Hydrogen production and transcriptional analysis of nifD, nifK and hupS genes in Rhodobacter sphaeroides OU001 grown in media with different concentrations of molybdenum and iron

Kars, Gokhan
Gündüz, Ufuk
Yucel, Meral
Turker, Lemi
Eroglu, Inci
Rhodobacter sphaeroides O.U.001 was grown in media with different concentrations of molybdenum and iron to study the expression level of nifD and nifK genes coding for the large subunit of Mo-nitrogenase and hupS gene coding for the small subunit of uptake hydrogenase. Hydrogen productions under the same growth conditions were also evaluated. Increasing concentrations of the molybdenum and iron stimulated hydrogen production and the highest total hydrogen accumulation was achieved in 16.51 mu M sodium molybdare (0.841 H-2/l culture at t =168 h) and 0.1 mM ferric citrate (1.141 H-2/l culture at t =240 h) containing media. Maximal expressions of nifD and nifK were observed from the late log phase until the mid-stationary phase of growth and hupS expression was seen as soon as the hydrogen was produced in the cells. Moreover, nifK, nifD and hupS expressions were significantly reduced in the molybdenum and iron starved cells. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.


Hydrogen and poly-beta-hydroxybutyric acid production at various acetate concentrations using Rhodobacter capsulatus DSM 1710
Demiriz, Burcu Ozsoy; Kars, Gokhan; Yucel, Meral; EROĞLU, İNCİ; Gündüz, Ufuk (2019-06-28)
In the present study, Rhodobacter capsulatus DSM 1710 was cultured in media having various concentrations of acetate (10-65 mM) to investigate simultaneous production of hydrogen and PHB. The highest cumulative hydrogen productions were observed using 50 mM (11.7 mmol H-2) and 65 mM (11.4 mmol H-2) acetate. However, molar productivity values were higher at 25 mM (0.50 mmol/Lc.h) and 50 mM (0.44 mmol/Lc.h) compared to 65 mM (0.35 mmol/Lc.h). Furthermore, the highest PHB production (234.7 mg/L) was attained u...
Hydrogen production properties of Rhodobacter capsulatus with genetically modified redox balancing pathways
Ozturk, Yavuz; Gokce, Abdulmecit; Peksel, Begum; Gurgan, Muazzez; Ozgur, Ebru; Gündüz, Ufuk; Eroglu, Inci; Yucel, Meral (2012-01-01)
Rhodobacter capsulatus produces molecular hydrogen under the photoheterotrophic growth condition with reduced carbon sources (organic acids). Under this condition, ubiquinol pool is over reduced and excess reducing equivalents are primarily consumed via the reduction of CO2 through the Calvin-Benson-Bassham (CBS) pathway, the dimethylsulfoxide reductase (DMSOR) system or by the reduction of protons into hydrogen gas with the use of nitrogenase to maintain a balanced intracellular oxidation-reduction potenti...
Effects of ammonium ion, acetate and aerobic conditions on hydrogen production and expression levels of nitrogenase genes in Rhodobacter sphaeroides OU001
Akkose, Sevilay; Gündüz, Ufuk; Yucel, Meral; Eroglu, Inci (2009-11-01)
In the present study, expression levels of nitrogenase encoding nifH and control genes nifA and prrA were examined at different physiological conditions in Rhodobacter sphaeroides O.U.001. In addition to variations in expression levels, changes in hydrogen production and growth were also investigated in response to different concentrations of ammonium source, acetate and aerobic conditions.
Enzyme prediction with word embedding approach
Akın, Erkan; Atalay, M. Volkan.; Department of Computer Engineering (2019)
Information such as molecular function, biological process, and cellular localization can be inferred from the protein sequence. However, protein sequences vary in length. Therefore, the sequence itself cannot be used directly as a feature vector for pattern recognition and machine learning algorithms since these algorithms require fixed length feature vectors. We describe an approach based on the use of the Word2vec model, more specifically continuous skip-gram model to generate the vector representation o...
Long-term biological hydrogen production by agar immobilized Rhodobacter capsulatus in a sequential batch photobioreactor
Elkahlout, Kamal; Alipour, Siamak; Eroglu, Inci; Gündüz, Ufuk; Yücel, Ayşe Meral (2017-04-01)
In this study, agar immobilization technique was employed for biological hydrogen production using Rhodobacter capsulatus DSM 1710 (wild type) and YO3 (hup-mutant) strains in sequential batch process. Different agar and glutamate concentrations were tested with defined nutrient medium. Agar concentration 4% (w/v) and 4 mM glutamate were selected for bacterial immobilization in terms of rate and longevity of hydrogen production. Acetate concentration was increased from 40 to 60-100 and 60 mM gave best result...
Citation Formats
G. Kars, U. Gündüz, M. Yucel, L. Turker, and I. Eroglu, “Hydrogen production and transcriptional analysis of nifD, nifK and hupS genes in Rhodobacter sphaeroides OU001 grown in media with different concentrations of molybdenum and iron,” INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, pp. 1536–1544, 2006, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30245.