scholarly journals Propionate production from carbon monoxide by synthetic co-cultures of Acetobacterium wieringae spp. and propionigenic bacteria

Author(s):  
João P. C. Moreira ◽  
Martijn Diender ◽  
Ana L. Arantes ◽  
Sjef Boeren ◽  
Alfons J.M. Stams ◽  
...  

Gas fermentation is a promising way for converting CO-rich gases to chemicals. We studied the use of synthetic co-cultures composed of carboxydotrophic and propionigenic bacteria to convert CO to propionate. So far isolated carboxydotrophs cannot directly ferment CO to propionate, and therefore this co-cultivation approach was investigated. Four distinct synthetic co-cultures were constructed, consisting of: Acetobacterium wieringae (DSM 1911T) and Pelobacter propionicus (DSM 2379T); Ac. wieringae (DSM 1911T) and Anaerotignum neopropionicum (DSM 3847T); Ac. wieringae strain JM and P. propionicus (DSM 2379T); Ac. wieringae strain JM and An. neopropionicum (DSM 3847T). Propionate was produced by all the co-cultures, with the highest titer (∼24 mM) measured in the co-culture composed of Ac. wieringae strain JM + An. neopropionicum, which also produced isovalerate (∼4 mM), butyrate (∼1 mM), and isobutyrate (0.3 mM). This co-culture was further studied using proteogenomics. As expected, enzymes involved in the Wood-Ljungdahl pathway in Ac. wieringae strain JM, which are responsible for the conversion of CO to ethanol and acetate, were detected; the proteome of An. neopropionicum confirmed the conversion of ethanol to propionate via the acrylate pathway. In addition, proteins related to amino acid metabolism and stress response were highly abundant during co-cultivation, which raises the hypothesis that amino acids are exchanged by the two microorganisms accompanied by isovalerate and isobutyrate production. This highlights the importance of explicitly looking at fortuitous microbial interactions during co-cultivation to fully understand co-cultures behavior. IMPORTANCE Syngas fermentation has great potential for the sustainable production of chemicals from wastes (via prior gasification) and flue gases containing CO/CO2. Research efforts need to be driven to expanding the product portfolio of gas fermentation, which is currently limited to mainly acetate and ethanol. This study provides the basis for a microbial process to produce propionate from CO using synthetic co-cultures composed of acetogenic and propionigenic bacteria and elucidates the metabolic pathways involved. Furthermore, based on proteomics results, we hypothesize that the two bacterial species engage in an interaction that results in amino acid exchange, which subsequently promotes isovalerate and isobutyrate production. These findings provide a new understanding of gas fermentation and a co-culturing strategy for expanding the product spectrum of microbial conversion of CO/CO2.

2011 ◽  
Vol 54 (4) ◽  
pp. e458-e460 ◽  
Author(s):  
Sylvia Keller ◽  
Danielle Prechtl ◽  
Charalampos Aslanidis ◽  
Uta Ceglarek ◽  
Joachim Thiery ◽  
...  

FEBS Journal ◽  
2014 ◽  
Vol 281 (20) ◽  
pp. 4691-4704 ◽  
Author(s):  
Wolf‐Dieter Lienhart ◽  
Venugopal Gudipati ◽  
Michael K. Uhl ◽  
Alexandra Binter ◽  
Sergio A. Pulido ◽  
...  

Amino Acids ◽  
2005 ◽  
Vol 29 (3) ◽  
pp. 213-219 ◽  
Author(s):  
P. Soares-da-Silva ◽  
M. P. Serrão

2015 ◽  
Vol 29 (6) ◽  
pp. 2583-2594 ◽  
Author(s):  
Kate L. Widdows ◽  
Nuttanont Panitchob ◽  
Ian P. Crocker ◽  
Colin P. Please ◽  
Mark A. Hanson ◽  
...  

2006 ◽  
Vol 80 (2) ◽  
pp. 810-820 ◽  
Author(s):  
Svenja Bleker ◽  
Michael Pawlita ◽  
Jürgen A. Kleinschmidt

ABSTRACT Single-stranded genomes of adeno-associated virus (AAV) are packaged into preformed capsids. It has been proposed that packaging is initiated by interaction of genome-bound Rep proteins to the capsid, thereby targeting the genome to the portal of encapsidation. Here we describe a panel of mutants with amino acid exchanges in the pores at the fivefold axes of symmetry on AAV2 capsids with reduced packaging and reduced Rep-capsid interaction. Mutation of two threonines at the rim of the fivefold pore nearly completely abolished Rep-capsid interaction and packaging. This suggests a Rep-binding site at the highly conserved amino acids at or close to the pores formed by the capsid protein pentamers. A different mutant (P. Wu, W. Xiao, T. Conlon, J. Hughes, M. Agbandje-McKenna, T. Ferkol, T. Flotte, and N. Muzyczka, J. Virol. 74:8635-8647, 2000) with an amino acid exchange at the interface of capsid protein pentamers led to a complete block of DNA encapsidation. Analysis of the capsid conformation of this mutant revealed that the pores at the fivefold axes were occupied by VP1/VP2 N termini, thereby preventing DNA introduction into the capsid. Nevertheless, the corresponding capsids had more Rep proteins bound than wild-type AAV, showing that correct Rep interaction with the capsid depends on a defined capsid conformation. Both mutant types together support the conclusion that the pores at the fivefold symmetry axes are involved in genome packaging and that capsid conformation-dependent Rep-capsid interactions play an essential role in the packaging process.


2008 ◽  
Vol 27 (6) ◽  
pp. 816-821 ◽  
Author(s):  
Agneta Berg ◽  
Bo Michael Bellander ◽  
Michael Wanecek ◽  
Åke Norberg ◽  
Urban Ungerstedt ◽  
...  

2004 ◽  
Vol 79 (2) ◽  
pp. 185-197 ◽  
Author(s):  
Marcel CG van de Poll ◽  
Peter B Soeters ◽  
Nicolaas EP Deutz ◽  
Kenneth CH Fearon ◽  
Cornelis HC Dejong

2011 ◽  
Vol 187 (3) ◽  
pp. 399-401 ◽  
Author(s):  
Karin Sekulin ◽  
Angela Hafner-Marx ◽  
Jolanta Kolodziejek ◽  
Dirk Janik ◽  
Peter Schmidt ◽  
...  

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 613-613 ◽  
Author(s):  
Konstantin Byrgazov ◽  
Renate Kastner ◽  
Michael Dworzak ◽  
Gregor Hoermann ◽  
Oskar A. Haas ◽  
...  

Abstract We have identified a novel fusion gene in an 18-month old child with juvenile myelomonocytic leukemia (JMML) displaying a reciprocal chromosomal translocation t(5;7)(q33;p11.2). Molecular investigation at diagnosis revealed absence of mutations in KRAS, NRAS, PTPN11, or cCBL, but FISH analysis identified a rearrangement involving the PDGFRB gene located on chromosome 5q33. After temporary responses to imatinib (IM) and subsequently nilotinib (NIL) treatment, resistance associated with disease relapses was observed. Employment of the 5’-RACE technique facilitated identification of the PDGFRB fusion partner on chromosome 7p11.2, the NDEL1 gene encoding the nudE neurodevelopmental protein 1-like 1. The NDEL1 gene has not been implicated in any other reciprocal translocation to date, and it is conceivable that its ability to form dimers could drive permanent kinase activation of PDGFRβ. The chimeric mRNA contains the 5´exons 1-5 of NDEL1 fused in frame to the PDGFRB exons 10-22 containing the transmembrane and tyrosine kinase domains. To assess the oncogenicity of the fusion protein, Ba/F3 cells were transduced with the NDEL1-PDGFRB gene construct. The observation of IL3-independent growth confirmed the oncogenic potential of the novel fusion gene. The observed clinical resistance to IM and NIL prompted us to analyze the entire PDGFRB kinase domain for the presence of mutations by Sanger sequencing of overlapping amplicons. A point mutation in the activation (A) loop converting aspartate at the position 850 into glutamate (D850E) was detected in peripheral blood specimens from the time of first and second relapses, but not in the diagnostic sample. The crystal structure of the PDGFRβ TKD is not available, but protein modelling suggested that the mutation D850E destabilizes the inactive confirmation of the A-loop. This notion was in line with the observed clinical resistance to IM and NIL, but suggested sensitivity of the mutant to dasatinib (DAS). To test the predicted TKI responses, Ba/F3 cells transduced with wild type or mutant NDEL1-PDGFRB were tested in MTT assays against a panel of TKIs: Ba/F3-NDEL1-PDGFRBWT cells were sensitive to IM (IC50 = 60 nM), NIL (100 nM), DAS (5 nM), sorafenib (SOR; 20 nM), and ponatinib (PON; 10 nM), but insensitive to bosutinib (BOS; >2500 nM). Conversely, Ba/F3-NDEL1-PDGFRBD850E cells exhibited high resistance to IM (>2500), a 10-fold higher IC50 for NIL (1000 nM) and a 100-fold higher IC50 for SOR (2500 nM), but retained sensitivity to PON (15 nM) and DAS (15 nM). Mutations in the A-loop of different tyrosine kinases such as PDGFRα (D842V) or c-Kit (D816V) associated with resistance to IM have already been described in different tumor entities. However, the mutation D850E in the PDGFRβ TKD with apparent insensitivity to IM, NIL, and SOR revealed a completely different pattern of resistance than the same amino acid exchange at the corresponding site of PDGFRα (D842E). The latter mutation was previously shown to be sensitive to IM, NIL, and SOR with IC50 values of 4, 12.5, and 0.25 nM, respectively. This difference is intriguing because the exchange of a negatively charged amino acid, aspartate, to an amino acid with the same physical properties, glutamate, is not known to exert a major structural effect on the protein conformation, as observed for the D842E mutation in PDGFRα. We speculate that the great difference between the presence of the same amino acid exchange at corresponding positions in PDGFRα and PDGFRβ is the main interaction amino acid partner residue of aspartate at the position +3 which may influence the stability of the A-loop in its inactive conformation. In PDGFRα, it is histidine whose physical interaction with aspartate might not be affected by the change to glutamate. By contrast, the electrostatic bonds between arginine as the +3 residue in PDGFRβ might be greatly weakened by the elongation of the side chain in glutamate in comparison with aspartate, thus destabilizing the inactive conformation of the A-loop resulting in resistance to type II TKIs. To our knowledge, this is the first observation of an exchange between two negatively charged amino acids in a tyrosine kinase associated with a major change in responsiveness to TKI treatment. This finding is currently under further investigation, and may extend our understanding of structural interactions leading to TKI resistance. (Supported by the FWF SFB grant F4705-B20). Disclosures Valent: Novartis: Consultancy, Honoraria, Research Funding.


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