• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.528-534
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• 2005

Hairy root cultures have demonstrated great promise in terms of their biosynthetic capability toward the production of secondary metabolites, but continue to constitute a major challenge with regard to large-scale cultures. In order to assess the possibility of conducting mass production of biomass, and the extraction of useful metabolites from Panax ginseng. P. ginseng hairy roots, transformed by Rhizobium rhizogenes KCTC 2744, were used in bioreactors of different types and sizes. The most effective mass production of hairy roots was achieved in several differently Sized air bubble bioreactors compared to all other bioreactor types. Hairy root growth was enhanced by aeration, and the production increased with increasing aeration rate in a 1 L bioreactor culture. It was determined that the hairy root growth rate could be substantially enhanced by increases in the aeration rate upto 0.5vvm, but at aeration rates above 0.5vvm, only slight promotions in growth rates were observed. In 20 L air bubble bioreactors, with a variety of inoculum sizes, the hairy roots exhibited the most robust growth rates with an inoculum size of 0.1% (w/v), within the range 0.1 to 0.7% (w/v). The specific growth rates of the hairy root decreased with increases in the inoculum size.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.318-324
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• 1996

The effects of light on the growth and ginsenosides production were examined in the hairy roots of Panax ginsen C.A. Meyer induced by Agrobacterium rhizogines A4. The 9rowth of ginseng hairy roots in 1/2MS liquid medium was significantly decreased with an increment of light intensity (1,000~7,000 lux). The growth of hairy roots under 7,000 lux condition was decreased at 17% compared to the dark condition. The production of 7 ginsenosides in hairy root was very high in 3,500 lux condition. The production of ginsenoside-Rg, and Rf increased 3.3 and, 2.4 times respectively as compared to dark condition. The growth of hairy roots was inhibited by blue light, while ginsenosides production was increased. The sucrose demands of hairy roots was examined in light condition(3,500 lux). The growth of hairy roots in 1/2MS liquid medium with various sucrose concentrations(1~4%) was high in IVp sucrose, while ginsenosides production was high in 3% sucrose condition. The growth and ginsenosides production were high when hairy roots were cultured in dark condition for 1 week and then transferred to light condition(3,500 lux) for 4 weeks. It is suggested that ginsenosides production could be accelerated by light intensity of specific wavelength in cultures of ginseng hairy roots.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.88-94
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• 2005

Plant tissue culture studies have been done for the preservation of medicinal plant resources and efficient production of pharmaceutically important secondary metabolites. Micropropagation methods for Cephaelis ipecacuanha have been established and these methods enabled much more efficient propagation of the plants than the conventional methods using seedling or layering. The C. ipecacuanha plants derived from tissue culture grew uniformly in the field and they showed higher alkaloid contents compared to the plants grown from seedlings. Hairy root cultures of C. ipecacuanha and Panax ginseng have been established by infection with Agrobacterium rhizogenes, and the production of important pharmaceuticals by these cultures have been successfully demonstrated. In the case of C. ipecacuanha, the highest alkaloid yields from the hairy roots cultured for 8 weeks were 2.75-fold cephaeline (5.5 mg) and one third emetine (0.7 mg) compared with those from the roots of one-year old plant propagated through shoot-tip culture and cultivated in a greenhouse (2.0 mg cephaeline and 2.0 mg emetine). In the case of P. ginseng, ginsenoside contents in the hairy roots optimally cultured for 4 weeks were much higher than those in the roots of 4-year old field-grown plant. Thus our medicinal plant tissue cultures demonstrate desirable properties. However, they are always exposed to danger of microbial contamination or unexpected trouble of culture facilities. Cryopreservation of plant tissue cultures is a reliable method for long-term preservation. Cryopreservation studies on these cultures are also presented.

• KSBB Journal
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• v.9 no.2
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• pp.157-164
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• 1994

Hairy root clones of Panax ginseng were established by selection of some hairy roots formed on the leaf, stem and root segments transformed with Agrobacterium rhizogenes strain $A_4$. The transformed roots grew well in MS medium under the dark condition. To confirm the transformation with Ri-T-DNA, dot blot hybridization and opine analysis were Performed. Among four hairy roots induced from different part of ginseng, the HB3 hairy roots were examined for selection of high-saponin-producing clones. Four clones isolated from HB3 hairy root cultures displayed various phenotypes characterized by growth and total saponin content. Maximum growth was obtained for cultures of HB3-10 clone and the content of total saponin was 0.55 wt%. However, higher amount of total saponin was obtained with HB3-2 clone cultures(0.74 wt%) in spite of lower growth. Dot blot hybridization confirmed the introduction of Ri-T-DNA in the plant genome. In the opine test, agropine and mannopine were detected from all hairy root clones.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.65-70
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• 1995

The synthesis of betalain in hairy root cultures of Phytolacca esculenta van Houtte required the light, but the growth of hairy roots was inhibited 5 times under light condition(1500 1X) compared to dark condition. To investigate the growth inhibition of hairy roots under light condition, we surveyed the effects of several antioxidants on growth and betalain production if suspension cultures of hairy roots was increased 1.2-1.4 times under dark condition and 1.3-1.9 times under light condition by the treatment of ascorbic acid, glutathione, $\alpha$-tocopherol, sodium pyrosulfate and propylgallic acid. The betalain production was increased 1.2-2.1 times by antioxidants under light condition. The combination treatment of antioxidants didn't have any significant effect on the growth of hairy roots and betalain synthesis. The antioxidants of the betalain production were more effect under blue light than others. It was discussed that the endogenous oxidants may be produced under blue light.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.250-253
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• 2000

We researched effects of growth on initial inoculum size, liquid volume, and medium feeding rate etc. Cell suspension inoculated at low cell concentrations showed a typical growth reduction, whereas root cultures showed an improvement in growth. In this paper, Hairy roots showed high growth rate at 0.4 % inoculum size and 100 mL liquid volume in 250 mL flask cultures.

• KSBB Journal
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• v.5 no.3
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• pp.207-214
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• 1990

Growth properties of carrot hairy roots transformed by Agrobacterium rhizogenes were compared in flask and bioreactor. Oxygen transfer coefficient KLa was measured during the cultivation in bioreactor. In flask cultures, initially sucrose 30g/l was nearly exhausted after 20days. pH was dropped from initially 5.8 to 4.79 after 4 days, but it is stable after that time. Finally, after 28 days, hairy roots were grown about twelve times. In view of the results studied optimum conditions, hairy roots were maintained high growth rates in sucrose 50g/l, pH 5.8, total nitrogen 60mM. Also in bioreactor cultures, fixed stainless sieve in bottom and aerated 0.31 vvm, the results of cultivation by the use of sucrose 50g/l had grown about twenty-eight times and pH variations were liked in flask. As a results, growth rate of 1.756g fresh weight/day/g inoculum in bioreactor were higher about three times than 0.57g fresh weight/day/g inoculum in flask culture. KLa values were showed a tendency to decrease from 0.209 min-1 to 0.068 min-1.

• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.823-834
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• 2014

In order to solve the shortage of natural Tripterygium wilfordii Hook. f. plant resource for the production of the important secondary metabolites triptolide and wilforine, hairy roots were induced from its root calli by Agrobacterium rhizogenes. Induced hairy roots not only could be maintained and grown well in hormone-free half-strength Murashige and Skoog medium but also could produce sufficient amounts of both triptolide and wilforine. Although hairy roots produced approximately 15% less triptolide than adventitious roots and 10% less wilforine than naturally grown roots, they could grow fast and could be a suitable system for producing both secondary metabolites compared with other tissues. Addition of $50{\mu}M$ methyl jasmonate (MeJA) could slightly affect hairy root growth, but dramatically stimulated the production of both triptolide and wilforine, whereas $50{\mu}M$ salicylic acid had no apparent effect on hairy root growth with slightly stimulatory effects on the production of both secondary metabolites. Addition of precursor nicotinic acid, isoleucine, or aspartic acid at the concentration of $500{\mu}M$ had varying effects on hairy root growth, but none of them had stimulatory effects on triptolide production, and only the former two had slightly beneficial effects on wilforine production. The majority of triptolide produced was secreted into the medium, whereas most of the produced wilforine was retained inside of hairy roots. Our studies provide a promising way to produce triptolide and wilforine in T. wilfordii hairy root cultures combined with MeJA treatment.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.23-23
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• 2002

We established hairy root cultures of F. esculentum transformed with A. rhizogenes for in vitro rutin production. Additionally, we describe the effects of different media and plant growth regulators on growth and rutin biosynthesis in buckwheat hairy root cultures. Excised leaves of P. tinctorium from 10-day-old seedlings were used as the explant material for co-cultivation with A. rhizogenes 15834. The hairy culture of Fagopyrum esculentum Moench. was established by infecting leaf explants with Agrobacterium rhizogenes 15834. About four to five weeks after co-cultivation with A. rhizogenes, 10 hairy roots were excised from the necrotic explant tissues. After repeated transfer to fresh medium for three months, ten clones were transferred to MS liquid culture medium. The growth and rutin production of each clone differently response to the MS liquid medium. Among these clones, H8, which had exhibited good growth rate and one of the highest rutin productivity, was selected for the following experimment.(중략)

• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.7-14
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• 1999

In order to survey anthraquinone productivity from in vitro root culture, transformed hairy roots of Rumex crispus were induced from leaf segments by infection with Agrobacterium rhizogenes strain $A_4$ and compared with adventitious roots. The optimum condition of adventitious root formation from leaf segments was 5 $\mu$M NAA added to MS medium. Mannopine was detected in the extract of hairy roots by paper electrophoresis, but not in adventitious roots. Secondary root tips of both adventitious roots and hairy roots elongated without lateral root branching in hormone free MS medium, but primary root tips showed more rapid growth with extensive lateral root branching. MS basal medium was the best for growth of the adventious roots and hairy roots for anthraquinone content. Adventitious root tips and hairy root tips cultured in liquid MS medium supplemented with 0.05 $\mu$M NAA and 0.1 $\mu$M kinetin (contained 5% sucrose) showed the maximal growth and anthraquinone content. Anthraquinone content of hairy roots was increased by the culture periods, but was reduced after 25 days of culture.