Sensor systems,electronic tongues and electronic noses,for the monitoring of biotechnological processes

Production of biofuel is based on the conversion by microorganisms of complex organic substrates into the methane or ethanol, which are consequently used as energy sources. Real time monitoring of the fermented media composition is of paramount for the effectiveness of the whole process. However, despite the fact that products worth billions of dollars are produced through fermentation processes annually, analytical instruments used for these processes’ monitoring remain relatively primitive. Established laboratory techniques produce exhaustive information about media composition but analysis is often quite time-consuming, expensive, requires skilled personnel and hardly can be automated. Lack of on-line sensors for the fermentation monitoring is commonly stressed in the literature. One of the techniques particularly suitable for this purpose is chemical sensors. Such features as low prices, relatively simple instrumentation, minimal sample preparation and easy automation of measurements make chemical sensors an attractive tool for industrial process control. However, practical use of chemical sensors in complex media is often hindered by their insufficient selectivity. For example, only pH and oxygen probes are routinely used in bio-reactors. One of the emerging approaches permitting to overcome the selectivity problems is the use of systems instead of discrete sensors. Such systems for liquid and gas analysis were named electronic tongues and electronic noses correspondingly. They are capable to perform both quantitative analysis (components’ concentrations) and classification or recognition of multicomponent media. This review presents recent achievements in the R&D and applications of electronic tongues and noses to the monitoring of biotechnological processes. JIMB-2008: BioEnergy—Special issue.     

Design and development of batch type acetifier for wine-vinegar production

A batch type acetifier based on the principal of acetic acid fermentation was designed and tested for production of wine-vinegar from the pineapple peel waste. The pineapple peels along with starter solution was fed to the inner SS perforated peel-solid separator tank 130 mm dia having perforations of 50 mm size. The concentric perforated peel-solid separator circular tank was fitted inside the collecting tank having 255 mm dia. The pineapple peels and starter solution in perforated peel-solid separator tank was agitated and atomized by tubing agitator 200 mm long having 1 mm dia. hole to spray fermented solution at 20 rpm. The agitator was connected with stirring pump. Lift pump was fitted at the bottom of the collecting tank to lift and supply fermented solution to agitator. The capacity of the batch type Acetifier based on present working design was 3.5 liters of wine-vinegar per day for 8 hours for a quality end product at 2% acidity.     

Inhibition of bacterial growth and galactosyltransferase activity of WbwC by α, ω-bis(3-alkyl-1H-imidazolium)alkane salts: Effect of varying carbon content

A series of compounds was designed and synthesized having two imidazolium rings separated by a polymethylene spacer and having alkyl substituents on each of the imidazolium rings. The compounds were assayed for their effects on the activity of galactosyltransferase WbwC, and also on the growth of Gram-negative and Gram-positive bacteria, as well as human cells. The inhibition observed on enzyme activities and cell growth was dependent on the total number of carbons in the spacer and the alkyl substituents on the imidazolium rings. These readily synthesized, achiral compounds have potential as antimicrobial and antiseptic agents.     

发展我国大规模细胞培养生物反应器装备制造业

生物反应器在生物工程装备制造业的产业化方面具有极其重要的意义。在分析了生物反应器产业的产品特点后,对我国生物反应器产业的现状和今后发展作了讨论。对以代谢流分析为核心的生物反应器、带pH测量与补料控制的摇床、动物细胞大规模培养生物反应器研制、生物反应器中试系统设计、大型生物反应器设计与制造技术研究等几个重要开发内容进行深入讨论,最后对细胞过程的系统生物学研究与生物反应器作了展望。     

Die Differenzierung isolierter Nerven- und Gliazellen aus trypsiniertem Rückenmark von Hühnerembryonen in Gewebekulturen

Zusammenfassung Cervikales und thorakales Rückenmark 6 und 7 Tage alter Hühnerembryonen wurde trypsiniert. Die isolierten Rückenmarkszellen wurden kultiviert und anschließend licht- und elektronenmikroskopisch untersucht.Unmittelbar nach der Isolierung kann man die Zellen morphologisch nicht unterscheiden. Nach wenigen Stunden der Inkubation beobachtet man ein erstes Auswachsen feiner Portsätze. Nach ca. 12stündiger Kulturzeit beginnt eine Zusammenlagerung der Zellen in Zellklumpen und lockeren Zellverbänden immer deutlicher zu werden, ohne daß eine aktive Zellbewegung sichtbar wird. Die Zusammenlagerung der Zellen geht mit einer feinstrukturell verfolgbaren Ausreifung einher.Am Ende der 1. Woche findet man neben einigen astrocytären Gliazellen auch zahlreiche andere polymorphe Formen, die sich weder als Astroglia- noch als Oligodendroglia-Zellen typisieren lassen. Letztere konnten während der kurzen Inkubationsdauer weder licht- noch elektronenmikroskopisch identifiziert werden.Die Nervenzellen zeigen eine Zunahme ihrer Organellen und eine Zusammenlagerung ihres endoplasmatischen Retikulums zu Ergastoplasmaformationen. Axone und Dendriten sind bereits nach 3tägiger Inkubation erkennbar.Ein eindeutiges Kriterium der Nervenzellausreifung stellt die Bildung von Synapsen dar, die nach dem 5. Tag der Inkubation deutlich wird. Es bilden sich axo-dendritische, axosomatische und axo-axonale Synapsen.Die mögliche physiologische Bedeutung der Synapsen auf Grund ihrer Ultrastruktur und die Bedeutung der 'membrane junctions wird diskutiert.

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On the differentiation of isolated nerve and glia cells from trypsinized spinal cord of chicken embryos cultivated in vitroA light- and electronmicroscopical investigation

Summary Cervical and thoracic segments of the spinal cord of six and seven days old chicken embryos were trypsinized. The isolated cells have been cultivated in vitro and studied both light- and electronmicroscopically.Immediately after isolation, neurons or glial cells can not be distinguished by morphological criteria. After a few hours in vitro, however, the first sprouting of fibres is visible. About 12 hours later an aggregation of cells in bulks or loosely woven nets becomes more and more prominent, without an active cellmovement visible. The aggregational process of the previously dissociated cells is combined with ultrastructural differentiation.At the end of the first week in vitro one could recognize besides some astrocytes a great number of those cells which were neither astroglia-nor oligodendroglia-cells. The latter were not detectable during our short periods of cultivation.Those cells showing an enhancement of organelles and their endoplasmic reticulum formed an ergastoplasm after five to seven days in vitro are definitely nerve cells, whose axons and dendrites appear after three days of incubation.The most convincing criteria of nerve cell maturation is the appearance of synapses, which increase in number from the fifth day of incubation onwards.Axo-dendritic, axo-somatic and axo-axonal synapses are present.A possible physiological significance of the synapses in relation to their ultrastructural features and the importance of the membrane junctions has been discussed.

Die Verff. danken Fräulein R. Dietrich und Frau M. C. Weinrichter für technische Assistenz.     

Catharanthus roseus: micropropagation and in vitro techniques

Different methods of in vitro culture of Catharanthus roseus provide new sources of plant material for the production of secondary metabolites such as indole alkaloids. Callus, cell suspension, plantlets, and transgenic roots cultured in the bioreactor are used in those experiments. The most promising outcomes include the production of the following indole alkaloids: ajmalicine in unorganised tissue, catharanthine in the leaf and cell culture in the shake flask and airlift bioreactor, and vinblastine in shoots and transformed roots. What is very important, enzymatic coupling of monomeric indole alkaloids, vindoline and catharanthine, is possible to form vinblastine in cell cultures. The method of catharanthine and ajmalicine production in the suspension culture in bioreactors has been successful. In this method, elicitation may be used acting on different metabolic pathways. Also of interest is the method of obtaining arbutin from the callus culture of C. roseus conducted with hydroquinone. The transformed root culture seems to be the most promising for alkaloid production. The genetically transformed roots, obtained by the infection with Agrobacterium rhizogenes, produce higher levels of secondary metabolites than intact plants. Also, whole plants can be regenerated from hairy roots. The content of indole alkaloids in the transformed roots was similar or even higher when compared to the amounts measured in studies of natural roots. The predominant alkaloids in transformed roots are ajmalicine, serpentine, vindoline and catharanthine, found in higher amounts than in untransformed roots. Transformed hairy roots have been also used for encapsulation in calcium alginate to form artificial seeds.