Effect of calcium, phosphate and nitrogen on cell growth and biosynthesis of cell wall polysaccharides by Silene vulgaris cell culture

Medium nutrients such as calcium, phosphorus, nitrogen and nitrate to ammonium ratio have significant influence on the growth, biosynthetic and biochemical characteristics of polysaccharides produced by Silene vulgaris (M.) G. cell culture. Cell growth and production of polysaccharides was limited by an absence of any of these components in the medium. Optimal growth of the callus and production of arabinogalactan were achieved at 1.5-4.5 μM calcium while the optimal production of pectin named silenan was observed at 3.0-4.5 μM. The phosphate contents in the medium in the range of 0.63-3.75 μM were favorable for callus growth. Production of silenan was maximal at 1.25-3.75 μM phosphate. Optimal growth of the callus was achieved at 30-90 μM nitrogen. Maximal production of silenan was observed at 60 μM nitrogen while the optimal production of arabinogalactan was at 90 μM nitrogen (at ratio of NH4+:NO3− as 1:2). A presence both of nitrate and ammonium is needed for the silenan biosynthesis (the NH4+:NO3− ratio as 1:1 and 1:2). Yields and volumetric production of arabinogalactan were maximal at deletion of ammonium from the nutrient medium (ratio 0:1). Absence of calcium or nitrogen in the medium leads to a decrease of the galacturonic acid residues in silenan. The galactose residues contents in arabinogalactan were decreased in the absence of nitrogen and calcium in the medium.