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VOCATIONAL TRAINING IN EXIMUS TECHNOLOGIES

YOU ARE INFORMED THAT VOCATIONAL TRAINING FOR ENGG. STUDENTS ARE GOING TO HELD IN EXIMUS TECHNOLOGIES OF 1 MONTH. THE CAUTION MONEY IS OF Rs 500/-- AND TRAINING MONEY IS OF Rs 1500/- .MOREOVER TRAINING WILL BE HELD AT ITS HEADQUATER IN PUNE(INDIA).TRAINING WILL BE IN PHASES AND BATCHES AND DIRECTORS OF THE COMPANY WILL DECIDE ABOUT THE EXECUTION. THE COMPANY BOARD ARE NOT RESPONSIBLE FOR ANY SECURITY AND RISKS.THE CORPORATE RULES WILL NOT BE HARMED AT ANY CONDITIONS.CERTIFICATE WILL ONLY BE PROVIDED AND GRADES WILL BE ALLOTED ACCORDING TO THE PERFORMANCE OF THE STUDENT.PROJECTS FOR TRAINING WILL BE DECIDED BY BOARD OF DIRECTORS OF THE COMPANY.TRAINING AND CAUTION MONEY CAN BE GIVEN BY CASH OR BY DEMAND DRAFT IN FAVOUR OF " EXIMUS TECHNOLOGIES" PAYABLE AT PUNE.

BIOREACTORS FOR BIOTECHNOLOGISTS

WHAT ARE BIOREACTORS????

A bioreactor is a vessel in which is carried out a chemical process which involves organisms or biochemically active substances derived from such organisms.

Bioreactors are commonly cylindrical, ranging in size from some liter to cube meters,and are often made of stainless steel.

Bioreactor design is quite a complex engineering task. Under optimum conditions the microorganisms or cells will reproduce at an astounding rate. The vessel's environmental conditions like gas (i.e., air, oxygen, nitrogen, carbon dioxide) flowrates, temperature, pH and dissolved oxygen levels, and agitation speed need to be closely monitored and controlled. One bioreactor manufacturer, Broadley-James Corporation, uses vessels, sensors, controllers, and a control system, digitally networked together for their bioreactor system.

Continuous flow stirred tank reactors (chemostat) In the continuous flow, stirred tank reactor (CSTR or chemostat) fresh medium is fed into the bioreactor at a constant rate, and medium mixed with cells leaves the bioreactor at the same rate. A fixed bioreactor volume is maintained and ideally, the effluent stream should have the same composition as the bioreactor contents. The culture is fed with fresh medium containing one and sometimes two growth-limiting nutrients such as glucose. The concentration of the cells in the bioreactor is controlled by the concentration of the growth-limiting nutrient. A steady state cell concentration is reached where the cell density and substrate concentration are constant. The cell growth rate (µ) is controlled by the dilution rate (D) of growth limiting nutrient.

Cell culture bioreactors are categorized into two types: 1. Those that are used for cultivation of anchorage dependent cells (e.g. primary cultures derived from normal tissues and diploid cell lines. 2. Those that are used for the cultivation of suspended mammalian cells (e.g. cell lines derived from cancerous tissues and tumors, transformed diploid cell lines, hybridomas). In some cases the bioreactor may be modified to grow both anchorage dependent and suspended cells. Ideally any cell culture bioreactor must maintain a sterile culture of cells in medium conditions which maximize cell growth and productivity.

Fouling can harm the overall sterility and efficiency of the bioreactor, especially the heat exchangers. To avoid it the bioreactor must be easily cleanable and must be as smooth as possible (therefore the round shape).

Heat exchange is needed to maintain the bioprocess at a constant temperature. Biological fermentation is a major source of heat, therefore in most cases bioreactors need water refrigeration. They can be refrigerated with an external jacket or, for very large vessels, with internal coils.

Optimal oxygen transfer is perhaps the most difficult task to accomplish. Oxygen is poorly soluble in water -and even less in fermentation broths- and is relatively scarce in air (20.8%). Oxygen transfer is usually helped by agitation, that is also needed to mix nutrients and to keep the fermentation homogeneous. There are however limits to the speed of agitation, due both to high power consumption (that's proportional to the cube of the speed) and the damage to organisms due to excessive tip speed.

Bioreactor treatment may be performed using microorganisms growing in suspension in the fluid or attached on a solid growth support medium. In suspended growth systems, such as fluidized beds or sequencing batch reactors, contaminated groundwater is circulated in an aeration basin where a microbial population aerobically degrades organic matter and produces carbon dioxide, water, and biomass. The biomass is settled out in a clarifier, then either recycled back to the aeration basin or disposed of as sludge. In attached growth systems, such as upflow fixed film bioreactors, rotating biological contactors (RBCs), and trickling filters, microorganisms are grown as a biofilm on a solid growth support matrix and water contaminants are degraded as they diffuse into the biofilm. Support media include solids that have a large surface area for bacterial attachment.

A bioreactor landfill operates to rapidly transform and degrade organic waste. The increase in waste degradation and stabilization is accomplished through the addition of liquid and air to enhance microbial processes. This bioreactor concept differs from the traditional “dry tomb” municipal landfill approach.

A bioreactor landfill is not just a single design and will correspond to the operational process invoked. There are three different general types of bioreactor landfill configurations:

Aerobic - In an aerobic bioreactor landfill, leachate is removed from the bottom layer, piped to liquids storage tanks, and re-circulated into the landfill in a controlled manner. Air is injected into the waste mass, using vertical or horizontal wells, to promote aerobic activity and accelerate waste stabilization. Anaerobic - In an anaerobic bioreactor landfill, moisture is added to the waste mass in the form of re-circulated leachate and other sources to obtain optimal moisture levels. Biodegradation occurs in the absence of oxygen (anaerobically) and produces landfill gas. Landfill gas, primarily methane, can be captured to minimize greenhouse gas emissions and for energy projects. Hybrid (Aerobic-Anaerobic) - The hybrid bioreactor landfill accelerates waste degradation by employing a sequential aerobic-anaerobic treatment to rapidly degrade organics in the upper sections of the landfill and collect gas from lower sections. Operation as a hybrid results in the earlier onset of methanogenesis compared to aerobic landfills The Solid Waste Association of North America (SWANA) has defined a bioreactor landfill as "any permitted Subtitle D landfill or landfill cell where liquid or air is injected in a controlled fashion into the waste mass in order to accelerate or enhance biostabilization of the waste." The United States Environmental Protection Agency (EPA) is currently collecting information on the advantages and disadvantages of bioreactor landfills through case studies of existing landfills and additional data so that EPA can identify specific bioreactor standards or recommend operating parameters.

Features Unique to Bioreactor Landfills: The bioreactor accelerates the decomposition and stabilization of waste. At a minimum, leachate is injected into the bioreactor to stimulate the natural biodegradation process. Bioreactors often need other liquids such as stormwater, wastewater, and wastewater treatment plant sludges to supplement leachate to enhance the microbiological process by purposeful control of the moisture content and differs from a landfill that simple recirculates leachate for liquids management. Landfills that simply recirculate leachate may not necessarily operate as optimized bioreactors.


APPLICATIONS OF BIOREACTOR

****Application of bioreactor design principles to plant micropropagation
Principles of oxygen consumption, oxygen transport, suspension, and mixing are discussed in the context of propagating aggregates of plant tissue in liquid suspension bioreactors. Although micropropagated plants have a relatively low biological oxygen demand (BOD), the relatively large tissue size and localization of BOD in meristematic regions will typically result in oxygen mass transfer limitations in liquid culture. In contrast to the typical focus of bioreactor design on gas–liquid mass transfer, it is shown that media-solid mass transfer limitations limit oxygen available for aerobic plant tissue respiration. Approaches to improve oxygen availability through gas supplementation and bioreactor pressurization are discussed. The influence of media components on oxygen availability are also quantified for plant culture media. Experimental studies of polystyrene beads in suspension in a 30-l air-lift and stirred bioreactors are used to illustrate design principles for circulation and mixing. Potential limitations to the use of liquid suspension culture due to plant physiological requirements are acknowledged.



******Application of bioreactor system for large-scale production of Eleutherococcus sessiliflorus somatic embryos in an air-lift bioreactor and production of eleutherosides

Embryogenic callus was induced from leaf explants of Eleutherococcus sessiliflorus cultured on Murashige and Skoog (MS) basal medium supplemented with 1 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D), while no plant growth regulators were needed for embryo maturation. The addition of 1 mg l−1 2,4-D was needed to maintain the embryogenic culture by preventing embryo maturation. Optimal embryo germination and plantlet development was achieved on MS medium with 4 mg l−1 gibberellic acid (GA3). Low-strength MS medium (1/2 and 1/3 strength) was more effective than full-strength MS for the production of normal plantlets with well-developed shoots and roots. The plants were successfully transferred to soil. Embryogenic callus was used to establish a suspension culture for subsequent production of somatic embryos in bioreactor. By inoculating 10 g of embryogenic cells (fresh weight) into a 3 l balloon type bubble bioreactor (BTBB) containing 2 l MS medium without plant growth regulators, 121.8 g mature somatic embryos at different developmental stages were harvested and could be separated by filtration. Cotyledonary somatic embryos were germinated, and these converted into plantlets following transfer to a 3 l BTBB containing 2 l MS medium with 4 mg l−1 GA3. HPLC analysis revealed that the total eleutherosides were significantly higher in leaves of field grown plants as compared to different stages of somatic embryo. However, the content of eleutheroside B was highest in germinated embryos. Germinated embryos also had higher contents of eleutheroside E and eleutheroside E1 as compared to other developmental stages. This result indicates that an efficient protocol for the mass production of E. sessiliflorus biomass can be achieved by bioreactor culture of somatic embryos and can be used as a source of medicinal raw materials.


*****Anaerobic Membrane Bioreactors: Applications and Research Directions.

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***Possible New Approach To Purifying Drinking Water using biotechnology
A genetic tool used by medical researchers may also be used in a novel approach to remove harmful microbes and viruses from drinking water. In a series of proof-of-concept experiments, engineers demonstrated that short strands The relatively new technology, known as RNA interference (RNAi), makes use of short snippets of genetic material that match -- like a lock and key -- a corresponding segment of a gene in the target. When these snippets enter a cell and attach to the corresponding segment, they can inhibit or block the action of the target gene. This approach is increasingly being used as a tool in biomedical research, but has not previously been applied to environmental issues. Methods currently used to treat water -- chlorine and ultraviolet (UV) light -- can be expensive to operate and the results of the treatment itself can affect the taste and smell of the water. Although these methods have been employed for years, problems can emerge once the treated water enters the distribution system, where pathogens are also present. For this reason, water is often over-chlorinated at the plant so that it remains in high enough concentrations in the pipes to neutralize pathogens. This explains why people living the closer to a treatment plant will be more likely to taste or smell the chemical than those farthest away from the plant, the researchers said. Additionally, chlorine can react with other organic matter in the system, leading to potentially harmful by-products. The researchers are currently conducting additional experiments targeting other regions of the fungus' genome. For their proof-of-concept experiments, they tested RNAi on a non-essential, yet easy to monitor, gene. They are now testing this approach to silence or block genes essential to the viability of the pathogen. *The experiments were funded by Duke's Pratt School of Engineering.of genetic material could successfully target a matching portion of a gene in a common fungus found in water and make it stop working.




**** Fruit Fly Protein Acts As Decoy To Capture Tumor Growth Factors

Researchers at the University of Pennsylvania School of Medicine have shown how Argos, a fruit fly protein, acts as a "decoy" receptor, binding growth factors that promote the progression of cancer. Knowing how Argos neutralizes tumor growth may lead to new drug designs for inhibiting cancer. Many types of tumors grow because of over-expression of a protein known as the epidermal growth factor receptor (EGFR) or a peptide hormone called epidermal growth factor (EGF) that binds and activates EGFR. Argos mimics EGFR by binding to EGF. But, unlike EGFR, Argos does not signal cells to grow. Approaches using molecules that neutralize growth factors have proven themselves in other cases. The Avastin antibody works well to block the molecule that activates the vascular endothelial growth factor receptor and several drugs can block tumor necrosis factor-α in arthritis, including Remicade, Humira and Enbrel. An Argos-like drug would work the same way in EGFR signaling, suggests Lemmon. In the current study, Lemmon and colleagues have worked out the details of the three-dimensional structure of Argos when it binds to Spitz. "We were surprised to find that Argos has three very similar domains that capture Spitz by surrounding it like a C-clamp," explains Lemmon. Although Argos binding to Spitz mimics the characteristic binding of EGFR to EGF, Argos and EGFR do not share the same amino acid sequence or structural similarities. The structure of Argos was studied by X-ray crystallography, a technique that shows where each atom of the protein is located. Computer analysis is then used to put together all the data into a three-dimensional projection of the growth factor and its binding molecule. Daryl E. Klein, Steven E. Stayrook, Fumin Shi, and Kartik Narayan, all of Penn, are co-authors on the study. This work was supported by grants from the National Cancer Institute and the U. S. Army Breast Cancer Research Program.

***Researchers Devise New Way Of Mapping The Viscosity Of Cells

A fluorescent dye can be used to map how viscous, or 'gloopy', different parts of a cell are, according to new research published in the Journal of the American Chemical Society. Changes in viscosity have been linked to disease and malfunction in human cells. For example, changes in the viscosity of the membranes of red blood cells have been observed in diabetes patients. Knowing more about these changes could lead to a greater understanding of how some diseases affect the human body.

***New Mouse Model Mimics Hyperglycemia, Aids In Diabetes Research


Researchers have genetically engineered a laboratory mouse in which pancreatic beta cells can regenerate after being induced to die. The new animal model's regenerative ability may provide future insights into improved treatments of diabetes, which affects millions of Americans.The model, named the PANIC-ATTAC mouse, mimics what occurs in humans with type 1 diabetes, a condition that develops when the body's immune system destroys pancreatic beta cells, as well as in type 2 diabetes, where beta cells die from working overtimeDr. Scherer said this model lends itself to studying conditions of temporary hyperglycemia such as gestational diabetes, a condition in which pregnant women who have never had diabetes develop hyperglycemia. Gestational diabetes usually disappears after pregnancy, but it is not clear whether these transient bouts of elevated glucose can cause permanent damage in the vasculature that persists even after normal glucose levels have been restored. Dr. Zhao Wang, a postdoctoral researcher at UT Southwestern and lead author of the study, said the strength of the PANIC-ATTAC mouse as a research tool lies partly in the ability to test how specific pharmaceuticals impact beta-cell regeneration. "We can test which drugs can more rapidly repair the damage," Dr. Wang said. "We can also test which drugs are protective. That's probably more important physiologically because it allows us to screen for interventions that could protect beta cells during the early stages of diabetes to slow down and prevent the onset of hyperglycemia."



***Biotechnology seen as a key to solving food crisis

Biotechnology can help solve the world's food crisis with benefits such as flood-resistant rice in Bangladesh or higher cotton yields in Burkina Faso, a senior U.S. official said at a U.N. food summit on Tuesday. Some green groups say genetically-engineered crops threaten biodiversity while many European consumers are wary of eating products dubbed by critics as "Frankenfoods." Schafer said biotechnology, including genetically-modified organisms (GMOs), could help produce more food by raising yields and producing crops in developing nations that are resistant to disease and pests. "Genetic engineering offers long-term solutions to some of our major crop production problems," said Philippine Agriculture Minister Arthur Yap. But he said that it was not a panacea for all of his country's agricultural problems. Progress being made in the Philippines included research into rice and coconuts resistant to disease, he said. "We're also working on virus-resistant papaya, papaya hybrids with a longer shelf life that should be ready for market in 2009," he said.