriptome and proteome levels were chosen for gene inactivation and phenotypic analyses of the respective mutant strains, which verified the importance of the so-called Isp hydrogenase supercomplex for efficient oxidation of sulfide and a crucial role of Alvin_2107 for the oxidation of sulfur stored in sulfur globules to sulfite. In addition, we analyzed the sulfur globule proteome and identified a new sulfur globule protein (SgpD; Alvin_2515).
