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Abstract
INTRODUCTION
Wastewater treatment was the most important problem in recent years. Thus, advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of heavy metals and petroleum hydrocarbons (Puntambekar and Ranjeker, 1989 and Mezzanotte, 2002). By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Microbes may be exploited to break stable oilfield emulsions to produce pipeline quality oil. Molecular approaches are being used to broaden the substrate specificity and increase the rates and extents of desulfurization. Bacterial processes are being commercialized for removal of H2S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Thus, new strains of Bacillus were presented that produce lipase and other enzymes for the degradation of oleaginous materials such as fats, greases and cooking oils, and protease enzymes to degrade proteins. This novel strain and the enzymes produced thereby have a number of applications, including wastewater treatments, agricultural uses, laundry and dish detergents, drain cleaners and spot removers, among others (Kozo et al., 1979; Raquel et al., 2007 and Reshma et al., 2007).
Novel mutant strain Pseudomonas fluorescens 3P has been found to be capable of degrading and removing anionic and/or non-ionic surface active agents, detergents and like materials. Thus, this mutant could be cultured in wastewater from any type of industrial plant containing anionic and/or non-ionic surface active agents. The mutant strain of this invention can be employed in ion exchange resin treatment systems, in tricking filter systems, in carbon adsorption systems, in activated sludge treatment systems, in outdoor lagoons or pools, etc. (James, 2006). Molecular biology technique presented a huge helpful for wastewater treatment, Wikstrom (2002) demonstrated that microbial community changes over time in a nitroaromatic-contaminated groundwater upon amendment with hydrocarbons previously unknown to the microbial community (extrinsic) and hydrocarbons previously known to the microbial community (intrinsic).
Microbial growth, biodegradation, and community structure changes measured by random amplified polymorphic DNA (RAPD) and quantitative PCR (qPCR) targeting catechol-2,3-dioxygenase (C23O) genes were monitored over time. All amended substrates were biodegraded after both substrate amendments except for 2,4-DNT, which was only partially degraded after the second amendment. Unique microbial communities were developed in flasks amended with phenol, benzoic acid, and naphthalene. In addition protoplast fusion technique was applied for enhancement heredity desirable genotype between different bacterial genera. Kanevski et al. (1983) carried out hybridization by fusion between protoplasts of A. tumefaciens and different Pseudomonas sp. All the eight strains which selected on screening media were true chromosomal hybrid and heredity tumor formation as a character of A. tumefaciens, but nine strains which were selected by