Dataset Information

Induction by Bradyrhizobium diazoefficiens of different catabolic pathways for growth in D-mannitol or L-arabinose leading to pronounced differences in CO2 fixation, O2 consumption, and lateral-flagellum production

ABSTRACT: Bradyrhizobium diazoefficiens, the soybean N2-fixing symbiont, uses mannitol or arabinose as carbon and energy source, among other substances. In this bacterium, growth with mannitol led to higher biomass production, and inhibited the synthesis of its secondary (lateral) flagellar system, regarding growth with arabinose. A proteomic comparison of bacteria grown in mannitol or arabinose suggested that mannitol may be degraded by the Calvin-Benson-Bassham pathway, while arabinose seems degraded by the L-2-keto-3-deoxyarabonate pathway, both pathways sharing only the reactions from pyruvate to CO2. Despite these differences, the stoichiometric balances resulted in similar O2 consumption and ATP production per C-mole of substrate. The poly-3-hydroxybutyrate biosynthesis pathway was stimulated in mannitol, while in arabinose there was a consistent increase in enzymes for the synthesis of nicotinamide adenine dinucleotide from aspartate, suggesting a surplus of reducing power in mannitol. This may agree to previous reports showing higher O2 consumption rate in arabinose, which taking into account the similarity in O2 consumption balance, suggests higher maintenance energy demand in this carbon and energy source. Since lateral flagella are produced only in arabinose, we wondered whether their energy demand might explain this difference. Hence, we compared the O2 consumption rates in mannitol and arabinose of the wild-type and a lafR::Km mutant devoid of lateral flagella. We observed that, while there was a three-fold higher O2 consumption rate in the wild-type in arabinose with respect to mannitol, there was no difference in the mutant, suggesting that lateral flagella behave as parasitic structures in this medium.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Bradyrhizobium Japonicum Usda 110

TISSUE(S): Prokaryotic Cell

DISEASE(S): Disease Free

SUBMITTER: Carolina Cogo

LAB HEAD: Anibal Roberto Lodeiro

PROVIDER: PXD008263 | Pride | 2018-06-25

REPOSITORIES: Pride

ACCESS DATA

Publications

Induction by Bradyrhizobium diazoefficiens of Different Pathways for Growth in D-mannitol or L-arabinose Leading to Pronounced Differences in CO2 Fixation, O2 Consumption, and Lateral-Flagellum Production.

Cogo Carolina C Pérez-Giménez Julieta J Rajeswari Chandrasekar B CB Luna María F MF Lodeiro Aníbal R AR

Frontiers in microbiology 20180605

Bradyrhizobium diazoefficiens, a soybean N2-fixing symbiont, constitutes the basic input in one of the most prominent inoculant industries worldwide. This bacterium may be cultured with D-mannitol or L-arabinose as carbon-plus-energy source (C-source) with similar specific growth rates, but with higher biomass production with D-mannitol. To better understand the bacterium's carbon metabolism, we analyzed, by liquid chromatography and tandem mass spectrometry (MS), the whole set ...[more]

PMID: 29922265

Similar Datasets

Project description:Algal photo-bio hydrogen production, a promising method for producing clean and renewable fuel in the form of hydrogen gas, has been studied extensively over the last few decades. In this study, microarray analyses were used to obtain a global expression profile of mRNA abundance in the green alga Chlamydomonas reinhardtii at five different time points before the onset and during the course of sulphur depleted hydrogen production. The present work confirms previous findings on the impacts of sulphur deprivation but also provides new insights into photosynthesis, sulphur assimilation and carbon metabolism under sulphur starvation towards hydrogen production. For instance, while a general trend towards repression of transcripts encoding photosynthetic genes was observed, the abundance of Lhcbm9 (encoding a major light harvesting polypeptide) and LhcSR1 (encoding a chlorophyll binding protein) was strongly elevated throughout the experiment, suggesting remodeling of the photosystem II light harvesting complex as well as an important function of Lhcbm9 under sulphur starvation. This study presents the first global transcriptional analysis of C. reinhardtii during hydrogen production using five major time points at Peak Oxygen, Mid Oxygen, Zero Oxygen, Mid Hydrogen and Peak Hydrogen. Keywords: Time course, sulfur deprivation, hydrogen production. Time course microarray analyses were used to analyze the global gene expression in sulfur depleted hydrogen producing C. reinhardtii. When depleted of sulfur, a sealed an illuminated C. reinhardtii culture slowly becomes anaerobic and produces hydrogen gas. Based on the changes in the dissolved O2 level and H2 production rate, the whole course of H2 production from the starting of S deprivation to the end of H2 production can be divided into five phases including an Aerobic Phase (I) in which the dissolved O2 level goes up (I), an O2 Consumption Phase (II), an Anaerobic Phase (III), a H2 Production Phase (IV) and a Termination phase (V). Samples were taken from three different bioreactors (biological replicates) at the following time points after the start of S depletion: 6 h, 16 h, 21 h, 37 h and 52 h corresponding to Peak O2, Mid O2, Zero O2, Mid H2 and Peak H2.

Project description:L-Arabinose occurs at economically relevant levels in lignocellulosic hydrolysates. Especially at low concentrations of L-arabinose, its uptake via the Gal2 galactose transporter is an important rate-controlling step in the complete conversion of these feedstocks by engineered, pentose-metabolizing Saccharomyces cerevisiae strains. Chemostat-based transcriptome analysis yielded 16 putative sugar transporter genes in the filamentous fungus Penicillium chrysogenum whose transcript levels were at least three-fold higher in L-arabinose-limited cultures than in glucose-limited and ethanol-limited cultures. Of five genes that showed an over 30-fold higher transcript level in arabinose-grown cultures, only one (Pc20g01790) restored growth on L-arabinose upon expression in an engineered L-arabinose-fermenting S. cerevisiae strain in which GAL2 had been deleted. Sugar-transport assays indicated that Pc20g01790this transporter, designated as PcAraT, encodes functions as a high-affinity (Km = 0.13 mM) L-arabinose-proton symporter that does not transport xylose or glucose. An L-arabinose-metabolizing S. cerevisiae strain co-expressing Pc20g01790PcAraT and GAL2 showed lower residual substrate concentrations in L-arabinose-limited chemostat cultures (4 mg L-1) than a congenic strain in which L-arabinose import exclusively depended on Gal2 (1.8 g L-1). Inhibition of L-arabinose transport by these sugars was less pronounced than observed with Gal2. A hexose-phosphorylation-deficient, L-arabinose-metabolizing S. cerevisiae strain expressing PcAraT Pc20g0190 grew on 20 g L-1 L-arabinose in the presence of 20 g L-1 glucose, which completely inhibited growth on L-arabinose of a congenic strain dependent on L-arabinose transport via Gal2. Its high affinity and specificity for L-L-arabinose, combined with limited sensitivity to inhibition by glucose and D-D-xylose make PcAraT/ Pc20g01790 a valuable transporter gene for application in metabolic engineering strategies aimed at engineering S. cerevisiae strains for efficient conversion of lignocellulosic hydrolysates.

Dataset Information

Induction by Bradyrhizobium diazoefficiens of different catabolic pathways for growth in D-mannitol or L-arabinose leading to pronounced differences in CO2 fixation, O2 consumption, and lateral-flagellum production

Publications

Induction by <i>Bradyrhizobium diazoefficiens</i> of Different Pathways for Growth in D-mannitol or L-arabinose Leading to Pronounced Differences in CO<sub>2</sub> Fixation, O<sub>2</sub> Consumption, and Lateral-Flagellum Production.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure