The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform
Max Kennedy - One of the best experts on this subject based on the ideXlab platform.
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Raw Materials Selection and Medium Development for Industrial Fermentation Processes
Manual of Industrial Microbiology and Biotechnology Third Edition, 2010Co-Authors: Randolph Greasham, Samun K. Dahod, Max KennedyAbstract:This chapter focuses primarily on raw materials and Medium development for microbial fermentation processes. Chemically defined media have been used routinely in the laboratory to study the microbial biosynthesis of primary and secondary metabolites. Today, most fermentation processes employ complex media. However, chemically defined media are becoming popular where process consistency is very important, such as the production of biologics. When the chemically defined Medium was compared with the initial, optimized complex Medium for producing the secondary metabolite by Streptomyces, the chemically defined Medium reduced the Medium cost by 4.5-fold and increased the titer by 80% at the 800-liter scale. Glucose is the most frequently used carbohydrate in the fermentation industry. The white crystalline sucrose is generally used in small-scale applications and in seed fermentors. Other sugars that are used less frequently in the fermentation industry include maltose, mannitol, sorbitol, and xylose. Oils can supply both the energy and the growth carbon needs of the organism. The most important oil in the U.S. fermentation industry is soybean oil. The sources derived from agricultural products are the workhorse ingredients of the fermentation industry. They include the products of commodities such as various grains and soybean. The soybean flours, meals, and grits head the list of applications in antibiotic fermentations. Metal-chelating agents such as EDTA are often included in fermentation media. Crude preparations of enzymes such as amylase, protease, and cellulase are used to precondition the Medium. Invariably, these enzymes are used at the mixing stage before Medium Sterilization.
Deng Mao-zi - One of the best experts on this subject based on the ideXlab platform.
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Observation of 100～700 mL Liquid Medium Sterilization Effect with Microwave
Journal of Microbiology, 2012Co-Authors: Deng Mao-ziAbstract:Sterilization effect of the microwave oven for a small amount of liquid Medium was studied,respectively sterilized 100~700 mL liquid Medium by microwave,determined their sterilizing time and test the quality of the Medium which have achieved the Sterilization effect by inoculation different bacteria in it.The results showed that liquid media of 100,200,300,400,500,600 and 700 mL sterilized in 4.5,5.0,7.0,9.0,12.0,19.0 and 25.0 min respectively accomplished the most effective Sterilization effects.No bacteria grew when kept even in room temperature for 15 days.No bacteria grew in the Medium which had been inoculated Bacillus subtilis var.niger ATCC9372.No significant difference of growth in the liquid Medium inoculated with Staphylococcus aureus,E.coli and ordinary Proteus and after they were transferred in colony,form,staining features as well as their biochemical reactions.Experiment show that 2 450 MHz,700 W of microwave oven can not only rapidly sterilize 100~700 mL liquid Medium effectively but also the nutrients of liquid Medium could not be destroyed.
Randolph Greasham - One of the best experts on this subject based on the ideXlab platform.
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Raw Materials Selection and Medium Development for Industrial Fermentation Processes
Manual of Industrial Microbiology and Biotechnology Third Edition, 2010Co-Authors: Randolph Greasham, Samun K. Dahod, Max KennedyAbstract:This chapter focuses primarily on raw materials and Medium development for microbial fermentation processes. Chemically defined media have been used routinely in the laboratory to study the microbial biosynthesis of primary and secondary metabolites. Today, most fermentation processes employ complex media. However, chemically defined media are becoming popular where process consistency is very important, such as the production of biologics. When the chemically defined Medium was compared with the initial, optimized complex Medium for producing the secondary metabolite by Streptomyces, the chemically defined Medium reduced the Medium cost by 4.5-fold and increased the titer by 80% at the 800-liter scale. Glucose is the most frequently used carbohydrate in the fermentation industry. The white crystalline sucrose is generally used in small-scale applications and in seed fermentors. Other sugars that are used less frequently in the fermentation industry include maltose, mannitol, sorbitol, and xylose. Oils can supply both the energy and the growth carbon needs of the organism. The most important oil in the U.S. fermentation industry is soybean oil. The sources derived from agricultural products are the workhorse ingredients of the fermentation industry. They include the products of commodities such as various grains and soybean. The soybean flours, meals, and grits head the list of applications in antibiotic fermentations. Metal-chelating agents such as EDTA are often included in fermentation media. Crude preparations of enzymes such as amylase, protease, and cellulase are used to precondition the Medium. Invariably, these enzymes are used at the mixing stage before Medium Sterilization.
Prakash S. Masurekar - One of the best experts on this subject based on the ideXlab platform.
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Nutritional and engineering aspects of microbial process development
Progress in Drug Research, 2008Co-Authors: Prakash S. MasurekarAbstract:Today we use many drugs produced by microorganisms. However, when these drugs were discovered it was found that the yields were low and a substantial effort had to be put in to develop commercially viable processes. A key part of this endeavor was the studies of the nutritional and the engineering parameters. In this chapter, the basic principles of optimizing the nutritional and engineering aspect of the production process are described with appropriate examples. It was found that two critical components of nutritional Medium, carbon and nitrogen source regulated the synthesis of the compounds of interest. Rapidly utilizable carbon source such as glucose supported the growth but led to catabolite repression and alternative carbon sources or methods of addition had to be devised. Inorganic nitrogen sources led to undesirable changes in pH of the Medium. Organic nitrogen sources could influence the yields positively or negatively and had to be chosen carefully. Essential nutrients like phosphates often inhibited the synthesis and its concentration had to be maintained below the inhibitory levels. On many occasions, trace nutrients like metal ions and vitamins were found to be critical for good production. Temperature and pH were important environmental variables and their optimum values had to be determined. The media were designed and optimized initially with 'one variable at a time' approach and later with experimental design based on statistics. The latter approach is preferred because it is economical, considers interactions between Medium components and allows rapid optimization of the process. The engineering aspects like aeration, agitation, Medium Sterilization, heat transfer, process monitoring and control, become critical as the process is scaled-up to the production size. Aeration and agitation are probably the most important variables. In many processes dissolved oxygen concentration had to be maintained above a critical value to obtain the best yields. The rheological properties of fermentation broth significantly affect the aeration and mixing efficiency. The removal of heat from the large fermentors can be difficult under certain conditions. However, new designs of impellers, availability of sensors to monitor important physiological and process variables and advent of computers have facilitated successful scale-up of fermentation processes.
Ronaldo Nobrega - One of the best experts on this subject based on the ideXlab platform.
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Xylitol production from D-xylose in a membrane bioreactor
Desalination, 2002Co-Authors: Luis F. Figueiredo Faria, Nei Pereira, Ronaldo NobregaAbstract:Abstract Economical feasibility of xylitol production by microorganisms depends directly on the efficiency of conversion and productivity. A potential alternative to ensure this objective is continuous bioconversion. Xylitol production and separation methodology by a biotechnological route using the benefits of membrane technology were investigated. Xylitol produced by a strain of Candida guilliermondii was obtained using a synthetic Medium containing D-xylose in a continuous membrane bioreactor. Moreover, hollow-fiber membranes were prepared and modules suitable for continuous fermentation Medium Sterilization were designed. The membrane that presented the best performance had maximum pore diameter of 0.2 μm and permeability of 42.9 L/(m 2 .h.bar) for a simulated Medium. The best results obtained with this system for the continuous production of xylitol in a membrane bioreactor was attained with a dilution rate of 0.03 h −1 , providing an efficiency of D-xylose conversion of 86% and productivity values up to 1.14 g of xylitol/L.h.