Metabolic pairing of aerobic and anaerobic production in a one-pot batch cultivation

Abstract

BackgroundThe versatility of microbial metabolic pathways enables their utilization in vast number of applications. However, the electron and carbon recovery rates, essentially constrained by limitations of cell energetics, are often too low in terms of process feasibility. Cocultivation of divergent microbial species in a single process broadens the metabolic landscape, and thus, the possibilities for more complete carbon and energy utilization.ResultsIn this study, we integrated the metabolisms of two bacteria, an obligate anaerobe Clostridium butyricum and an obligate aerobe Acinetobacter baylyi ADP1. In the process, a glucose-negative mutant of A. baylyi ADP1 first deoxidized the culture allowing C. butyricum to grow and produce hydrogen from glucose. In the next phase, ADP1 produced long chain alkyl esters (wax esters) utilizing the by-products of C. butyricum, namely acetate and butyrate. The coculture produced 24.5 ± 0.8 mmol/l hydrogen (1.7 ± 0.1 mol/mol glucose) and 28 mg/l wax esters (10.8 mg/g glucose).ConclusionsThe cocultivation of strictly anaerobic and aerobic bacteria allowed the production of both hydrogen gas and long-chain alkyl esters in a simple one-pot batch process. The study demonstrates the potential of ‘metabolic pairing’ using designed microbial consortia for more optimal electron and carbon recovery.Electronic supplementary materialThe online version of this article (10.1186/s13068-018-1186-9) contains supplementary material, which is available to authorized users.

Characterization of a novel bacterial cellulose producer for the production of eco-friendly piezoelectric-responsive films from a minimal medium containing waste carbon

“…Biochemical characterizations were conducted in MA/9 (g/L; 5.52 Na 2 HPO 4 Á2 H 2 O, 3.4 KH 2 PO 4 , 1 NH 4 Cl, 0.008 nitrilotriacetic acid, 1 NaCl, 0.25 MgSO 4 Á7 H 2 O, 0.02 CaCl 2 Á2 H 2 O, 0.001 FeCl 3 and 0.2% casein amino acids) (Salmela et al 2018), and Peptone-Yeast extract (PY) medium (Asai and Shoda 1958) (g/L, 3 peptone and 2 yeast extract). Growth only in the presence of 30% glucose, 0.35% acetic acid, 3% ethanol, and 3% ethanol with 4% acetic acid, acetate and lactate oxidation tests, and catalase test were conducted as described previously (Asai and Shoda 1958).…”

“…Substrate utilization, and liquid end metabolites were analyzed using HPLC equipped with 300 mm 9 8 mm Shodex SUGAR column (Phenomenex), SIL-20AC HT autosampler (Shimadzu), RID-10A refractive index detector (Shimadzu), and 0.01 M H 2 SO 4 as the mobile phase. The HPLC samples were prepared as described previously (Salmela et al 2018).…”

Anaerobic oxidation of methane in sediments of a nitrate-rich, oligo-mesotrophic boreal lake

“…Organic fermentation products in porewaters were analyzed using high performance liquid chromatography (HPLC) equipped with Shodex SUGAR column (300 mm × 8 mm, Phenomenex, Torrance, CA, USA), autosampler (SIL-20AC HT, Shimadzu, Kioto, Japan), refractive index detector (RID-10A, Shimadzu), and 0.01 M H2SO4 as the mobile phase. The HPLC samples were prepared as described in Salmela et al (2018). The identification and quantification of the liquid metabolites (lactate, acetate and propionate) were conducted using external standards.…”

Towards bioproduction of poly-α-olefins from lignocellulose

“…In previous studies, the metabolisms of Acinetobacter baylyi ADP1 and Clostridia butyricum were paired for combined wax ester and hydrogen gas or 1,3-propanediol production from glucose and glycerol. 28,29 Here, more challenging substrates were investigated for the production of alkenes. 1-Undecene (C 11 ) biosynthesis from both cellulose and technical lignin was investigated by cultivating C. cellulolyticum and engineered A. baylyi ADP1 in a coupled two-stage system.…”