Biodegradation of a polymeric material is chemical degradation brought by the action of naturally occurring microorganisms such as bacteria and fungi via enzymatic action into metabolic products of microorganisms e. Synthetic plastics are emerging environmental contaminants that have been found to accumulate within marine waters worldwide. The term biodegradation is often used in relation to sewage treatment, environmental remediation bioremediation and to. Ex plastics have high chemical resistances due to their excessive molecular size for biodegradation. A new test method for determining biodegradation of plastic. Microbial biodegradation and bioremediation 1st edition.
Environmental issues bacteria health aspects biodegradation methods enzymes microorganisms environmental aspects. Biodegradation and mineralization of polystyrene by. Environmental issues bacteria health aspects biodegradation methods enzymes microorganisms environmental aspects usage plastics polymers. Plastics, micro organisms, biodegradation, degradation, metagenomics introduction the current rate of global use of polyethylene and plastic product is approximately 12% per annum, and this continues to rise. Biodegradable plastics are materials designed to degrade under environmental conditions or in municipal. Final analysis showed that alkanolamine concentrations were reduced to levels below the det ection limit following treatment, from an initial concentration of 15,000 mgkg.
Microbial biodegradation of polyurethane plastics a thesis submitted to the university of manchester for the degree of master of philosophy in the faculty of biology, medicine and health 2017 mohd naqiuddin mohd zairi school of biological sciences. Bioremediation for degradation of marine plastic waste. Prospects for microbiological solutions to environmental. The conditions described in this standard do not necessarily correspond to the optimum conditions for the maximum degree of biodegradation to occur. The biodegradation of polythene bags was significantly higher up to 4. Biodegradable plastics are materials designed to degrade under environmental conditions or in municipal and industrial biological waste treatment facilities, and thus open the way for new waste management strategies 9. Biodegradation of synthetic and natural plastic by. A number of microorganisms have the ability to degrade different types of plastic under suitable conditions, but due to the hardness of these polymers and their nonsolubility in water, biological decomposition is a slow process. Polythene and plasticdegrading microbes in an indian mangrove soil.
Biodegradation of synthetic and natural plastic by microorganisms. Evaluation of the polymers and plastics biodegradation rate and mechanism by the most promising microbial cultures and enzymes. The microbial biodegradation has been at accepted and process still underway for its enhanced efficiency. Biodegradation and mineralization of polystyrene by plastic. It is arranged in a logical way to facilitate the decisionmaking process for selecting biodegradation as a remediation option.
Degradation of plastics and plasticdegrading bacteria in cold. Usage of certain microorganisms and enzymes to degrade polymers are classified as the biodegradation method of polymers. Microbial degradation of pu is dependent on the many properties of the polymer such as molecular orientation, crystallinity, crosslinking and chemical groups present in the molecular chains which determine the accessibility to degradingenzyme systems. The program makes use of excel 2007 files to store identification.
The different types of microbes degrade different groups of plastics. Plastics are typically composed of artificial synthetic polymers. Through biodegradation, bacteria and fungi can convert these highly inert synthetic polymers to simpler compounds. This singlesource reference encompasses all categories of pollutants and their applications in a convenient, comprehensive package. The biodegradation level is evaluated by determining the carbon dioxide co2 production released by the test reactors.
Isolated microbes in the degradation of plastics were analyzed in liquid. A new test method is described for assessing biodegradation of plastic material under simulated soil conditions. Environmentally degradable plastics based on oxobiodegradation of conventional polyolefins norman c billingham1, emo chiellini2, andrea corti2, radu baciu3 and david m wiles4 1 department of chemistry, university of sussex, brighton, bn1 9qj, uk, and epi europe ltd. Isolation of biodegradable plastic degrading bacteria from deep sea. Identification and selection of microorganisms and enzymes capable of degrading petroleumbased plastic wastes polyolefines, polystyrene, polyvinyl chloride i. Libro dorf svoboda pdf biodegradation of a plastic awtm a highsolids anaerobic digestion unit is an important phenomenon because it will affect the decomposition of other waste materials enclosed by the plastic and the resulting quality and appearance of the digestate after an anaerobic digestion x5511. Due to plastics resilience against degradation and its. Biodegradation is carried out by microorganisms bacteria and fungi that naturally live in the environment. Plastic waste or debris are one of the most hazardous pollutant entering the seas and oceans, after oil spills and sewage discharge. Environmentally degradable plastics based on oxo biodegradation of conventional polyolefins norman c billingham1, emo chiellini2, andrea corti2, radu baciu3 and david m wiles4 1 department of chemistry, university of sussex, brighton, bn1 9qj, uk, and epi europe ltd. In marine environments, microorganisms function as pioneering surface colonizers and drive critical ecosystem processes including primary production, biogeochemical cycling and the biodegradation of anthropogenic pollutants.
By harnessing these natural forces of biodegradation, people can reduce wastes and clean up some types of environmental contaminants. Isolation and testing of polyethylene degrading microorganisms. Biodegradable plastics plastics that will fully decompose to carbon dioxide, methane, water, biomass and inorganic compounds under aerobic or anaerobic conditions and the action of living organisms. Natural plastics are made from plant and animal sources, or produced by a range of microorganisms, must be introduced. The extracellular enzymes secreted by microorganisms depolymerize the cell wall components. The use of microorganisms for bioremediation of pahcontaminated environments seems to be an attractive technology for restoration of polluted sites. Biodegradation of oilbased plastics in the environment. Some types of plastics have been shown to be biodegradable, and their degradation mechanisms have progressively become clearer.
Furthermore, this aids in removal of the contaminants from the environment and prevent them from entering the. Involvement of microorganisms for degradation of plastics the microorganism s role is very important for plastic degradation. Degradable polymers that are naturally degraded by the action of microorganisms such as bacteria, fungi and algae. The level of biodegradation of ldpe sheets with bacterial and fungal inoculums from different sampling. Present paper investigates the possibility of plastic degradation by microbes. Generally, the biodegradation of plastic by microorganisms is a very slow process, and some microorganisms cant degrade certain plastics 8. Microbial degradation of lowdensity polyethylene ldpe. Bacteria are single celled organisms that dominate in soils.
Gentamicinfeeding mealworms lost the ability to depolymerize ps and. This knowledge is useful for the molecular design of biodegradable polymers and for the molecular evolution and breeding of degradation enzymes and microbes. Biodegradable plastics produced by microorganisms author. Biodegradation and valorization pathways for petroleumbased. Environmental and biotechnological perspectives on. Materials decompose differently in compost, soil, landfill, fresh or. Efficiency of biodegradation it is important to understand that the process of biodegradation is not 100% efficient, that is, the degradation of the polymer can rarely reach 100%.
Table showing different microbes and their plastic degrading efficiencies. This process refers to the degradation and assimilation of polymers by living microorganisms to produce degradation products. The role of gut bacteria of mealworms the larvae of tenebrio molitor linnaeus in polystyrene ps degradation was investigated. In comparison, biodegradable plastics are made from renewable resources that are completely biodegrade in their natural forms, such as components of living plants, animals and algae as source of cellulose, starches, protein and algal materials. Their structure is not naturally occurring, so plastics are not biodegradable. Pdf file of the complete article 857k, or click on a. Plastic bags are made from polyethylene pe which is a polymer consisting of.
Pyrolysis enables plastics to be degraded through reducing their molecular size to short biodegradable fragments. Result of degradation of plastic sample by bacteria after 1 month. As observed in several experiments, even though complete degradation of plastics by microorganisms is not possible. Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Biodegradation is defined as reduction in the molecular weight by naturally occurring microorganisms such as bacteria, fungi, and actinomycetes. Although many studies reported on their potential biodegradation by microbes in and from terrestrial environments, very little is known about the biodegradability of these plastics in freshwater systems and only recently more reports on their biodegradation by marine microorganismsin marine environment were made available. Review on the current status of polymer degradation. Biodegradation refers to the physical or chemical changes induced in a material by any environmental factor such as light, moisture, heat or wind along with biological agents such as bacteria or fungi. Knowledge on the total amount and distribution of plastics in the marine environment is extremely limited. An inert substrate can be activated with soil extract and nutrient and used in place of soil in biodegradation tests. Generally, the biodegradation of plastic by microorganisms is a very slow process, and some microorganisms cant degrade certain plastics. Biodegradation is expected to be the major mechanism of loss for most chemicals released into the environment. Biodegradation of plastics by microorganisms is more widely spread in. Constraints introduction plasticmaterials occupya specificpositioninthe spectrumof anthropogenic chemicals of environmental concern.
The biodegradation of pahs can be considered on one hand to be part of the normal processes of the carbon cycle, and on the other as the removal of manmade pollutants from the environment. Much interest is generated by the degradation of existing plastics using. Biodegradation from wikipedia, the free encyclopedia yellow slime mold growing on a bin of wet paper iupac definition degradation caused by enzymatic process resulting from the action of cells. Bacterial degradation of synthetic plastics explore to. Request pdf biodegradation of synthetic and natural plastic by microorganisms plastic disposal is one of the greatest problems facing the. Microbial enzymes induce the rate of biodegradation of ldpe very effectively without causing harm to the environment. Biodegradation and valorization pathways for petroleum. Polythene and plasticdegrading microbes in an indian. Microorganism as plastic biodegradation agent towards sustainable environment. The scope of this field guide is limited to aerobic biodegradation, also known as landfarming or land treatment, of oilcontaminated soils. Through composting, we accelerate natural biodegradation and convert organic wastes to a valuable resource. These studies on the biodegradation of plastics have increased our knowledge of degrading microbes, degradation enzymes and their genes, and polymer structures for biodegradation.
Among the three processes, biodegradation is the most environmental friendly process 5. Final report exploring the potential of native microbial. The mechanism of biodegradation of plastic involves biodeterioration, biofragmentation, assimilation and mineralization. Microbial counts in the degrading materials were recorded up to 79. Although many studies reported on their potential biodegradation by microbes in and from terrestrial environments, very little is known about the biodegradability of these plastics in freshwater systems and only recently more reports on their biodegradation by marine microorganisms in marine environment were made available. Biodegradation of polyalcohol ethoxylate by a wastewater microbial consortium.
Bioplastics produced by microorganisms iman rusmana department of biology bogor agricultural university. A typical biodegradation workplan can be found in appendix a. Microbial degradation of plastics means breaking down plastic polymers into its monomers and oligomers by microorganisms. A new test method for determining biodegradation of. Biodegradation of this plastic has been poorly explored, and most of. A comparative study of commercially available plastic. A single teaspoon of soil can contain between 1 million to 1 billion bacterial cells. Biodegradation refers to the process of chemical breakdown of a substance due to the action of living organisms. Generally, it is the action of microorganisms present in soil, water or special environments such as compost heaps that is responsible for biodegradation. Isbn 9789535111542, pdf isbn 9789535163503, published 20614. The extracellular enzymes are too large to penetrate deeply into the polymer material, and so, act only on the polymer surface, consequently the biodegradation of plastics is usually a surface erosion process. Microorganism as plastic biodegradation agent towards.
Biodegradable plastics are materials designed to degrade under environmental conditions or in municipal and industrial biological waste treatment facilities, and. Feb, 2016 microbial enzymes induce the rate of biodegradation of ldpe very effectively without causing harm to the environment. Gentamicin was the most effective inhibitor of gut bacteria among six antibiotics tested. Gut bacterial activities were essentially suppressed by feeding gentamicin food 30 mgg for 10 days. Wastewater treatment also accelerates natural forces of biodegradation. They can also be produced by a range of microorganisms 14.
Plastic can degrade by a variety of mechanisms such as chemical, thermal, photoxidation and biodegradation, all of which take an extremely long time depending on the molecular weight of polymer, it could take up to years for some types of plastics to degrade microorganisms can also play a vital role in this process, as over 90 genera of bacteria, fungi and actinomycetes have the. Pdf plastics are polymers of higher molecular mass of synthetic or. Biodegradability of polyethylene by bacteria and fungi from. Microbial degradation of lowdensity polyethylene ldpe by. Microbial biodegradation and bioremediation brings together experts in relevant fields to describe the successful application of microbes and their derivatives for bioremediation of potentially toxic and relatively novel compounds. Pdf degradation of plastic materials using microorganisms. This standard specifies a method for the determination of the ultimate anaerobic biodegradability of plastics by anaerobic microorganisms. In the previous article, bioremediation processes involved in treatment and removal of oil hydrocarbon pollutants was discussed. This singlesource reference encompasses all categories of pollutants and their applications in a convenient. These fungi secrete enzymes and other cofactors to degrade a wide variety of chemicals. Lignin is the material found in woody plants and it makes 2030% of wood. Nevertheless, there are many factors affecting the efficiency of this process and risks associated to the use of gem in the field.
Moreover, we highlight the advantages of microorganisms isolated from this environment for eliminating plastic waste from ecosystems. Table 2 shows the list of microorganisms and their plastic degrading efficiencies. Recent work has included studies of the distribution of synthetic polymerdegrading microorganisms in the environment, the isolation of. Degradation of plastic materials using microorganisms openventio. Biodegradation is the decomposition of organic material by microorganisms. Most of the biodegradation studies on plastics are being carried out using microorganisms. Microbial biodegradation is the use of bioremediation and biotransformation methods to harness the naturally occurring ability of microbial xenobiotic metabolism to degrade, transform or accumulate environmental pollutants, including hydrocarbons e. Plastic is a general term used for a wide range of high molecular weight organic polymers obtained mostly from the various hydrocarbon and petroleum derivatives. Discarded plastics, besides being highly visible are a rapidly increasing percentage of solid waste in landfills, resistant to biodegradation leading to pollution, harmful to the natural environment.