Rhodopseudomonas Spheroides Research Articles

Dynamic experiments of acid mine drainage with Rhodopseudomonas spheroides activated lignite immobilized sulfate-reducing bacteria particles treatment

Aiming at the problem that the treatment of acid mine drainage (AMD) by sulfate-reducing bacteria (SRB) biological method is susceptible to pH, metal ions, sulfate and carbon source. Lignite immobilized SRB particles (SRB-LP) and Rhodopseudomonas spheroides (R. spheroides) activated lignite immobilized SRB particles (R-SRB-LP) were prepared using microbial immobilization technology with SRB, R. spheroides and lignite as the main substrates. The dynamic experimental columns 1# and 2# were constructed with SRB-LP and R-SRB-LP as fillers, respectively, to investigate the dynamic repair effect of SRB-LP and R-SRB-LP on AMD. The mechanism of AMD treated with R-L-SRB particles was analyzed by scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectrometer and low-temperature nitrogen adsorption. The result showed that the combination of R. spheroides and lignite could continuously provide carbon source for SRB, so that the highest removal rates of SO42−, Cu2+ and Zn2+ in AMD by R-SRB-LP were 93.97%, 98.52% and 94.42%, respectively, and the highest pH value was 7.60. The dynamic repair effect of R-SRB-LP on AMD was significantly better than that of SRB-LP. The characterization results indicated that after R-SRB-LP reaction, the functional groups of −OH and large benzene ring structure in lignite were broken, the lignite structure was destroyed, and the specific surface area was 1.58 times larger than before reaction. It illustrated that R. spheroides provided carbon source for SRB by degrading lignite. The strong SRB activity in R-SRB-LP, SRB can co-treat AMD with lignite, so that the dynamic treatment effect of R-SRB-LP on AMD is significantly better than that of SRB-LP.

Strain engineering and bioprocessing strategies for biobased production of porphobilinogen in Escherichia coli

Strain engineering and bioprocessing strategies were applied for biobased production of porphobilinogen (PBG) using Escherichia coli as the cell factory. The non-native Shemin/C4 pathway was first implemented by heterologous expression of hemA from Rhodopseudomonas spheroids to supply carbon flux from the natural tricarboxylic acid (TCA) pathways for PBG biosynthesis via succinyl-CoA. Metabolic strategies were then applied for carbon flux direction from the TCA pathways to the C4 pathway. To promote PBG stability and accumulation, Clustered Regularly Interspersed Short Palindromic Repeats interference (CRISPRi) was applied to repress hemC expression and, therefore, reduce carbon flowthrough toward porphyrin biosynthesis with minimal impact to cell physiology. To further enhance PBG biosynthesis and accumulation under the hemC-repressed genetic background, we further heterologously expressed native E. coli hemB. Using these engineered E. coli strains for bioreactor cultivation based on ~ 30 g L−1 glycerol, we achieved high PBG titers up to 209 mg L−1, representing 1.73% of the theoretical PBG yield, with improved PBG stability and accumulation. Potential biochemical, genetic, and metabolic factors limiting PBG production were systematically identified for characterization.Graphical

Construction of engineering bacteria degrading residual polyacrylamide in coal slime water by protoplast fusion technique

Polyacrylamide (PAM) is widely used as flocculant in coal preparation. A protoplast fusant with enhanced degradation ability of PAM was obtained by intergeneric protoplast fusion between Rhodopseudomonas spheroids and Bacillus subtilis. The protoplast preparation was optimised and inactivation of both parents was performed in different ways. The degradation abilities of domesticated R. spheroides, B. subtilis and mixed bacteria (v/v, 1.00) were compared with protoplast fusant. The results showed that the optimal dosage for R. spheroides protoplast preparation was determined to be 20.00% sucrose, 1.00 mg/mL lysozyme, 0.20% EDTA and 60.00 min. Under such conditions, the protoplast formation rate and the protoplast regeneration rate were 63.70% and 8.90%, respectively. The optimal dosage for B. subtilis protoplast preparation was determined to be 20.00% sucrose, 1.50 mg/mL lysozyme and 60.00 min. Under such conditions, the protoplast formation rate and the protoplast regeneration rate were 58.50% and 9.45%, respectively. The protoplast inactivation of R. spheroides and B. subtilis were optimally conducted by ultraviolet radiation (70.00 s) and by heat at 55.00°C (50.00 min), respectively. The degradation ability of protoplast fusant was obviously improved. Furthermore, using microscopic observation, it was found that both parents form protoplasts by the way of apical release.

RETRACTED: Clothianidin wastewater treatment and the accumulation of high-value biochemical by Rhodopseudomonas spheroides

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Authors and the Editor-in-Chief. The paper is retracted because of a high level of duplication of "Rhodopseudomonas palustris wastewater treatment: cyhalofop-butyl removal, biochemicals production and mathematical model establishment. Bioresource. Tech. 2019, 282: 390-397 As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. The first author, Pan Wu, takes full responsibility for these actions, a stance supported by Dalian Minzu University and Northeast Agricultural University, Harbin, where the research took place.

Bio-degradation of Activated Carbon by Rhodopseudomonas spheroides

Bio-degradation of Activated Carbon by Rhodopseudomonas spheroides

Study on Rhodopseudomonas Spheroides as Coal Microbial Flocculant

Orthogonal test was employed to inspect the flocculation of Rhodopseudomonas spheroides in this text. The result showed that Rhodopseudomonas spheroides has good performance in flocculation effect of coal slurry. The hightest flocculation ratio is 93.4%. The optimum technological combination of flocculation test has been obtained:incubation time:12h,Coagulation aid dosage:2mL,Bacterium fluid amount:2mL,The categories of flocculants: the cell homogenates,pH:7.The FTIR analysis showed that the extractive of Rhodopseudomonas spheroides contain a large number of acidic Polysaccharides which has flocculent effect component.The main flocculation is “adsorption-bridge” between Molecular bioflocculant and coal slurry.

Studies on the Biosynthesis of Corrinoids and Porphyrinoids. X.Biosynthetic Studies of Bacteriochlorophyll-a in Rhodopseudomonas spheroides: Incorporation of 2H, 13C and 15N-Labeled Substrates and Origin of the Hydrogen Atoms.

The biosynthetic pathway of bacteriochlorophyll-a in Rhodopseudomonas spheroides was investigated by administration of [2-13C]glycine, L-[methyl-13C]methionine, L-[1-13C]glutamic acid and 13C- or 15N-labeled δ-aminolevulinic acid (ALA). The origin of the hydrogen atoms was studied by following the incorporation into bacteriochlorophyll of 13C-labeled ALA in a medium containing 50% D2O and that of 2H-, 13C-labeled ALA. The labeled bacteriochlorophylls were converted into more stable methyl bacteriopheophorbides, which were subjected to 13C-NMR analyses to obtain information about the biosynthetic origin of the hydrogen atoms. The use of 13C-enriched bacteriochlorophylls and methyl bacteriopheophorbides allowed us to make 13C-NMR signal assignments for all carbons of the porphyrin nucleus.

TETRAPYRROLE‐DEPENDENT PHOTODYNAMIC HERBICIDES

TETRAPYRROLE‐DEPENDENT PHOTODYNAMIC HERBICIDES

Photochemical electron transfer reactions in the acceptor complex of reaction centers of Rhodopseudomonas spheroides treated with sodium dodecyl sulfate

We have compared some photochemical properties of the reaction-center complex of Rhodopseudomonas spheroides (wild-type) treated with various amounts of either sodium dodecyl sulfate (SDS) or dodecyl dimethylamine N-oxide. In the presence of the latter, the native structure and activity of the reaction center are preserved even at high concentrations of detergent. In contrast, SDS denatures the protein. It does this by a cooperative process, as shown by the sigmoidal relationship between primary photochemical activity and SDS concentration. SDS binds to the reaction center at up to about 6 g SDS/g protein. The most notable modifications brought about by low SDS concentrations are: a slowing down of rereduction of P+ by Q-B from 1 s-1 to 0.25 s-1 and, to a lesser extent, of P+ by Q-A; the reoxidation of Q-A and Q-B by N,N,N',N'-tetramethyl-1,4-phenylenediamine is accelerated as an exponential function of SDS concentration. In this case Q-A become more accessible to external acceptors but not Q-B. It is thought that these changes are mainly due to progressive binding of SDS resulting in the unfolding of the protein, probably accompanied by the loss of the metal. Herbicides partly protect the reaction center against SDS denaturation, but their efficiency to block electron transfer between QA and QB is greatly reduced in the altered reaction centers present in the transition region of the denaturation curve. It is concluded that in the early region of the SDS denaturation curve, no dissociation of the reaction center in subunits occurs. In the transition region, it appears that the reaction center reaches the critical state in which mainly dissociation of polypeptide H from the complex of chains L and M and loss of QA take place.

Primary structure of the bc1 complex of Rhodopseudomonas capsulata: Nucleotide sequence of the pet operon encoding the Rieske cytochrome b, and cytochrome c1 apoproteins

The nucleotide sequence of the pet operon of Rhodopseudomonas capsulata strain SB1003 has been determined. This operon consists of the petA, petB and petC genes, which encode the Rieske FeS protein, cytochrome b and cytochrome c 1, respectively, all components of the ubiquinol-cytochrome c 2 oxidoreductase. The deduced amino acid sequences of the pet genes show homology to the corresponding proteins from other organisms, and particularly high homologies (over 90% for amino acid and nucleotide sequences) to the previously described fbc operon from a strain previously identified as Rhodopseudomonas spheroides GA. The amino acid sequences of the pet proteins are discussed with reference to the structure and function of the ubiquinol-cytochrome c 2 oxidoreductase.

Red blood cell rhodanese: Its possible role in modulating δ-aminolaevulinate synthetase activity in mammals

1. 1. The optimum conditions for measuring rhodanese activity in human erythrocytes were established. The mean control values for males (112 nmol SCN/30 min/mg protein) and females (127 nmol SCN/30 min/mg protein) were determined. 2. 2. Rhodanese activity was measured in different porphyric patients. The activity was diminished in porphyria cutanea tarda (PCT), acute intermittent porphyria (AIP), variegate porphyria (VP) and lead intoxication (Pb), remaining in erythropoietic protoporphyria (EPP). 3. 3. δ-Aminolaevulinate synthetase (ALA-S) activity was increased in PCT, AIP, VP and Pb showing no changes in EPP. 4. 4. It is suggested that a similar scheme, to that proposed for the control of ALA-S in Rhodopseudomonas spheroides and soybean callus, is also operating in animals.

3-Hydroxyisobutyrate dehydrogenase, an impurity in commercial 3-hydroxybutyrate dehydrogenase.

The enzymic determination of D-3-hydroxybutyrate and acetoacetate normally involves the use of 3-hydroxybutyrate dehydrogenase (HBDH, EC 1.1.1.30) of bacterial origin. We show that HBDH from Rhodopseudomonas spheroides (BCL, grade II) contains a 3-hydroxyisobutyrate dehydrogenase (HIBDH) activity: activity with 3-hydroxyisobutyrate as substrate was greater than 10% of that with 3-hydroxybutyrate. However, HBDH could be prepared essentially free of HIBDH activity by incubation at 37 degrees C in the presence of 1 mM-CaCl2, to produce an enzyme preparation that may be used for the specific determination of 3-hydroxybutyrate. Use of the purified enzyme preparations indicated that a major product of valine metabolism in hemidiaphragms from 40 h-starved rats was 3-hydroxyisobutyrate rather than 3-hydroxybutyrate.

Preliminary characterization by X-ray diffraction of crystals of photochemical reaction centres from wild-type Rhodopseudomonas spheroids

Reaction centres from wild-type Rhodopseudomonas spheroides(strain Y) in a solution of octylglucoside have been crystallized with polyethylene glycol as precipitant, either by vapour diffusion or dialysis. Orthorhombic crystals (space group P2 12 12 1) diffract to 3.5 Å resolution. The unit cell parameters are a = 142.5 A ̊ , b = 141.5 A ̊ , c = 80 A ̊ : they are compatible with the presence of one reaction centre per asymmetric unit.

The stereospecificity of oxidation of alpha-[4R-2H]NADH by dehydrogenases.

The stereospecificity of the enzyme-dependent oxidation of alpha-[4R-2H]NADH has been determined for four dehydrogenases: two pro-R specific enzymes, pig heart malate dehydrogenase and yeast alcohol dehydrogenase; and two pro-S specific enzymes, rabbit muscle glycerol-3-phosphate dehydrogenase and Rhodopseudomonas spheroides 3-hydroxybutyrate dehydrogenase. In all cases, an enzyme-dependent and substrate-specific oxidation to alpha-NAD+ is observed with the stereochemistry of oxidation identical with that found for the oxidation of the correspondingly labeled beta-NADH. The ability of dehydrogenases from diverse sources to utilize alpha-NADH in a stereochemically competent fashion is discussed in relation to proposed interactions between the nicotinamide sugar moiety and active site residues or obligatory alignments of the pyridine and sugar moieties.

Direct and simultaneous measurements of light-driven pH gradient and ATP synthesis by 31P-NMR for the chromatophores of Rhodopseudomonas spheroides G1C

Direct and simultaneous measurements of light-driven pH gradient and ATP synthesis by 31P-NMR for the chromatophores of Rhodopseudomonas spheroides G1C

Labelling of chlorophylls and precursors by [2-14C]glycine and 2-[1-14C]oxoglutarate in Rhodopseudomonas spheroides and Zea mays. Resolution of the C5 and Shemin pathways of 5-aminolaevulinate biosynthesis by thin-layer radiochromatography.

The C-5 of 5-aminolaevulinate, a tetrapyrrole precursor which accumulates when inhibitory laevulinate is present, is derived from either the C-2 of glycine by the 5-aminolaevulinate-synthase-mediated Shemin pathway or the C-1 of 2-oxoglutarate by the C5 pathway. Thin-layer-radiochromatographic procedures are described for determining whether [2-14C]glycine or 2-[1-14C]oxoglutarate labelled the macrocycle of bacteriochlorophyll a, in addition to or rather than the methyl ester or phytyl ester moieties of the side-chains. The method was also used for detecting whether the same substrates label the formaldehyde (C-5) or the succinate (C-1 to C-4) fragments, obtained by periodate cleavage of 5-aminolaevulinate. These methods therefore can readily distinguish between the Shemin and C5 pathways as was demonstrated by using Rhodopseudomonas spheroides and Zea mays (maize), respectively, as examples of each pathway. Both [2-14C]glycine and, to a lesser extent 2-[1-14C]oxoglutarate labelled the macrocycle of bacteriochlorophyll a formed during adaptation of respiring R. spheroides cells to photosynthetic (anaerobic, illuminated) conditions. This and earlier evidence suggested augmentation of the Shemin pathway by a minor C5 pathway contribution. The present studies revealed only Shemin pathway activity: with laevulinate present, [2-14C]glycine formed 5-[5-14C]aminolaevulinate as proved by H14CHO production during periodate cleavage. These methods were sufficiently sensitive also to detect the incorporation of 14CO2, from degradation of either substrate, into 5-aminolaevulinate via the Shemin pathway thus labelling the succinate fragment produced with periodate: this explains bacteriochlorophyll a labelling by 2-[1-14C]oxoglutarate and proves double labelling of 5-aminolaevulinate by [2-14C]glycine. The same techniques were applied to etiolated maize leaves exposed to aerobic illuminated conditions with laevulinate and either 2-[1-14C]oxoglutarate or [2-14C]glycine as substrates. Only the C5 pathway was detected: 2-[1-14C]oxoglutarate was converted to 5-[5-14C]aminolaevulinate, which yielded H14CHO on periodate cleavage. This is not inconsistent with our earlier 13C-NMR studies [Porra, R.J., Klein, O. and Wright, P. E. (1983) Eur. J. Biochem. 130, 509-516] showing that the C5 pathway formed all the 5-aminolaevulinate for chlorophyll biosynthesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Electric linear dichroism of chromatophores, pigment-protein and reaction center complexes derived from Rhodopseudomonas spheroides

Electric linear dichroism of chromatophores, pigment-protein and reaction center complexes derived from Rhodopseudomonas spheroides

Examination of protein sequence homologies: I. Eleven Escherichia coli L7/L12-type ribosomal "A" protein sequences from eubacteria and chloroplast.

Seven complete and four partial sequences of Escherichia coli L7/L12-type ribosomal "A" proteins obtained from various bacteria (E. coli, Bacillus subtilis, Micrococcus lysodeikticus, Rhodopseudomonas spheroides, Desulfovibrio vulgaris, Streptomyces griseus, Bacillus stearothermophilus, Clostridium pasteurianum, Arthrobacter glacialis, and Vibrio costicola) and spinach chloroplast have been reexamined using a computer program that searches for homologous tertiary structures. Comparison matrices for the sequences show that they match the sequence of E. coli L7 (EL7) if one assumes the insertion or deletion of certain residues at sites corresponding to residues 1, 38, 49, and 92 of EL7. That two additional insertion points are found only in the spinach chloroplast protein suggests that the chloroplast protein probably diverged from the bacterial forms. Further phylogenetic relationships among these 11 prokaryote-type "A" proteins are discussed with respect to average correlation coefficients computed, taking into account the existence of the gaps.

13C nuclear magnetic resonance studies on bacteriochlorophyll a biosynthesis in Rhodopseudomonas spheroides S

The 13C NMR spectra were analyzed in bacteriochlorophyll a and magnesium protoporphyrin methyl ester formed in Rhodopseudomonas spheroides S. in the presence of l-[1- 13C]glutamate and [2- 13C]glycine. After reassignment of three α-pyrrolic carbons (C-9, -14 and -16) of bacteriochlorophyll a, the spectra showed that C-2 of glycine was preferentially incorporated into the eight-carbon atoms in these tetrapyrrole macrocycles derived from C-5 of 5-aminolevulinic acid (ALA). C-2 of glycine was also incorporated specifically into methyl ester carbon of magnesium protoporphyrin IX methyl ester and methoxyl carbon of methoxycarbonyl group attached to isocyclic ring of bacteriochlorophyll a. No enrichment of these nine-carbon atoms was observed in the spectrum of bacteriochlorophyll formed in the presence of l-[1- 13C]glutamate, showing exclusive operation of ALA synthase on bacteriochlorophyll biosynthesis.

Purification and some properties of .DELTA.-aminolevulinic acid synthases from Protaminobacter ruber and Rhodopseudomonas spheroides.

´-Aminolevulinic acid (´-ALA) synthases from Protaminobacter ruber and Rhodopseudomonas spheroides were highly purified and characterized. The molecular weights of the ´-ALA synthases from P. ruber and R. spheroides were estimated to be 97,000 and 87,000, respectively. The optimum pH was about 8.0 for both enzymes. The P. ruber-enzyme showed Kms of 1.05 mM for glycine and 0.77 μM for pyridoxal-5’-phosphate (PLP), while the R. spheroides-enzyme showed Kms of 8.33 mM for glycine and 15 ´M for PLP. The P. ruber-enzyme was less stable during storage at 4°C or 37°C than the R. spheroides-enzyme. As to the effects of end-products, the P. ruber-enzyme was not inhibited by hemin, while the R.spheroides-enzyme was considerably inhibited by hemin. A higher concentration of vitamin B12 stimulated the reaction of the ´-ALA synthases, especially the P. ruber-enzyme.