Biotechnology & Immunology PDF

Biotechnology  Biofuel cell Conversion of chemical energy to electrical energy using organisms. A typical cell: anode and cathode compartment separated by a cation specific membrane.  Biofuel cell Two types of microbial fuel cells: 1- Mediator mic...

Biotechnology  Biofuel cell Conversion of chemical energy to electrical energy using organisms. A typical cell: anode and cathode compartment separated by a cation specific membrane.  Biofuel cell Two types of microbial fuel cells: 1- Mediator microbial fuel cell: Microbial cells: electrochemically inactive. Mediators: thionine, methyl blue, expensive, toxic.  2- Mediator less microbial fuel cell Does not require mediators. Using electrochemically active bacteria that transfer electrons to the electrode. Example: bacteria that have pili on their external membrane.  Applications of biofuel cells: 1- Production of electric current. 2- Production of reducing power. Biotechnology & Immunology Vaccines A) Production of vaccines Production of vaccines requires highly controlled operating conditions and strict GMP. It usually involves the growth of bacterial cultures in sophisticated high- grade fermenter. Vaccines A) Production of vaccines The fermentations are designed to produce optimal yield of cells or cell components. Internal pressure should not exceed the atmospheric pressure to reduce risk of leakage, and exhaust gases from fermenters must pass through sterilizing filters, incinerator or both.  Fermentations for vaccine productions based on whole cells aim to maximize cell production. For inactivated whole cell vaccines, downstream usually follows cell inactivation by heat treatment or by addition of formaldehyde. The microbial cells, inactivated or live, are then separated by centrifugation. For the production of vaccines based on toxins or surface antigens, the growth conditions are designed to maximize the yield of these components. Excreted toxins and loosely bounded surface antigens are purified from the culture broth and the harvested cells must be safely discarded. Toxins are inactivated either by heat treatment or by the addition of formaldehyde to produce Toxoid, which possesses antigenic activity without toxicity.  Monoclonal antibody In normal immunization procedure, injection of purified antigen leads to the production of antibodies with wide range of specificities for different epitopes on the Ag. It is usually impossible to separate the different types of Abs.  Monoclonal antibody Monoclonal Ab: Each antibody binds only one specific antigen. Monoclonal antibodies (mAb or moAb) are antibodies that are made by identical immune cells, in contrast to polyclonal antibodies, which are made from several different immune cells.  Monoclonal antibody (cont.) For most research, diagnostic, and therapeutic purposes, monoclonal antibodies are preferable. Monoclonal antibodies: antibodies derived from a single clone and thus specific for a single epitope.  Monoclonal antibody (cont.) The principle is the fusion of lymphocytes cells from an immunized animal with cells from cultured myeloma cell line (cancer cells) to produce hyberidoma, which has both the antibody-producing ability of the B-cell and the exaggerated longevity and reproductivety of the myeloma.  Hybridomas are produced by injecting a specific antigen into a mouse, collecting an antibody-producing cell from the mouse's spleen, and fusing it with a tumor cell called a myeloma cell.  Myeloma cell is selected because of their inability to grow in 8-azaguanine as they have no certain enzyme.  The hybridoma cells multiply indefinitely in the laboratory and can be used to produce a specific antibody indefinitely. Polyethylene glycol (PEG) is the agent used to fuse the 2 types of cells (promote membrane fusion). Monoclonal antibody (cont.) Animals (usually mice or rats) are immunized with Ag. Once the animal exhibited a good Ab response, the spleen is removed and a cell suspension is prepared. These cells fuse with a myeloma cell line by adding PEG which promote membrane fusion. Small proportion of the cells fuses successfully.  The fusion mixture is then set up in culture medium containing HAT medium (Hypoxanthin, Aminopterin, Thymidine). HAT is non toxic to spleen cells Myeloma cells have metabolic defect and die. Therefore, the only survive is fused cells.  Spleen cells (unfused to myeloma cells, may fuse to each other) can use this by-pass pathway, so HAT is not toxic to them but they die naturally due to their normal short life span (1-2 weeks).  Myeloma cells (unfused with spleen cells, may fuse to each other) have metabolic defect and can’t use this by- pass, so they die in HAT medium.  Only fused cells: (hybridoma) survive because they have the bypass of spleen cells and the immortality of myeloma cells and they are antibody producers. The technology of producing pure MCA is called hybridoma technology. Applications: Monoclonal antibodies have revolutionized medicine and research with their specificity and versatility, playing crucial roles in therapy, diagnostics, and preventive measures across a broad spectrum of diseases. Their continued development holds promise for even more innovative applications in the future.  Monoclonal antibodies (mAbs) are highly specific antibodies produced from a single clone of immune cells. They have numerous applications across various fields: 1. **Therapeutics: - **Cancer Treatment:** mAbs are used in targeted therapies to bind to specific cancer cell antigens, marking them for destruction by the immune system.. - **Autoimmune Diseases:** mAbs are used to treat conditions such as rheumatoid arthritis by inhibiting inflammatory pathways.  2. **Diagnostics** - **Disease Detection:** mAbs are integral in diagnostic tests, such as ELISA, to detect biomarkers for various diseases, including infections and cancers. - **Imaging:** Radiolabeled mAbs are used in imaging techniques like PET scans to visualize tumors or specific organ systems. 3. **Preventive Medicine** - **Vaccines:** mAbs can be utilized in vaccine development to enhance immune responses. Some monoclonal antibodies are also used for passive immunization against infectious diseases, such as RSV in infants.  4. **Transplantation** - **Rejection Prevention:** mAbs can help prevent organ rejection in transplant patients by targeting specific immune pathways. 5. **COVID-19 Treatment** - **Therapeutics:** During the COVID-19 pandemic, several mAbs were developed to target the virus, providing treatment options for infected patients and offering potential prophylactic measures for at-risk individuals. Environmental Biotechnology  Methane Biogas or natural gas or methane gas is produced by the process of anaerobic digestion of organic material (ex: sewage) by anaerobes.  Methane Anaerobic digestion is a complex biochemical process of biologically-mediated reactions by a group of microorganisms to convert organic compounds into methane and carbon dioxide.  Stages of anaerobic digestion.  Anaerobic digestion The digestion process begins with bacterial hydrolysis of the input materials in order to break down insoluble organic polymers such as carbohydrates and make them available for other bacteria. Acidogenic bacteria then convert the sugars and amino acids into carbon dioxide, hydrogen, ammonia, and organic acids.  Anaerobic digestion Acetogenic bacteria then convert these resulting organic acids into acetic acid, hydrogen, and carbon dioxide. Methanogenic bacteria finally are able to convert these products to methane and carbon dioxide.  Biogas Chemical composition of biogas%: Methane, CH4 50-75 Carbon dioxide, CO2 25-50 Nitrogen, N2 0-10 Hydrogen, H2 0-1 Hydrogen sulfide, H2S 0-3 Oxygen, O2 0-2 Biogas may require treatment or 'scrubbing' to refine it for use as a fuel.  Advantages of Biogas The methane in biogas can be burned to produce heat and electricity. Biogas does not contribute to increasing atmospheric carbon dioxide concentrations because the gas is not released directly into the atmosphere and the carbon dioxide comes from an organic source with a short carbon cycle. The nutrient-rich solids left after digestion can be used as fertilizer.  Biotechnology in hazardous waste management: In recent years , biotechnology has made considerable progress, and with growing knowledge of the relevant microbiological processes, the possibilities for using biotechnology in dealing with environmental problems have increased dramatically, especially in the field of solid waste and waste treatment.  Biotechnology in hazardous waste management: Biological treatment have advantages over the physiochemical methods; that biological methods, in most cases convert xenobiotics (substances that are foreign to the biosphere) into organic products (mineralization) that are part of natural recycling processes. The system could be applied in: 1- The purification of polluted air. 2- Decontamination of soil and waste water.  Bioremediation The basic principle of bioremediation involves utilizing the activity of microorganisms naturally available in soils and waters or selected organism inoculated into the environment, to degrade the pollutant in situ.  Bioremediation The degradation reactions are usually leading to removing the toxicity. The rate of degradation can be optimized by the addition of inorganic nutrients such as P & N in order to enhance the growth rate of the degrading organisms. Pollutants Pollutants are naturally occurring compounds in the environment that are present in unnaturally high conc. Ex: crude oil Refined oil Phosphates Heavy metals Xenobiotics They are chemically synthesized compounds that have never occurred in nature. Ex: pesticides herbicides plastics  Biodegradation of xenobiotics Resistance to biodegradation is seen in some natural organic compounds such as lignocellulose. The phenomenon is reported with xenobiotics. These are synthetic chemicals with structures that are foreign to the biosphere. Consequently, many of these compounds are recalcitrant (resist biodegradation).  Biodegradation of xenobiotics The industry produce huge amounts of these compounds which are potentially hazardous pollutants include some pesticides, insecticides, herbicides, halogenated aliphatic and aromatic compounds, and polycyclic aromatic hydrocarbons. Many of these enter the environment from industrial wastewaters.  The reasons for the presence of recalcitrant molecules are: 1- The compounds are highly stable. 2- The presence of highly stable bond which are not easily degraded. 3- The presence of halogens and sulphonates always increase the stability of the compound such as chlorinated aromatic compounds.  Generally, the compounds are degraded by the organisms through either: Metabolism, in which the m.o. are able to utilize the target compound as a carbon source. In this case, the xenobiotic molecules are disappeared with a concomitant increase in cell mass. Some compounds are decomposed and converted into inorganic elements or into CO2 and H2O (mineralization). Co-metabolism: where the microorganisms. are capable to transform the environmental pollutants without using the transformed compound as a carbon source with no increase in cell numbers. The transformation processes might convert the xenobiotic into non-toxic compounds, or might reduce its toxicity. Mechanism of biodegradation: Aerobic metabolism Microbes use oxygen in their metabolism to degrade contaminants. Mechanism of biodegradation: Anaerobic metabolism Microbes substitute another chemical for oxygen to degrade contaminants. Nitrate, iron, sulfate, CO2, uranium. Aerobic biodegradation: Organic chemical (benzene) + O2 (electrons transfer to O2 as electron acceptor) → CO2 + H2O + Biomass (increased no. of bacteria). Anaerobic biodegradation: Organic chemical (toluene) + NO3 (electrons transfer to nitrate as electron acceptor) → CO2 + N2+ H2O + Biomass. THANK YOU