Biochemical Processes of Oil Degradation

Bio chemical Processes of inunct Degradation1. INTRODUCTIONSurfactants atomic number 18 surface active compound that go down the interfacial tension between deuce liquids, or that between a liquid and a solid. Surfactants be organic compound that contain twain hydrophobic (head part of the surfactant) and deliquescent (tail part of the surfactant) moieties. Thus surfactant contains both water insoluble i.e. water repellent group as intumesce as water soluble i.e. water loving group. Biosurfactants ar excessively surface active compound worry chemical surfactants but foreign the chemical surfactant, biosurfactant be synthesized by microbes like bacteria, fungi and yeast. Biosurfactants comprise the properties of move surface tension, stabilizing emulsions, promoting frothing and are usually non-toxic and biodegradable. Recently raise in biosurfactant has increased because of its diversity, flexibility in operation, and more eco-friendly then chemical surfactant (BS Saha ran et al., 2011 Eduardo J. gudina et al., 2011).Biochemical processes of crude colour humiliation carried out by microbes involves several fount of enzymatic re legal actions driven by oxygenase, dehydrogenase and hydroxylase (Hamamura N et al., 2008). These enzymes cause aliphatic and aromatic hydroxidation, oxidative deamination, hydrolysis and other biochemical mutation of original anele color substance leading to formation of large way out of intermediate degradation outputs. However, a major limitation of microbial degradation of rock cover crude is its hyydrophobicity. Biosurfactant produced by oil contaminating bacteria accelerate the uptake of crude oil hydro coulombs by bacterial cells and similarly view wiped out(p) toxicity and extravagantly biodegradability (Batista SB et al., 2006). So, crude oil degrading bacteria with the ability to produce biosurfactant is widely recommended for fast degradation of crude oil. (Kumar M et al., 2006).Furthermore p ossibility of their production on large scale, selectivity, exercise under intense conditions and their future applications in environmental fortification also these develop been increasingly attracting the attention of the scientific and industrial community. These molecules build a potential to be apply in a variety of industries like cosmetics, pharmaceuticals, humectants, food preservative and detergents (BS Saharan et al., 2011). But the production of biosurfactant on labor level is still challenge because of using high costly unreal media for microbial growth. Biosurfactants are classified on the basis of diversity in their grammatical construction and their microbial origin. They contain a hydrophilic group, that contain an mordant, peptide cations, or anions, mono-, di- or polysaccharides and a hydrophobic group of un sodding(a) or saturated hydrocarbon chains or fat person acerbics. Biosurfactants produced by a variety of microorganisms mainly bacteria, fungi and yeasts are diverse in chemical composition and their constitution and the amount depend on the type of microbes producing a particular biosurfactant.1.1 salmagundi of BiosurfactantBiosurfactants are classified in to both major group maven is low molecular weight surface active agent claim biosurfactant and high molecular weight substance called bio-emulsifier that is especially used as enhancement of emulsification of hydrocarbon. Further these two major group is divided in to six major group know as glycolipids, lipopolysaccharides, lipoproteins-lipopeptides, phospholipids, hydroxylated and cross tie in fatty acids.(a) GlycolipidsMostly biosurfactants are glycolipds. They are lipids with a carbohydrate attached. The participation is by means of either an ether or ester group. Among the glycolipids, the best known are rhamnolipids sophorolipids and trehalolipids.Fig 1 Glycolipid(b) RhamnolipidsRhamnolipids is a group of biosurfactant that studied extensively. These are produc ed by many species of Pseudomonas and welcome tremendous antimicrobial application against several common microorganisms, which is an essential belongings of all cosmetics due to the periodical contamination of the product by the human touch (Lourith N et al., 2009). Rhamnolipids is a type of glycolipid biosurfactant that contain either a one or two molecule of -hydroxyde ignoreoic acid. In 1999 the structure of rhamnolipid produced by P. aeruginosa on mannitol and nepthalene by liquid chromotography was compared. And it was found that for mannitol the most common rhamnolipid contained two rhamnoes and two 3-hydroxydecaonic acid and whereas rhamnolipid produced by nepthalene contained two rhamnoes and one 3-hydroxydecaonic acid.Fig 2 building of mono and di rhamnolipid(c) Trehalolipids It is another type of glycolipids that containing trehalose hydrophobic moieties. Such type of biosurfactant structure is diverse in hydrophobic moieties, varying from short fatty acid to long fa tty acid chain. In general it is observed that the bacteria showing Grams positive produces Trehalolipids biosurfactant (Anderson RJ et al, 1983).Fig 3 social system of Trehalose lipid(d) Sophorolipids Such glycolipids are synthesized by yeast these are the mazy mixture of both free acid and lactone form. The acidic SL contain fatty acid as tail where as SL lactonic are formed by the esterification between carboxylic end of the fatty acid and 4 of the sophorose end. chiefly lactonic SL has better surface tension lowering property whereas the acidic SL encounter better potential to form foam and solubility properties (Nuneza A. et al., 2003).Fig 4 Structure of Sophorolipid lactonized and acid Form.1.2 Lipopeptides and lipoproteinsLipopeptide biosurfactants are cyclic compounds and they are mostly uncaring from Bacillus and Pseudomonas type bacteria Lipopeptides mainly be of hydrophilic peptides, generally they consist 7 and 10 amino acids long, linked to a hydrophobic fatty ac id structure. Bacillus cyclic lipopeptides consist of tercet major groups known as the surfactin, iturin and fengycin families. Surfactin is the most commonly studied and it contains 7 amino acid cyclic sequences connected to a C13C16 fatty acid (Kakinuma A. et al.,1969).Fig 5 Structure of aminolipopetide Fig 6 Structure of cyclic aminolipopetide1.3 Polymeric BiosurfactantsPolymeric biosurfactant are high weight molecular biopolymers which consist polysaccharides, proteins, lipopolysaccharides, lipoproteins or mixture of theses biopolymers. A wide variety of microbes produces polymer biosurfactant. Polymer biosurfactant exhibits properties like high viscosity, tensile strength, and resistance to shear. The following are example of different type of polymeric biosurfactant.1.4 Advantages and Uses of BiosurfactantThe unique properties of biosurfactant (Microbial step to the fore Active Agents) such as low toxicity, relative ease of preparation and widespread applicability, make it d ifferent from chemical semisynthetic surfactant and now it has become recently an important product of biotechnology for industrial and medical applications and they allow to re propertyment of chemical synthetic surfactant. They can be used as emulsifiers, de-emulsifiers, wetting agents, spreadhead agents, foaming agents, functional food ingredients and detergents in various industrial sectors such as, crude and Petrochemicals, Organic Chemicals, Foods and Beverages, Cosmetics and Pharmaceuticals, Mining and Metallurgy, Agrochemicals and Fertilizers, Environmental Control and Management, and many others.Table 1. salmagundi of biosurfactants and their use in remediation of weighty metal and hydrocarbon contaminated locates. (Magdalena Pacwa-Pociniczak et al., 2011)stabilisation of the hydrocarbon-in-water emulsionsDispersion of limestone in waterStabilization of hydrocarbon-in-water emulsionsAlasanAcinetobacter radioresistens KA-53BiodispersanAcinetobacter calcoaceticus A2Lipo sanCandida lipolyticaMannoproteinSaccharomyces cerevisiaeThere are many advantages of biosurfactant as compare to chemically synthesized surfactants.Some of those areBiodegradability well-off to biodegradable as compare to the chemical surfactant (Kosari N, 1992).Low toxicityBiocompatibility and digestibility, that allows their application in cosmetics, pharmaceuticals and food seasonings.Easily availability of raw somatic The raw material need for production of biosurfactant are easily available, biosurfactant producing microorganism can be uninvolved from the industrial waste like oil contaminated blur, petrol pump vomited, and also can be isolated from municipal waste.Use in environmental control Biosurfactants can be efficiently used in handling industrial emulsions, control of oil squishs, biodegradation and lowering the toxicity of industrial discharges and in bioremediation of polluted soil.Specificity in their action, since biosurfactant has particular(prenominal) org anic functional group and often specific in their action. This is especially used in lowering the toxicity of the pollutant, used in enhancing the emulsification property, used as raw material in cosmetic, medicinal and foodstuff applications.1.5 scratchy oil downslopesThe crude oil spills are one of the main environmental pollutants. Their abundance and persistence in several polluted environmental areas have been reported (Mohammed M. A., 2004). fossil oil spillage may be caused by infixed disasters like earthquakes in the sea surface or due to accidental leaks during exploration, refining, storage and transportation. The causes can be numerous but the consequences are the same. In case of crude oil, the different types such as heavy or light crude oil can need the clean-up procedures. unmannered oil spreads precise rapidly on the sea surface and afterwards a short period of time the thickness of the oil film can be at least 1mm. It is therefore necessary to prevent the sp reading to reach the shoreline. Once it reaches the shoreline, it contaminates the soil and cause a great misemploy to the soil ecosystem as well.Some of the largest oil spills that have taken place all over the world are at Iran, Iraq, Persian Gulf, Uzbekistan, Kuwait, unite States, Gulf of Mexico, Pakistan and even in India. The most recent oil spill in India is the spill of ONGC Trunk oil melodic line burst, at Uran, Mumbai on 21st January 2011. Around 40 to 45 metric tons of oil was spilled in Mumbai coast that spread well-nigh 4 sq km area. galore(postnominal) such disasters reported one seeping oil from a drop ship. In August 2010, oil spill at Gopalpur beach Orissa in April 2010 causing the death of many Ridley overturns that breed there during that period. It hence becomes a necessity to clean up this oil in order to merely the shipboard soldier life. Clean-up and recovery of hydrocarbons from an oil spill is difficult and the strategies for cleaning up an oil spill are greatly affected by a variety of factors such as the type of oil spilled, the temperature of the water body, and the types of shorelines and beaches involved. A number of approaches and technologies have been developed for spreading of oil spills in marine shorelines and freshwater environments. many mechanised and chemical methods can be apply to clean-up the spills (Zhu et al., 2001).Fig 7 Crude oil spill1.6 Methods applied in cleaning of oil spills1.6.1 Physical methodsBooms.Skimmers.Manual removal (Wiping).Mechanical removal.Washing. deposition relocation or Surface washing.Tilling.In-situ burning1.6.2 Chemical methodsDispersants.Demulsifies.Solidifiers.Surface film chemicals.Although various conventional cleaning methods such as physiological methods like the first response selection, rarely achieve complete putting to death of oil spills. According to the Office of Technology Assessment (U.S. Congress, 1991), current mechanical methods typically recover no more than 10 -15 percent of the oil after a major spill. Chemical methods are faster in action but they are toxic to the biota present in the spill environment. Bio-surfactants can be used for cleaning of crude oil spillage.1.7 Hydrocarbons of Crude oil crudes are further categorized into troika broad groups, concord to their molecular weight. General statements can be made for each of the three categories namely light weight, medium weight, and heavy weight components (Scholz et al., 1999). Crude oils are composed of various combinations of these three categories with the following general characteristics.1.7.1 Light freight ComponentsThese are components which have carbon atoms ranging from C1 to C10 which are smaller molecules with few verse of atoms. They are characterized by high volatility, right away dissolvable and evaporate and quit little or no residue because of their short residence time. Many of these components (e.g., benzene, and toluene) are thought to be more bioavailable to sentient beings by primary icon route (respiratory system). Being highly flammable and readily inhaled, and therefore are of concern for human health and safety.1.7.2 Medium Weight ComponentsThese are components which have carbon atoms ranging from C11 to C22 which have complex molecules. It has low rate of evaporation and dissolves very slowly that take several days with some residue remaining. non as bioavailable as lower weight components, it is less likely to affect aquatic animals. Its primary impression route is respiratory system and gets readily absorbed through skin.1.7.3 Heavy Weight ComponentsThese are components which have carbon atoms more than C23. It has the longest residence time with very little sack due to evaporation or dissolution. It can cause chronic resolution through smothering as residue in the water mainstay and sediments (tarballs, etc). Its primary exposure route is direct topical contact. Some heavy weight components contain carcinogens that ar e absorbed through the skin. Its risk of exposure is increased due to long residence time, probability of contact, and adsorption property of the oil components.Table 2 List of oil spill incidents since 20101.8 Oil Spills and Their EffectsRecently on 21st January 2011, ONGC trunk oil pipeline burst at Uran, Mumbai. About 40 to 45 metric tons of oil was spilled and spread around 4 sq km area. On seventh August, 2010 a foreign cargo ship, collided with another vessel about 10 km off Mumbai harbor, that spilled the oil in spite of the hectic put in made by Navy and Coast Guard to contain the leak, around 700 tons of fuel oil and 28 tons of diesel oil was spilled. Thousands of eggs of the endangered Olive Ridley Turtles on the beach adjoining river Rushikulya in Ganjam district have failed to hatch this division because of the recent 924 tons of furnace oil spill at a nearby port. Rushikulya Sea turtle rampart committee have found that the hatching of the eggs, which ended last week, have gone down by 40 to 50 percent this year as the eggs, numbering thousands, got spoiled after the leaked oil soaked the nesting site on the beach. A number of incidents have been reported happening each year. Some of the oil spill incidents are listed in the Table 2.Oil spills kill wildlife and scathe the ecosystem that can last for generations by forcing changes in facts of life and compromising complex food webs. Oil spill damage to the waterways of birds and animals, destroys the animal immune systems, interrupt breeding and fouling of breeding grounds. Besides, they thin bird and turtle egg shells and also damage the fish larvae, causing deformities. They cause damage to sea grass beds and other shelter/feeding areas, tainting of algae, which perform a vital role in waterway ecosystems.Due to oil spill on soil the insects and worms living in it are killed due to hydrocarbon toxicity, deprivation of oxygen supply and it reduce the pH of the soil. This affects the fertilit y of soil and its productiveness in terms of the growth of plants (Wokocha G.A., 2011). As a result soil eco system is getting disturbed and it effects the plant growth. Soil oil also contaminates ground water and it causes illness to the human beings and animals when consumed.