The biotechnology sector, when defined with colors is like a rainbow, with each color denoting a particular sub-sector. The color green in biotechnology represents the areas of agricultural and environmental biotechnology. While agricultural biotechnology involves the use of scientific tools and techniques to develop the agricultural sector, the environmental biotechnology focuses on using microorganisms to prevent, reduce, and treat environmental pollution.
Green biotechnology deals with the use of environmentally friendly solutions as an alternative to traditional agricultural, horticulture, and animal breeding process. Example of agricultural applications of green biotechnology is the use of genetically altered plants or animals, development of transgenic plants, genetic engineering of plants, manipulation and use of microorganisms to facilitate crop growth, producing fertile and resistant seeds, etc. Similarly, ecological applications include bioremediation, development of biofuels and biofertilizers, applications in geomicrobiology, microbial ecology, solid waste management, wastewater treatment, etc.
Tools and Applications of Green Biotechnology in Agriculture
Agritech is believed to defend hunger in a more eco-friendly manner without disturbing the natural environmental health. It makes use of biological processes and technologies to produce more fertile and resistant plants and ensures the promotion of biofertilizers and biopesticides.
1. Tissue Culture and Micropropagation
One of the prominent tools in plant biotechnology is micropropagation, meaning the practice of rapidly multiplying stock plant material in tissue culture to produce a large number of progeny plants in a limited time and space. It is an excellent technique to multiply genetically modified breed, pathogen-free transplants, seedless varieties, or those plants that do not respond well to vegetative propagation. Plant tissue culture makes use of many other tools and techniques such as germplasm conservation, embryo culture, genetic transformation, protoplast fusion, haploid production, somatic embryogenesis and organogenesis, suspension culture, callus culture, root culture, etc.
2. Crop Modification
Crop modification techniques are being used for hundreds of years to improve the quality and quantity of the crop. In the past, sexually compatible mates were crossbred through traditional techniques. Today, modern scientific techniques such as mutagenesis, polyploidy, somatic hybridization, RNA interference, transgenics, and genome editing are widely used. Similarly, molecular marker-assisted breeding is also in use in breeding of many crops, thus making the technique efficient in introgression of important genes into various crops. Examples include bacterial blight resistance in rice, increased beta-carotene content in rice, cassava and banana, and submergence tolerance in rice.
3. Improved Nutritional Contents
Crops are fortified or enriched with nutrients to supply essential nutrients in regular diets and staple crops and reduce malnutrition in developing countries. For example, potato, a genetically engineered potato in India, produces about one-third to one-half more protein than usual along with a substantial amount of all the essential amino acids. Similarly, golden rice is genetically engineered to biosynthesize beta-carotene, the precursor of vitamin A. This helps to prevent death and childhood blindness caused by vitamin A deficiency.
4. Improved Agronomic Traits
Tools of biotechnology are largely efficient in enhancing the agronomic traits of plants and agricultural crops. Such traits include insect resistance, herbicide tolerance, virus resistance, disease resistance, temperature tolerance, drought tolerance, delayed fruit ripening, increased dietary value, improved food processing and storage, and the elimination of toxins and allergens in crop plants. In the past decade, several crops have been genetically engineered to introduce Bt toxin genes isolated from Bacillus thuringiensis. This gene codes for the insecticidal Bt protein that kills insects such as tobacco budworm, flies, mosquitoes, beetles, etc. One of the earliest examples of Bt toxin engineered crops is Bt cotton. Similarly, resistance to synthetic herbicides has been genetically engineered into corn, soybeans, cotton, canola, sugar beets, rice, and flax.
Tools and Applications of Green Biotechnology in Environmental Biotechnology
Environmental biotechnology makes use of living systems to solve environmental problems. Environmental biotechnology is fundamentally rooted in waste in its various guises, such as remediation of contamination caused by previous use, the impact of the reduction of current activity, and the control of pollution. This aspect of biotechnology includes preventing the discharge of pollutants to the environment, cleaning up contaminated environments, and generating valuable resources for human society. Therefore, the principal aim of this field is to manufacture products in environmentally harmonious ways that allow for the minimization of harmful solids, liquids or gaseous output, and the cleaning of residual effects of earlier human occupation.
Bioremediation makes use of living organisms (primarily microorganisms) to destroy or immobilize waste materials and environmental pollutants. The general approaches to bioremediation are to restore environmental health by enhancing natural biodegradation by native organisms. It also involves applying nutrients or aeration (biostimulation) or the addition of microorganisms (bioaugmentation) for the process. The benefits of bioremediation are that it is an economical process and causes less disruption to the environment. Bioremediation has been successfully used to clean up pollutants, including pesticides, sewage, gasoline, crude oil toxic chemicals, and solvents. Degradation of organic solvents such as toluene and conversion of styrene oil into biodegradable plastic polyhydroxyalkanoates (PHA) by Pseudomonas putida is a well-known example to many. Besides, various bacteria, fungi, algae, and archaea are involved in biodegradation or bioconversion of pollutants and heavy metals.
2. Bioenergy and Biofuel
A significant application of green biotechnology is the conversion of biomass into heat and electricity and biofuels through thermochemical and biochemical conversion processes and extraction process. Such processes are pyrolysis, gasification, alcoholic fermentation, anaerobic digestion, and transesterification. Potential biofuel products are butanol as a direct replacement for gasoline, bioethanol, biomethanol, biogas, and biodiesel.
Biofertilizers are important in sustainable agricultural practices to replace the use of toxic and harmful chemicals. Used as microbial inoculants or microbial preparations, biofertilizers improve the nutritional conditions of the soil. Examples of microbial biofertilizers are nitrogen-fixing bacteria (Frankia, Cyanobacteria, Acetobacter, Alcaligenes, Azospirillum, Bacillus, Rhizobium, Clostridium, Klebsiella, Pseudomonas, Enterobacter, etc.) Other types of biofertilizers are plant growth-promoting Rhizobacteria, phosphate solubilizers such as Alcaligenes, Erwinia, Serratia, Rhizobacteria, etc. Symbiotic mycorrhizal fungi is a fungal biofertilizer involved in land reclamation and restoration.
Agricultural biotechnology, on the one hand, is securing global food production through its various tools, and on the other hand, it is enhancing the food products with nutritional benefits. Likewise, environmental biotechnology is securing global ecological health with natural life forms. Green Biotechnology is therefore expected to bring green revolution through agricultural development while safeguarding the natural environmental health concomitantly.