Microorganisms: Applications in Pharma, Agriculture & Environment
Microorganisms in the Pharmaceutical Industry
Major pharmaceutical products derived from microorganisms include:
- Antibiotics: Substances produced by microorganisms that inhibit the growth of or kill other microorganisms. Known antibiotics differ in chemical structure:
- β-lactam Antibiotics: Penicillins and Cephalosporins
- Aminoglycosides: Streptomycin
- Macrolides: Erythromycin
- Tetracyclines: Broad-spectrum antibiotics
- Vaccines: Preparations obtained from dead or attenuated pathogens used to induce active immunity. Often, an antigenic component (like a viral coat protein) is produced using genetic engineering.
- Enzymes, Proteins, or Hormones: Obtained through genetic engineering by cloning human protein genes into appropriate microorganisms.
- Steroidal Hormones: Derived via biotransformation, a process involving growing microorganisms in a fermenter and adding a chemical precursor that is transformed into the desired final product. This process yields cortisone (used for inflammation, allergies, arthritis) and steroids used in human fertility treatments.
Microorganisms in Agriculture and Livestock
Noxious Relations
Diseases Produced in Plants
Caused by:
- Bacterial Pathogens: Such as Agrobacterium, which causes galls (tumors), wilts, leaf spots, and delayed fruit ripening in plants. Agrobacterium commonly affects vines.
- Viruses: Cause two main types of alterations: mosaics (yellow spots on leaves) and crinkling or deformation of leaves.
- Fungi: These agents spread and are transmitted by air, water, or vectors like insects.
Diseases Produced in Animals
Diseases affecting livestock that may be transmitted to humans are called zoonoses.
- Pathogenic Bacteria: Examples include blackleg, caused by Clostridium species, which leads to infections in ruminants (eradication requires burning carcasses as spores survive), and glanders, which attacks equines causing weakness.
- Viruses: Such as swine fever, causing internal bleeding and sepsis in animals.
- Protozoa: For example, coccidiosis, affecting poultry in coops.
Beneficial Relations
Recycling of Nutrients
Microorganisms, particularly decomposing bacteria, are responsible for recycling organic matter back into inorganic nutrients that can be taken up by plants. This principle underlies the use of manure.
Atmospheric Nitrogen Fixation
Leguminous plants like rice, soybeans, alfalfa, beans, peas, lentils, and chickpeas benefit from symbiosis with Rhizobium bacteria. Other plants of interest, such as alder, emborrachacabras, and myrtles, are pioneer species in nitrogen-poor soils due to their symbiosis with Frankia actinomycetes.
Bacteria in the digestive system (rumen) of ruminants exist in symbiosis and can digest cellulose.
Microorganisms in Environmental Phenomena
This involves the removal of pollutants through the use of microorganisms (bioremediation).
Biodegradation of Oil
A large number of bacteria (e.g., Pseudomonas, Mycobacteria), molds, yeasts, and some green algae can oxidize hydrocarbons. Degradation requires specific conditions like oxygenation, disintegration (dispersion), and appropriate pH factors. Volatile hydrocarbons evaporate, and some components can be carcinogenic. Long-chain aromatic and aliphatic hydrocarbons are removed by bacterial action, provided appropriate disintegration is achieved and nutrients like phosphorus and nitrogen are added.
Biodegradation of Xenobiotic Compounds
Xenobiotic compounds refer to industrial chemicals, such as plastics and pesticides, that have not previously existed in nature.
Biodegradation of Plastics and Similar Materials
This concerns plastics and related packaging materials like polyurethane and polystyrene. Successes include developing photobiodegradable plastics (altered by the sun’s ultraviolet rays to produce compounds assimilated by microorganisms) and incorporating starch or microbial plastics (like PHB).
Pesticide Biodegradation
This includes herbicides, insecticides, and fungicides used in agriculture. Their degradation is often difficult, and some, like DDT, persist unchanged for many years. Some success has been achieved using bacteria under anoxic conditions that dechlorinate highly carcinogenic chlorocarbon compounds.
Waste Water Treatment
This involves treating water originating from domestic sewage and industrial process discharges using microbial processes.