relation: https://khub.utp.edu.my/scholars/20/ title: Optimization and elucidation of interactions between ammonium, nitrate and phosphate in Centella asiatica cell culture using response surface methodology creator: Omar, R. creator: Abdullah, M.A. creator: Hasan, M.A. creator: Marziah, M. creator: Siti Mazlina, M.K. description: The effects of macronutrients (NO3-, NH4+ and PO43-) on cell growth and triterpenoids production in Centella asiatica cell suspension cultures were analyzed using the Box-Behnken response surface model experimental design. In screening and optimization experiments, PO43- as a single factor significantly influenced cell growth where increasing the phosphate level from 0.1 to 2.4 or 2.6 mM, elevated cell growth from 3.9 to 14-16 g/L. The optimum values predicted from the response surface model are 5.05 mM NH4 +, 15.0 mM NO3- and 2.6 mM PO43-, yielding 16.0 g/L cell dry weight with 99 fitness to the experimental data. While the NH4 +-NO3- interaction influenced cell growth positively in the optimization experiment, NH4 + and NO3- as single factors; and interactions of NO3--PO43-, NH4+-PO43- and NH4+-NO3- were all negative in the screening experiment. Cell growth and the final pH level were positively affected by PO43-, but negatively affected by NH4+ and NH4 +-PO43- interactions. The different effects of factors and their interactions on cell growth and final pH are influenced by a broad or narrow range of macronutrient concentrations. The productions of triterpenoids however were lower than 4 mg/g cell dry weight. © KSBB. publisher: Korean Society for Biotechnology and Bioengineering date: 2005 type: Article type: PeerReviewed identifier: Omar, R. and Abdullah, M.A. and Hasan, M.A. and Marziah, M. and Siti Mazlina, M.K. (2005) Optimization and elucidation of interactions between ammonium, nitrate and phosphate in Centella asiatica cell culture using response surface methodology. Biotechnology and Bioprocess Engineering, 10 (3). pp. 192-197. ISSN 12268372 relation: https://www.scopus.com/inward/record.uri?eid=2-s2.0-21644455627&doi=10.1007%2fBF02932012&partnerID=40&md5=40ed59299b1ede7ac7e9675abe54da10 relation: 10.1007/BF02932012 identifier: 10.1007/BF02932012