• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.230-233
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• 2012

Rhizobium radiobacter T6102 was morphologically purified by the aniline blue agar plates to give two distinct colonies; white smooth mucoid colony (T6102W) and blue rough colony (T6102B). The coenzyme $Q_{10}$ ($CoQ_{10}$) was produced just by T6102W, showing 2.0 mg/g of $CoQ_{10}$ content, whereas the T6102B did not produce the $CoQ_{10}$. All of the used $CoQ_{10}$ biosynthetic precursors enhanced the $CoQ_{10}$ production by T6102W. Specifically, the supplementation of 0.75 mM isopentenyl alcohol improved the $CoQ_{10}$ concentration (19.9 mg/l) and content (2.4 mg/g) by 42% and 40%, respectively.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.346-349
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• 2010

Coenzyme $Q_{10}$ ($CoQ_{10}$) production from Rhizobium radiobacter T6102 was monitored under various oxygen supply conditions by controlling the agitation speeds, aeration rates, and dissolved oxygen levels. As the results, the $CoQ_{10}$ production was enhanced by limited oxygen supply. To investigate whether the $CoQ_{10}$ production is associated with its physiological functions of electron carrier and antioxidant, the effects of sodium azide and hydrogen peroxide on the $CoQ_{10}$ production were studied, showing that the $CoQ_{10}$ contents were slightly enhanced with increasing sodium azide (up to 0.4 mM) and hydrogen peroxide (up to $10\;{\mu}M$) concentrations. These results suggest the plausible mechanism where the limited electron transfer stimulating the environments of limited oxygen supply and oxidative stress could accumulate the $CoQ_{10}$, providing the relationship between the $CoQ_{10}$ physiological functions and its regulation system.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.1045-1048
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• 2007

Two genes, dps encoding decaprenyl diphosphate synthase and dxs encoding 1-deoxy-D-xylulose 5-phosphate synthase, were isolated from Rhizobium radiobacter ATCC 4718. DNA sequencing analysis of the dps and dxs genes revealed an open reading frame of 1,077 bp and 1,920 bp, respectively. The heterologous expression in Escherichia coli BL21(DE3) was carried out in order to identify their functions. Recombinant E. coli BL21(DE3) harboring the dps gene produced $CoQ_{10}$ as well as $CoQ_8$ and $CoQ_9$, whereas E. coli harboring only the dxs gene produced more $CoQ_8$ compared with the wild-type E. coli. Additionally, the coexpression of dps and dxs genes in E. coli was carried out. The recombinant E. coli harboring only the dps gene produced $0.21{\pm}0.04\;mg/l$ of $CoQ_{10}$, whereas the coexpressed E. coli with dps and dxs genes produced $0.37{\pm}0.07\;mg/l$ of $CoQ_{10}$. HPLC analysis also showed that the $CoQ_{10}$ fraction (100% of the total CoQs distribution) was increased from $15.86{\pm}0.66%$ (only dps) to $29.78{\pm}1.80%$ (dps and dxs).

• 한국토양비료학회지
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• 제35권1호
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• pp.12-26
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• 2002

근류형성에 의한 생물학적 질소고정기능을 갖는 여러종의 근류균을 대상으로 분자생물학적 계통 분류의 기초자료를 얻기 위하여 Azorhizobium, Bradyrhizobium, Mesorhizobium, Rhizobium, Sinorhizobium 속의 33 균주에 대한 ITS 영역의 염기서열을 이용한 계통 분류가 이루어 졌다. 이들 균주중 대부분의 균주는 한 종류의 ITS 영역을 가지는 반면, 일부균주는 2개의 서로 다른 ITS 염기서열을 가지는 것으로 나타났다. 실험에 이용된 모든 균주들간의 ITS 영역의 염기서열 상동성은 28 - 95%로 매우 변이폭가 컸으며, 이들 염기서열의 계통 분석에 의하면 4가지 그룹으로 구분되었다. Sinorhizobium 속의 모든 균주 및 Rhizobium giardinii 는 그룹 I으로 구분되었다 그룹 II는 R. giardinii를 제외한 모든 Rhizibium 속의 균주를 포함하고 있으며, 계통수의 topology는 매우 불안정한 것으로 나타났다. 특히, R. radiobacter와 R. rubi는 계통분류학적 위치가 불명확한 것으로 나타났다. Bradyrhizobium 속의 균주는 Azorhizobium caulinodans 와 함께 그룹 III로 구분되었고, 그룹 IV는 Mesorhizobium 속의 균주로 이루어 ㅈ다. 특히, Mesorhizobium 속균주의 ITS 영역의 염기서열 상동성이 높게 나타났다.

• 한국수정란이식학회지
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• 제28권1호
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• pp.49-55
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• 2013

The objective of this study was to evaluate several types of uterine bacteria in Hanwoo. uterine bacteria from randomly selected 5 uterus was collected by flushing methods into a sterilized 1.5 ml centrifuge tube and was inoculated onto MacConkey agar and blood agar, respectively. After being incubated for 5% $CO_2$, aerobic or anaerobic condition at $37^{\circ}C$ during 48h, bacterial colonies were selected and re-inoculated onto blood agar plates. Re-cultured colonies were identified by Gram staining and finally identified using Vitek system. The identified bacteria were Staphylococcus lentus, Staphylococcus sciuri, Staphylococcus vitulinus, Staphylococcus warneri of Gram (+) and Rhizobium radiobacter, Sphingomonas paucimobilis of Gram (-) bacteria. Although, pathogenicity of identified bacteria was unclear, the bacteria can have an effect on the uterine microenvironment. Therefore, repetitive research will be required to determine the effects of bacteria in cattle exposed to a various environment.

• 한국균학회지
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• 제37권2호
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• pp.144-149
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• 2009

The occurrences of the major diseases and the densities of air-born microbes were surveyed in the cultivation facilities for oyster mushroom (Pleurotus ostreatus), king oyster mushroom (Pleurotus eryngii), and enoki mushroom (Flammulina velutipes) in different areas of Korea. Green mold disease was most often developed in oyster mushroom bed cultivation with the disease incidence rate of approximate 10% while the disease incidences from bottle and plastic envelop cultivation were less than 1~2%. In the bed cultivation, the major air-born microbes in the growth room were Aspergillus, Penicillium, Trichoderma, and Curvularia with the total fungal population density of 567~1,297 CFU/$m^3$ . However, only Trichoderma and Penicillium were detected in the growth rooms and innoculation rooms of bottle and plastic envelop cultivation with the densities of 350~700 CFU/$m^3$ and 160~260 CFU/$m^3$, respectively. The bacterial diseases become evident in the growth rooms of bottle and plastic envelop cultivation with the approximate incidence rate of 10%. The identified bacterial species were Brevibacillus levelkil, Rhizobium radiobacter, Brevundimonas vesicularis, Pseudomonas mosselii, Microbacterium testaceum. Sphingomonas panmi, Sphingomonas yabuuchiae, Paracocus dinitrificans, Curtobacterium flaccumfaciens pv. flaccumfaciens and some unidentified bacteria with the densities of 40~6,359 CFU/$m^3$ in the growth rooms and 9 CFU/$m^3$ in the inoculation room. This study indicated that the green mold disease by fungal strains was the major mushroom disease in the bed cultivation and suggested that the contamination of bacteria and fungi together in the growth media could result in severe production loss. The plastic envelope and bottle cultivation were evidenced to be less susceptible to such contaminations.