title: Biosynthesis and physicochemical characterization of a bacterial polysaccharide/polyamide blend, applied for microfluidics study in porous media.
abstract: Screening among some new isolated bacteria from oily samples, which were capable of producing extracellular polymeric substances (EPSs), one was selected and identified as Bacillus sonorensis. An efficient micro-total analysis approach was carried out to assay the produced EPSs by this bacterium. Sucrose and yeast concentrations as carbon and nitrogen sources, respectively, sodium salt concentration and initial pH were selected to be the variables in experimental design. Production of EPS in optimal condition was increased by 5.3 times. Further EPS purification was carried out to identify the biopolymers. The bacteria produced high molecular weight biopolymers with a number average molecular weight (M̅n) of 9.1×106g/mol determined by gel permeation chromatography (GPC). Biopolymer characterization demonstrated the biosynthesis of both polysaccharides and polyamides by the bacteria. For the biopolymer blend, thermal properties and morphological characteristics were studied using simultaneous differential scanning calorimetric and thermal gravimetric analyses (DSC/TGA) and field emission scanning electron microscope (FESEM) analyses. Finally, the biopolymer blend was injected into an oil saturated glass micro model to study the enhancement of oil recovery by biopolymer flooding in contrast with water flooding. It was found that oil recovery increased by 36%, from 23% using water flooding to 59% for biopolymer injection.
authors.affiliation: Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran. Electronic address: Maryam.ijadi@modares.ac.ir.
authors.forename: Maryam Ijadi
authors.initials: MI
authors.lastname: Bajestani
authors.affiliation: Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran. Electronic address: mousavi_m@modares.ac.ir.
authors.forename: Seyyed Mohammad
authors.initials: SM
authors.lastname: Mousavi
authors.affiliation: Petroleum Engineering Group, Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran. Electronic address: ajafari@modares.ac.ir.
authors.forename: Arezou
authors.initials: A
authors.lastname: Jafari
authors.affiliation: Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran.
authors.forename: Seyed Abbas
authors.initials: SA
authors.lastname: Shojaosadati
mesh_terms: D001407:Bacillus / Q000302:isolation & purification* / Q000378:metabolism; D055598:Chemical Phenomena; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D009757:Nylons / Q000737:chemistry*; D010316:Particle Size; D010578:Petroleum / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000737:chemistry*; D016062:Porosity; D012212:Rheology; D014867:Water / Q000737:chemistry
chemical_list: D009757:Nylons; D010578:Petroleum; D011135:Polysaccharides, Bacterial; D014867:Water
keywords: Bacillus sonorensis; Enhanced oil recovery; Physicochemical properties; Polysaccharide/polyamide blend