bluuebunny/crossref_metadata_2025 huggingface dataset:
Biosensors, Aptamers (Aptasensors)
Authors: Bini Alessandra , Mascini Marco , Turner Anthony P.F.
Published: April 2010

Aptamers are single‐stranded DNA or RNA ligands which can be selected for different targets, starting from a huge library of molecules containing randomly created sequences. Aptamers have been selected to bind very different targets, from proteins to small organic dyes. The different fields of analytical chemistry, when dealing with systems based on biomolecular interactions, are still dominated by immunoassays, but detailed analytical studies are now demonstrating that some of the limitations of these conventional assays can be circumvented by alternative recognition reagents such as aptamers. Aptamers have been extensively used in many analytical applications such as chromatography, electrophoresis, mass spectrometry, molecular beacons, sensors and biosensors. This chapter focuses on the particular case of biosensors employing aptamers as new biorecognition elements, which are known as “aptasensors”. This chapter describes the specific features of aptamers and reports on their employment for the development of aptasensors, especially as applied to the detection of clinically‐relevant proteins for diagnostic assays. However, the large variety of aptamers which have been selected to bind low molecular weight molecules leads to the possible use of these oligonucleotides in a wider range of applications such as assays for the analysis of environmental and food samples, as well as detection terrorist threat agents that are biological.
Biocatalysis, Cofactor Regeneration
Authors: Zhang Jie , Xu Jian‐He
Published: April 2010

Biocatalysis and biotransformation could provide valuable chemicals for the industry via eco‐friendly processes. Among the biocatalysts, except cofactor‐independent hydrolases, the cofactor‐dependent enzymes are the second class to perform the bioreactions. However, the complexity and high costs of cofactors limit the application of such enzymes in a wider field. Thus, it is necessary to regenerate cofactorsin situ. Regeneration of cofactors, such as NADH, NADPH, ATP, sugar nucleotides, 3′‐phosphoadenosine‐5′‐phosphosulfate (PAPS), have been studied extensively in the past 30 years. Different methodologies for cofactor regeneration including chemical, electrochemical, photochemical, enzymatic and permeabilized cells methods have been developed. These methods are reviewed in this chapter, along with some successful examples in industrial application.
Biofuel Cells, Performance Characterization
Authors: Watanabe Kazuya
Published: April 2010

Biofuel cells are devices for generating electricity from chemical fuels (such as hydrogen and organic compounds) using biological catalysts (i.e. enzymes and/or living microbes) for electrode reactions. They could be divided into two categories based on types of catalysts; namely, enzyme fuel cells (EFCs), and microbial fuel cells (MFCs). In this article, procedures for evaluating biofuel cells are described, since appropriate evaluation is fundamental to developing efficient processes and also for comparing biofuel cells developed in different laboratories. Special focus is on the evaluation of MFCs, since MFCs need more diverse criteria than EFCs for performance evaluation; however, EFC evaluation is also possible using the procedures and parameters described in the article.
Bioprinting, Inkjet Deposition
Authors: Saunders Rachel , Derby Brian
Published: April 2010

Inkjet printing is a versatile deposition and patterning technology that can be used for the controlled placement of picoliter volumes of fluids. The mechanisms of drop generation are reviewed and the fluid requirements for successful printing discussed. Inkjet printing has been successfully used for the deposition of biomaterials, proteins, and living cells. The response of these materials to the printing process is discussed. A number of practical applications are discussed, including biosensors, experimental cell biology, and tissue engineering or regenerative medicine.
Biopharmaceutics, Pharmacokinetics, and Pharmacodynamics of Protein Therapeutics
Authors: Vaddady Pavan K. , Meibohm Bernd
Published: April 2010

There is a growing interest in the role of proteins as therapeutic agents. Protein drugs often have specific characteristics that affect their pharmacokinetics (PK) and/or pharmacodynamics (PD) and make them distinctively different from small molecule drugs. Understanding the processes involved in the disposition of a protein molecule following administration such as its absorption, distribution, and elimination gives insights for developing and designing optimum dosage regimens as well as dosage forms. Similarly, the relationship between the drug concentration and associated biochemical and physiological processes related to the drug's mechanism of action is essential to discern its efficacy and toxicity potential. This article focuses on the relevance of PK and PD affecting the efficacy, safety, and use of protein therapeutics. It emphasizes on the available administration routes, explores different ways a protein molecule takes to reach its target tissue, and discusses the most relevant mechanisms by which protein therapeutics are eliminated from the body. It furthermore discusses a variety of PK/PD modeling approaches most commonly used for the characterization of the dose‐exposure–response relationship of biologics.
Single‐Use (
SU
) Systems
Authors: Maigetter Robert Z. , Piombino Tom , Wood Christian , Gervais Tom , Thomasin Claudio , Shingle Bryan , Wareheim Dave A. , Clark David
Published: April 2010

This chapter will focus on the opportunities for SU systems and their acceptance into bioprocess facilities building new or retrofitting with 100% SU. The first section of the chapter will examine the more traditional stainless steel bioreactors and tanks, how they have been replaced by SU, and how existing and new facilities could incorporate both. Subsequent sections will address cell culture, purification, fill and finish, media and buffer, and end with a presentation of costs.
Biophotoreceptor Arrays
Authors: Knopf George K. , Wang Wei Wei
Published: April 2010

Biophotoreceptor arrays are hybrid electronic devices that utilize spectrally sensitive neuronal cells and biomolecules as the primary photon‐detecting element in a distributed network of light sensors. The patterned microelectrode arrays that interface with the biological material are constructed from readily available silicon‐based circuitry or, more recently, electrodes imprinted on flexible polymer substrates. From an engineer's perspective, these biological materials present new design opportunities for developing imaging systems that more closely emulate the signal detection and information processing structures found in nature. Several important attributes of natural vision include highly sensitive light receptors based on molecular phototransduction, a nonregular distribution of sensing elements on the imaging surface, and nonplanar image formation in the eye. The primate retina is one illustrative example of how phototransduction and neuronal interactions can lead to efficient imaging of dynamic three‐dimensional environments. The extraction and deposition of nerve cells and molecular proteins on microelectrode array platforms provide researchers with a means to observe the behavior of these distributed sensing systems. Organic and flexible polymer electronics represent a new technology that permit the creation of nonrigid photoreceptor arrays which replicate the curved imaging surfaces of single aperture and apposition compound eyes. A simple motion detection system is presented as an illustration of how photosensitive biomaterials and flexible printed electronics provide an alternative paradigm for developing new types of imaging systems. An important area where biomedical researchers can exploit engineered biophotoreceptor arrays is the fabrication of biocompatible artificial retinas and prosthetic devices for patients with severe visual impairment.
Biopolyester Particles: Preparation and Applications
Authors: Rasiah I.A. , Parlane N. , Grage K. , Palanisamy R. , Jahns A.C. , Atwood J.A. , Rehm B. H.A.
Published: April 2010

Over the past few decades, there has been a growing awareness of the potential uses of biodegradable polymers in biotechnology and medicine. In particular, micro‐ and nano‐sized particles which are made from natural resources, exhibiting biodegradability, biocompatibility, and low toxicity have been the subject of intense research and development in many areas. Apart from their beneficial material properties, these particles allow variations in structure and composition to be designed, thereby tailoring them for specific applications. This review presents a broad overview of the main categories of biopolyester particles described in the literature, and putting emphasis on the composition and preparation of each group, followed by the wide variety of applications and potential uses described to date.
Bioprinting
Authors: Phamduy Theresa B. , Corr David T. , Chrisey Douglas B.
Published: April 2010

Bioprinting refers to the spatially‐controlled deposition of disparate biomaterials that is carried out by various printing techniques for the bottom‐up transfer of cells, biomolecules, and scaffold. The applications and techniques for bioprinting discussed in this chapter address the emergent demands of sub‐micrometer patterns for fundamental study, device construction, and bottom‐up tissue engineering. The advantages of bioprinting stem from its unique attributes of controllability, automated deposition, CAD/CAM construction, bottom‐up writing, and rapid prototyping. As advancements in biotechnology gravitate towards the micro‐scale and nano‐scale, precise deposition of biomaterial patterns becomes critical for many applications, including biomedical devices. In addition, the drive for the rapid prototyping of tissue constructs requires the combination of computer aided design and high‐resolution repeatability that bioprinting is able to achieve. Examples of bioprinting methods include patterning, ink‐jet based bioprinting, laser deposition, and nanobioprinting. Bioprinting is poised to be a significant tool for metric transfers of fragile biomaterials in both biomedical engineering research and industrial biotechnology applications.
High‐Throughput Technologies in Bioprocess Development
Authors: Carrier Trent , Heldin Eva , Ahnfelt Mattias , Brekkan Eggert , Hassett Richard , Peppers Steve , Rodrigo Gustav , Van Slyke Greg , Zhao David (Xiaojian)
Published: April 2010

Bioprocess development is a relatively new field for the application of high‐throughput technologies (HTT). Similar to historical applications in drug discovery, these new tools are generally being applied to increase throughput and efficiency to either enable improved performance by testing a larger experimental design space or improve speed for development for biological pipelines. In surveying the general application of these technologies in the biotechnology industry, it becomes clear that HTT have targeted a few key steps within upstream and downstream process development workflows (also called HTPD i.e. high‐throughput process development). The primary focus for upstream HTT has been cell line selection and cell culture development, whereas downstream HTT has centered on the chromatography unit operation. The successful implementation of these technologies has come with many lessons learned on technology selection, workflow validation, and study execution. Furthermore towards improving the application of HTT, analytical techniques in combination with experimental design strategies have been developed that enable larger and more complete scientific investigation of experimental conditions. The complete set of tools, techniques, and design strategies have yielded tangible benefits for early adopters, particularly where capacity and timeline restrictions create workflow bottlenecks. Applied properly, high‐throughput technologies can be an important tool in meeting the bioprocess challenges of today and tomorrow.
Bioreactor Scale‐Down
Authors: Palomares Laura A. , Lara Alvaro R. , RamÍRez Octavio T.
Published: April 2010

In this chapter, scale‐down methodology is described as a useful tool to study the effects of fluctuating conditions on large‐scale bioreactors. The scale‐down approach focuses on simulating, on the laboratory scale, the environmental conditions prevalent on the large scale and analyzing the effects of these fluctuations on cell physiology. The scale‐down approach consists of the following steps: regime analysis of the large‐scale conditions, their simulation on laboratory systems, optimization and modeling of the cultures, and the application of the results on the large scale. These steps are presented and discussed. A review of the published scale‐down studies in cell culture and microbial fermentation is also included. Finally, an overview of the most commonly used scale‐down systems for simulating environmental fluctuations is presented, emphasizing their advantages and limitations for their use on microbial or animal cells models.
Bioreactors, Fluidized‐Bed
Authors: Storhas Winfried
Published: April 2010

The traditional 50‐year old fluidized‐bed technology has become an important tool in new patterns for modern biotechnological processes. All biotechnological processes use biocatalysts as cells or isolated enzymes. To handle these biocatalysts in an economical way, they have to be kept in the bioreactor. Therefore carrier systems are used.

A suitable concept to handle economically carrier systems for retention enzymes and cells in a system is the fluidized‐bed reactor (FBR). FBRs can be run between two velocities. Starting with a very low superficial velocity, the packing of carriers keeps in the fixed‐bed manner till the incipient fluidization point. Then, the system changes into an FBR and remains there till the entrainment velocity (wash‐out point).

To design FBR one uses fluidized bed state diagram (Reh). With the dimensionless numbers Archimedes and Omega in the fluidized bed state diagram all the necessary conditions can be found for the process, especially the suitable velocity. This can occur between the incipient fluidization and the entrainment velocity. The key for the final design is the power input into the bioreactor.
Bioreactors, Stirred Tank for Culture of Plant Cells
Authors: Doran Pauline M.
Published: April 2010

Bioreactors with mechanical stirring offer important advantages for large‐scale culture of suspended plant cells. Greater power can be input to the culture compared with air‐driven reactors; for viscous broths containing high cell densities, this translates into better mixing and oxygen transfer. The availability of two independent means of manipulating the hydrodynamic environment, adjusting the stirring speed and gas flow rate, also allows greater flexibility of reactor operation than in air‐driven systems. Yet, these potential advantages may never be realized in full in any particular plant cell application because the mechanical forces generated by conventional impellers and the shear sensitivity of the cells limit the operating conditions that can be employed. Reactor engineering and innovation in this area are aimed at finding an appropriate balance between the beneficial and destructive effects of energy dissipation and hydrodynamic shear in plant cell suspensions. To this end, a wide range of vessel, impeller, and sparger configurations has been applied in experimental studies. This article outlines the function of stirring equipment with reference to plant cell systems and the effect of reactor operating conditions on culture performance.
Bioreduction
Authors: Skorupa Parachin Nádia , Carlquist Magnus , Gorwa‐Grauslund Marie‐F
Published: April 2010

Bioreduction has emerged over the years as an alternative method to organic synthesis for the generation of chiral precursors of commercial interest. Bioreductions operate under mild conditions of pH and temperature with the help of highly regio‐ and enantio‐selective oxidoreductase enzymes.

In this contribution, the different oxidoreductase families involved in bioreductions are exemplified and their main characteristics are presented. The wide spectrum of oxidoreductase substrates (including ketones, diketones, ketoesters, aldehydes, alkenes, and keto acids) is discussed and both preparative and industrial scale examples are reported. The advantages and disadvantages of using isolated enzymatic systems versus whole‐cell systems for bioreduction are discussed in terms of cost, specificity, stereoselectivity, and cofactor regeneration. The contribution is also reviewing strategies for improving the biocatalyst at the cell or enzyme level, which include process engineering, metabolic engineering as well as structure‐based and nonstructure‐based enzyme engineering. Finally, the potential role of metagenomics for isolating novel biocatalysts from different environments is discussed.
Bioremediation
Authors: Ward Owen P.
Published: April 2010

Bioremediation, which exploits biological processes to remove contaminants from the biosphere, is generally a low‐cost option among remediation alternatives. The organisms involved are predominantly microbes which have the capacity to survive contaminant toxicity and access and transform the contaminants. Many contaminants are organic solvents which disrupt membranes, and cells may develop defence mechanisms including formation of outer cell‐membrane‐protective material, often hydrophobic or solvent efflux pumps. Many of the contaminants are hydrophobic and microbial species appear to take up these substances by a combination of biosurfactant secretion and direct cell‐contaminant association. Bioremediation may involve aerobic or anaerobic microbial activities. Aerobic degradation often involves introduction of oxygen atoms in reactions mediated by monooxygenases, dioxygenases, hydroxylases, oxidative dehalogenases, or chemically reactive oxygen atoms generated by enzymes such as ligninases or peroxidases. Anaerobic degradations of predominant contaminants such as petroleum hydrocarbons, typically involve initial activation reactions followed by oxidative catabolism mediated by anoxic electron acceptors. Many microbes participate in bioremediation processes by mineralizing the organic contaminants to end‐products such as carbon dioxide and water, or to metabolic intermediates which are used as primary substrates for cell growth. Cells may be able to biotransform the contaminant without being able to utilize the contaminant for growth in a process known as cometabolism. Microbes have also evolved biocatalytic systems which indirectly mediate the transformation of some recalcitrant molecular species, mediated by enzymes which generate chemically reactive species which in turn, attack the recalcitrant molecules.

Major strategies for implementing bioremediation processes include biostimulation and bioaugmentation approaches. Biostimulation involves adding supplements to a contaminated site with the objective of stimulating growth of the microbial population already present there, which may be capable of degrading the contaminants. Where the contaminated environment does not contain microbes capable of degrading the contaminants, there may be a case for addition of a selected and acclimated microbial inoculum. This is termed bioaugmentation. Widely used process configurations include slurry bioreactors, landfarming, soil‐pile composting systems, engineered soil piles,in situsubsurface bioremediation and phytoremediation. Bioremediation accounts only for a small fraction of the remediation market because arguably, some of the processes implemented failed to meet the required contaminant reduction criteria. For bioremediation processes to gain access to a more substantial proportion of the remediation market, processes must be judiciously selected to be technically dependable and cost‐effective.
Biosensors, Environmental
Authors: Bassi Amarjeet S.
Published: April 2010

In this article, the principles and applications of biosensors for environmental monitoring are presented. Biosensors represent an interesting and relevant approach to overcome the shortcomings in the diverse areas of environmental monitoring. Biosensors can complement laboratory‐based analytical techniques and can also be applied for real‐time field applications. The current approaches using nano and micro sensors, multiple arrays, and interfacing with remote monitoring systems are making biosensor technology the technology of choice for environmental mapping, robots, security, and other areas of relevance. In this article, the principles of biosensors for environmental applications are reviewed. Some new approaches available for biosensor design are also presented.
Biosensors, Foodborne Pathogen Detection
Authors: Bhunia Arun K. , Nanduri Viswaprakash , Bae Euiwon , Hirleman E. Dan
Published: April 2010

In recent years, foodborne pathogens have become a significant concern due to increasing numbers of outbreaks and the resulting fatalities and economic losses. In addition to improving hygienic practices in food production and preparation, improvement in pathogen testing is urgently needed. Conventional culture‐based methods are lengthy, involve multiple steps, and lack sensitivity. Even the so‐called antibody‐ or nucleic acid‐based “rapid methods” require a minimum of 24–48 h to complete. Faster and more sensitive detection methods are needed, and biosensor‐based methods have the capacity to meet that need. In this review, we describe developments in the area of select sensors that show promise for foodborne pathogen detection, including
Fourier Transform InfraRed spectroscopy
(FTIR), light scattering,
surface plasmon resonance
(SPR), fiber optic, microfluidic protein biochip, and mammalian cell‐based sensors. FTIR and light‐scattering sensors are considered label‐free methods since they do not require any probes or labeling reagents. SPR is a semi‐label‐free method since it requires recognition molecules such as antibodies, nucleic acids, aptamers, or bacteriophages for detection. The remaining methods require labeling reagents and probes. Application and utilization of these biosensors in pathogen detection are also highlighted.
Biotransformation, Process Optimization, Kinetics and Engineering Aspects
Authors: Hilterhaus Lutz , Liese Andreas , Kragl Udo
Published: April 2010

The use of biotransformations in the food, pharmaceutical, and chemical industries has increased steadily since the early 1970s. Applications range from synthesis in the milligram scale for precious oligosaccharides up to multiton scale for bulk chemicals either using whole cells or isolated enzymes. When new processes are being developed, the special properties of the biocatalyst must be considered, as well as the basic elements of chemical engineering. There is a strong interaction among the individual aspects, which may be considered for process optimization.

The intention of this article is to outline the basic strategy for the development of a biocatalytic step. For some selected examples the beneficial role of biochemical engineering is demonstrated.
Large‐Scale Chromatography Columns, Modeling Flow Distribution
Authors: Fang Zhiwu
Published: April 2010

Liquid chromatography has become an indispensable tool in the pharmaceutical and biotechnology industries for preparative and large‐scale purifications to obtain high purity biopharmaceutical products. However, imperfect packing of the column bed and complex rheological behaviors of resin particles pose a great challenge for any modeling effort.

A systematic study, based on rigorous physics, which attempts to understand the intrinsic complicated interrelationships between column packing, hardware design, flow distribution, and separation efficiency would be of great help to chromatography practitioners. Seeing this need, this article makes an effort to perform a systematic study of the chromatography processes from start to finish and to provide mathematical models and case studies for each stage. First, the author discusses the challenges in scaling up chromatography column packing and examines the wall effect through a dimensional analysis, then follows it by introducing a one‐dimensional model, describing column packing and scale‐up. Next, the author presents a case study on a commercial scale column with a special headplate design and investigates the impact of hardware design on flow distribution, using the technique of computational fluid dynamics (CFD). Finally, this article presents simulations on the transport of elute and computation on the height equivalent to a theoretic plate (HETP) in a modeled, large column set for no retention, ion exchange, and affinity systems. The author discovers that the hardware design exerts a great impact on the flow distribution in the columns and thus affects the column separation efficiency to a large extent.
Spectral Data Comparability–Acceptance Criteria Definition by Statistical Analysis
Authors: Bierau Horst , Tranter George E. , Le Pevelen Delphine D. , Giartosio Carlo E. , Jone Carl S.
Published: April 2010

An approach is proposed to define unequivocal acceptance criteria for circular dichroism (CD) spectra, which eliminates operator bias associated with visual assessment of sample versus reference spectra. It is based on a statistical analysis of reference data obtained and allows distinguishing the variation inherent in a given set of reference spectra from genuine structural differences that may be present in a sample. This approach was successfully applied for comparing CD spectra in the framework of a comparability study of a marketed biopharmaceutical. Moreover, the proposed approach is generic and may readily be adapted to analyze spectral data obtained from techniques other than CD.
Clostridium
Authors: Schiel Bettina , Dürre Peter
Published: April 2010

Species of the genusClostridiumare Gram‐positive, strictly anaerobic or moderately aerotolerant bacteria, producers of endospores, and unable of dissimilatory sulfate reduction. Clostridia are able to metabolize a variety of substances, and the respective fermentation pathways are diverse. Meanwhile, all techniques (culturing techniques and techniques for genetic manipulation) necessary to effectively work with clostridia in the laboratory are established. Clostridia are often considered as dangerous to humankind. This is due to the well‐known speciesC. botulinumandC. tetaniproducing the most dangerous natural toxins (botulinum toxin and tetanus toxin, respectively). Albeit very famous, these and some other dangerous species represent a minority within the genusClostridium. The majority of the approximately 150 validly describedClostridiumspecies are absolutely safe to mankind, and moreover, they are of utmost importance for biotechnological processes (e.g. production of biofuels, bulk chemicals) and medical treatments (e.g. cancer treatment). Even the above mentioned botulinum toxin is nowadays used to treat diseases, and it is even more popular as a tool in cosmetics. The versatile use of differentClostridiumspecies turns the genus to the avant‐garde of industrially useful microorganisms. The biotechnological and medical potentials of this genus are underlined by a number of books devoted to this specific group of bacteria that have been published in the last 19 years.
Protein Crystallization, Kinetics
Authors: Profio Gianluca Di , Curcio Efrem , Drioli Enrico
Published: April 2010

Protein crystallization has become today a fundamental operation in scientific, technological, and industrial sectors. The principal aim of crystal growers is to obtain protein crystals with specific characteristics. Large, well‐diffracting crystals are necessary for tridimensional structure resolution at atomic level by X‐ray diffraction analysis, while smaller, monodispersed in size and uniformly shaped crystals are required in some industrial sectors as, for example, environmental protection, chemical synthesis, and heterogeneous catalysis. However, the production of crystals with opportune properties can only be realized by a fine control of the crystallization kinetics throughout its several steps. The main difficulty in achieving this goal is the poor understanding of the crystallization mechanism in its various aspects, especially for proteins, due to their structural complexity. Generally, theories developed for small molecules crystallization have been extended to proteins. However, although in certain circumstances proteins crystallize by the same mechanisms, they have some of their own peculiarities. These differences can be ascribed to the asymmetric and weak bonding configuration at the protein surface, the tendency to aggregate inn‐mers, the sensitivity to contaminants and impurities, the formation of precipitates, oils or gels and the low diffusivities in solution. As a result, protein crystallization is a complicated physical–chemical process not fully described by simple theory.

In this contribution, the different steps involved during protein crystallization are discussed. These include the initial interaction of protein in solution, their aggregation to form stable nuclei—even when it is promoted by heterogeneous substrates, the growth to macroscopic crystals, and the case of growth in forced solution convection regime.
Dehydrogenases, Electrochemical Cofactor Regeneration
Authors: Kornberger Petra , Giffhorn Friedrich , Kohring Gert‐Wieland
Published: April 2010

Dehydrogenases represent a valuable tool in biotechnology for the production of fine chemicals and reactive compounds and as the building blocks of pharmaceutical and agrochemical active substances. Their activity in regiospecific and enantioselective hydroxyl group oxidation and ketone reduction has attracted increasing interest with respect to production processes, design of biosensors, and construction of biofuel cells. However, the electron transfer cofactors necessary for their enzymatic activity are usually high priced and, therefore, have to be regenerated in the corresponding processes. In the last few decades, multiple regeneration procedures have been developed for different groups of dehydrogenases with application potential; for example, whole cell systems, cofactor regeneration with a second substrate and/or a second enzyme, and photochemical or electrochemical methods. Here, we discuss the different systems with focus on electrochemical restoration of redox equivalents.
Cleaning and Sanitization in Downstream Processing
Authors: Sofer Gail , Robinson Craig , Yourkin Jonathan , Pitarresi Tina , Birse Darcy
Published: April 2010

Downstream processing of biopharmaceuticals typically includes chromatography and filtration unit operations. Downstream processing enables the production of highly purified biological therapeutic products for preclinical testing, clinical and commercial use. The design and implementation of suitable cleaning protocols are part of regulatory commitments ensuring the consistent production and control of manufacturing conditions for biotherapeutics. In current modern biomanufacturing, cleaning and validation remain critical concerns for industrial biotechnology products and processes. In this article, the review focuses on cleaning and sanitization of chromatography media, membranes, and equipment for the production of biotherapeutics and
in vivo
diagnostics. The Cleaning and Cleaning Validation principles described in this review apply to the production of a range of biotechnology products including biotherapeutics such as vaccines [nucleic acid (DNA, RNA) viruses, antigens, and polysaccharides], MAbs, recombinant proteins (rProteins), and peptides.
Energy Metabolism of Cells Used for Industrial Production
Authors: Butler Michael , Sparling Richard , Court Deborah
Published: April 2010

The metabolic pathways of bacterial, fungal and animal cells used in industrial bioprocesses are described. Some of the pathways of catabolism utilizing carbohydrates such as glucose for energy and reducing equivalents are common to many of these cells. Cells used in industrial processes are commonly selected or genetically engineered to allow the synthesis of specific products required in large quantities. Some of these products are the end‐points of catabolic pathways and include ethanol, acetate and lactate. Secondary metabolites have been the source of many pharmaceutical products such as antibiotics, which are produced from fungal fermentation. Animal cells in culture have been the basis of bioprocesses used to produce recombinant glycoproteins many of which are developed as novel biopharmaceuticals. These cultures require careful design of culture conditions to maximize cell growth and productivity.
Enzymes,D‐Amino Acid Oxidases
Authors: Pilone Mirella S. , Pollegioni Loredano
Published: April 2010

This article is an up‐to‐date report on the biotechnological applications in the industry of the flavoproteinD‐amino acid oxidase, in the past and in the present.D‐Amino acid oxidase constitutes a model FAD‐dependent protein due to widespread interest and extensive investigations in the years in mechanistic and structural research, on the basic features of flavin chemistry, reactivity, and their modulation by the protein moiety. Actually, a number of successful and unexpected outcomes came forD‐amino acid oxidase from biotechnology and their industrial applications: production of semi‐synthetic cephalosporin intermediates (as 7‐amino cephalosporanic acid, a milestone in the antibiotics industry), the resolution of racemic mixtures of amino acids (even unnatural ones), the analytical determination ofD‐amino acid content in biological samples by biosensors (including the determination ofD‐serine in brain cells), and a gene therapy for tumor treatment. All the biotechnological processes reported are described in detail, as well as the underlying technology. The most relevant patents are also reported.
Enzymes, Detergent
Authors: Maurer Karl‐Heinz
Published: April 2010

Enzymes used in laundry and dish‐wash detergents represent one of the major application fields of enzymes. The hydrolases used in detergents are considered essential for removal of stains originating from nature. Some enzymes like cellulases do also contribute to antigraying effects by pigment removal and antiredeposition activity. Enzymes (proteases) were first introduced in laundry detergents at the end of the 1960s. Since then, they have become an important topic for product differentiation and performance claims. Thus the work on improving enzyme performance in terms of improved performance and stability in storage and process has become a major field of enzyme development. All relevant technologies for enzyme engineering have been applied in the meantime, resulting in a patent landscape of extreme complexity. In order to allow for efficient and economic production of technical enzymes, classical strain improvement has been combined with recombinant production systems early on.

Detergent enzymes represent the only example of biocatalysis performed in a household setting. Since the potential for inhalation sensitization has been identified with detergent proteases on workers, the risk assessment both, for occupational as well as for the consumer setting has been a key topic that has been successfully managed since 1970.

The upcoming field of synthetic biology promises to deliver further improvement of production systems and new enzymatic activities.
Enzyme‐Catalyzed Asymmetric Reduction of Ketones
Authors: Gröger Harald , Borchert Sonja , Kraußer Marina , Hummel Werner
Published: April 2010

The enantioselective transformation of a prochiral C=O double bond into the corresponding reduced CH–OH single bond plays a major role in asymmetric synthesis since this type of transformation represents a straightforward and an atom‐economical approach toward the synthesis of optically active alcohols. Owing to the importance of chiral alcohols in the field of chiral drug production, enantioselective ketone reduction also gained tremendous industrial interest. For the enantioselective reduction of ketones, numerous efficient catalytic routes have been developed up‐to‐date. As outstanding chemocatalytic technologies, metal‐catalyzed asymmetric hydrogenation of ketones and borane reduction are widely applied on industrial scale. Complementing these chemocatalytic technologies for the production of enantiomerically pure alcohols, enantioselective biocatalytic reduction of ketones turned out to be a highly efficient and competitive alternative technology. Notably, biocatalytic ketone technologies already made the “jump” from an interesting academic synthetic tool toward an industrially feasible technology platform. Besides high catalytic efficiency and excellent enantioselectivities, robustness and industrial large‐scale feasibility are further key features of enantioselective ketone reduction processes with biocatalysts. Thus, it is no surprise that the suitability for industrial purpose, in particular, for large‐scale manufacture of enantiomerically pure alcohols as drug intermediates, has been already demonstrated by a broad range of technical applications in the chemical and pharmaceutical industry.
Enzymes, Starch Conversion
Authors: Pedersen Sven
Published: April 2010

The enzymes used in starch processing are reviewed with emphasis on the conversion of starch to high fructose corn syrup (HFCS). Steeping is discussed as well as major developments in liquefaction, saccharification, and isomerization.

A major trend in starch processing today is the enzymatic production of slowly digestible and resistant starch for low calorie foods and foods for diabetics. Such starches may be produced by branching enzymes and amylomaltase. The properties of these enzymes and the production processes for the novel starches are described.

The production of glucose, maltose syrups, and maltodextrins amount worldwide to approximately 18 million tons and therefore represents a substantial segment of the use of starch. The production methods and the enzymes used for maltose syrups are summarized.

Recent references to important developments in enzymatic starch production are listed.
Enzymes, Extremely Thermophilic
Authors: Harris James M. , Adams Michael , Kelly Robert M.
Published: April 2010

The availability of enzymes with optimal functional temperatures above 70°C has had considerable impact on basic and applied elements of biocatalysis. Not only have extremely thermophilic enzymes expanded the known thermal range of biological systems but they have also ushered in a new era in applied biocatalysis that is less restricted by limitations related to thermoactivity and thermostability. While much effort has been directed at understanding the intrinsic basis for enzyme stabilization at high temperatures, there is still much to be learned to appreciate this complex biomolecular trait. Nonetheless, strategic uses of extremely thermophilic enzymes continue to emerge and prospects for expanded use of biocatalysts in a variety of bioprocess settings are promising. As genome sequence information from extremely thermophilic microorganisms is mined for novel biocatalysts and molecular biological tools for improving enzyme function are refined, the future is bright for biologically based catalysis.
Virus Retentive Filters
Authors: Miesegaes George , Lute Scott , Aranha Hazel , Brorson Kurt
Published: April 2010

Ensuring the absence of detectable viruses in biopharmaceutical products is imperative from both a regulatory and patient safety standpoint. Biopharmaceutical viral safety is the result of multiple orthogonal barriers operating in concert; incorporation of virus clearance methods is an important strategy to achieving product safety. Filtration through virus retentive filters is currently a key unit operation during the production of biopharmaceuticals and plasma‐derived products. Careful process design and appropriate validation are critical for the successful implementation and performance of virus retentive filters. Here we elaborate on both process design and validation information, describe virus filters currently on the market, and discuss the historical experience with virus retentive filters as reported in the scientific literature. Detailed information for filter users can be found in a comprehensive technical report (TR 41) promulgated by the Parenteral Drug Association (PDA) (1).
Flux Analysis of Mammalian Cell Culture
Authors: Martens Dirk E. , Tramper Johannes
Published: April 2010

Animal cells are used for the production of vaccines and pharmaceutical proteins. The increase in demand for these products requires an increase in volumetric productivity of animal cell culture processes, which can be attained through an increase in biomass concentration and/or specific productivity. At the same time, the correct glycosylation pattern must be preserved to guarantee the correct biological activity of the protein. To optimize the volumetric productivity and to keep the desired glycosylation pattern of the protein, knowledge of cell physiology including cell metabolism is essential.

The metabolism of animal cells is complex; because metabolism is distributed over different compartments, animal cells have complex nutritional demands and substantial waste metabolism occurs. Metabolic flux modeling can be a useful tool to reduce this complexity and to obtain a better understanding of cell metabolism. The models can be used to obtain fundamental understanding of metabolism, design media, and processes and for process control. For these applications, it would be useful to further develop genome‐scale models for mammalian cells.

In this article, first, the theory and concepts of metabolic flux analysis are treated using a simplified example of mammalian cell catabolism. Subjects that are discussed are as follows: model construction and simplification, methods to calculate fluxes, underdetermined systems, consistency testing, and rate balancing. Next, a comprehensive metabolic network model for mammalian cells is presented and specific problems associated with flux analysis in mammalian cells, such as the different underdetermined parts, are discussed. Finally, applications for metabolic network models in animal cell culture are briefly discussed.
Haploid Plant Production, Pollen, Anther, and Ovule Culture
Authors: Veilleux Richard E.
Published: April 2010

Haploid plants with the gametic chromosome number can be obtained in many genera of angiosperms by redirection of gametophytic development to sporophytic development. This can be achievedin vitrothrough anther, microspore of ovule culture; alternatively, haploid plants can be obtainedin vivothrough parthenogenesis after wide hybridization, or occurring as one of a pair of twin seedlings. Doubled haploids can be derived from haploids by application of colchicine or through tissue culture regeneration from callus. The allelic simplicity of haploid plants or their corresponding doubled haploids facilitates genetic studies and hybrid breeding strategies. Doubled haploid cultivars of self‐pollinating crops, such as wheat and barley, have been released directly following field trials. For cross‐pollinating crops, doubled haploids have been used as parents of hybrid cultivars.
Immobilized Cells
Authors: Verica Manojlović , Branko Bugarski , Viktor Nedović
Published: April 2010

Cell immobilization consists of retaining living cells in a discrete spatial location to achieve high cell concentration. Immobilization of cells has been shown to offer many advantages for biomass and metabolite production when compared to free cell systems. Therefore, various types of living cells have been successfully immobilized for numerous applications. Different approaches have been used for immobilizing cells such as entrapment in polymeric networks, attachment or adsorption to a preformed carrier membrane, microencapsulation, and self‐aggregation of cells. A microcapsule consists of a semipermeable, spherical membrane surrounding the solid/liquid core. This review focuses on current knowledge and techniques used in the microencapsulation of cells to enhance their viability during processing or utilization in commercial products or targeted delivery. Further, the main process requirements, available carrier materials, and bioreactor designs aimed for successful implementation of immobilized cell technology will be summarized and discussed.
Kinetics, Enzymes
Authors: Cornish‐Bowden Athel
Published: April 2010

The kinetic behavior of enzymes is studied to elucidate mechanisms of action, to understand the role of enzymes in the cell, and to manipulate their activity in biotechnological applications. Most experiments are designed as if the only purpose was the elucidation of mechanisms, but the others are also important. Drug development not only requires thorough understanding of enzyme inhibition, and in particular that competitive inhibitors often have very little effect in a living system, but also that systems of enzymes often behave differently from what may be expected by studying them individually in isolation.
Kinetics, Microbial Growth
Authors: Panikov Nicolai S.
Published: April 2010

The article summarizes basic principles, methods, and the most essential results of kinetic studies in microbiology. Microbial kinetics is based on experimental studies of all dynamic manifestations of microbial life (growth, survival, death, product formation, mutations, cell cycles, environmental effects) and analysis of underlying mechanisms using mathematical models. The article starts from introduction to basic principles of growth stoichiometry (quantitative relationships between substrates and products of microbial processes) and enzyme kinetics and then, step‐by‐step surveys simple and structured models of microbial growth, cell cycle, mutation, and population dynamics. Special emphasis is given to similarity and difference in kinetic terms as applied to chemical reactions, enzyme‐catalyzed processes, and microbial growth. The last part of the chapter is devoted to characterization of diversity of cultivation methods including various continuous methods (chemostat, turbidostat, pH‐auxostat, viscostat, bistat), batch, fed‐batch, phased and dialysis culture, plug‐flow, columns packed, colonies and biofilms.
Lactonohydrolase
Authors: Shimizu Sakayu , Kataoka Michihiko
Published: April 2010

The enzyme catalyzing the reversible or irreversible hydrolysis of carboxylic esters into the corresponding carboxylic acids and alcohols plays an important role in the biosynthesis and biodegradation of various compounds. In particular, the structures and functions of lipase and esterase have been well analyzed. Lactonohydrolases also catalyze the hydrolysis of carboxylic esters, but act on the intramolecular ester bonds of the lactone compounds. They are involved in the synthesis and degradation of various lactone compoundsin vivo. Although the activities of lactonohydrolases have been detected in various organisms, there have not been any early detailed studies on their enzyme chemistry. In the last few decaded, several novel microbial lactonohydrolases were newly isolated and their application to bioprocesses for the production of useful compounds was examined.

This articles deals with diveristy of lactonohydrolase, and their application to bioprocess technology.