2.3 Enrichment, isolation, and cultivation of bacterial strains from crude oil and corrosion-scale samples
Half a milliliter of each crude oil sample or 1.0 g of the corrosion-scale sample was added to 20 ml of SPYSw and YPSw media, and cultivated at 25°C for 3 weeks. Each of the resultant cultures was diluted 40-fold in the same medium, and cultivated again for 3 weeks. This procedure was repeated several times. Finally, each of the enriched cultures was streaked on 1.5% (w/v) agar slants of the same medium, and cultivated anaerobically for 7 days to isolate a single colony.