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Carbon chain elongation (CCE), a reaction within the carboxylate platform that elongates short-chain to medium-chain carboxylates by mixed culture, has attracted worldwide interest. The present study provides insights into the microbial diversity and predictive microbial metabolic pathways of a mixed-culture CCE microbiome on the basis of a comparative analysis of the metagenome and metatranscriptome. We found that the microbial structure of an acclimated chain elongation microbiome was a highly similar to that of the original inoculating biogas reactor culture; however, the metabolic activities were completely different, demonstrating the high stability of the microbial structure and flexibility of its functions. Additionally, the fatty acid biosynthesis (FAB) pathway, rather than the well-known reverse β-oxidation (RBO) pathway for CCE, was more active and pivotal, though the FAB pathway had more steps and consumed more ATP, a phenomenon that has rarely been observed in previous CCE studies. A total of 91 draft genomes were reconstructed from the metagenomic reads, of which three were near completion (completeness, >97%) and were assigned to unknown strains of ,, and The last two strains are likely new-found active participators of CCE in the mixed culture. Finally, a conceptual framework of CCE, including both pathways and the potential participators, was proposed. Carbon chain elongation means the conversion of short-chain volatile fatty acids to medium-chain carboxylates, such as -caproate and-caprylate with electron donors under anaerobic condition. This bio-reaction can both expand the resource of valuable biochemicals and broaden the utilization of low-grade organic residues in a sustainable biorefinery context. is conventionally considered model microbe for carbon chain elongation which uses the reverse β-oxidation pathway. However, little is known about the detailed microbial structure and function of other abundant microorganism in a mixed culture (or open culture) of chain elongation. We conducted the comparative metagenomic and metatranscriptomic analysis of a chain elongation microbiome to throw light on the underlying functional microbes and alternative pathways.

Antimony selenide (Sb 2 Se 3 ) has attracted increasing attention in photovoltaic applications due to its unique quasi-one-dimensional crystal structure, suitable optical band gap with a high extinction coefficient, and excellent stability. As a promising light-harvesting material, the available synthetic methods for the fabrication of a high-quality film have been quite limited and seriously impeded both the fundamental study and the efficiency improvement. Here, we developed a facile and low-cost hydrothermal method for in situ deposition of Sb 2 Se 3 films for solar cell applications. In this process, we apply KSbC 4 H 4 O 7 and Na 2 SeSO 3 as the antimony and selenium sources, respectively, in which thiourea (TU) serves as an additive to suppress the formation of Sb 2 O 3 impurities. As a result, improved phase purity and enhanced crystallinity of the Sb 2 Se 3 film are thus obtained, along with decreased trap states. Finally, the planar heterojunction Sb 2 Se 3 solar cell delivered a power conversion efficiency of 7.9%, which is thus far the highest reported efficiency among solution-processed Sb 2 Se 3 solar cells. This simple procedure and efficiency achievement demonstrate the great potential of the hydrothermal deposition process for the fabrication of high-efficiency Sb 2 Se 3 solar cells.

BackgroundThis study aimed at producing C6–C8 medium-chain carboxylates (MCCAs) directly from gaseous CO using mixed culture. The yield and C2–C8 product composition were investigated when CO was continuously fed with gradually increasing partial pressure.ResultsThe maximal concentrations of n-caproate, n-heptylate, and n-caprylate were 1.892, 1.635, and 1.033 mmol L−1, which were achieved at the maximal production rates of 0.276, 0.442, and 0.112 mmol L−1 day−1, respectively. Microbial analysis revealed that long-term acclimation and high CO partial pressure were important to establish a CO-tolerant and CO-utilizing chain-elongating microbiome, rich in Acinetobacter, Alcaligenes, and Rhodobacteraceae and capable of forming MCCAs solely from CO.ConclusionsThese results demonstrated that carboxylate and syngas platform could be integrated in a shared growth vessel, and could be a promising one-step technique to convert gaseous syngas to preferable liquid biochemicals, thereby avoiding the necessity to coordinate syngas fermentation to short-chain carboxylates and short-to-medium-chain elongation. Thus, this method could provide an alternative solution for the utilization of waste-derived syngas and expand the resource of promising biofuels.Electronic supplementary materialThe online version of this article (10.1186/s13068-017-1005-8) contains supplementary material, which is available to authorized users.

Literature-described targets of herbal ingredients have been explored to facilitate the mechanistic study of herbs, as well as the new drug discovery. Though several databases provided similar information, the majority of them are limited to literatures before 2010 and need to be updated urgently. HIT 2.0 was here constructed as the latest curated dataset focusing on Herbal Ingredients’ Targets covering PubMed literatures 2000–2020. Currently, HIT 2.0 hosts 10 031 compound-target activity pairs with quality indicators between 2208 targets and 1237 ingredients from more than 1250 reputable herbs. The molecular targets cover those genes/proteins being directly/indirectly activated/inhibited, protein binders, and enzymes substrates or products. Also included are those genes regulated under the treatment of individual ingredient. Crosslinks were made to databases of TTD, DrugBank, KEGG, PDB, UniProt, Pfam, NCBI, TCM-ID and others. More importantly, HIT enables automatic Target-mining and My-target curation from daily released PubMed literatures. Thus, users can retrieve and download the latest abstracts containing potential targets for interested compounds, even for those not yet covered in HIT. Further, users can log into ‘My-target’ system, to curate personal target-profiling on line based on retrieved abstracts. HIT can be accessible at http://hit2.badd-cao.net.

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The gas-phase pyrolysis of n-C4F10 has been studied experimentally in a plug flow, isothermal α-alumina reactor at atmospheric pressure and various residence times over the temperature range of 873 to 1148 K. The major products are C2F6, C2F4, C3F8, and C3F6 (CF3−CFCF2). Minor products include cyclo-C4F8 (c-C4F8) and CO2. CF4 is detected in trace amounts at high temperatures. A kinetic reaction scheme involving 20 species and 30 reactions is developed and used to model n-C4F10 pyrolysis. A generally satisfactory agreement between experimental and modeling results is obtained on the conversion levels of n-C4F10 and the rates of formation of C2F6 and C3F8.