Betalains are water-soluble plant pigments that are widely used as food colorants, and have a wide range of desirable biological activities, including antioxidant, anti-inflammatory, hepatoprotective, anti-cancer properties. They can be produced from various plants, notably beetroot, but betalain products obtained in this way also have some undesirable properties and are difficult to standardize. A potentially attractive alternative is to use hairy root cultures. In the study reported here, we found that betalain extracts obtained from hairy root cultures of the red beetroot B. vulgaris cv. Detroit Dark Red also had higher antioxidant activity than extracts obtained from mature beetroots: six-fold higher 2,2-dyphenyl-1-picrylhydrazyl radical scavenging ability (90.7% inhibition, EC(50) = 0.11 mg, vs 14.2% inhibition, EC(50) = 0.70 mg) and 3.28-fold higher oxygen radical absorbance capacity (4,100 microM TE/g dry extract, vs 1,250 microM TE/g dry extract). The high antioxidant activity of the hairy root extracts was associated with increased concentrations (more than 20-fold) of total phenolic concomitant compounds, which may have synergistic effects with betalains. The presence of 4-hydroxybenzoic acid, caffeic acid, catechin hydrate, and epicatechin were detected in both types of extract, but at different concentrations. Rutin was only present at high concentration (1.096 mg.g(-1) dry extract) in betalain extracts from the hairy root cultures, whereas chlorogenic acid was only detected at measurable concentrations in extracts from intact plants.

"Hairy root" systems, obtained by transforming plant tissues with the "natural genetic engineer" Agrobacterium rhizogenes, have been known for more than three decades. To date, hairy root cultures have been obtained from more than 100 plant species, including several endangered medicinal plants, affording opportunities to produce important phytochemicals and proteins in eco-friendly conditions. Diverse strategies can be applied to improve the yields of desired metabolites and to produce recombinant proteins. Furthermore, recent advances in bioreactor design and construction allow hairy root-based technologies to be scaled up while maintaining their biosynthetic potential. This review highlights recent progress in the field and outlines future prospects for exploiting the potential utility of hairy root cultures as "chemical factories" for producing bioactive substances.

Plant tissue and organ cultures in vitro usually face technological challenges. When submerged cultivation of plant cells in a controlled environment is desired, the characteristic growth morphology and physiology of differentiated organ cultures present a problem in process scale‐up. Temporary immersion systems (TIS) were developed several decades ago. These systems are providing the most natural environment for in vitro culture of plant shoots and seedlings. Over the past few years, TIS have been recognized as a perspective technology for plant micropropagation, production of plant‐derived secondary metabolites, expression of foreign proteins, and potential solutions in phytoremediation. Nowadays, several TIS, operating on similar or divergent technological principles, have been developed and successfully applied in the cultivation of various plant in vitro systems, including somatic embryos and transformed root cultures. In this article, the operational principle and technological design of the most popular TIS are reviewed. In addition, recent examples of the application of temporary immersion technology for in vitro cultivation of plant tissue and organ cultures at laboratory and pilot scales are discussed. Finally, future prospects and challenges to the industrial realization of that fast‐developing technique are outlined.

Chitin is one of the most abundant biopolymers and is present in many organisms in different forms. Its resistance to degradation has caused many problems in industry (waste decomposition) and agriculture (as protective structures in pests); this has led to increased interest in chitin-hydrolyzing enzymes: chitinases. Chitinases are enzymes that break down the 1→4 β-glycoside bond of N-acetyl d-glucosamine in chitin to produce mono-and oligomers. The inducible nature of chitinases, low activity of synthesized enzymes, and inertia of the substrate are only a few of the problems that can be solved by biotechnology to meet industry demands for green, energy-efficient, pollution-free, and economically profitable chitin use. This review aims to present the pitfalls and successes in research and production of chitinolytic enzymes, as well as to promote the use of chitinases in everyday practice. The focus is on the biosynthesis of chitinases: inducers, type of fermentation, and media composition. Methods for purification and future perspectives are also discussed.

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.

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The process of galanthamine and related alkaloids production by Leucojum aestivum shoot culture in a temporary immersion system was studied. It was established that temporary immersion approach is prospective for development of a biosynthetic process for obtaining valuable Amaryllidaceae alkaloids. Both immersion frequency and temperature had significant effect on biomass accumulation and the yields of galanthamine and related alkaloids. The maximal yield of galanthamine was achieved at the cultivation of L. aestivum shoot culture in temporary immersion RITA ® system at immersion frequency 15 min flooding and 8 h stand-by periods, at 26°C. Data on the relationships in the biological system "Nutrient medium-L. aestivum shoot culture-galanthamine" are presented as well.

Betalains have been widely used as natural colorants for many centuries, but their attractiveness for use as colorants of foods (or drugs and cosmetics) has increased recently due to their reportedly high anti-oxidative, free radical scavenging activities and concerns about the use of various synthetic alternatives. The main commercial sources of betalains are powders and concentrates of red beet (Beta vulgaris) or cactus pear (Opuntia ficusindica) extracts. However, in recent years the technical and commercial feasibility of various in vitro systems to produce them biotechnologically has been explored. These research activities have included assessments of novel approaches for cultivating plant cell or tissue cultures, and diverse bioreactor systems for increasing production levels of secondary metabolites. This paper reviews recent progress in plant in vitro systems for producing betalain pigments. In addition, the factors that could be manipulated, the bioreactor systems that could be used, and the strategies that could be applied to improve betalain production are discussed.