Rhizobium species, aerobic Gram-negative rods found in soils worldwide, are well-known tumor-inducing pathogens in plants. Since 1980, when the first case of prosthetic valve endocarditis caused by Rhizobium radiobacter was reported, R. radiobacter has been recognized as an opportunistic human pathogen. In Korea, three cases of infection by this organism have been reported. Recently, we experienced a case of R. radiobacter bacteremia in a patient who underwent chemotherapy for lymphoma. Here, we report the case with a review of the literature.
Agrobacterium tumefaciens ; Bacteremia ; Endocarditis ; Humans ; Korea ; Lymphoma ; Rhizobium ; Soil

Hairy root clones of Saussurea involucrata transformed with Agrobacterium rhizogenes strains R1601, R1000, and LBA9402 were established to investigate the flavonoid production. Opine synthesis and PCR analysis confirmed the integration of the T-DNA fragment of Ri plasmid from A. rhizogenes strain R1601 into the transformed root genome. The frequency of hairy root formation from root segments, which were pre-cultured 2 days in N6 solid medium without plant growth regulators, amounted to 100% following infection with R1601 strain of A. rhizogenes. The transformed roots were kept in hormone-free N6 liquid medium in the dark at 25 degrees C, 110r/min and routinely subcultured every 20 - 24 days. One hairy root clone, which grew vigorously with lateral branches, was periodically examined for the ability to produce flavonoid. The maximum of biomass and flavonoid yield achieved 66.7 g/L (fresh weight) and 102.3mg/g dry weight after incubation 20 days. The calli were induced from the hairy root culture in the presence of 0.5mg/L IBA and intact plantlets were regenerated from these calli. The regeneration plantlets from hairy roots, in which the flavonoid content were 53% in that of untransformed plants, weren't different in growth and morphology of the untransformed plantlets. Therefore plant regeneration from hairy roots may be also a means for producing transformed S. involucrata plants. Hairy root cultures of S. involucrata clearly showed higher flavonoid contents compared to the wild plant or the regeneration seedlings. As the wild S. involucrata grows only in special regions with peculiar climate, and cultivation of this species in a normal climate has been unsuccessful so far. The success in obtaining a method for high production of flavonoid might very well be one of the solutions for this problem in the future.
Culture Techniques ; Flavonoids ; biosynthesis ; Plant Roots ; growth & development ; Rhizobium ; physiology ; Saussurea ; growth & development

Two strains of bean rhizobia, Rhizobium vigna 01 (slow-growing Rhizobium) and Rh. vigna 03 (fast-growing Rhizobium), were adopted to study allelopathic effect of artemisinin on the rhizobia. The results showed a significant inhibition of the reproduction and growth of rhizobium by artemisinin. After about 8 hours by adding 40 mg x L(-1) artemisinin into the culture medium, the number of rhizobia was less than half of those in normal culture. The utilization of sucrose and glucose by rhizobia decreased significantly as the concentration of artemisinin increased in the culture medium, which could be one of the main reasons for the inhibition of reproduction and growth of rhizobia by artemisinin. In addition, the activities of extracellular protease and acid phosphatase released from rhizobia decreased significantly as the concentrations of artemisinin increased. Artemisinin refluxed from Artemisia annua could thus inhibit the formation of root nodules and interfered with energy supply and reception between bacteroid and host cells. y = e(-ax) + b reflected the relationships between nitrogenase activities (y) and concentrations of artemisinin (x). In the culture medium with 48 mg x L(-1) of artemisinin, nitrogenase activities were about zero, resulting in the inactivation of nitrogenase in nodules formed. In general, artemisin in A. annua grown soils may inhibit the reproduction and growth of rhizobia, nodule formation and nitrogen biofixation, leading to less nitrogen supply, poor growth and development, and low yields of beans.
Acid Phosphatase ; metabolism ; Artemisinins ; pharmacology ; Carbon ; metabolism ; Peptide Hydrolases ; metabolism ; Rhizobium ; drug effects ; growth & development

OBJECTIVETo establish a culture system for Psammosilene tunicoides hairy roots, and provide technological aid for the large-scale production of P. tunicoides material.

METHODThe young leaves and stem segments of sterile plantlets were infected with ACCC10060 strain, and subsequently a culture system suitable for hairy roots growth was further established.

RESULTWhen explants were co-cultured with ACCC10060 (A600 0.8) on B5 media containing 20 mg x L(-1) Acetosyringo (AS) for 48 h, the hairy roots could be successfully induced, and it could achieve a higher induction rate using young leaves as explants than that of stem segments. The transfected hairy roots possessed the ability of kanamycin resistance and growth on hormone-free media, and synthesis of opines. All above results demonstrated that the present hairy roots originated in the infection of P. tunicoides tissues by ACCC10060 strains. After 35 d culture in liquid hormone-free MS (1/2 strength), the biomass of hairy roots increased 14.11 times (fresh weight) and 8. 39 times (dry weight), respectively, and the content of total saponins in hairy roots reached to 0.857% (DW), by contrast, it's only 0.388% and 0.217% in callus and seedlings respectively.

CONCLUSIONEstablishment of hairy roots culture of P. tunicoides provided a foundation for industrial production of active components from P. tunicoides culture.

Biomass ; Caryophyllaceae ; growth & development ; microbiology ; Culture Techniques ; Plant Roots ; growth & development ; microbiology ; Rhizobium ; physiology ; Saponins ; analysis

A system for the Agrobacterium rhizogenes-mediated transformation and plant regeneration of A. venetum has been developed. The highest transformation frequency was 100%, achieved by using strain LBA9402 with root explants. The highest density of hairy roots reached 22 when root explants transformed by R1000 cultured in the dark. Adventitious shoots were obtained from profusely branched, fast-growing (type PBF) hairy roots, and the adventitious shoot induction frequency was 20%. Regenerated shoots rooted easily on hormone-free 1/2 MS solid medium in 2 weeks. Approximately 1/3 regenerated plants derived from hairy roots exhibited prolific roots with shortened internodes. Whereas other regenerated plants showed another phenotype: long intemodes, strong stems, and fleshy blades. However, all regenerated plants displayed a relatively fast development procedure and stronger than the aseptic seedlings. Polymerase chain reaction (PCR) analyses confirmed the hairy root lines and regenerated plants were induced by A. rhizogenes.
Apocynum ; genetics ; growth & development ; Plant Roots ; growth & development ; Regeneration ; Rhizobium ; genetics ; Tissue Culture Techniques ; Transformation, Genetic

In this study, eight-month-old ectomycorrhizae of Tuber borchii with Corylus avellana were synthesized to explore the influence of T. borchii colonization on the soil properties and the microbial communities associated with C. avellana during the early symbiotic stage. The results showed that the bacterial richness and diversity in the ectomycorrhizae were significantly higher than those in the control roots, whereas the fungal diversity was not changed in response to T. borchii colonization. Tuber was the dominant taxon (82.97%) in ectomycorrhizae. Some pathogenic fungi, including Ilyonectria and Podospora, and other competitive mycorrhizal fungi, such as Hymenochaete, had significantly lower abundance in the T. borchii inoculation treatment. It was found that the ectomycorrhizae of C. avellana contained some more abundant bacterial genera (e.g., Rhizobium, Pedomicrobium, Ilumatobacter, Streptomyces, and Geobacillus) and fungal genera (e.g., Trechispora and Humicola) than the control roots. The properties of rhizosphere soils were also changed by T. borchii colonization, like available nitrogen, available phosphorus and exchangeable magnesium, which indicated a feedback effect of mycorrhizal synthesis on soil properties. Overall, this work highlighted the interactions between the symbionts and the microbes present in the host, which shed light on our understanding of the ecological functions of T. borchii and facilitate its commercial cultivation.
Colon ; Corylus ; Fungi ; Magnesium ; Mycorrhizae ; Nitrogen ; Phosphorus ; Podospora ; Rhizobium ; Rhizosphere ; Soil ; Streptomyces

Agriculture ; Bibliography as Topic ; China ; Humans ; Rhizobium ; growth & development ; metabolism ; Soil Microbiology

Fifteen Rhizobium spp. from nodules of 6 common pulses collected from 6 districts of Assam were studied for their infectivity, intrinsic antibiotic resistance, nitrogenase activity and effect of dual inoculation with two native Arbuscular Mycorrhizal Fungi viz. Glomus mosseae(GM) and Gigaspora gilmarie(GG). Out of the 15 isolates 9 were found nodulation positive and 6 of them(AR1, BR8, BR12, AR10, UR10 & GR21) were subjected to intrinsic antibiotic sensitivity test of which AR1 showed resistance against all the 9 test antibiotics. Isolates AR1 and GR21 showed the highest(4.25 mole, gm(-1)hour(-1)) and the lowest(1.05 mole, gm(-1)hour(-1)) nitrogenase activity respectively. In Most Probable Number count, the maximum Rhizobium population 5.8x10(5), was found in both Blackgram and Greengram variety of pulses. The maximum dry weight of nodules(3.14 g), dry weight of shoot(10.08 g), nitrogen content(7.68 mg, plant(-1)), chlorophyll content(1.89 mg, g(-1)), phosphorus content of shoot(6.17 mg, g(-1)) and yield(535.67 kg, Ha(-1)) were found when AR1 dually inoculated with GM in Blackgram.
Anti-Bacterial Agents ; Chlorophyll ; Drug Resistance, Microbial ; Fungi* ; Nitrogen ; Nitrogenase ; Phosphorus ; Rhizobium*

When the brain is damaged, lipid peroxidation and malonate concentration are increased. The malonate activates the NMDA receptor and induces neuronal toxicity. To investigate the importance of malonate concentration as a prognostic factor, we measured its concentration in serum and urine of 20 patients with head trauma from August 1993 to Feburary 1994. Controls were 20 healthy volunteers. Blood and urine samplings ware taken at first day after head trauma. Malonate concentration in serum and urine was measured by utilizing the malonyl-CoA synthetase from Rhizobium trifolii. Direct spectrophotometric assay at 540 nm was used for purification and characterization. Mean serum malonate concentration in patients with head trauma was 1.83+/-.64 mM/L and 0.72+/-.20 mM/L in controls. The serum malonate concentration in patients was more significantly increased than controls (p<0.05). Mean malonate concentraion in urine was 0.61+/-.28 mM/L and 0.76+/-.24 mM/L in controls. There was no significant difference between patients and controls(p>0.05). A regression analysis on the relationship between malonate concentration, higher the malonate concentration, worse the Glasgow Outcome(r=0.64). In conclusion, when head injury occurs, concentration of serum malonate increases and this tends to be related to poor outcome. But, it must be further investigated to varify whether the relationship between traumatic brain injury and malonate concentration is more closely related without other factors affecting its concentration.
Brain ; Brain Injuries* ; Craniocerebral Trauma ; Glasgow Outcome Scale ; Healthy Volunteers ; Humans ; Ligases ; Lipid Peroxidation ; N-Methylaspartate ; Neurons ; Rhizobium

Ginseng is a valuable medicinal plant with ginsenosides as its mian effective components. Because ginseng is a perennial plant and has a very strict demand for soil conditions, the way of cultivating ginseng by cutting woods is still used in China at present and thus forest resources has been extremely destroyed. Increasing attention has been paid to the hairy roots induced by the infection of Agrobacterium rhizogenes in the production of plant secondary metabolic products for the hairy roots are characterized by rapid growth and stable hereditary and biochemical traits. That has opened a new way for the industrial production of ginseosides. However, there is little report for such studies from China. In this paper, hairy roots of ginseng were induced from the root explants of two-year-old ginseng by Agrobacterium rhizogenes A4 with directly inoculating. The transformed hairy roots could grow rapidly on MS medium and 1/2 MS medium without hormones. The cultured clones of the hairy roots were established on a solid 1/2 MS medium. After 4 - 5 subcultures the hairy roots still maintained a vigorous growth. A pair of primers were designed and synthesized according to the analytical results of RiA4TL-DNA sequence by Slightom et al . 0.8kb rolC was obtained by PCR using the genome DNA of hairy root of ginseng. Transformation was confirmed by PCR amplification of rolC genes from the hairy roots of P. ginseng. Growth rate of hairy roots on liquid medium increased by 2 times then that of the solid medium. The growth of the hairy roots can be divided into three stages: high speed in the first two weeks, middle speed in the 3 - 4 weeks and low speed hereafter. Changing the culture solution at 2 weeks regular intervals is conductive to maintaining the rapid growth of the hairy roots. By means of determination for specific growth rate and ginsenosides content, the high-yield hairy root clone R9923 was selected. The content of monomer gisenoside of Rg1, Re, Rf, Rbl, Rc, Rb2 and Rd in hairy root clone R9923 was determined by the HPLC. The total ginsenosides content in the hairy toot clone R9923 came up to 15.2 mg/g. The suitable culture conditions for ginseng hairy roots growing were 1/2 MS liquid medium (30 g/L glucose), in a shaker at 110 r/min, changing the culture solution at 2 weeks and subculture time 4 weeks. In the liquid fermented culture of 2L medium, the yield of the hairy roots could amount to 270.10 g in 4 weeks. The industrial production of ginsenosides has been preliminarily realized. Effect factors on biomass and ginsenosides content such as culture volume, inoculation, in steps cultural technology at the scale-up process of hairy roots culture were also explorated. Our results have laid a foundation for defining optimum culture manner for large-scale cultivation and large-scale production of ginsenosides.
Culture Media ; metabolism ; Culture Techniques ; methods ; Glucosides ; analysis ; Panax ; growth & development ; Plant Roots ; growth & development ; Rhizobium ; physiology