Industrial Crops and Products 36 (2012) 460–465 Contents lists available at SciVerse ScienceDirect Industrial Crops and Products journal homepage: www.elsevier.com/locate/indcrop Enhanced productivity of biomass and bioactive compounds through bioreactor cultures of Eleutherococcus koreanum Nakai adventitious roots affected by medium salt strength Eun-Jung Lee a,b , Kee-Yoeup Paek b,∗ a CBN PLANTECH Co. Ltd., Industry Academic Cooperation Foundation Agribusiness Incubator Center 206, Chungbuk National University, Cheongju 361-763, Republic of Korea b Research Center for the Development of Advanced Horticultural Technology, Chungbuk National University, Cheongju 361-763, Republic of Korea article info Article history: Received 4 August 2011 Received in revised form 25 October 2011 Accepted 26 October 2011 Available online 29 November 2011 Keywords: Adventitious root Bioactive compounds Biomass Bioreactor culture Medium salt strength abstract To develop a protocol of Eleutherococcus koreanum Nakai adventitious root culture for production of biomass and bioactive compounds through bioreactors, different strengths of Murashige and Skoog (MS) medium were tested. After 5 weeks of culture, root growth at low salt strengths (1/4, 1/2, and 3/4 MS) was better than that at high salt strengths (1 and 2 MS), and the highest fresh and dry weight was achieved at 1/2 MS. The roots cultured at strengths exceeding 1 MS showed physiological abnormalities such as shorter, thicker, and less numerous roots compared to other treatments. Strengths over 1 MS caused physical dehydration that stimulated proline accumulation in the roots and decreased water potential in the medium because of high osmotic stress. Total production of 5 target compounds (per 1 L medium), eleutheroside B and E, chlorogenic acid, total phenolics, and flavonoids, was decreased with increasing medium salt strength. However, the highest total production of eleutheroside B and E (per 1 L medium), the main bioactive compounds in this plant, were observed at 1/2 and 3/4 MS, respectively. Therefore, 1/2 MS is a suitable medium salt strength for both biomass and bioactive compound productions, and optimization of bioreactor culture conditions will benefit the large-scale production of E. koreanum- derived bioactive compounds for commercialization. © 2011 Elsevier B.V. All rights reserved. 1. Introduction In recent years, the demand for high value plant-based bioac- tive compounds for pharmaceuticals, health food, and cosmetic products is increasing (Cui et al., 2010a; Park et al., 2010). How- ever, although the plant-based bioactive compound business is expanding, the areas where the natural plants can be grown and cultivated are decreasing because of increasing population and environmental pollution. The amount and quality of bioactive com- pounds obtained from field-grown plants is limited for industrial businesses because they are affected by harvest time and envi- ronmental conditions (Jwa et al., 2000; Murthy et al., 2008). Thus, methods such as chemical synthesis, semi-synthesis, and in vitro culture techniques are being used for the production of uniform plant-based bioactive compounds (Jeong et al., 2009; Lin et al., 2011). Among these methods, the in vitro culture technique is consid- ered the most attractive method for producing large amounts of biomass and bioactive compounds because this method enables ∗ Corresponding author. Tel.: +82 43 266 3245; fax: +82 43 266 3246. E-mail address: paekky@chungbuk.ac.kr (K.-Y. Paek). the establishment of a pilot-scale bioactive compound produc- tion system such as a plant factory (Cui et al., 2010a; Rao and Ravishankar, 2002). The single phytomolecule business, such as the production of high-value plant-based bioactive compounds like taxol and ginsenosides, is an annual multibillion dollar business worldwide. This business has succeeded via culture techniques for plant cells and hairy or adventitious roots using pilot-scale bioreactors (Exposito et al., 2009; Murthy et al., 2008). How- ever, many problems remain regarding enhanced productivity of bioactive compounds from in vitro-grown plantlets. For instance, cultured cells grow slower and have higher water content than field-grown plants; this reduces the final productivity of bioac- tive compounds (Flores, 1987). Hairy roots, established through an Agrobacterium rhizogenes-mediated transformation event, are clonal root lines that are not dependent on exogenous hormones and are recognized as a viable constitutive and inducible plant bio- production system for specialized phytomolecules (Guillon et al., 2006). However, hairy roots usually produce opin-like substances that are lethal to mammalian cells, and genetically modified organ- isms (GMOs) are not accepted in several countries like Australia, France, Japan, Korea, and New Zealand (Cui et al., 2010a; Yoshikawa and Furuya, 1987). Adventitious roots, induced both directly or via callus, are normal roots that are dependent on auxin contained 0926-6690/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.indcrop.2011.10.033