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Optimizing illumination is essential for optimizing the growth of phototrophic cells and their production of desired metabolites and/or biomass. This requires appropriate modulation of light and other key inputs and continuous online monitoring of their metabolic activities. Powerful noninvasive systems for cultivating heterotrophic organisms include shake flasks in online monitoring units, but they are rarely used for phototrophs because they lack the appropriate illumination design and necessary illuminatory power. This study presents the design and characterization of a photosynthetic shake flask unit, illuminated from below by warm white light-emitting diodes with variable light intensities up to 2300 μmol m−2 s−1. The photosynthetic unit was successfully used, in combination with online monitoring of oxygen production, to cultivate Arthrospira platensis. In phototrophic growth under continuous light and a 16 h light/8 h dark cycle (light intensity: 180 μmol m−2 s−1), the oxygen transfer rate and biomass-related oxygen production were −1.5 mmol L−1 h−1 and 0.18 mmol O2 gx−1 h−1, respectively. The maximum specific growth rate was 0.058 h−1, during the exponential growth phase, after which the biomass concentration reached 0.75 g L−1. [ABSTRACT FROM AUTHOR]

Extracts of Salvia species are used in traditional medicine to treat various diseases. The economic importance of this genus has increased in recent years due to evidence that some of its secondary metabolites have valuable pharmaceutical and nutraceutical properties.The bioactivity of sage extracts is mainly due to their content of terpenes and polyphenols. The increasing demand for sage products combined with environmental, ecological and climatic limitations on the production of sage metabolites from field-grown plants have led to extensive investigations into biotechnological approaches for the production of Salvia phytochemicals. The purpose of this review is to evaluate recent progress in investigations of sage in vitro systems as tools for producing important terpenoids and polyphenols and in development of methods for manipulating regulatory processes to enhance secondary metabolite production in such systems. [ABSTRACT FROM AUTHOR]

Plants produce a variety of secondary metabolites to defend themselves against herbivores or to attract pollinating insects. Plant cell biotechnology offers excellent opportunities in order to use such secondary plant metabolites to produce goods with consistent quality and quantity throughout the year, and therefore to act independently from biotic and abiotic environmental factors. This article presents results of an extensive study of plant cell in vitro cultivation in a modern shake flask system with noninvasive online respiration activity monitoring unit. Comprehensive screening experiments confirm the successful transfer of a model culture (sunflower suspension) into the shake flask monitoring device and the suitability of this respiration activity monitoring unit as qualified tool for screening of plant in vitro cultures (sunflower and sage suspension). The authors demonstrate deviations between online and offline data due to varying water evaporation from different culture flask types. The influence of evaporation on growth-specific parameters thereby rises with increasing cultivation time. Furthermore, possibilities to minimize the impact of evaporation, either by adjusting the inlet air moisture or by measuring the evaporation in combination with an appropriate correction of the measured growth values are shown. [ABSTRACT FROM AUTHOR]