• Korean Journal of Microbiology
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• v.30 no.4
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• pp.265-268
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• 1992

In this study, we want to detect bacteriocin production in purple nonsulfur bacteria. As a results, it was showed that bacteriocin produced between some strains of Rhodobacter capsulatus, Rhodobacter sphaeroides and Rhodocyclus gelatinosus. In particular, it was appeared that cell membrane-bound bacteriocin was also produced by Rhodobacter capsulatus ATCC 17016.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.733-741
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• 2010

Dietary karaya saponin and Rhodobacter capsulatus (R. capsulatus) are known to have hypocholesterolemic actions, as reported in our previous studies. This study examined possible synergistic hypocholesterolemic effects of karaya saponin and R. capsulatus in broilers. A total of 150 broilers were allocated into 10 treatments: control, saponin 25 mg, saponin 50 mg, saponin 75 mg, saponin 25 mg+R. capsulatus 0.2 g, saponin 25 mg+R. capsulatus 0.4 g, saponin 50 mg+R. capsulatus 0.2 g, saponin 50 mg+R. capsulatus 0.4 g, saponin 75 mg+R. capsulatus 0.2 g and saponin 75 mg+R. capsulatus 0.4 g. Feed intake and feed efficiency were improved when karaya saponin and R. capsulatus were synergistically supplemented in the diet. Combinations of karaya saponin, especially supplementation of karaya saponin 50 mg+R. capsulatus 0.4 g were shown to have potential hypolipidemic actions in breast and thigh muscle cholesterol and triglycerides, serum cholesterol, low density lipoprotein-cholesterol and triglycerides, as well as improved high density lipoprotein (HDL)-cholesterol (p<0.05). Compared to the control, almost all the treatments significantly increased serum, liver and fecal concentrations of bile acids (p<0.05). Supplementation of both karaya saponin (75 mg) and saponin 50 mg+R. capsulatus 0.4 g reduced palmitic acid (C16:0) and stearic acid (C18:0) in a similar fashion (p<0.05). The ratios of PUFA:SFA or PUFA+MUFA:SFA in the thigh and breast muscle of broilers were greater in karaya saponin and R. capsulatus supplemented groups than in the control group. Thus, our study concluded that supplementation of karaya saponin synergistically with R. capsulatus in the diet of broilers is an effective way to obtain low-cholesterol, low-triglyceride and high HDL-cholesterol enriched poultry meat with a unique fatty acid balance.

• Korean Journal of Microbiology
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• v.32 no.1
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• pp.1-6
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• 1994

DNA-DNA hybridization by kinetic method was carried out between species of purple nonsulfur photosynthetic bacteria and nonphotosynthetic bacteria. The degrees of homology percent were shown to be low (2-35 D%) with the exception of high homology % (72-88 D%) for strains within a species and between Rhodobacter capsulatus and Rhodopseudomonas blastica. The D% between the purple nonsulfur photosynthetic bacteria, Rhodopseudomonas palustris, and nonphotosynthetic bacteria, Pseudomonas aeruginosa ATCC 27853 or Bradyrhizobium japonicum were a little higher (26-33 D%) than the D% between any other photosynthetic bacteria. The homology % between Rhodopseudomonas blastica and Rhodobacter capsulatus was 72 D%, which showed genetic relationship.

• KSBB Journal
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• v.31 no.3
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• pp.158-164
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• 2016

Plant growth promoting (PGP) hormones, which are produced in a small quantity by bacteria, affect in plant growth and development. PGPs play an important role on the crop productivity in agricultural field. In this study, a photosynthetic bacterial strain producing the PGP was isolated from paddy soil. Bacterial isolate was gram negative, rod-shaped and motility positive. From the 16s rRNA gene sequence analysis, the isolate was identified as Rhodobacter capsulatus PS-2. The mass cultivation of R. capsulatus PS-2 was optimized by considering of the carbon, nitrogen and inorganic salt sources. Optimal medium composition was determined as Na-succinate 4.5 g, yeast extract 5 g, $K_2HPO_4$ 1 g, $MgSO_4$ 5 g, per liter. From the result of 500 L fermentation for 2 days using the optimal medium, the viable cells were $8.7{\times}10^9cfu/mL$. R. capsulatus PS-2 strain produced the carotenoid and indole-3-acetic acid (IAA). The carotenoid extraction and quantitative analysis were performed by HCl-assisting method. Total carotenoid contents from R. capsulatus PS-2 culture broth were measured as $7.02{\pm}0.04$ and $6.93{\pm}0.05mg/L$ under photoheterotrophic and chemoheterotrophic conditions, respectively. To measure the productivity of IAA, colorimetric method was employed using Salkowski reagent at optical density 535 nm. The results showed that the highest content of IAA was $197.44{\pm}5.92mg/L$ in the optimal medium supplemented with 0.3% tryptophan.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.5
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• pp.630-639
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• 2010

Immune response and yolk cholesterol are crucial factors for commercial chicken producers. The objectives of this study were to investigate the effect of selenium-enriched Japanese radish sprouts (Se-enriched JRS) and R. capsulatus synergistically on immune response and cholesterol in laying hens. A total of 50 laying hens (20-wk old) were assigned to 5 dietary treatment groups, and fed diets supplemented with 2.5 ${\mu}g/kg$, 5 ${\mu}g/kg$, 10 ${\mu}g/kg$ Se-enriched JRS and 5 ${\mu}g/kg$ Se-enriched JRS+R. capsulatus (0.02%). Egg production and yolk color were significantly improved by the supplementation of Se-enriched JRS+R. capsulatus in the layer diet (p<0.05). Compared to the control, serum cholesterol concentration and triglyceride levels were decreased by all the treatments (p<0.05). After 8-wk of the experiment, supplementation of 5 ${\mu}g/kg$, 10 ${\mu}g/kg$ and Se-enriched JRS+R. capsulatus significantly reduced yolk cholesterol and triglycerides, while the greatest reduction was observed when R. capsulatus was incorporated with Se-enriched JRS. Spleen, bursa and thymus weight were significantly increased by both the 5 ${\mu}g/kg$ and 10 ${\mu}g/kg$ Se-enriched JRS. Compared to the control, supplementation of 5 ${\mu}g/kg$ and 10 ${\mu}g/kg$ Se-enriched JRS significantly increased serum IgG and yolk IgY concentration and foot web index activity by Newcastle Disease Virus (p<0.05). After 4-wk and 8-wk of supplementation, the highest number of leukocytes was observed with Se-enriched JRS+R. capsulatus (p<0.05). The highest concentration of serum and yolk Se was found in Se-enriched JRS plus R. capsulatus treatment. Combined dietary supplementation of Se-enriched JRS and R. capsulatus might be beneficial for better health, disease protection and overall production performance.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1327-1332
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• 2004

The hemA gene encoding 5-aminolevulinic acid synthase (ALAS) was cloned from Rhodobacter capsulatus, and its nucleotide sequence was determined. DNA sequencing data revealed one open reading frame coding for a protein with 401 amino acids that displayed high similarity to the amino acid sequences of other known ALASs. The hemA gene was then cloned and expressed under the control of constitutive promotor in E. coli. The recombinant E. coli strain was able to accumulate 5-aminolevulinic acid to 21 mM in the liquid medium supplemented with 45 mM glycine and 120 mM succinate. In addition, a marked effect of the pH of the culture medium on ALA production was observed, and the optimum pH for culture medium was determined to be 5.8-6.3.

• Journal of Microbiology
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• v.34 no.3
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• pp.255-262
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• 1996

The lipopolysaccharide (LPS) yields were measured in Rhodobacter capsulatus under several conditions by the ELISA method. The purification of LPS was done by affinity chromatography of IgG coupled CNBr-activated sepharose-4B instead of ultra-centrifugation. The purity of the LPS didn't show much difference between affinity chromatography and ultra-centrifugation method, but affinity chromatography method required much fewer organisms and was more convenient. LPS yield was measured in ng units by the ELISA method. Mannitol was a better single carbon source than other sugars, but mixing two carbon sources resulted in greater LPS yields than any sugar alone. LPS yield was directly proportional to $NH_ 4CI$ concentration, with optimum yields at 0.05% nitrogen. In contrest to LPS yields, which decreased at 0.005% nitrogen concentration total protein was increased 16 times. Calcium influenced LPS yields. At 0.7 mM $CaCI_ 2$, the LPS yield was 16.5 $\mu$g/mg DW, five times the yield without calcium.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.6
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• pp.831-837
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• 2013

An experiment was conducted to investigate the effects of dietary supplementation of Rhodobacter capsulatus KCTC-2583 on egg-yolk and serum cholesterol, egg production and quality parameters during the late laying periods in hens. A total of 160 Hy-Line Brown layers (54 wk-old) were randomly allotted to 4 treatment groups on the basis of laying performance. Each treatment had 4 replicates with 10 birds each (40 birds per treatment). Two hens were confined individually with cage size $35{\times}35{\times}40$ cm and each 10 birds (5 cages) shared a common feed trough between them forming one experimental unit. Dietary treatments were; basal diet supplemented with 0 (control), 0.05, 0.10 and 0.15% R. capsulatus KCTC-2583. Experimental diets were fed in meal form for 56 d. Dietary supplementation of increasing levels of R. capsulatus KCTC-2583 reduced (linear, p<0.05) egg-yolk cholesterol and triglycerides (d 28, 42 and 56) concentrations. Also, serum cholesterol and triglycerides (d 21, 42 and 56) concentrations were linearly reduced (p<0.05) with increasing dietary R. capsulatus KCTC-2583. Laying hens fed a diet supplemented with increasing levels of R. capsulatus KCTC-2583 had increased (linear; p<0.05) overall egg production, egg weight, egg mass and feed efficiency. However, dietary treatments had no effect (linear or quadratic; p>0.05) on feed intake of laying hens. At d 28 and 56, breaking strength and yolk colour of eggs were linearly improved (p<0.05) in laying hens fed dietary increasing levels of R. capsulatus KCTC-2583. Dietary treatment had no effects (linear or quadratic; p>0.05) on albumin height, shell thickness and shell weight at any period of experiment. These results indicate that dietary supplementation of R. capsulatus KCTC-2583 has the potential to improve the laying hen performance and lead to the development of low cholesterol eggs during late laying period in Hy-Line Brown hens.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.640-648
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• 2023

The purpose of this study was to determine the inhibitory effect of heavy metals [Cd(II), Ni(II), and Zn(II)] on the growth of Rhodobacter species (Rhodobacter blasticus, Rhodobacter sphaeroides, and Rhodobacter capsulatus) and their potential use for Cd(II), Ni(II), and Zn(II) bioremoval from liquid media. The presence of toxic heavy metals prolonged the lag phase in growth and reduced biomass growth for all three Rhodobacter species at concentrations of Cd, Ni, and Zn above 10 mg/L. However, all three Rhodobacter species also had a relatively high specific growth rate against each toxic heavy metal stress test for concentrations below 20 mg/L and possessed a potential bioaccumulation ability. The removal efficiency by all strains was highest for Cd(II), followed by Ni(II), and lowest for Zn(II), with the removal efficiency of Cd(II) by Rhodobacter species being 66% or more. Among the three strains, R. blasticus showed a higher removal efficiency of Cd(II) and Ni(II) than R. capsulatus and R. sphaeroides. Results also suggest that the bio-removal processes of toxic heavy metal ions by Rhodobacter species involve both bioaccumulation (intracellular uptake) and biosorption (surface binding).

• BMB Reports
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• v.40 no.5
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• pp.697-707
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• 2007

Cytochrome $cbb_3$ oxidase is a member of the heme-copper oxidase superfamily that catalyses the reduction of molecular oxygen to the water and conserves the liberated energy in the form of a proton gradient. Comparison of the amino acid sequences of subunit I from different classes of heme-copper oxidases showed that transmembrane helix VIII and the loop between transmembrane helices IX and X contain five highly conserved polar residues; Ser333, Ser340, Thr350, Asn390 and Thr394. To determine the relationship between these conserved amino acids and the activity and assembly of the $cbb_3$ oxidase in Rhodobacter capsulatus, each of these five conserved amino acids was substituted for alanine by site-directed mutagenesis. The effects of these mutations on catalytic activity were determined using a NADI plate assay and by measurements of the rate of oxygen consumption. The consequence of these mutations for the structural integrity of the $cbb_3$ oxidase was determined by SDS-PAGE analysis of chromatophore membranes followed by TMBZ staining. The results indicate that the Asn390Ala mutation led to a complete loss of enzyme activity and that the Ser333Ala mutation decreased the activity significantly. The remaining mutants cause a partial loss of catalytic activity. All of the mutant enzymes, except Asn390Ala, were apparently correctly assembled and stable in the membrane of the R. capsulatus.