Rhodobacter Sphaeroides Strain Research Articles

Construction of the Rhodobacter sphaeroides strain overproducing 5-aminolevulinic acid by insertion of endogenous promoter.

5-Aminolevulinic acid (ALA) is a precursor of heme and a natural amino acid synthesized in the cells of most living organisms. Currently, ALA is used as an ingredient in pharmaceuticals, supplements, cosmetics, feed, fertilizers, and other products. ALA is mainly produced by industrial fermentation by the photosynthetic bacterium Rhodobacter sphaeroides. In this study, we tried to improve the ALA productivity by R. sphaeroides using a genetic strategy to highly express ALA synthase (ALAS) genes. We inserted a constitutive promoter (PrrnB or Prsp_7571) upstream of genes encoding ALAS (hemA and/or hemT) to construct strains that constitutively express ALAS. The highest transcript levels of hemA were observed in the strain where PrrnB was inserted into the hemA promoter region and were 3.5-fold higher than those in the wild-type. The highest transcript levels of hemT were observed in the strain where PrrnB was inserted into the hemT promoter region and were 46-fold higher than those in the wild-type. The maximum ALAS activity was observed in crude cell extracts of the strain where PrrnB was inserted into the hemT promoter region under optimized growth conditions that was 2.7-fold higher than that in the wild type. This strain showed 12-fold accumulation of ALA compared to the wild-type. Thus, we improved ALA productivity without using exogenous DNA sequences. In the future, further improvement in ALA productivity may be expected by applying this approach to current industrial ALA-producing bacteria.

Construction of a Rhodobacter sphaeroides Strain That Efficiently Produces Hydrogen Gas from Acetate without Poly(β-Hydroxybutyrate) Accumulation: Insight into the Role of PhaR in Acetate Metabolism.

The purple nonsulfur phototrophic bacterium Rhodobacter sphaeroides produces hydrogen gas (H2) from acetate. An approach to improve the H2 production is preventing accumulation of an intracellular energy storage molecule known as poly(β-hydroxybutyrate) (PHB), which competes with H2 production for reducing power. However, disruption of PHB biosynthesis has been reported to severely impair the acetate assimilation depending on the genetic backgrounds and/or culture conditions. To solve this problem, we analyzed the relationship between PHB accumulation and acetate metabolism in R. sphaeroides. Gene deletion analyses based on the wild-type strain revealed that among the two polyhydroxyalkanoate synthase genes in the genome, phaC1, but not phaC2, is essential for PHB accumulation, and the phaC1 deletion mutant exhibited slow growth with acetate. On the other hand, a strain with the deletion of phaC1 together with phaR, which encodes a transcriptional regulator capable of sensing PHB accumulation, exhibited growth comparable to that of the wild-type strain despite no accumulation of PHB. These results suggest that PHB accumulation is required for normal growth with acetate by altering the expression of genes under the control of phaR. This hypothesis was supported by a transcriptome sequencing (RNA-seq) analysis revealing that phaR is involved in the regulation of the ethylmalonyl coenzyme A pathway for acetate assimilation. Consistent with these findings, deletion of phaC1 in a genetically engineered H2-producing strain resulted in lower H2 production from acetate due to growth defects, whereas deletion of phaR together with phaC1 restored growth with acetate and increased H2 production from acetate without PHB accumulation. IMPORTANCE This study provides a novel approach for increasing the yield of photofermentative H2 production from acetate by purple nonsulfur phototrophic bacteria. This study further suggests that polyhydroxyalkanoate is not only a storage substance for carbon and energy in bacteria, but may also act as a signaling molecule that mediates bacterial metabolic adaptations to specific environments. This notion will be helpful for understanding the physiology of polyhydroxyalkanoate-producing bacteria, as well as for their metabolic engineering via synthetic biology.

Comparative Genome Analysis Provides Molecular Evidence for Reclassification of the Photosynthetic Bacterium Rhodobacter sphaeroides EBL0706 as a Strain of Luteovulum azotoformans.

In this study, we conducted a genome-wide comparative analysis of a former Rhodobacter sphaeroides strain EBL0706, which is now recorded as Luteovulum sphaeroides EBL0706. The genome of EBL0706 was compared with that of Luteovulum azotoformans ATCC 17025, Luteovulum azotoformans KA25, and Luteovulum sphaeroides 2.4.1. The average nucleotide identity (ANI), tetra nucleotide signatures (Tetra), digital DNA–DNA hybridization (dDDH) values, comparative genome, and phylogenetic analysis proposed that EBL0706 is a strain of Luteovulum azotoformans. Functional annotations identified a total of 4034 protein-coding genes in the genome of EBL0706, including a complete photosynthetic gene cluster. This study provides genomic molecular verification for the strain EBL0706 to be reclassified to Luteovulum azotoformans.

Photofermentative biohydrogen generation from organic acids by Rhodobacter sphaeroides O.U.001: Computational fluid dynamics modeling of hydrodynamics and temperature.

Hydrogen gas is a clean-burning fuel suitable for powering public vehicles. Hydrogen fuel has the highest energy density (143 MJ kg-1 ). This research paper emphasizes three-dimensional hydrodynamics and temperature distribution during photobiohydrogen generation by Rhodobacter sphaeroides strain O.U.001 in a triple-jacketed 1 L photobioreactor (PBR). The fermentation broth has turbulent flow conditions and light gradients among various layers, which affect the light conversion efficiency of the PBR. From the carbon source (malic acid), various organic acids are produced within fermentation (lactate, acetate, and formate). Modeling and simulation studies by computational fluid dynamics confirmed uniform fluid dynamics and heat transfer throughout the annular PBR. The modified Gompertz equation gave good simulated fitting with an experimental value for H2 generation. R. sphaeroides O.U. 001 gave good simulated results for H2 generation with mathematical modeling of substrate consumption kinetics and substrate utilization for biomass.

Bioconversion of Fish Hatchery Waste as Feed in the Production of Live Feed

Purple Non-Sulfur Bacteria (PNSB), also known as phototrophic bacteria are widely distributed in both freshwater and marine environment and capable to grow in wide range of substrates. In this study, Bacterium Rhodobacter sphaeroides strain UMS2, a freshwater isolate was used in this study in utilization of fish hatchery waste. This study was conducted to determine the nutritional values of bioprocess product that was grown in fish hatchery waste. Finally, the waste bio-converted product was used as feed supplement to monitor the growth performance of live feed Tubifex spp. Inoculum of Rhodobacter sphaeroides strain UMS2 was developed in 112 synthetic media and 48-h culture of 30% (v/v) inoculum was used in fish hatchery waste during the bioprocess. The nutritional values of bio-converted product, except total ash (%), were not significantly improved with 30% (v/v) inoculum of Rhodobacter sphaeroides, strain UMS2. Feeding trial in bloodworm (Tubifex spp.) with bioconversion product conducted for 15 days to monitor growth (w/v) of live feed. Initial growth 1.42 ± 0.001 g/L of Tubifex spp. was stocked in 15 × 75 × 15 cm plastic tray connected with recirculated system. Tubifex spp. was observed to be comparatively higher (1.55 ± 0.12 g/L) while fed in the product that contained bacterium than the growth (1.44 ± 0.15 g/L) of Tubifex spp. fed in the bioconversion product of without bacterium. The inoculums size (30%) of bacterium not enough to support the growth of Rhodobacter sphaeroides, strain UMS2 in the bioconversion process to improve the nutritional values. However, while used as feed supplement it improved the growth performance of the Tubifex spp. So, bacterium Rhodobacter sphaeroides, strain UMS2 has potentiality to be used as feed supplement in the production of live feed.

Rhodobacter sediminicola sp. nov., isolated from a fresh water pond.

A phototrophic bacterium, designated as strain JA983T, was isolated from a freshwater pond in Gujarat, India. The strain was yellowish brown, catalase- and oxidase-positive, rod-to-oval shaped, Gram-stain-negative and motile. Growth was observed at 20-35 °C. NaCl was not required for optimum growth and up to 5 % was tolerated. Growth was observed at pH 6.0-8.0, with an optimum at pH 7.0. An unidentified glycolipid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two unidentified aminolipids (AL1, AL2) and two unidentified lipids (L1 and L2) are the polar lipids of JA983T. Q10 is the only quinone. C18 : 1 ω7c/C18 : 1 ω6c is the major fatty acid. JA983T showed highest 16S rRNA gene sequence similarity with the type strains of Rhodobacter sphaeroides (98.99%), Rhodobacter megalophilus (98.99 %), Rhodobacter johrii (98.99 %) and other members of the genus Rhodobacter with less than 98.7 % similarity. In a 16S rRNA gene sequence-based phylogenetic tree, JA983T formed a different sub-clade with its nearest phylogenetic members of genus Rhodobacter. Phenotypic, chemotaxonomic, phylogenetic and genomic [average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) differences indicated that JA983T is significantly different from other species of the genus Rhodobacter and thus represents a novel species of the genus for which the name Rhodobacter sediminicola sp. nov. is proposed. The type strain is JA983T (=KCTC 15782T=NBRC 113843T).

Engineering the transcriptional activator NifA for the construction of Rhodobacter sphaeroides strains that produce hydrogen gas constitutively.

Purple non-sulfur photosynthetic bacteria such as Rhodobacter sphaeroides and Rhodopseudomonas palustris produce hydrogen gas (H2) via proton reduction, which is catalyzed by nitrogenase. Although the expression of nitrogenase is usually repressed under nitrogen-sufficient conditions, a partial deletion of nifA, which encodes a transcriptional activator of nitrogen-fixation genes, has been reported to enable the constitutive expression of nitrogenase in R. palustris. In this study, we evaluated the effects of a similar mutation (nifA* mutation) on H2 production during the photoheterotrophic growth of R. sphaeroides, based on the notion that H2 production by nitrogenase compensates for the loss of CO2 fixation via the Calvin cycle, thereby restoring the redox balance. The chromosomal nifA* mutation resulted in the slight restoration of the photoheterotrophic growth of a mutant strain lacking ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO), the key enzyme of the Calvin cycle, when the strain was cultured in van Niel's yeast medium. In addition, the strain with the nifA* mutation produced detectable levels of H2 during photoheterotrophic growth with acetate and ammonium; however, the H2 production was considerably lower than that observed during the photoheterotrophic growth of the strain with acetate and L-glutamate, where L-glutamate serves as a poor nitrogen source, thereby causing nitrogenase derepression. On the other hand, introduction of a multicopy plasmid harboring nifA* markedly restored the photoheterotrophic growth of the RubisCO-deletion mutant in van Niel's yeast medium and resulted in efficient H2 production during the photoheterotrophic growth with acetate and ammonium.

Complete Genome Sequence of Rhodobacter sphaeroides Strain HJ, a Purple Nonsulfur Bacterium with the Ability To Produce High Levels of Hydrogen from Acetate.

Previously, Rhodobacter sphaeroides strain HJ was isolated to obtain a purple nonsulfur bacterium with the ability to produce high levels of hydrogen from acetate. However, the genome of this strain has not been previously sequenced. Therefore, the complete genome sequence of R. sphaeroides strain HJ is presented in this report.

Picosecond Dynamical Response to a Pressure-Induced Break of the Tertiary Structure Hydrogen Bonds in a Membrane Chromoprotein.

We used elastic incoherent neutron scattering (EINS) to find out if structural changes accompanying local hydrogen bond rupture are also reflected in global dynamical response of the protein complex. Chromatophore membranes from LH2-only strains of the photosynthetic bacterium Rhodobacter sphaeroides, with spheroidenone or neurosporene as the major carotenoids, were subjected to high hydrostatic pressure at ambient temperature. Optical spectroscopy conducted at high pressure confirmed rupture of tertiary structure hydrogen bonds. In parallel, we used EINS to follow average motions of the hydrogen atoms in LH2, which reflect the flexibility of this complex. A decrease of the average atomic mean square displacements of hydrogen atoms was observed up to a pressure of 5 kbar in both carotenoid samples due to general stiffening of protein structures, while at higher pressures a slight increase of the displacements was detected in the neurosporene mutant LH2 sample only. These data show a correlation between the local pressure-induced breakage of H-bonds, observed in optical spectra, with the altered protein dynamics monitored by EINS. The slightly higher compressibility of the neurosporene mutant sample shows that even subtle alterations of carotenoids are manifested on a larger scale and emphasize a close connection between the local structure and global dynamics of this membrane protein complex.

Draft Genome Sequences of Four Rhodobacter sphaeroides Strains Isolated from a Marine Ecosystem.

Rhodobacter sphaeroides is an alphaproteobacterium found in freshwater and marine ecosystems. To better understand the metabolic diversity within this species, we isolated and sequenced four R. sphaeroides isolates obtained from Trunk River in Woods Hole, Massachusetts. Here, we report the draft genome sequences of R. sphaeroides AB24, AB25, AB27, and AB29.

Efficacy of Purple Non Sulphur Bacterium <i>Rhodobacter sphaeroides</i> Strain UMSFW1 in the Utilization of Palm Oil Mill Effluent

Sustainable use of palm oil mill effluent (POME) has been the major focus in the recent development in palm oil industry due to the fact that environmental issue brought by POME. The purpose of this study was to determine the optimum incubation period of purple non-sulphur bacterium (PNSB) in reduction of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) in settled POME and to determine the dry cell weight, TN, TP and cell yield of PNSB. Pure isolate of Rhodobacter sphaeroides strain UMSFW1 was cultured in settled POME under anaerobic condition at 2500 lux illumination on light intensity at a temperature of 30°C ± 2°C for 144-h. Parameters such as COD (mg/L), dry cell biomass (g/L), TP (mg/L) and TN (mg/L) in settled POME and bacterial cells were analyzed. A total reduction of TN (43.9%) in settled POME and a total increase of TN (43.2%) in bacterial cell were recorded at the end of experiment. At the same time the reduction of 51.5% chemical oxygen demand was determined from the POME. The highest dry cell weight of 2.44 g/L with cell yield 0.39 (mg/cell/mg COD) was achieved at the end of experiment. A total 24.7% of TP reduction in settled POME was achieved in 144-h culture, but while a maximum 10% of TP in bacterial cell was achieved in 48-h culture. This study shows that PNSB Rhodobacter sphaeroides strain UMSFW1 grows well by using settled POME as substrate and is capable to remove TN in the settled POME and assimilate into bacterial biomass. This study could provide us a further insight in the nutrient removal and COD removal in the bioremediation process by bacterium Rhodobacter sphaeroides strain UMSFW1.

PH dependence of the charge recombination kinetics in bacterial RC reconstituted in liposomes

ABSTRACT:The photosynthetic Reaction Center from the carotenoidless mutant strain of the purple non sulphur bacterium Rhodobacter (R.) sphaeroides was reconstituted in artificial phospholipid vesicles (liposomes) to mimic the physiological membrane environment. The pH dependence in the interval 5 – 10 of the rate of the charge-recombination reactions from the final electron acceptors QA and QB to the primary electron donor (namely kAD and kBD) have been investigated. The liposomes were constituted of either the zwitterionic phosphatidylcholine (PC) or the negatively charged phosphatidylglycerol (PG), two of the main phospholipids found in the photosynthetic membrane of the bacterium. In both cases, the kAD has no pH dependence similarly to the detergent case. The kBD also has a pH dependence similar to the detergent case, having two distinct regions below pH 7 and above pH 9. Fitting of the titration curve to a function involving two protonation sites results in a marked shift of the pKAs between the different solubilizing environments. These differences are discussed in the frame of possible physiological implications.

Whole-genome sequence of purple non-sulfur bacteria, Rhodobacter sphaeroides strain MBTLJ-8 with improved CO2 reduction capacity

Rhodobacter sphaeroides consists of two chromosomes and many plasmids and incorporates many environmentally important functional gene. Rhodobacter sphaeroides MBTLJ-8 was derived from R. sphaeroides 2.4.1 using chemical mutagenesis and is characterized by enhanced production of physiological active compounds as well as improved carbon dioxide reduction capacity. We reported the complete genome sequence and characteristics based on genomic information of this bacteria.Therefore, this genome sequence provides elucidation for improved CO2 fixation and enhanced physiological active compounds production, and will be used as the efficient photosynthetic bacteria for the biological CO2 reduction system.

Resolving the roles of the Rhodobacter sphaeroides HemA and HemT 5-aminolevulinic acid synthases.

Strains of the phototrophic alpha-proteobacterium Rhodobacter sphaeroides vary in the number of enzymes catalyzing the formation of 5-aminolevulinic acid (ALA synthases) that are encoded in their genomes. All have hemA, but not all have hemT. This study compared transcription of these genes, and also properties of their products among three wild-type strains; 2.4.3 has hemA alone, 2.4.1 and 2.4.9 have both hemA and hemT. Using lacZ reporter plasmids all hemA genes were found to be upregulated under anaerobic conditions, but induction amplitudes differ. hemT is transcriptionally silent in 2.4.1 but actively transcribed in 2.4.9, and strongly upregulated under anaerobic-dark growth conditions when cells are respiring dimethyl sulfoxide, vs. aerobic-dark or phototrophic (anaerobic-light) conditions. Two extracytoplasmic function (ECF)-type sigma factors present in 2.4.9, but absent from 2.4.1 are directly involved in hemT transcription. Kinetic properties of the ALA synthases of all three strains were similar, but HemT enzymes are far less sensitive to feedback inhibition by hemin than HemA enzymes, and HemT is less active under oxidizing conditions. A model is presented that compares and contrast events in strains 2.4.1 and 2.4.9.

Cooperative Photoprotection by Multicompositional Carotenoids in the LH1 Antenna from a Mutant Strain of Rhodobacter sphaeroides.

To explore the photoprotection role of multicompositional carotenoid (Car) in photosynthetic purple bacteria, we investigated, by means of triplet excitation profile (TEP) combined with steady-state optical spectroscopies, the core light-harvesting complex-reaction center of a mutant strain of Rhodobacter sphaeroides (m-LH1-RC) at room temperature. TEP spectra revealed that spheroidene and derivative (Spe) preferentially protect bacteriochlorophylls (BChls) of relatively lower site energy by quenching the triplet excitation (3BChl*); however, spirilloxanthin (Spx) does so irrespective to the site energy of BChls. Triplet excitation results showed the triplet excitation energy-transfer (EET) reaction in a timescale of ∼0.5 μs from Spe and derivatives as a major component (∼85%) to Spx as a minor component (∼8%), suggesting the coexistence of different kinds of Cars in the individual LH1 complex. The nonequivalent quenching potency and the triplet EET reaction between Cars constitute the cooperative photoprotection by multicompositional Cars in bacterial photosynthesis.

Carotenoid to bacteriochlorophyll energy transfer in the RC-LH1-PufX complex from Rhodobacter sphaeroides containing the extended conjugation keto-carotenoid diketospirilloxanthin.

RC-LH1-PufX complexes from a genetically modified strain of Rhodobacter sphaeroides that accumulates carotenoids with very long conjugation were studied by ultrafast transient absorption spectroscopy. The complexes predominantly bind the carotenoid diketospirilloxanthin, constituting about 75% of the total carotenoids, which has 13 conjugated C=C bonds, and the conjugation is further extended to two terminal keto groups. Excitation of diketospirilloxanthin in the RC-LH1-PufX complex demonstrates fully functional energy transfer from diketospirilloxanthin to BChl a in the LH1 antenna. As for other purple bacterial LH complexes having carotenoids with long conjugation, the main energy transfer route is via the S2-Qx pathway. However, in contrast to LH2 complexes binding diketospirilloxanthin, in RC-LH1-PufX we observe an additional, minor energy transfer pathway associated with the S1 state of diketospirilloxanthin. By comparing the spectral properties of the S1 state of diketospirilloxanthin in solution, in LH2, and in RC-LH1-PufX, we propose that the carotenoid-binding site in RC-LH1-PufX activates the ICT state of diketospirilloxanthin, resulting in the opening of a minor S1/ICT-mediated energy transfer channel.

The roles of probiotic purple nonsulfur bacteria to control water quality and prevent acute hepatopancreatic necrosis disease (AHPND) for enhancement growth with higher survival in white shrimp (Litopenaeus vannamei) during cultivation

This study aimed to investigate the potential of a mixed probiotic purple nonsulfur bacteria (PNSB) for controlling water quality and preventing acute hepatopancreatic necrosis disease (AHPND) to promote growth performance and increase survival of white shrimp (Litopenaeus vannamei) in postlarval stage during cultivation. Four probiotic PNSB (Rhodobacter sphaeroides strains SS15, S3W10, TKW17 and Afifella marina STW181) were investigated for controlling water quality using a mixed culture at a ratio of 1: 1 (roughly 1×108cellsmL−1 for each, every week 1–7) as follows; T1 (S3W10+SS15), T2 (S3W10+TKW17) and T3 (S3W10+STW181) and found that throughout 8weeks shrimp cultivation the most effective sets to reduce NH4+ and promote shrimp growth (based on weight and total length) were T1 and T3, respectively. Hence, PNSB strains (SS15, S3W10 and STW181) were used as a mixed culture (1: 1: 1, roughly 1×108cellsmL−1 for each at weeks 1, 2 and 3) assessing their potential to prevent AHPND by challenge test on shrimp with a virulent strain AHPND-causing Vibrio parahaemolyticus SR2 (roughly 1×105cellsmL−1 at day 15) during shrimp cultivation for 30days. Inoculated PNSB sets (positive control: only PNSB inoculation, and treatment: both PNSB and SR2 inoculations) significantly decreased (P<0.05) the levels of NH4+, NO2−, NO3− and chemical oxygen demand (COD) with significantly higher (P<0.05) of dissolved oxygen (DO) compared to native control (no inoculation) and challenge test (only SR2 inoculation). The maximal growth performance of shrimp was observed in the positive control; while no significant difference (P>0.05) was observed for other sets. PNSB survived and colonized in intestinal shrimp tract to prevent AHPND by increasing 11% survival rate of infected shrimp by strain SR2. The correlation coefficient between PNSB population and shrimp survival showed a positive strong correlation, but a negative strong correlation between vibrios population and shrimp survival. Overall results proved that a mixed three probiotic PNSB are a good candidate for applying in white shrimp cultivation to maintain water quality and to protect shrimp diseases for promoting shrimp growth with higher survival rate.

The effect of Cu (I) and Cu (II) ions' low concentrations on growth, biohydrogen production and the FoF1-ATPase activity of Rhodobacter sphaeroides

Various metal ions play a key role in growth and biohydrogen (H2) production by phototrophic bacteria through incorporation into or stimulation of the responsible enzymes and/or related metabolic pathways. This study shows, that Cu (I) ions, at low concentration (<5 μM), suppressed the growth of Rhodobacter sphaeroides strain MDC6521, isolated from mineral springs in Armenia, but enhanced the H2 yield by this bacterium. In contrast, Cu (II) ions with the same concentrations inhibited H2 yield. These ions also affected the medium redox potential during R. sphaeroides growth. N,N′-dicyclohexylcarbodiimide-sensitive ATPase activity of R. sphaeroides membrane vesicles was increased in the presence of both ions. Cu ions at low concentrations are suggested to affect biohydrogen production pathways or responsible enzymes in R. sphaeroides, proton FoF1-ATPase of which could be a target for these ions.

Inoculum Sizes of Locally Isolated Phototrophic Bacterium on the Utilization of Palm Oil Mill Effluent

To produce Rhodobacter sphaeroides strain UMSPSB3 biomass with the reduction of chemical oxygen demand (COD) from palm oil mill effluent. Locally isolated phototrophic bacterium with different inoculum levels were used in Palm Oil Mill effluent (POME). Collected POME was characterized before used as substrate. Inoculum of bacterium was grown in synthetic media and 48 hours inoculum was used to utilize the substrate. Biotechnological laboratory, Borneo Marine Research Institute, University Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia, between February 2014 to April 2014. Growth characteristics of bacterium Rhodobacter sphaeroides strain UMSPSB3 was monitored at different light intensities. Later phototrophic bacterium Rhodobacter sphaeroides strain UMSPSB3 was grown in settled non-sterilized Palm Oil Mill effluent (POME). The growth characteristics of bacterium in term of dry cell weight and total carotenoids production, and reduction of COD were compared using 10%, 20% and 30% (v/v) levels of inoculum developed in synthetic 112 media.

Preliminary Evaluation of the Pigments Content from Rhodobacter Sphaeroides at Stages during Photosynthetic Growth

Under photosynthetic growth, purple non–sulfur photosynthetic bacterium Rhodobacter sphaeroides can use a diverse array of substrates for the source of carbon donor. Substrates such as acetate and succinate are most commonly used to study energetic and metabolic networks, especially in the production and consummation of NADPH during the citric acid cycle (TCA cycle) and ethylmalonyl–CoA pathway, respectively. Although the utilization of both substrate, the bacterium will grow at different growth rate and this also influence the biosynthesis of photosynthetic pigments as important components for overall photosynthesis. For this study, Rhodobacter sphaeroides strain 2.4.1, GA and G1C have been grown in acetate and succinate. Here, preliminary results on the evaluation the pigment ratio at different stages of the growth is reported, especially on the growth in succinate substrate.