Die Bedienung ländlicher Räume als Aufgabe aller Verkehrsträger: planungsrelevante Fakten

In mehreren Forschungsprojekten wurden 50 Siedlungen in dünn besiedelten Gebieten Nord- und Süddeutschlands untersucht. Die Bedienungsqualität der vorhandenen ÖPNV-Netze wurde bewertet und alle Haushalte wurden schriftlich befragt. Die Rücklaufquoten lagen um 50%. Als Ergebnis zeigte sich, dass der öffentliche Verkehr im dünnbesiedelten ländlichen Raum der Bundesrepublik Deutschland ohne größere Bedeutung ist. Selbst bei drastischen Verbesserungen des öffentlichen Verkehrsangebots nahm hier die Nachfrage nur stark unterproportional zu. Trotzdem ist der öffentliche Verkehr im ländlichen Raum besser als sein Ruf. In der vergleichenden Bewertung des ÖPNV-Angebots urteilte jedoch die betroffene Bevölkerung 2-3 Schulnoten (von 5) schlechter als die Verkehrsexperten. Bei dieser Bewertung konnten ÖPNV- und MIV-Benutzer nicht mehr getrennt werden, da die Zahl der ÖPNV-Benutzer bereits statistisch zu klein war. Der dargestellte Evolutionszyklus zeigt einen Funktionsverlust des Linienbusses als Mobilitätsprodukt von gestern. Allgemeine Messlatte ist heute und hier der Pkw vor der Haustür. Die systematische Unkenntnis des täglichen Linienbusses spricht aber auch für Wahrnehmungsdefizit, das sich durch preiswerte Maßnahmen aus der Welt schaffen lässt. Auch sie gehören gerade hier zur unumgänglichen und umfassenden Neuorganisation des ÖPNV.Several research projects investigated the provision of public transport in 50 communities in sparsely populated areas of North and South Germany. The levels of service were evaluated and all households were surveyed by questionnaire in 1979 and 1980. The response rates were between 48 and 58%. The results showed the very low importance of public transport in sparsely populated areas of the Federal Republic of Germany. Even after dramatic improvements in the provision of line bus service the corresponding rise in demand was much lower. Nevertheless public transport in rural areas is better than its reputation. The local population rated the quality of service significantly lower than transport experts. Because the number of bus passengers was already so low it was not possible for statistical reasons to distinguish between the rating of car users and public transport users. As the evolution cycle explains here the line bus is an mobility product of yesteryear. The most important yardstick today is the car in front of the front door. In addition the daily line bus is hardly noticed. Therefore rural areas require the comprehensive reorganization of their public transport system and low cost measures to improve the awareness of the existence of public transport

A benzene-degrading nitrate-reducing microbial consortium displays aerobic and anaerobic benzene degradation pathways

All sequence data from this study were deposited at the European Bioinformatics Institute under the accession numbers ERS1670018 to ERS1670023. Further, all assigned genes, taxonomy, function, sequences of contigs, genes and proteins can be found in Table S3.In this study, we report transcription of genes involved in aerobic and anaerobic benzene degradation pathways in a benzene-degrading denitrifying continuous culture. Transcripts associated with the family Peptococcaceae dominated all samples (2136% relative abundance) indicating their key role in the community. We found a highly transcribed gene cluster encoding a presumed anaerobic benzene carboxylase (AbcA and AbcD) and a benzoate-coenzyme A ligase (BzlA). Predicted gene products showed >96% amino acid identity and similar gene order to the corresponding benzene degradation gene cluster described previously, providing further evidence for anaerobic benzene activation via carboxylation. For subsequent benzoyl-CoA dearomatization, bam-like genes analogous to the ones found in other strict anaerobes were transcribed, whereas gene transcripts involved in downstream benzoyl-CoA degradation were mostly analogous to the ones described in facultative anaerobes. The concurrent transcription of genes encoding enzymes involved in oxygenase-mediated aerobic benzene degradation suggested oxygen presence in the culture, possibly formed via a recently identified nitric oxide dismutase (Nod). Although we were unable to detect transcription of Nod-encoding genes, addition of nitrite and formate to the continuous culture showed indication for oxygen production. Such an oxygen production would enable aerobic microbes to thrive in oxygen-depleted and nitrate-containing subsurface environments contaminated with hydrocarbons.This study was supported by a grant of BE-Basic-FES funds from the Dutch Ministry of Economic Affairs. The research of A.J.M. Stams is supported by an ERC grant (project 323009) and the gravitation grant “Microbes for Health and Environment” (project 024.002.002) of the Netherlands Ministry of Education, Culture and Science. F. Hugenholtz was supported by the same gravitation grant (project 024.002.002). B. Hornung is supported by Wageningen University and the Wageningen Institute for Environment and Climate Research (WIMEK) through the IP/OP program Systems Biology (project KB-17-003.02-023).info:eu-repo/semantics/publishedVersio

Benzoate-Coenzyme A Ligase from Thauera aromatica: an Enzyme Acting in Anaerobic and Aerobic Pathways

In the denitrifying member of the β-Proteobacteria Thauera aromatica, the anaerobic metabolism of aromatic acids such as benzoate or 2-aminobenzoate is initiated by the formation of the coenzyme A (CoA) thioester, benzoyl-CoA and 2-aminobenzoyl-CoA, respectively. Both aromatic substrates were transformed to the acyl-CoA intermediate by a single CoA ligase (AMP forming) that preferentially acted on benzoate. This benzoate-CoA ligase was purified and characterized as a 57-kDa monomeric protein. Based on V(max)/K(m), the specificity constant for 2-aminobenzoate was 15 times lower than that for benzoate; this may be the reason for the slower growth on 2-aminobenzoate. The benzoate-CoA ligase gene was cloned and sequenced and was found not to be part of the gene cluster encoding the general benzoyl-CoA pathway of anaerobic aromatic metabolism. Rather, it was located in a cluster of genes coding for a novel aerobic benzoate oxidation pathway. In line with this finding, the same CoA ligase was induced during aerobic growth with benzoate. A deletion mutant not only was unable to grow anaerobically on benzoate or 2-aminobenzoate, but also aerobic growth on benzoate was affected. This suggests that benzoate induces a single benzoate-CoA ligase. The product of benzoate activation, benzoyl-CoA, then acts as inducer of separate anaerobic or aerobic pathways of benzoyl-CoA, depending on whether oxygen is lacking or present