Vacuum distillation residue upgrading by an indigenous Bacillus cereus

Background: biological processing of heavy fractions of crude oils offers less severe process conditions and higherselectivity for refining. biochemical processes are expected to be low demand energy processes and certainlyecofriendly.results: a strain of biosurfactant producing bacterium was isolated from an oil contaminated soil at tehran refinerydistillation unit. based on selected phenotypic and genotypic characteristic including morphology, biochemicalproprety, and 16 srrna sequencing identified as a novel strain of bacillus cereus (jq178332). this bacterium enduresa wide range of ph, salinity and temperature. this specific strain utilizes both paraffin and anthracene as samples ofaliphatic and polycyclic aromatic hydrocarbons. the ability of this bacterium to acquire all its energy and chemicalrequirements from vacuum distillation residue (vr), as a net sample of problematic hydrocarbons in refineries, wasstudied. sara test astm d4124-01 revealed 65.5% decrease in asphaltenic, 22.1% in aliphatics and 30.3% inaromatics content of the vr in msm medium. further results with 0.9% saline showed 55% decrease in asphaltenecontent and 2.1% aromatics respectively.conclusion: remarkable abilities of this microorganism propose its application in an ecofriendly technology toupgrade heavy crude oils.