Systems Environmental Health and Energy Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran.
Infectious Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran.
Biodegradation. 2021 Jun;32(3):327-341. doi: 10.1007/s10532-021-09941-2. Epub 2021 Apr 15.
A halotolerant bacterial strain was isolated from oily-contaminated sites of Persian Gulf, which characterized as Pseudomonas aeruginosa (AHV-KH10) by 16S rRNA gene sequencing. This strain was used for bioremediation of diesel-contaminated sediments. Biosurfactant production was initially screened by using oil displacement test and drop-collapse method, followed by measurement of surface tension (ST) of growth medium. Produced biosurfactant was a rhamnolipid type biosurfactant and lowered the ST to 33.4 mN/m at the given critical micelle concentration (CMC) of 75 mg/L. Addition of 3 CMC rhamnolipid, inoculums size of 15 mL, biodegradation in slurry phase and salinity level of 6% led totally to a diesel biodegradation rate of 70% for initial concentration of 1000 mg/kg after 35 days. The maximum diesel removal occurred at the salinity content of 6% indicating the moderately halo-tolerant characteristics of isolated strain. Evaluation of bacterial growth showed a biomass yield of 0.33 mg /mg in selected conditions. The field performance of Pseudomonas aeruginosa AHV-KH10 was proved through the removal of the TPH content in unwashed sediment, which varied from 2390 to 1875 mg/kg within four months.
从波斯湾含油污染区分离到一株耐盐细菌，经 16S rRNA 基因测序鉴定为铜绿假单胞菌（AHV-KH10）。该菌株用于柴油污染沉积物的生物修复。通过油驱试验和滴陷法初步筛选生物表面活性剂的产生，然后测量生长培养基的表面张力（ST）。所产生的生物表面活性剂是一种鼠李糖脂型生物表面活性剂，在给定的临界胶束浓度（CMC）为 75mg/L 时，将 ST 降低到 33.4mN/m。添加 3CMC 鼠李糖脂、15mL 接种量、在泥浆相中生物降解和盐度为 6%，导致初始浓度为 1000mg/kg 的柴油生物降解率达到 70%，35 天后。最大的柴油去除率出现在盐度为 6%的条件下，表明分离菌株具有中度耐盐特性。细菌生长的评估表明，在选定条件下的生物量产率为 0.33mg/mg。通过去除未清洗沉积物中的 TPH 含量，证明了铜绿假单胞菌 AHV-KH10 的现场性能，在四个月内从 2390 至 1875mg/kg 不等。
