bluuebunny/crossref_metadata_2025_split huggingface dataset:
Halophiles, Industrial Applications
Authors: DasSarma Priya , Coker James A. , Huse Valerie , DasSarma Shiladitya 
Published: April 2010

AbstractHalophilic (salt‐loving) microorganisms have evolved physiological and genetic characteristics for success in their harsh saline environments. These characteristics include internal compatible solutes, efficient ion pumps, UV absorbing pigments, and acidic proteins, which help them to resist osmotic stress and the denaturing effects of salts, as well as the accompanying intense solar radiation. Many of the same characteristics which help them to counteract the deleterious effects of their environment also constitute valuable resources for biotechnology and nanotechnology. Although currently established applications of halophiles are limited primarily to compatible solutes in the cosmetic industry, and β‐carotene and hydrolases in the nutritional and food industries, many other novel applications are under development. They include specialized applications for films of bacteriorhodopsin from halophiles for a variety of optical nanodevices, including high‐capacity computer storage, and for stable enzymes from halophiles for use as industrial catalysts, some capable of functioning in organic solvents. Metabolic activities of halophiles are also being tapped for a variety of environmental applications, such as bioremediation of pollutants in saline wastewaters. Some subcellular components, such as polyhydroxyalkanoate granules, gas vesicles, and phospholipid vesicles, and bioactive compounds like halocins are being developed for medical applications. Applications of halophilic microorganisms are varied and represent significant commercial opportunities in the chemical, environmental, biofuel, medical, and educational industries.
Mixed Culture Processes
Authors: Shioya Suteaki 
Published: April 2010

AbstractIn this article, some of the mixed culture systems are introduced to show their potential for effective bioproduction, their application in nisin and kefiran production processes and utilization of ligno‐cellulosic biomass. Nisin is an antimicrobial peptide produced byLactococcus lactis. Nisin production was growth‐associative but the growth of lactic acid bacteria was inhibited by the decrease in pH and lactate accumulation. To prevent decrease in pH as well as accumulation of lactate, a yeast,Kluyveromyces marxianus, isolated from a type of yogurt, kefir, was co‐cultured. This yeast can assimilate the excess lactate. Since lactate concentration in the medium could be maintained at a low level and pH level could be kept optimal by a pH control system developed here,L. lactisgrew with a high specific growth rate. By applying this strategy, a high accumulation of nisin was obtained.In the kefiran production process,Lactobacillus kefiranofaciensand Saccharomyces cerevisiae, are co‐cultured for enhancement of productivity.L. kefiranofaciensproduces an exopolysaccharide called kefiran, which contains approximately equal amounts of glucose and galactose. Bacterial polysaccharides are usually associated with the outer surface of the bacterium. They may either form an amorphous layer of polysaccharides called capsular kefiran in the form of a capsule surrounding the cell, or be excreted into the medium as extracellular kefiran. Co‐culture with S.cerevisiaeenhanced the capsular kefiran production, which resulted in increased production of total kefiran.From the composting of an aquatic plant, a cellulose‐degrading microorganism was isolated and identified asThermobifida fusca. This strain was applied to reconstruct the composting as a responsible microorganism was not successful. The aid of another microorganism,Ureibacillus thermosphaericus, was found to be necessary. The role of the strain has been revealed in this article and the microorganisms will be useful for pretreatment of ligno‐cellulosic biomass for further applications such as bio‐ethanol production.Now mixed culture systems should be re‐reviewed as a potential system for effective bioproduction.
Monocots, Tissue Culture
Authors: Neelwarne Bhagyalakshmi , Brettell Richard 
Published: April 2010

Abstract
Monocots (monocotyledonous plants) are one of the two major divisions of flowering plants, and are characterized by having parallel‐veined leaves and an embryo with a single cotyledon. Techniques of tissue and cell culture have been successfully applied to a wide range of monocot species, which include cereals and other grasses, lilies, orchids, and palms. The techniques described in this article include callus culture, cell suspension culture, regeneration of plants, protoplast culture, anther and pollen culture, and shoot tip and meristem culture. The article also covers practical applications that use technologies based on tissue and cell cultures. Examples are the rapid propagation of clonal plants, and the production of doubled haploid plants for plant breeding. Genetic transformation has also been achieved through application of tissue and cell culture techniques to grasses and cereals, bananas, pineapples, onions, garlic, and duckweeds. A further application under development is the industrial production of secondary metabolites.
Monooxygenases,Baeyer–Villiger Applications in Organic Synthesis
Authors: Rehdorf Jessica , Bornscheuer Uwe T. 
Published: April 2010

AbstractIn this article the occurrence and biochemical properties of Baeyer–Villiger monooxygenases is reviewed. The main emphasis is on their application in organic synthesis for the production of optically pure compounds by desymmetrization processes, kinetic resolutions, and regiodivergent reactions. Furthermore, recent advances in technical approaches for efficient cofactor regeneration are covered. Finally, industrial applications of selected examples with BVMOs (Baeyer–Villiger monooxygenases) as well as improvements in large‐scale production are provided, followed by an overview about recent directed evolution and rational protein design approaches.
Optical Resolution, Biocatalysis
Authors: Omata Tetsuo , Senda Shuji , Ninomiya Yasuo 
Published: April 2010

Abstract

Introduction

Optical Resolution with Lipase‐Catalyzed Transesterification

Optical Resolution with Lipase‐Catalyzing Hydrolysis

Optical Resolution by Lipase‐Catalyzing Esterification

Optical Resolution by Hydantoinase‐Catalyzing Hydrolysis

Optical Resolution by Oxidoreductase‐Catalyzing Oxidation and Reduction

Conclusion

References
Secondary Alcohols, Optically Active, Micorbial Production
Authors: Yamada‐Onodera Keiko 
Published: April 2010

AbstractThe usefulness of optically active substances has been recognized in various fields, and recently the differences between enantiomers are becoming clear especially in medical supplies. The necessity for the enantioselective synthesis has been increasing. The advantages of biocatalysis over chemical synthesis are that enzyme‐catalyzed reactions are highly enantioselective and that they can be performed at ambient temperature and atmospheric pressure, thus avoiding the harsh conditions which cause isomerization, racemization, epimerization, and rearrangement. A lipase has been used to produce optically active secondary alcohols because it has the ability to catalyze hydrolysis of ester bonds with high enantioselectivity. The enantioselective ketone‐reduction and alcohol‐oxidation by secondary alcohol dehydrogenase have been also of interest for the production of various chiral alcohols. Many Alcohol dehydrogenases (ADH) used for this purpose are nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP) dependent. Several trials have been achieved for improvement of efficiency mainly in coenzyme recycling. Whole cell reaction is advantageous with respect to saving expensive purification of the desired enzymes. Desired enzymes can be expressed in transformants to make biocatalytic processes economically efficient. Preparative application for industrial purpose will be demonstrated.
Oxygen Transfer Rate Determination: Chemical, Physical and Biological Methods
Authors: Garcia‐Ochoa Felix , Gomez Emilio 
Published: April 2010

AbstractA proper mechanical design of the bioreactor is aimed at maintaining the environmental and nutritional conditions for optimal growth and/or product formation. Among the various environmental and nutritional factors that influence the aerobic bioprocess, oxygen is a critical parameter since it is the only nutrient that has to be provided continuously, even in batch cultures.The oxygen transfer rate (OTR) determination is essential in order to establish aeration efficiency and to quantify the effects of the operation variables on the requirement of oxygen since dissolved oxygen concentration is dependent on transport processes. Under these conditions OTR (andKLa) is one of the key parameters involved in the design, operation, and scale‐up of bioreactorsThere are several approaches to determine OTR. The most common measuring methods applied can be classified depending on whether the determination is realized in the absence of microorganisms or with dead cells (chemical and physical methods), or in the presence of biomass that consumes oxygen at the same time that the measurement is carried out (biological methods).Sometimes when OTR from a physical method is determined, it must take into account the enhancement factor,E. In recent literature predictive methods have been proposed to calculatekLaandE, and thus find the value of OTR. This approach is much more reliable than those based on the use of empirical equations.In this chapter, OTR description is discussed and the main experimental methods forkLadetermination are described; recent predictive methods forkLaandEare also presented.
Plant Cell Culture, Secondary Product Accumulation
Authors: Zhou Xin , Zhong Jian‐Jiang 
Published: April 2010

AbstractPlant cell culture is an effective technology for the production of valuable plant‐derived secondary metabolites which can be used as pharmaceuticals, food additives, nutraceuticals, etc. The biosynthesis of secondary metabolites by cell culture is safe, controllable, and economical in contrast to field cultivation of their parent plants; but it is also affected by many internal and external factors. In this chapter, the background of secondary product accumulation by plant cell culture is overviewed at first. The progress in recent years toward manipulation of environmental factors, bioprocessing strategies, and elicitation and signal transduction engineering are summarized with typical examples for each case. Furthermore, advances in modulation of secondary metabolite accumulation including heterogeneity engineering, metabolic engineering, and omics study of secondary metabolite biosynthesis, are also reviewed. Further developments in rational bioprocessing and in systems biotechnology of plant cells for metabolite production are expected in the future.
PlasmidDNAReplication
Authors: Tolmasky Marcelo E. , Actis Luis A. , Crosa Jorge H. 
Published: April 2010

AbstractPlasmids are extrachromosomal replicons found in gram‐negative and gram‐positive bacteria as well as in some lower eukaryotic organisms. They are present in bacterial cells replicating at a specific number of copies per cell. Their size varies from a few to several hundred kilobase pairs and bacterial cells can harbor more than one plasmid species. The medical importance of plasmids that code for antibiotic resistance and those that contribute directly to microbial pathogenicity is well‐documented, is the role played by plasmids in bacteria of importance in agriculture and industry. These extrachromosomal elements are of equal importance, however, for the study of the structure and function of DNA. Plasmids utilize a wide variety of strategies to initiate and regulate their replication. In this chapter we examine the replication of plasmids ColE1, whose replication system is part of most plasmids vectors; R6K, an iteron‐containing plasmid that possesses three replica origins; plasmids belonging to the RepABC family found in a‐proteobacteria; and of pT181, a group of plasmids found in gram‐positive bacteria. In addition,we also discuss linear plasmids.
Bioprocess Monitoring
Authors: Carloni A. , Turner Anthony P.F. 
Published: April 2010

AbstractBioprocess monitoring is required in order to develop, optimize and maintain biological process at optimum efficiency. This contribution briefly overviews the main technologies in current use and under development to measure the physical and chemical parameters critical to optimum production. The types of devices currently available are described together with their operating principles. New sensing technologies that could revolutionize the industry by facilitating the production of new products or by radically improving yields of high‐value added materials are also reviewed.
L
‐Amino Acids Production by Aminoacylase
Authors: Sato Tadashi , Tosa Tetsuya 
Published: April 2010

Abstract

Optical resolution of racemic amino acids can be carried out by physicochemical, enzymatic, and biological methods. Chemically synthesized acyl‐
DL
‐amino acid is asymmetrically hydrolyzed by aminoacylase to give
L
‐amino acid and the unhydrolyzed acyl
D
‐amino acid.
Protein Glycosylation
Authors: Brooks Susan A. 
Published: April 2010

AbstractMore than half of the proteins synthesized by humans are glycosylated. That is, the proteins have one or moreN‐orO‐linked glycan chains attached to them. Proteins are naturally synthesized in a range of glycoforms, and their glycosylation profile influences their activity, stability, immunogenicity, serum half life, and other biological properties. While the general mechanisms of human protein glycosylation are well established, what influences the fine control of glycosylation patterns is not well understood. Furthermore, the cells of organisms other than humans glycosylate their proteins differently. This is of interest to the biotechnology industry, which commonly uses nonhuman cells for protein expression. Proteins expressed in cells of nonhuman species are glycosylated differently to how they would be by human cells and this is of particular relevance to expression of glycoproteins destined for potential administration to humans. Inappropriate glycosylation profiles result in altered and undesirable pharmokinetic properties. In this chapter, the mechanisms of human protein glycosylation are explained. Glycosylation in cells of nonhuman species, including prokaryotes, fungi and yeasts, insects, plants, and mammals other than humans are introduced, with an emphasis on glycosylation differences of importance to the biotechnology industry. Important advances in engineering glycosylation in nonhuman cell expression systems are highlighted.
Pullulan, Microbial Production Methods
Authors: Lin Yun , Thibault Jules , Leduy Anh 
Published: April 2010

AbstractPullulan is a water‐soluble polysaccharide produced through fermentation withAureobasidium pullulans. Pullulan has been used as specialty food for decades in Japan. Owing to its relatively high price, recent developments on pullulan are mainly focused on its application in biomedical engineering and pharmaceutical industry. Both laboratory and commercial pullulan production methods are reviewed. Among several problems associated with pullulan fermentation, the highly viscous fermentation broth remains the biggest challenge. The viscous non‐Newtonian broth creates major difficulties in mixing, oxygenation, process monitoring, sampling, and downstream product recovery. Many approaches to improve the fermentation efficiency have been attempted. One promising method is to use close clearance impellers, such as reciprocating plate mixer, instead of standard Rushton turbines in order to achieve more uniform mixing. Other unconventional techniques, such as cell immobilization, hyperbaric fermentation, and nonsterile fermentation, have also been discussed. However, these technologies need more research and investigation before they can be implemented at an industrial scale.
Rheology of Filamentous Microorganisms, Submerged Culture
Authors: Papagianni Maria 
Published: April 2010

AbstractThe article discusses the factors that affect the rheological behavior of filamentous fermentation broths, rheological measurements, rheological models, control of the rheological properties of filamentous fermentations, and instrumentation. The rheological characteristics of a fermentation broth affect directly its mixing behavior and all forms of mass and heat transfer. This can have a profound influence not only on the course and outcome of fermentation but also on the response of sensors used for monitoring and control. Beyond fermentation, the rheological properties of the final culture broth make a major determinant of the ease or difficulty of downstream processing. Rheological properties are determined mainly by the concentration of biomass and fungal morphology. The filamentous growth form is the dominal morphological form in most processes. Long, thin, branched filaments create a network that gives very viscous fermentation broths with a pronounced non‐Newtonian character. Although the influence on the rheological properties of the broth on bioreactor performance is widely recognized, systematic studies of the rheological properties and the use of rheometry in fermentation processes are still limited. On‐line rheometry and image analysis applications in morphological studies have been valuable tools and provided a better understanding of the relationship between rheology and morphology. However, comparisons of data from different sources are rather problematic because of the different applied methods and instruments and the different morphological parameters evaluated. A wide variety of rheometers is available in the market today and it is expected that the area of fermentation broth rheology will be benefited in the future from advances in micro‐ and nanofluidics applications. Such applications are expected to provide precise control over experimental conditions and in‐depth rheological information on the studied systems.
Scale‐Up, Stirred Tank Reactors
Authors: Nienow Alvin W. 
Published: April 2010

AbstractScale‐up is best approached by considering the need to provide the optimum environment for the cell. It is inevitably a compromise and needs appropriate small‐scale data as discussed here. However, arbitrary and inflexible “scale‐up rules” are not useful. The most critical aspects of scale‐up are oxygen and carbon dioxide mass transfer and their concentration in the broth, all of which depend on the air sparge rate and power input from the selected impeller(s). The Rushton turbine is discussed followed by the now‐preferred hollow‐blade and up‐pumping, high solidity ratio hydrofoils. Bulk blending/homogeneity (especially at the high aspect ratios found on the commercial scale), holdup, and foaming and heat transfer in turbulent conditions as found with small‐sized microorganisms are considered, followed by the additional complexity that arises with these parameters when dealing with high viscosity, rheologically complex broths with mycelial and biopolymer fermentations. The impact of scale‐up on two aspects of bioperformance is considered, namely, mechanical stress from agitation and stresses from the inevitable poorer homogeneity. It is concluded that mechanical stresses are only important with mycelial fermentations and the impact depends on the organism. Stresses due to spatial differences in dO2and in pH batch fermentations, as well as nutrients in fed batch, cause a poorer performance at the commercial scale. Such information is vital for enabling a realistic appreciation beforehand of the likely large‐scale bioperformance, and for guiding design. Finally, with the present understanding of the physical and biological aspects of bioprocesses, computational fluid dynamics (CFD) is unlikely to be able to significantly improve it.
Suspension Culture, Animal Cells
Authors: Birch John R. 
Published: April 2010

AbstractSuspension culture has become the method of choice for the production of a wide range of therapeutic proteins and a number of vaccines. Some recombinant proteins, particularly antibodies, are required in quantities of hundreds of kilograms and even tons per annum. To meet these demands, industrial processes up to 20,000‐L scale have been developed based on stirred reactors, typically operated in batch or fed‐batch mode. For antibodies, optimization of fed‐batch processes has led to very high productivity, and yields of grams per liter are frequently reported. Continuous, perfused systems are also used. Several types of cells are used in these suspension processes, the most common being CHO. It is now possible to grow CHO and other cell types in large‐scale suspension culture using chemically defined media that contain no proteins or animal‐derived materials.
Transcription, Translation, and the Control of Gene Expression in Mammalian Cells
Authors: Mullick Alaka , Massie Bernard 
Published: April 2010

AbstractThe last few years have seen rapid progress in the field of gene expression, and at least part of the motivation has come from the domain of biotechnology, wherein, recombinant proteins have become important players in therapeutics. Depending upon the stage of development, there may be a need for small quantities of several related proteins or extremely large quantities of a restricted number of proteins. In either case, protein expression systems are essential. It has been possible to develop efficient expression systems because of the phenomenal increase in our understanding of the molecular mechanism that are involved in gene expression. Of interest is the fact that recent findings are not limited to defining further details of known processes, certain advances, such as the role of chromatin in DNA biochemistry and RNA silencing, have revolutionized the way we think about gene expression.
Vent Gas Analysis
Authors: Pollard David , Christensen Jens 
Published: April 2010

AbstractThe monitoring of exhaust gas provides a universal method for fermentation characterization as most biological processes involve exchange or consumption of gases and volatile compounds. The monitoring of gas concentrations, such as carbon dioxide and oxygen, in the entry inlet and outlet gas streams and incorporation into liquid and gas balances makes it possible to quantify rates of gas utilization on production and respiratory quotient. This allows online real time monitoring of the physiological state of the fermentation, including growth kinetics and substrate consumption. A range of measuring methods for vent gas analysis are described including industrial application examples.
Viral Vaccine Production in Cell Culture
Authors: Auniņš John G. 
Published: April 2010

AbstractCell culture for the purposes of viral vaccine cultivation is reviewed from the perspective of the industrial practitioner. This article covers the mechanics of virus production, followed by a discussion of the steps in virus replication, process affectors of virus cultivation. It concludes with a series of examples of virus vaccine processes, emphasizing the principles discussed in the previous sections as they translate to industrial practice.