Venkateswaran K, Harayama S
Marine Biotechnology Institute, Kamaishi Laboratories, Iwate, Japan.
Can J Microbiol. 1995 Sep;41(9):767-75. doi: 10.1139/m95-106.
The distribution of oil-degrading bacteria in the coastal water and sediments of Hokkaido, Japan, was surveyed. The potential of mixed microbial populations to degrade weathered crude oil was not confined to any ecological components (water or sediment) nor to the sampling stations. One microbial culture that was stable during repeated subculturing degraded 45% of the saturates and 20% of the aromatics present in crude oil in 10 days during the initial screening. The residual hydrocarbons in this culture were extracted by chloroform and dispersed in a fresh seawater-based medium and subsequently inoculated with microorganisms from the first culture. After full growth of the second culture, the residual hydrocarbons were again extracted and dispersed in a fresh medium in which microorganisms from the second culture had been inoculated. This sequential process was carried out six times to enrich those microorganisms that grew on the recalcitrant components of crude oil. After repeated exposure of the residual crude oil to the enriched microorganisms, about 80% of the initially added crude oil was degraded. The cultures obtained after each enrichment cycle were kept, and the degradation of fresh crude oil by the enriched microorganisms was examined. The degradative activity of the enriched cultures increased as the number of enrichment cycles increased. A microbial population that had been selected six times on the residual crude oil could degrade 70% of the saturates and 30% of the aromatics of crude oil. Thus, growth of a microbial population on residual crude oil improved its ability to biodegrade crude oil.
对日本北海道沿海水域和沉积物中的石油降解细菌分布进行了调查。混合微生物群体降解风化原油的潜力并不局限于任何生态组分（水或沉积物），也不局限于采样站。一种在反复传代培养过程中稳定的微生物培养物，在初始筛选期间，10天内降解了原油中45%的饱和烃和20%的芳烃。该培养物中的残留烃用氯仿萃取，分散在新鲜的海水基培养基中，随后接种来自第一种培养物的微生物。第二种培养物充分生长后，再次萃取残留烃并分散在接种了来自第二种培养物的微生物的新鲜培养基中。这个顺序过程进行了六次，以富集那些能在原油难降解组分上生长的微生物。将残留原油反复暴露于富集的微生物后，约80%的初始添加原油被降解。保存每次富集循环后获得的培养物，并检测富集微生物对新鲜原油的降解情况。随着富集循环次数的增加，富集培养物的降解活性增强。在残留原油上经过六次筛选的微生物群体能够降解原油中70%的饱和烃和30%的芳烃。因此，微生物群体在残留原油上的生长提高了其对原油的生物降解能力。
