Chain elongation in anaerobic reactor microbiomes to recover resources from waste

Different microbial pathways can elongate the carbon chains of molecules in open cultures of microbial populations (i.e. reactor microbiomes) under anaerobic conditions. Here, we discuss three such pathways: 1. homoacetogenesis to combine two carbon dioxide molecules into acetate; 2. succinate formation to elongate glycerol with one carbon from carbon dioxide; and 3. reverse β oxidation to elongate short-chain carboxylates with two carbons into medium-chain carboxylates, leading to more energy-dense and insoluble products (e.g. easier to separate from solution). The ability to use reactor microbiomes to treat complex substrates can simultaneously address two pressing issues: 1. providing proper waste management; and 2. producing renewable chemicals and fuels.The authors thank Wolfgang Bucket (MPI Marburg) for assistance with Figure 1. C.M.S. and L.T.A. were supported by the U. S. Army Research Laboratory and the U. S. Army Research Office under contract/grant number W911NF-12-1-0555. H.R. was supported for this work by the Cornell University Agricultural Experiment Station federal formula funds, Project No. NYC-123452 received from the National Institutes for Food and Agriculture (NIFA), U.S. Department of Agriculture. K.R. was supported by the European Research Council Starter Grant Electrotalk and the Multidisciplinary Research Partnership Ghent Bio-Economy. A.J.M.S. was supported by the Chemical Sciences division of the Netherlands Science Foundation (CW-TOP 700.55.343) and the European Research Council (ERC grant 323009)

Family-Centered Preventive Intervention for Military Families: Implications for Implementation Science

In this paper, we report on the development and dissemination of a preventive intervention, Families OverComing Under Stress (FOCUS), an eight-session family-centered intervention for families facing the impact of wartime deployments. Specific attention is given to the challenges of rapidly deploying a prevention program across diverse sites, as well as to key elements of implementation success. FOCUS, developed by a UCLA-Harvard team, was disseminated through a large-scale demonstration project funded by the United States Bureau of Navy Medicine and Surgery (BUMED) beginning in 2008 at 7 installations and expanding to 14 installations by 2010. Data are presented to describe the range of services offered, as well as initial intervention outcomes. It proved possible to develop the intervention rapidly and to deploy it consistently and effectively

A communal catalogue reveals Earth's multiscale microbial diversity

Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

A communal catalogue reveals Earth’s multiscale microbial diversity

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

Long-Term <i>n</i>‑Caproic Acid Production from Yeast-Fermentation Beer in an Anaerobic Bioreactor with Continuous Product Extraction

Multifunctional reactor microbiomes can elongate short-chain carboxylic acids (SCCAs) to medium-chain carboxylic acids (MCCAs), such as <i>n</i>-caproic acid. However, it is unclear whether this microbiome biotechnology platform is stable enough during long operating periods to consistently produce MCCAs. During a period of 550 days, we improved the operating conditions of an anaerobic bioreactor for the conversion of complex yeast-fermentation beer from the corn kernel-to-ethanol industry into primarily <i>n</i>-caproic acid. We incorporated and improved in-line, membrane liquid–liquid extraction to prevent inhibition due to undissociated MCCAs at a pH of 5.5 and circumvented the addition of methanogenic inhibitors. The microbiome accomplished several functions, including hydrolysis and acidogenesis of complex organic compounds and sugars into SCCAs, subsequent chain elongation with undistilled ethanol in beer, and hydrogenotrophic methanogenesis. The methane yield was 2.40 ± 0.52% based on COD and was limited by the availability of carbon dioxide. We achieved an average <i>n-</i>caproate production rate of 3.38 ± 0.42 g L^–1 d^–1 (7.52 ± 0.94 g COD L^–1 d^–1) with an <i>n</i>-caproate yield of 70.3 ± 8.81% and an <i>n</i>-caproate/ethanol ratio of 1.19 ± 0.15 based on COD for a period of ∼55 days. The maximum production rate was achieved by increasing the organic loading rates in tandem with elevating the capacity of the extraction system and a change in the complex feedstock batch