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Current global environmental issues raise unavoidable challenges for our use of natural resources. Supplying the human population with clean water is becoming a global problem. Numerous organic and inorganic impurities in municipal, industrial, and agricultural waters, ranging from microplastics to high nutrient loads and heavy metals, endanger our nutrition and health. The development of efficient wastewater treatment technologies and circular economic approaches is thus becoming increasingly important. The biomass production of microalgae using industrial wastewater offers the possibility of recycling industrial residues to create new sources of raw materials for energy and material use. This review discusses algae‐based wastewater treatment technologies with a special focus on industrial wastewater sources, the potential of non‐conventional extremophilic (thermophilic, acidophilic, and psychrophilic) microalgae, and industrial algae‐wastewater treatment concepts that have already been put into practice.

Laser speckle photometry (LSP) is an innovative, non-destructive monitoring technique based on the detection and analysis of thermally or mechanically activated speckle dynamics in a non-stationary optical field. With the development of speckle theories, it has been found that speckle patterns carry information about surface characteristics. Therefore, LSP offers a great potential for the characterization of material properties and monitoring of manufacturing processes. In contrast to the speckle interferometry method, LSP is very simple and robust. The sample is illuminated by only one laser beam to generate a speckle pattern on the surface. The signals obtained are directly recorded by a CCD or CMOS camera. By appropriate optical solutions for the beam path, typically, resolutions of less than 10 μm are reached if larger areas are illuminated. LSP is definitely a contactless, quick and quality relevant material characterization and defect detection method, allowing process monitoring in many industrial fields. Examples from online biotechnological monitoring and laser based manufacturing demonstrate further potentials of the method for process monitoring and controlling.

Hairy roots are used to produce plant agents and additives. Due to their heterogeneous structure and growth characteristics, it is difficult to determine growth-related parameters continuously and in real time. Laser speckle contrast analysis is widely used as a non-destructive measurement technique in material testing or in medical technology. This type of analysis is based on the principle that moving objects or particles cause fluctuations in stochastic interference patterns known as speckle patterns. They are formed by the random backscattering of coherent laser light on an optically rough surface. A Laser Speckle Imager, which is well established for speckle studies of hemodynamics, was used for the first time for non-invasive speckle measurements on hairy roots to study dynamic behavior in plant tissue. Based on speckle contrast, a specific flux value was defined to map the dynamic changes in the investigated tissue. Using this method, we were able to predict the formation of lateral strands and to identify the growth zone in the apical root region, as well as dividing it into functional regions. This makes it possible to monitor physiological processes in the apical growth zone in vivo and in real time without labeling the target structures.

The diversity and complexity of biotechnological applications are constantly increasing, with ever expanding ranges of production hosts, cultivation conditions and measurement tasks. Consequently, many analytical and cultivation systems for biotechnology and bioprocess engineering, such as microfluidic devices or bioreactors, are tailor-made to precisely satisfy the requirements of specific measurements or cultivation tasks. Additive manufacturing (AM) technologies offer the possibility of fabricating tailor-made 3D laboratory equipment directly from CAD designs with previously inaccessible levels of freedom in terms of structural complexity. This review discusses the historical background of these technologies, their most promising current implementations and the associated workflows, fabrication processes and material specifications, together with some of the major challenges associated with using AM in biotechnology/bioprocess engineering. To illustrate the great potential of AM, selected examples in microfluidic devices, 3D-bioprinting/biofabrication and bioprocess engineering are highlighted.

Oleanolic (OA) and ursolic acid (UA) are plant secondary metabolites with diverse pharmacological properties. To reach reasonable productivities with plant cell suspension cultures, elicitation is a widely used strategy. Within the presented work, the effects of different elicitors on growth and production of OA and UA in a Salvia fruticosa cell suspension culture were examined. Beside commonly used elicitors like jasmonic acid (JA) and yeast extract, the influence of medium filtrates of the endophytic fungi Aspergillus niger and Trichoderma virens was investigated. The best eliciting effects were achieved with JA and fungal medium filtrates. Both increased the triterpene content by approximately 70 %. Since JA showed significant growth inhibition, the volumetric triterpene yield did not increase. But, adding fungal filtrates increased the volumetric triterpene yield by approximately 70 % to 32.6 mgOA l(-1) and 65.9 mgUA l(-1) for T. virens compared to the control with 19.4 mgOA l(-1) and 33.3 mgUA l(-1). An elicitation strategy combining fungal medium filtrate of T. virens with sucrose feeding significantly enhanced cell dry weight concentration to 22.2 g l(-1) as well as triterpene content by approximately 140 %. In total, this led to an approximately 500 % increase of volumetric triterpene yield referring to the control with final values of 112.9 mgOA l(-1) and 210.4 mgUA l(-1). Despite the doubled cultivation duration, productivities of 6.7 mgOA l(-1) day(-1) and 12.4 mgUA l(-1) day(-1) were reached. These results demonstrate methods by which increased productivities of triterpenes can be achieved to attain yields competing with intact plants.

Regardless if a kinetic expression of a light-dependent bioprocess is being sought, the parameters of that kinetic function are being adjusted, or a scaling-up process is being carried out to predict the productivity of a reactor, it is necessary to know the light availability in the culture volume. The emission characteristics of the radiation source, the geometry of the reactor as well as the optical properties of the suspension that resides within it must be known to achieve the latter. Here, we present an approach to quantify the optical properties of microalgae suspensions. A simple methodology, consisting in illuminating a suspension of microalgae with a characterised polychromatic radiation source and assessing how the directions are modified, and the amount of energy carried by the light beams after crossing the suspension, was successfully employed. Subsequently, through an optimisation program, the experimental culture data has been used to determine the spectral absorption and scattering coefficients of photons, and the suspension´s scattering phase function. For a given microalgal culture, eight samples corresponding to a cultivation time of one week were analysed, utilising an energy balance, independently of the biomass or pigment concentration. Altogether the results presented here suggest that this methodology could be adapted to other suspensions, allowing accessible ways to evaluate the radiative characteristics of phototrophic microorganisms in the complex context of the evolution through time of the radiant energy field inside a photobioreactor. Fil: Ibañez, Manuel Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Leonardi, Rodrigo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Heinrich, Josué Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Steingroewer, Juliane. Technische Universität Dresden.; Alemania Fil: Walther, Thomas. Technische Universität Dresden.; Alemania Fil: Felix, Krujatz. Technische Universität Dresden.; Alemania

Systematic analysis of the extrusion process in 3D bioprinting is mandatory for process optimization concerning production speed, shape fidelity of the 3D construct and cell viability. In this study, we applied numerical and analytical modeling to describe the fluid flow inside the printing head based on a Herschel–Bulkley model. The presented analytical calculation method nicely reproduces the results of Computational Fluid Dynamics simulation concerning pressure drop over the printing head and maximal shear parameters at the outlet. An approach with dimensionless flow parameter enables the user to adapt rheological characteristics of a bioink, the printing pressure and needle diameter with regard to processing time, shear sensitivity of the integrated cells, shape fidelity and strand dimension. Bioinks consist of a blend of polymers and cells, which lead to a complex fluid behavior. In the present study, a bioink containing alginate, methylcellulose and agarose (AMA) was used as experimental model to compare the calculated with the experimental pressure gradient. With cultures of an immortalized human mesenchymal stem cell line and plant cells (basil) it was tested how cells influence the flow and how mechanical forces inside the printing needle affect cell viability. Influences on both sides increased with cell (aggregation) size as well as a less spherical shape. This study contributes to a systematic description of the extrusion-based bioprinting process and introduces a general strategy for process design, transferable to other bioinks.

In this study, Nocardia iowensis was used to transform oleanolic acid (OA) into oleanane derivatives. The first derivative, which was found after 24 h of cultivation, was the known and already described OA methyl ester. After 1 week, two other derivatives (oleanonic acid methyl ester and an unknown metabolite) were identified as new products of a biotransformation by N. iowensis. These oleanane metabolites were characterized by HPLC, HPLC-ESI-MS, and HPLC-1H NMR spectroscopy. The biotransformation was performed by suspended and immobilized cells (ICs) of N. iowensis. Cells immobilized in alginate beads were used in order to prepare a continuous process. The substrate uptake of free and ICs was similar, whereas the peak area of OA methyl ester of the ICs was only about 10% of the native cells. However, the final product (oleanonic acid methyl ester) concentrations were similar in both approaches, whereas the unknown metabolite 3 was only detected transiently in the medium of ICs. Based on these results, a new biosynthetic pathway for the biotechnological production of oleanonic acid methyl ester is proposed.

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.

Oleanolic acid (OA) and ursolic acid (UA) are triterpenic acids with diverse biological activities that are of interest to the pharmaceutical industry. To investigate the scope for producing these compound using cell suspension cultures of Salvia species, calli from Salvia officinalis, S. virgata and S. fruticosa were induced using several plant growth regulator combinations. Eleven lines were selected for suspension induction from a pool of calli. Six suspension cultures were established successfully and cultivated in the respiration activity monitoring system (RAMOS®) to obtain online data on their growth kinetics and to establish appropriate sampling schedules for the determination of their OA and UA production. Based on their observed growth behaviour, OA and UA contents, and aggregation properties, one suspension culture from each studied Salvia species was selected for further optimisation. The µmax values for these suspension cultures ranged from 0.20 to 0.37 day−1, their OA and UA contents were greater than 1.3 and 1.2 mg g−1, respectively, and they afforded maximum volumetric yields of 21.0 mg l−1 for OA and 32.8 mg l−1 for UA. These results will be useful in the development of a refined Salvia suspension-based process for OA and UA production.

The energy-intensive dewatering of algae biomass, the first step of most downstream processes, remains one of the big challenges for economically relevant photoautotrophic bioprocesses. Due to its scalability and easy construction, froth flotation using the interactions between cells and bubbles shows considerable potential for this type of cost-efficient initial dewatering step. Comprehensive knowledge on both the physico-chemical conditions and the cellular surface properties are an important precondition to harvest cells by flotation. This study investigates the impact of changing the medium composition, specifically varying the pH and adding (bio-) collectors, on the zeta potential of Chlorella vulgaris SAG 211-1b. Decreasing the pH value from physiological to acidic conditions (pH 1–1.5) resulted in a strongly reduced cellular zeta potential. As validated by dispersed-air flotation, this yields a significantly enhanced cell recovery R > 95 %. The impact of the synthetic collector cetyltrimethylammonium bromide and the biopolymer chitosan on the cellular zeta potential and flotation performance was studied, resulting in a 3.3-fold decrease in the surfactant dose when chitosan was used . The basic mechanisms of cell-chitosan interaction were analysed in terms of particle size distribution and surface tension measurements, revealing interactions between flocculation and adsorption during the dispersed-air flotation of C.vulgarisSAG 211-1b.

Plants contain a wide range of interesting secondary metabolites, which are used as phytopharmaceuticals, fine chemicals as well as additives for foodstuffs and cosmetics. The conventional extraction from whole plants or parts of them is limited due to several environmental and geographical influencing factors. Plant in vitro cultures can be considered as alter-native solution to obtain valuable secondary metabolites. This technique allows a year-round production in closed bioreactor systems under sterile and optimal conditions with constant high-level quality and quantity.

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.

Plant cells contain a wide range of interesting secondary metabolites, which are used as natural pigments and flavoring agents in foods and cosmetics as well as phyto-pharmaceutical products. However, conventional industrial extraction from whole plants or parts of them is limited due to environmental and geographical issues. The production of secondary metabolites from in vitro cultures can be considered as alternative to classical technologies and allows a year-round cultivation in the bioreactor under optimal conditions with constant high-level quality and quantity. Compared to plant cell suspensions, differentiated plant in vitro systems offer the advantage that they are genetically stable. Moreover, the separation of the biomass from culture medium after fermentation is much easier. Nevertheless, several investigations in the literature described that differentiated plant in vitro systems are instable concerning the yield of the target metabolites, especially in submerged cultivations. Other major problems are associated with the challenges of cultivation conditions and bioreactor design as well as upscaling of the process. This article reviews bioreactor designs for cultivation of differentiated plant in vitro systems, secondary metabolite production in different bioreactor systems as well as aspects of process control, management, and modeling and gives perspectives for future cultivation methods.

Triterpenes are a versatile group of biologically active ingredients present in several phytoextracts. They often occur as glycoconjugates with a distinct bioactivity from their aglycone counterparts. Deglycation of triterpenes can be performed by enzymatic and chemical reactions, whereas biotransformation is generally more specific and occurs without unwanted alterations to the molecule. Further structural modification of the triterpenes to enhance their pharmaceutical relevance can be efficiently carried out by the application of biotransformational processes using microorganisms or isolated enzymes. In particular, the whole-cell process is favorable if cofactor-dependent modifications are preferred, such as hydroxylations/oxidations of the lead compound. However, the isolation of triterpenes from domestic plant material has some disadvantages such as extract variability and instability. These problems can be overcome through the use of cell culture technology, where the ex vivo cultivated cells are used for the reproducible production of the target compound. The relevant topics that should be addressed to establish a (biotransformational) production process of pharmaceutically relevant triterpenes are covered in this review. In particular, we focus on the production process using tissue engineering, the corresponding analytical techniques, and the biotransformation reaction required to obtain bioactive compounds from precursor molecules.

In advance of industrial applications of in vitro plant cell or tissue cultures e. g., as bioactive ingredients for pharmaceuticals, an intense characterization concerning growth and productivity has to be performed. Innovative respiration measurement techniques in shake flask scale were applied to investigate and compare heterotrophic, photomixotrophic and hairy root cultures of sunflower. Furthermore, the qualification of a monitoring system for screening of plant in vitro cultures is discussed.

Due to their potential to produce a great variety of valuable products bioprocesses using plant cells and microalgae are of growing industrial interest. The cultivation of eukaryotic production systems is challenged by slow growth rates, uncontrolled formation of cell aggregates, adherence to surfaces, shear sensitivity due to their huge cell size and by maintaining the productivity. Because of the high complexity of the biological systems there is only limited knowledge about the physiological and kinetic dependencies on the cultivation conditions. Therefore, advanced micro-cultivation systems are necessary enabling a detailed investigation on the micro- (cellular-scale, e.g. viability, morphologyEL) and macro-scale (process-scale, e.g. product formation kinetics, substrate consumptionEL). Additive technologies have the potential to meet these complex biological requirements. This work describes the design of two micro-cultivation environments for suspended and immobilized microalgae and plant cells by additive technologies. First, a milliliter-scale (V = 15 mL) Flat-Panel-Airlift photobioreactor equipped with optical sensors for the real-time measurement of dry weight concentration, chlorophyll fluorescence, pH, dO2 and dCO2 is presented. As a second example, we present a method called Green Bioprinting which was derived from tissue engineering bioprinting approaches and describes the fabrication of three-dimensional hydrogel-based immobilization structures for microalgae, plant cells and even structural organized co-cultures of different cell types. It was shown that the hydrogel-environment provided excellent growth and viability conditions using Chlamydomonas reinhardtii and Ocimum basilicum. The Green Bioprinting technology enables the study of cell-cell interactions (e.g. symbiotic living organisms) or the design of three-dimensional immobilization structures to perform cascaded bioprocesses.

Small-scale cultivation systems with real-time-monitoring of suspension parameters are important for high-throughput bioprocess development. This manuscript describes the design and characterization of a new photobioreactor (PBR) approach using 3D-printing and organic light emitting diodes (OLEDs) in the design step. The structurally complex miniaturized PBR periphery was manufactured from polyamide using the selective laser sintering technology. The MicrOLED-PBR - the first Flat-Panel-Airlift photobioreactor (FPA-PBR) with a working volume below 20 mL - was equipped and validated with non-invasive optical sensors for cell- (microalgal dry weight concentration and chlorophyll fluorescence) and suspension parameters (pH, dO 2 and dCO 2 ) allowing multiparametric high-resolution physiological studies of microalgae growth at low photon flux densities. The OLED modules used in the MicrOLED-PBR were characterized with respect to their spectral photosynthetically active radiation efficiency (35.31%), maximum photon flux density (83 μmol m − 2 s − 1 ) and resulting photon flux density profiles across the layer thickness of the FPA-cultivation chamber (10 mm) according to Lambert-Beers law (150 μmol m − 2 s − 1 for dual-plane external illumination). The hydrodynamic properties of the FPA-cultivation chamber, i.e. its volumetric oxygen transfer coefficient k L a (1.5–57 h − 1 ), superficial gas velocity (0.8–42 m h − 1 ), mixing time (1.5–34.5 s) and gas hold-up (0.016–0.2) were comparable to those for lab- and production-scale FPA-PBRs at volumetric aeration rates of 0.5–5.0 L h − 1 . The application of the MicrOLED-PBR was demonstrated for optimizing the CO 2 conditions during batch-mode growth of Chlamydomonas reinhardtii 11-32b. By analyzing the suspension dynamics in real-time limitations of dissolved carbon dioxide were identified at a CO 2 amount of 0.1 vol% whereas 2.0 vol% CO 2 was identified as optimum conditions for growing C. reinhardtii 11-32b in the MicrOLED-PBR.

Analyses of food-borne pathogens are of great importance in order to minimize the health risk for customers. Thus, very sensitive and rapid detection methods are required. Current conventional culture techniques are very time consuming. Modern immunoassays and biochemical analysis also require pre-enrichment steps resulting in a turnaround time of at least 24 h. Biomagnetic separation (BMS) is a promising more rapid method. In this study we describe the isolation of high affine and specific peptides from a phage-peptide library, which combined with BMS allows the detection of Salmonella spp. with a similar sensitivity as that of immunomagnetic separation using antibodies.

Bei der Lebensmittelproduktion spielt die Qualitatssicherung eine entscheidende Rolle, da sie unmittelbar Einfluss auf die Gesundheit der Verbraucher hat. Ein Kernproblem ist dabei das sichere und schnelle Identifizieren mikrobieller Kontaminationen. Die relevanten Keime sind oft in der komplexen Stoffmatrix der Lebensmittelprobe eingeschlossen und damit fur einen Nachweis nicht problemlos zuganglich. Derzeit gebrauchliche mikrobiologische Untersuchungsmethoden basieren auserdem zum grosen Teil auf zeitaufwandigen konventionellen Kultivierungsverfahren, bei denen bis zu sieben Arbeitstage benotigt werden, ehe ein zuverlassiges Ergebnis vorliegt. Auf dieser Grundlage ist eine prozessnahe Qualitatskontrolle nicht moglich. Vorgestellt werden neue Losungsansatze fur schnelle Nachweisverfahren, in die moderne molekularbiologische und biotechnologische Methoden, wie die biomagnetische Separation, eingebunden sind.

Detection of food-borne pathogens is of great importance in order to minimize the risk of infection for customers. These analyses should be as fast as possible. Any detection method requires enrichment and quantitative analysis of the enriched microbes. Conventional enrichment methods, which take several days, need to be replaced by faster techniques such as immunomagnetic separation (IMS). This technique is based on the use of paramagnetic microspheres coated with antibodies as ligands that have specific affinity to the microbes that have to be detected. In the studies reported here, a rapid method for the detection of Salmonella enterica serovar Typhimurium (Salmonella Typhimurium), combining IMS and Direct Epifluorescence Filter Technique (DEFT), was developed. It was focused on releasing the target cells from the magnetic beads after IMS, because this is a premise for combining IMS, as an alternative pre-enrichment, with DEFT. Otherwise, the high number of beads form a layer on the filter membrane that makes the following microscopic analysis for the detection of the contaminants impossible. The CELLectionTM Dynabeads® used in this study, are coated with recombinant streptavidin (rSA) via a DNA linker. The rSA binds biotinylated antibodies that are able to capture target cells. The DNA linker provides the cleavable site, so that the beads can be removed from the captured cells after isolation. In this study a releasing procedure was developed. This procedure allows for an average 74 % ± 4 % of the bead-bound Salmonella Typhimurium cells to be released from the beads after IMS, so that the detection of the separated cells by DEFT will be possible.

Analyses of food-borne pathogens are of great importance in order to minimize the risk of infection for customers. These analyses should be as fast as possible. Any detection method requires enrichment and quantitative analysis of the enriched microbes. Conventional enrichment methods, which take several days, need to be replaced by faster techniques such as biomagnetic separation (BMS). This technique involves the use of paramagnetic microspheres coated with ligands that have special affinity to the microbes that have to be detected. In the studies reported here, enrichment experiments by BMS were carried out using the non-pathogenic E. coli DSM 498 as a model strain and beads coated with a polyethylenimine (PEI) anion-exchange material. The results show that the number of cells separated, as a proportion of the total, was positively correlated with the bead concentration and the length of the period they were mixed together. In addition, a mathematical model, based on the rate of impact between two different sorts of particles, was developed to describe the proportion of separated cells as a function of incubation time and the concentration, size and density of the beads and cells. This is the first mathematical description of cell-bead interactions to be based on well-understood physicochemical principles. The model was confirmed by separation experiments in which the concentration of beads and the incubation period were varied. The developed model enables optimization of the amount of beads added and the reaction period necessary for complete cell separation and thus minimization of costs in BMS.

Plant cell cultures produce active agents for pharmaceuticals, food and cosmetics. However, up to now process control for plant cell suspension cultures is challenging. A positive impact of cell immobilization, such as encapsulation in hydrogel beads, on secondary metabolites production has been reported for several plant species. The aim of this work was to develop a method for bioprinting of plant cells in order to allow fabrication of free-formed three-dimensional matrices with defined internal pore architecture for in depth characterization of immobilization conditions, cell agglomeration and interactions. By using extrusion-based 3D plotting of a basil cell-laden hydrogel blend consisting of alginate, agarose and methylcellulose (alg/aga/mc), we could demonstrate that bioprinting is applicable to plant cells. The majority of the cells survived plotting and crosslinking and the embedded cells showed high viability and metabolic activity during the investigated cultivation period of 20 d. Beside its compatibility with the plant cells, the novel alg/aga/mc blend allowed fabrication of defined 3D constructs with open macropores both in vertical and horizontal direction which were stable under culture conditions for several weeks. Thus, Green Bioprinting, an additive manufacturing technology processing live cells from the plant kingdom, is a promising new immobilization tool for plant cells that enables the development of new bioprocesses for secondary metabolites production as well as monitoring methods.

Tocopherols, collectively known as vitamin E, are lipophilic antioxidants, which are synthesized only by photosynthetic organisms. Due to their enormous potential to protect cells from oxidative damage, tocopherols are used, e.g., as nutraceuticals and additives in pharmaceuticals. The most biologically active form of vitamin E is α-tocopherol. Most tocopherols are currently produced via chemical synthesis. Nevertheless, this always results in a racemic mixture of different and less effective stereoisomers because the natural isomer has the highest biological activity. Therefore, tocopherols synthesized in natural sources are preferred for medical purposes. The annual sunflower (Helianthus annuus L.) is a well-known source for α-tocopherol. Within the presented work, sunflower callus and suspension cultures were established growing under photomixotrophic conditions to enhance α-tocopherol yield. The most efficient callus induction was achieved with sunflower stems cultivated on solid Murashige and Skoog medium supplemented with 30 g l−1 sucrose, 0.5 mg l−1 of the auxin 1-naphthalene acetic acid, and 0.5 mg l−1 of the cytokinin 6-benzylaminopurine. Photomixotrophic sunflower suspension cultures were induced by transferring previously established callus into liquid medium. The effects of light intensity, sugar concentration, and culture age on growth rate and α-tocopherol synthesis rate were characterized. A considerable increase (max. 230 %) of α-tocopherol production in the cells was obtained within the photomixotrophic cell culture compared to a heterotrophic cell culture. These results will be useful for improving α-tocopherol yields of plant in vitro cultures.

An agent-based model for simulating the in vitro growth of Beta vulgaris hairy root cultures is described. The model fitting is based on experimental results and can be used as a virtual experimentator for root networks. It is implemented in the JAVA language and is designed to be easily modified to describe the growth of diverse biological root networks. The basic principles of the model are outlined, with descriptions of all of the relevant algorithms using the ODD protocol, and a case study is presented in which it is used to simulate the development of hairy root cultures of beetroot (Beta vulgaris) in a Petri dish. The model can predict various properties of the developing network, including the total root length, branching point distribution, segment distribution and secondary metabolite accumulation. It thus provides valuable information that can be used when optimizing cultivation parameters (e.g., medium composition) and the cultivation environment (e.g., the cultivation temperature) as well as how constructional parameters change the morphology of the root network. An image recognition solution was used to acquire experimental data that were used when fitting the model and to evaluate the agreement between the simulated results and practical experiments. Overall, the case study simulation closely reproduced experimental results for the cultures grown under equivalent conditions to those assumed in the simulation. A 3D-visualization solution was created to display the simulated results relating to the state of the root network and its environment (e.g., oxygen and nutrient levels).

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.

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.cit-journal.com P15.18 Untersuchung der Dehydrierung und der oxidativen Dehydrierung von n-Butan an Platin und V-basierten Katalysatoren in einem Zwei-Zonen-Wirbelschichtreaktor Prof. Dr. O. Deutschmann (E-Mail: olaf.deutschmann@kit.edu), J. Rischard, Dr. C. Diehm, Dr. L. Maier Karlsruher Institut fur Technologie (KIT), Institut fur Technische Chemie und Polymerchemie (ITCP), Engesserstrase 18, D-76131 Karlsruhe, Germany Karlsruher Institut fur Technologie (KIT), Institut fur Katalyseforschung und -technologie (IKFT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany DOI: 10.1002/cite.201450578

Plant in vitro cultures are a prospective alternative for biochemicals production, for example the triterpenes oleanolic and ursolic acid present in plants and cell cultures of Salvia sp. Our objective was to develop a suitable analysis protocol for evaluation of triterpenic acid yield in plant raw material and in vitro cultures supporting selection processes. Moreover, valuable bioactive compounds had to be revealed. Thus, different strategies enhancing the separation for a sensitive and effective HPLC-UV method were investigated and the developed method was validated for linearity, precision, accuracy, limits of detection and quantification. A baseline separation of these isomers enabled detection limits of below 0.4 μg/mL and quantification limits of about 1.2 μg/mL. Over the tested concentration range a good linearity was observed (R2 > 0.9999). The variations in the method were below 6% for intra- and inter-day assays of concentration. Recoveries were between 85–98% for both compounds using ethanol as extraction solvent. Additionally, metabolite profiling of cell suspension culture extracts by GC-MS has shown the production variability of different plant metabolites and especially the presence of plant phenols and sterols. These studies provide a method suitable for screening plant and cell culture productivity of triterpenic acids and highlighted interesting co-products of plant cell cultures.