Topic 7: Environmental Biotechnology on Eco-Efficiency and Eco-Friendly Bio-products
Eco-Efficiency
Eco-efficiency analysis = offer comprehensible information for a large number of applications concerning the multifactorial problems within relatively short times and at relatively low cost.
Environmental biotechnology has a great potential to be an economically beneficial and at the same time economically profitable in many areas.
Environmental challenges increasingly affect the competitiveness, not only in terms of clean-up and pollution-control costs, but also in marketplace.
Eco-efficiency: the heart of success in the economic world as a way to maximize efficiency, while minimizing the impact on the environment.
Key Objectives
Optimizing the use of resources
Reducing environment impact
Increasing product or service value
Biotechnology in general and environmental biotechnology in particular can be considered as one of the most useful means to attain eco-efficiency and for decision making because offers a number of practical benefits
Example: Minimization of pesticide use is one of the main practices for sustainable farming, but also a proactive consideration for the future of an eco-efficient agriculture, as an illustration for one element of eco-efficiency: reduce toxic dispersion.
Eco-Friendly Bio-Products for Environmental Health
Biotechnology ~ profitable utilised in certain sectors of agricultural and energy resources, helped in minimising the deterioration of environmental health indirectly, through the development of different bio-products.
Bio-products
are materials, chemicals and energy derived from renewable biological resources.
Bio-pesticides
Use of synthetic chemical pesticides has increased phenomenally, in agricultural as well as in household in controlling pests and insects.
Environmental implications – highly hazardous and non-degradable in nature.
Lead to development and use of bio-pesticides or biocides
Types of bio-pesticides
Microbial pesticides
Plant pesticides
Biochemical pesticides
Microbial pesticides consist of a microorganism (e.g., a bacterium, fungus, virus, or protozoan) as the active ingredient. Microbial pesticides can control many different kinds of pests, although each separate active ingredient is relatively specific for its target pest
Most successful bio-control agent is Bacillus thuringensis (a spore forming bacterium).
pesticidal substances that plants produce from genetic material that has been added to the plant.
Examples: gene for the Bt pesticidal protein and introduce the gene into the plant's own genetic material. Then the plant, instead of the Bt bacterium, manufactures the substance that destroys the pest.
Both the protein and its genetic material are regulated by EPA; the plant itself is not regulated.
naturally occurring substances that control pests by non-toxic mechanisms.
Bio-fertilizers
include substances, such as insect sex pheromones, that interfere with mating, as well as various scented plant extracts that attract insect pests to traps.
substance which contains
living microorganisms
when applied to seed, plant surfaces, or soil, colonizes the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant
Use of different types of microorganisms such as Azotobactor, Blue green algae, Rhizobium and Azospirillum;
Azotobacter are used for the development of various vegetable plants such as mustard, maize, wheat and cotton
Azospirillum is applied in the millets, sorghum, sugarcane, maize and wheat field
Rhizobium is used to increase the capacity of nitrogen fixation in the leguminous plants;
Nostoc, Tolypothrix, Anabaena, and Aulosira are known as blue green algae. Anabaena and Azolla fix atmospheric nitrogen and enrich the soil fertility.
Biological Hydrogen Generation
Microalgae and cyanobacteria, including Chlorella, Scenedesmus, Microcystis, Oscillatoria and Anabeana can metabolise molecular hydrogen
Hydrogenase enzyme plays an important rule in oxidation and reduction of molecular H2
Example: Phosphate solubilizing bacteria such as Pseudomonas putida and Pantoea agglomerans strain P5 are the examples of phosphate solubilizing bacteria.
How biotechnology helps in improving these?
Fixation of atmospheric N to ammonia is depending on key enzyme nitrogenase
Controlled by “nif gene”, found to be a cluster of many gene loci
Genetic analysis of N-fixation has been thoroughly worked out for K. pneumonia (commonly found in soil and water)
“Nif gene” of Klebsiella has been successfully cloned into E. coli and other fungus
vermiculture and VAM
(Vascular Arbuscular Mycorrhiza)
biodegradable matter in the soil by different species of earthworm into a darkmass called vermicast.
Organic matters in soil are partly converted into a more bioavailable forms.
Helps to maintain sustainability of soil with additional hormones and enzymes for better plants growth and discourages pathogens growth.
Bio-Energy and Bio-Fuels
Human activities = largely become energy dependent
Primary energy sources = non-renewable fossil fuels like coal and mineral oils (petroleum and gasoline) apart from forest wood
Continuation of using these resources = depleting finite sources + putting ecosystem under great pressure of pollution hazards
Led to turning to renewable alternate sources of energy of biological origin
Supplement the conventional sources
Provide a course effective means of generating cleaner environment
Biotechnology strategies for “organic synthetic” fuel generation are based on microbial processing of plant biomass to yield maximum fuels like methane gas, alcohols (ethanol/methanol) and generation of H2 gas
Biodegradable plastics
Plastics
their rampant use and production of huge plastic wastes, integrity of our environment and eco-balance is being threatened, and recycling them produce toxic chemical
the best way is to produce biodegradable plastics ~ consumable by scavenging microbes
biodegradable plastics can be based on natural or synthetic resins.
Natural biodegradable plastics are based primarily on renewable resources and can be either naturally
produced or synthesised from renewable resources.
Non-renewable synthetic biodegradable plastics are petroleum-based. As any marketable plastic product must meet the performance requirements of its intended function
The classes of biodegradable plastics considered, in terms of the degradation mechanism, are:
1) Biodegradable
2) Compostable
3) Hydro-biodegradable
4) Photo-biodegradable
5) Bioerodable
Example
-Naturally produced polyesters including PVB, PHB and PHBH
-Renewable resource polyesters such as PLA
-Synthetic aliphatic polyesters including PCL and PBS
Applications:
-Sheet and non woven packaging
-Bottles
-Planter boxes and fishing nets
-Food service cups, cutlery, trays, and straws
Some of potential disposal environments for biodegradable plastics are:
composting facilities or soil burial;
anaerobic digestion;
wastewater treatment facilities;
Environmental benefits:
Compost derived in part from biodegradable plastics increases the soil organic, while reducing chemical inputs and suppressing plant disease
Biodegradable shopping and waste bags disposed of to landfill may increase the rate of organic waste degradation in landfills while enhancing methane harvesting potential, decrease in lanfill space usage
less energy requred
adverse environmental risks
-Pollution in waterways due to high BOD concentrations
-Migration of plastic degradation by-products
to groundwater and surface water bodies
-Trauma and death of marine species
-Possible increase in the incidence of littering
-Soil and crop degradation
Alcohol as Fuels
Usage alcohol fuel in worlwide
Source of alcohol used as fuel
- Alcohol is good automobile fuel due to its high fuel value
- Alcohol obtained from petrochemical process
- Crops like sugar cane, sugar beet and cassava used to derive ethanol
- Serves as an octane-enhancer in automobiles, used sometimes singly or mixed with petroleum
Brazil- alcohol termed as green petrol and has been a gran success, due to its usage pollution minimized
Germany - automobile engines partially modified to run with alcohol
America & Sweden - lignocellulosic material is being suitably striped off the lignin content, free cellulose converted into alcohol
Some oil companies in US using 20% ethanol in the alcohol mixture and plan to increase alcohol proportion more to have 'clean air'
Sugar baggase(waste) - good source of alcohol production by treating it with thermophilic-alkalophilic bacterium- isolated from white ant mound by microbiology department
In search of cheaper alcohol source - lignocellulosic wastes are used from sugarcane bagasse & banana peels
lignocellulosic materials involve in delignification of cellulosic biomass through action of lignin degrading fungus, Phaenerchetae