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 Azospirillum 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 ℃ 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 flu-orenthene but not pyrene. The removal of phenanthrene, fluorenthene or pyrene is enhanced by adding strain PE 1501-1 in sterile soils.%研究了一株固氮螺菌属(Azospirillum)的菲降解菌PE1501-1在不同培养条件(温度、初始pH值、菲初始浓度、共基质)下的生长特性,并初步考察了该菌株在液体培养基和土壤中对4环PAHs-荧蒽和芘的潜在降解能力.结果表明,在含菲50 mg/L的无机盐液体培养基中,该菌株的最适生长温度为30C；偏酸性环境更有利于菌株生长,液体培养基初始pH5.0时菌株生长最好；该菌株能耐受菲的初始浓度超过200 mg/L,但菲初始浓度较高时菌株生长出现较明显的延迟期；添加乙酸、溶解性富里酸或溶解性胡敏酸作为菲的共基质对菌株生长有短暂的促进作用；在液体培养基中菌株能以菲或荧蒽为唯一碳源和能源充分生长,并对荧蒽有一定程度的去除能力,但对芘的降解能力很低；将该菌株接种到灭菌污染土壤中,可有效提高菲、荧蒽或芘的去除效果.
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