Abstract
As a first step of our study, enrichment culture was carried out to cultivate microorganisms for microbial enhanced oil recovery. 49 samples were collected from places, like agricultural fields, small rivers running through cities and oil fields, where organic matters and/or hydrocarbons were thought to be present. As a result, 41 and 3 out of 49 samples cultivated enrichment cultures with the use of kerosene as substrates at 30 and 50°C respectively.
The growth rate, and the pH and the interfacial tension as representatives of the function of bacteria were used for selection, and 9 enrichment cultures were selected: Two for large increase of cell number, three for decrease of pH, two for low IFT and two for thermostable metabolism at 50°C.
As the influence of salinity, no growth was found at 5% salinity, though 8 out of 9 cultures grew at 2% salinity.
