Optimization of cultivation conditions of Salvia viridis L. shoots in the Plantform bioreactor to increase polyphenol production

Abstract

Salvia viridis is a rich source of pharmacologically-important polyphenolic compounds with anti-inflammatory, antioxidant and anticancer activities. The aim of the present study was to optimise the large-scale cultivation of sage shoots in the Plantform bioreactor. It evaluated the effect of culture duration (two or three weeks), the use of a semi-continuous system and the immersion frequency in a liquid medium (every 80 or 170 min) on the growth and accumulation of secondary metabolites. The content of bioactive phenolic acids and phenylethanoids in the obtained material was determined using HPLC. The most efficient growth parameters, expressed as fresh (26.99 g) and dry weight (3.51 g) as well as proliferation ratio (18.6), were observed for shoots grown in a fed-batch system, immersed every 80 min; this approach yielded a 33-fold biomass increase within four weeks. However, the most efficient production of bioactive compounds was achieved for shoots grown for three weeks in a batch system, immersed every 80 min: total phenolic acid, total phenylethanoid and total phenol contents of 18.3, 11.4 and 29.7 mg/g DW. In these conditions, within three weeks, total phenolic acid level was almost 10 times higher than that found in the aerial parts of four-month-old soil-grown plants with a similar phenylethanoid level. Hence, the described S. viridis shoot culture cultivated in the Plantform bioreactor may be an alternative efficient source of plant material rich in valuable compounds.