The effects of different culture conditions including temperature

pH

initial phenanthrene concentration and cosubstrates on the growth of a phenanthrenedegrading strain PE15011 affiliated to the genus 〖WTBX〗Azospirillum〖WTBZ〗 were studied. The potential degradation of fluoranthene and pyrene by strain PE15011 in liquid culture medium or soil microcosm were investigated. The strain shows better growth under slightly acid culture conditions. Optimal temperature and pH are as 30 °C and 5.0 respectively in a mineral salts liquid medium with phenanthrene at 50 mg/L as the sole substrate. The strain is able to tolerate higher initial phenanthrene concentration than 200 mg/L

while an obvious lag phase is observed when the strain is exposed to high initial phenanthrene concentration. The growth of strain PE15011 is transitorily enhanced by the individual addition of acetic acid

dissolved fulvic acid or dissolved humic acid as the cosubstrate of phenanthrene. Strain PE15011 is able to grow in liquid culture media by utilizing phenanthrene or fluorenthene as the sole carbon and energy source with the potential to degrade fluorenthene but not pyrene. The removal of phenanthrene

fluorenthene or pyrene is enhanced by adding strain PE15011 in sterile soils.