@article {3086,
	title = {Transcriptomic profiles of Clostridium ljungdahlii during lithotrophic growth with syngas or H and CO compared to organotrophic growth with fructose.},
	journal = {Sci Rep},
	volume = {7},
	year = {2017},
	month = {2017 Oct 13},
	pages = {13135},
	abstract = {<p>Clostridium ljungdahlii derives energy by lithotrophic and organotrophic acetogenesis. C. ljungdahlii was grown organotrophically with fructose and also lithotrophically, either with syngas - a gas mixture containing hydrogen (H), carbon dioxide (CO), and carbon monoxide (CO), or with H and CO. Gene expression was compared quantitatively by microarrays using RNA extracted from all three conditions. Gene expression with fructose and with H/CO was compared by RNA-Seq. Upregulated genes with both syngas and H/CO (compared to fructose) point to the urea cycle, uptake and degradation of peptides and amino acids, response to sulfur starvation, potentially NADPH-producing pathways involving (S)-malate and ornithine, quorum sensing, sporulation, and cell wall remodeling, suggesting a global and multicellular response to lithotrophic conditions. With syngas, the upregulated (R)-lactate dehydrogenase gene represents a route of electron transfer from ferredoxin to NAD. With H/CO, flavodoxin and histidine biosynthesis genes were upregulated. Downregulated genes corresponded to an intracytoplasmic microcompartment for disposal of methylglyoxal, a toxic byproduct of glycolysis, as 1-propanol. Several cytoplasmic and membrane-associated redox-active protein genes were differentially regulated. The transcriptomic profiles of C. ljungdahlii in lithotrophic and organotrophic growth modes indicate large-scale physiological and metabolic differences, observations that may guide biofuel and commodity chemical production with this species.</p>},
	keywords = {Carbon Dioxide, Carbon Monoxide, Clostridium, Fructose, Hydrogen, NADP, Transcriptome},
	issn = {2045-2322},
	doi = {10.1038/s41598-017-12712-w},
	author = {Aklujkar, Muktak and Leang, Ching and Shrestha, Pravin M and Shrestha, Minita and Lovley, Derek R}
}
@article {404,
	title = {Interspecies electron transfer via hydrogen and formate rather than direct electrical connections in cocultures of Pelobacter carbinolicus and Geobacter sulfurreducens.},
	journal = {Appl Environ Microbiol},
	volume = {78},
	year = {2012},
	month = {2012 Nov},
	pages = {7645-51},
	abstract = {<p>Direct interspecies electron transfer (DIET) is an alternative to interspecies H(2)/formate transfer as a mechanism for microbial species to cooperatively exchange electrons during syntrophic metabolism. To understand what specific properties contribute to DIET, studies were conducted with Pelobacter carbinolicus, a close relative of Geobacter metallireducens, which is capable of DIET. P. carbinolicus grew in coculture with Geobacter sulfurreducens with ethanol as the electron donor and fumarate as the electron acceptor, conditions under which G. sulfurreducens formed direct electrical connections with G. metallireducens. In contrast to the cell aggregation associated with DIET, P. carbinolicus and G. sulfurreducens did not aggregate. Attempts to initiate cocultures with a genetically modified strain of G. sulfurreducens incapable of both H(2) and formate utilization were unsuccessful, whereas cocultures readily grew with mutant strains capable of formate but not H(2) uptake or vice versa. The hydrogenase mutant of G. sulfurreducens compensated, in cocultures, with significantly increased formate dehydrogenase gene expression. In contrast, the transcript abundance of a hydrogenase gene was comparable in cocultures with that for the formate dehydrogenase mutant of G. sulfurreducens or the wild type, suggesting that H(2) was the primary electron carrier in the wild-type cocultures. Cocultures were also initiated with strains of G. sulfurreducens that could not produce pili or OmcS, two essential components for DIET. The finding that P. carbinolicus exchanged electrons with G. sulfurreducens via interspecies transfer of H(2)/formate rather than DIET demonstrates that not all microorganisms that can grow syntrophically are capable of DIET and that closely related microorganisms may use significantly different strategies for interspecies electron exchange.</p>},
	keywords = {Coculture Techniques, Deltaproteobacteria, Electricity, Electron Transport, Electrons, Formates, Geobacter, Hydrogen, Microbial Interactions},
	issn = {1098-5336},
	doi = {10.1128/AEM.01946-12},
	author = {Rotaru, Amelia-Elena and Shrestha, Pravin M and Liu, Fanghua and Ueki, Toshiyuki and Nevin, Kelly and Summers, Zarath M and Lovley, Derek R}
}
