The biomass production of Cymbopogon citratus shoots cultivated in bioreactors according to the temporary immersion (TIS) principle was assessed under different growth conditions. The effect of gassing with CO 2 -enriched air, reduced immersion frequency, vessel size and culture time on total phenolic and flavonoid content and free radical scavenging effect of the methanolic extracts was measured. From the TIS-culture of C. citratus, seven compounds were isolated and identified as caffeic acid (1), chlorogenic acid (2), neochlorogenic acid (3), p-hydroxybenzoic acid (4), p-hydroxybenzoic acid 3-O--d-glucoside (5), glutamic acid (6) and luteolin 6-C-fucopyranoside (7). The occurrence of compounds 1Ð7 and their variability in C. citratus grown under different TIS conditions was determined by HPLC. The free radical scavenging effect of the methanolic extract and compounds was measured by the discoloration of the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). The main metabolites in 6-and 8-week-old cultures, both in 5 and 10 l vessels, were chlorogenic acid (2) (100Ð113 mg%) and neochlorogenic acid (3) (80Ð 119 mg%), while in the cultures with CO 2 -enriched air and reduced immersion frequency the main compound detected in the extracts was glutamic acid (6) (400 and 670 mg% for the green and white biomass and 619 and 630 mg% for the green and white biomass, respectively). The most active compounds, as free radical scavengers, in the DPPH discoloration assay were caffeic acid (1), chlorogenic acid (2), neochlorogenic acid (3) and the flavonoid luteolin 6-C-fucopyranoside (7).

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Axillary buds, collected from greenhouse-grown plants of Bambusa vulgaris Schrad. ex Wendl (B. vulgaris), were incubated on a static liquid culture medium, Murashige and Skoog (MS) medium with 2% (w/v) sucrose, and supplemented with 12.0 µM 6-benzyladenine (BA). They were transferred to a temporary immersion system (TIS) using liquid MS medium supplemented with 0 (CK-free medium), 6.0, 12.0, 18.0 µM BA. The morphological and anatomical indicators were measured. The BA influenced in vitro multiplication of B. vulgaris. The best results were achieved in the SIT with a concentration of 6.0 µM of BA, which increased the number of shoots (5.1 shoots/explant) in the absence of hyperhydric shoots. Results demonstrated that the water content in the sprouts increased with 12.0 and 18.0 µM BA every four hours. Furthermore, these high levels of BA contributed to a lower accumulation of phenolic compounds and lignin content. The total chlorophyll significantly increased when using 6.0 uM BA, but decreased both parameters with other treatments. These results favor to increase the number of shoots/explants during in vitro multiplication. They will also optimize the in vitro culture conditions, leading to an improvement of in vitro propagation methods for this species.