• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.558-562
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• 2000

A strain of non-sulfur photosynthetic bacteria possessing large amount of ubiquinone-10 in the cell mass, was isolated from waste water collected from the Nakdong River. It was identified as Rhodobacter sp. N-2 by a series of studies on its morphological. cultural and physiological characteristics. The organism appeared to got higher cell mass under circumstances of anaerobic growth conditions than under photosynthetic aerobic cultures. Biotin and thiamin and niacin could be used as good growth factors.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.233-235
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• 2003

한국 서해안과 남해안 47개소의 해수와 mud 시료로부터 광합성세균으로 유추되는 13개의 균주를 분리하였고, agar-shake tube method와 RAPD-PCR을 이용하여 4개 서로 다른 균주를 순수분리 하였다. 4개의 균주 중 폐수분해능이 가장 뛰어난 균을 선정하여, 형태학적, 배양적, 생화학적 특성 및 16S rRNA sequencing에 의한 동정결과 purple, sulfur bacteria 쪽에 가까웠으나 형태학적, 배양학적, 생화학적 특성이 purple, non-sulfur bacteria의 Rhodobacter 속에 가장 근접하여, Rhodobacter sp. EGH-24로 명명하였다.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1293-1301
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• 2003

A species of facultative photo-organotrophic, purple, non-sulfur bacterium was isolated from the 47 point at west and south coast of Korea in September 2001. Separated 13 samples of changes with red color under 28-32$^{\circ}C$, 3000 lux, anaerobe conditions for 7 days cultivated in basal medium. For pure isolation from 13 samples, we used agar-shake tube method (0.4 ％ agar) and separated 5 strains through 13-repetition test. EGH-24 and EGH-30 was identified as the same strain through the RAPD(Random Amplified Polymorphic DNA)-PCR of strain EGH-9, EGH-13, EGH-23, EGH-24, EGH-30. Four isolates cultivated in synthesis wastewater for wastewater biodegradation test. EGH-24 was selected with efficient wastwater treating strain. Based on the results obtained from morphology, nutrient requirements, major bacteriochlorophyll content, 16S-rDNA phylogenetic analysis, EGH-24 strain may be identified as a new strain of the genus Rhodobacter and named Rhodobacter sp. EGH-24.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.163-170
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• 2008

This experiment was conducted to determine the development of mixed organic fertilizer using photosynthetic bacteria and mass production of mixed microbial compound for the environment-friendly agriculture. Photosynthetic bacteria, Rhodobacter sp. SA16 was isolated from soil collected by plastic film house. The SA16 strain was identified based on 16S rDNA sequence analysis and it is closely related to Rhodobacter sp.(100% similarity). The mixed organic fertilizer using SA16 was made of $N-P_2O_5-K_2O=60-10-20\;g\;kg^{-1}$ with combined soybean cake, sesame cake, powdered blood, fish meal, powdered bones and red-yellow soil. The mixed organic fertilizer 0.45, 0.90 and 1.35 Mg $ha^{-1}$ application in Ihyeon series was treated based on soil testing for lettuce cultivation in plastic film house. These results showed that the yield was increased the 18 and 19%over control by the mixed organic fertilizer application 0.45 and 0.90 Mg $ha^{-1}$, respectively. In the physical properties of the soil, the porosity of mixed organic fertilizer 1.35 Mg $ha^{-1}$ treatment was highest at 58.8%. Our results clearly revealed that the organic fertilizer using Rhodobacter sp. SA16 and mass production of mixed strains could be a useful technology in pursuing environment-friendly agriculture.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.409-411
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• 2003

A species of facultative photo-organotrophic, purple, non-sulfur bacterium was isolated from the west coast and the south coast 47 area of Korea at 2001 September. Separated 13 samples of changes with red color under $28{\sim}32\;^{\circ}C$, 3000 lux, anaerobe conditions for 7 days cultivated in Basal medium. For a pure isolation from 13 samples it used agar-shake tube method (0.4 % agar) and it separated 5 strains through 13-repetition test. The RAPD(Random Amplified Polymorphic DNA)-PCR result of strains (EGH-9, EGH-13, EGH-23, EGH-24, EGH-30) that EGH-24 and EGH-30 was same strain. For wastewater biodegradation test that 4 isolation strains cultivated in synthesis wastewater in 7 days. EGH-24 was high 63000 mg/L (CODcr) to 43400 mg/L (CODcr). EGH-24 was selected with efficient wast water treated strain. Based on the results obtained from morphology, nutrient requirements, major bacteriochlorophyll content, 165-rDNA phylogenetic analysis, this strain may be identified as a new strain of the genus Rhodobacter and named Rhodobacter sp. EGH-24.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.1
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• pp.51-57
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• 2009

Biofouling in seawater reverse osmosis (SWRO) desalination process causes many problems such as flux decline, biodegradation of membrane, increased cleaning time, and increased energy consumption and operational cost. Therefore biofouling is considered as the most critical problem in system operation. To control biofouling in early stage, detection of the most problematic bacteria causing biofouling is required. In this study, six model bacteria were chosen; Bacillus sp., Flavobacterium sp., Mycobacterium sp., Pseudomonas aeruginosa, Pseudomonas fluorescens, and Rhodobacter sp. based on report in the literature and phylogenetic analysis of seawater intake and fouled RO membrane. The adhesion to RO membrane, the high pressure resistance, and the hydrophobicity of the six model bacteria were examined to find out their fouling potential. Rhodobacter sp. and Mycobacterium sp. were found to attach very well to RO membrane surface compared to others used in this study. The test of hydrophobicity revealed that the bacteria which have high hydrophobicity or similar contact angle with RO membrane ($63^{\circ}$ of contact angle) easily attached to RO membrane surface. P. aeruginosa which is highly hydrophilic ($23.07^{\circ}$ of contact angle) showed the least adhesion characteristic among six model bacteria. After applying a pressure of 800 psi to the sample, Rhodobacter sp. was found to show the highest reduction rate; with 59-73% of the cells removed from the membrane under pressure. P. fluorescens on the other hand analyzed as the most pressure resistant bacteria among six model bacteria. The difference between reduction rates using direct counting and plate counting indicates that the viability of each model bacteria was affected significantly from the high pressure. Most cells subjected to high pressure were unable to form colonies even thought they maintained their structural integrity.

• Biomedical Science Letters
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• v.14 no.2
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• pp.91-96
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• 2008

Light Emitting Diode (LED) of 880 nm was used as a function of luminosity in culture of the photosynthetic bacteria including Rhodobacter sp.. An array of 880 run LED was driven with an energy density of $6.0mW/cm^2$. In processing time, we were able to show that the cell growth were gained of significant changes in the pigment and in the dry weight. And we also showed that photosynthetic bacteria had the resonable relativity of optical density to dry weight. LED-880nm is of great significance for the potential use of photo-bioreactor construction.

• Journal of Microbiology and Biotechnology
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• v.26 no.5
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• pp.959-966
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• 2016

Chlorophyll synthase (ChlG) and bacteriochlorophyll synthase (BchG) have a high degree of substrate specificity. The BchG mutant of Rhodobacter sphaeroides, BG1 strain, is photosynthetically incompetent. When BG1 harboring chlG of Synechocystis sp. PCC 6803 was cultured photoheterotrophically, colonies arose at a frequency of approximately 10^-8. All the suppressor mutants were determined to have the same mutational change, ChlG_I44F. The mutated enzyme ChlG_I44F showed BchG activity. Remarkably, BchG_F28I, which has the substitution of F at the corresponding 28^th residue to I, showed ChlG activity. The K_m values of ChlG_I44F and BchG_F28I for their original substrates, chlorophyllide (Chlide) a and bacteriochlorophyllide (Bchlide) a, respectively, were not affected by the mutations, but the K_m values of ChlG_I44F and BchG_F28I for the new substrates Bchlide a and Chlide a, respectively, were more than 10-fold larger than those for their original substrates, suggesting the lower affinities for new substrates. Taken together, I44 and F28 are important for the substrate specificities of ChlG and BchG, respectively. The BchG activity of ChlG_I44F and the ChlG activity of BchG_F28I further suggest that ChlG and BchG are evolutionarily related enzymes.

• Journal of Mushroom
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• v.16 no.3
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• pp.225-230
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• 2018

This study was conducted to reuse spent mushroom substrates (SMS) of Pleurotus ostreatus and improve their nitrogen content by bacterial treatment. Two kinds of bacteria were used to investigate the increase in total nitrogen (T-N) content. Bacillus sp. (GM20-4) was isolated from SMS of oyster mushroom, and Rhodobacter sphaeroides (RS) was obtained from Gwangju Si Agricultural Technology Center. SMS samples were collected from three oyster mushroom cultivation farms located in Gyeonggi-do province, Korea. When dried SMS was inoculated with 30% culture broth of GM20-4 and RS and incubated at room temperature ($25{\pm}2^{\circ}C$) for 5 days, T-N content increased. To investigate the T-N content of other SMS, three dried SMS samples (A, B, and C) were treated by the same method using GM20-4 and RS. As a result, the T-N content of sample B was 20% higher than that of the control, whereas the T-N content of samples A and C increased to 17% and 12%, respectively. The change in T-N content by bacterial treatment of wet SMS was slightly higher than that of the control. The changes in amino acid content were also found to be higher than those in the control in all SMS samples by GM20-4 and RS treatment. Aspartic acid and glutamic acid contents were the highest among all amino acid compositions. Especially, the aspartic and glutamic acid contents of sample B increased by 2.9 folds higher than the control.

• Journal of Microbiology and Biotechnology
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• v.20 no.5
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• pp.853-861
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• 2010

High substrate costs decrease the profitability of polyhydroxyalkanoates (PHAs) production, and thus low-cost carbon substrates coming from agricultural and industrial residuals are tested for the production of these biopolymers. Among them, crude glycerol, formed as a by-product during biodiesel production, seems to be the most promising source of carbon. The object of this study was to characterize the mixed population responsible for the conversion of crude glycerol into PHAs by cultivation-dependent and -independent methods. Enrichment of the microbial community was monitored by applying the Ribosomal Intergenic Spacer Analysis (RISA), and the identification of community members was based on 16S rRNA gene sequencing of cultivable species. Molecular analysis revealed that mixed populations consisted of microorganisms affiliated with four bacterial lineages: ${\alpha}$, ${\gamma}$-Proteobacteria, Actinobacteria, and Bacteroides. Among these, three Pseudomonas strains and Rhodobacter sp. possessed genes coding for polyhydroxyalkanoates synthase. Comparative analysis revealed that most of the microorganisms detected by direct molecular analysis were obtained by the traditional culturing method.