Carbon preference index (CPI) of long-chain n-alkanes preserved in surface soil increases gradually from southeastern China to the north margin of Loess Plateau.Along this latitudinal transect,the CPI value correlates...Carbon preference index (CPI) of long-chain n-alkanes preserved in surface soil increases gradually from southeastern China to the north margin of Loess Plateau.Along this latitudinal transect,the CPI value correlates to relative humidity,precipitation,and temperature with a negative linear relationship,respectively,whereas the correlation of CPI to temperature is relatively weak.In the Wuyi,Shennongjia,and Tianshan Mountains,CPI values do not change systemically with altitude increasing (or temperature decreasing).However,mean value of CPI for the individual mountain increases in turn from the humid mountain to the arid.These results jointly suggest that aridity (or humidity) is a dominate climate factor in altering soil CPI value.High CPI values of geological records therefore indicate the arid paleoclimate.Though long-chain n-alkanes in soil are derived mainly from leaf wax of terrestrial vascular plants,the regular latitudinal variations of soil CPI might not be caused by the change of vegetation.We speculate that increased long-chain n-alkanes from microbes and/or enhanced biodegradation in the humid climate lead to the decrease of soil CPI.展开更多
通过富集分离筛选高效长链烷烃降解菌,采用形态学、生理生化实验、16S r DNA序列比对进行菌种鉴定,通过UV和GC-MS检测菌株对长链烷烃降解特性。结果表明:分离到1株长链烷降解烃菌,经鉴定为希瓦氏菌属,命名为Shewanella sp.LZ02。该菌生...通过富集分离筛选高效长链烷烃降解菌,采用形态学、生理生化实验、16S r DNA序列比对进行菌种鉴定,通过UV和GC-MS检测菌株对长链烷烃降解特性。结果表明:分离到1株长链烷降解烃菌,经鉴定为希瓦氏菌属,命名为Shewanella sp.LZ02。该菌生长温度范围0~45℃,最适生长温度35℃,在接种量为106CFU/m L,原油浓度为0.5%(W/V),振荡培养7 d时,降解率可达62.90%。GC-MS分析表明:石油中长链烷烃C15~C21被完全降解,C22~C32部分降解,降解方式为单末端氧化。展开更多
基金supported jointly by National Natural Science Foundation of China (Grant No. 41103001)Knowledge Innovation Program of Chinese Academy of Sciences (Grant Nos. KZCX2-YW-Q1-15,KZCX2-YW-Q1-03)
文摘Carbon preference index (CPI) of long-chain n-alkanes preserved in surface soil increases gradually from southeastern China to the north margin of Loess Plateau.Along this latitudinal transect,the CPI value correlates to relative humidity,precipitation,and temperature with a negative linear relationship,respectively,whereas the correlation of CPI to temperature is relatively weak.In the Wuyi,Shennongjia,and Tianshan Mountains,CPI values do not change systemically with altitude increasing (or temperature decreasing).However,mean value of CPI for the individual mountain increases in turn from the humid mountain to the arid.These results jointly suggest that aridity (or humidity) is a dominate climate factor in altering soil CPI value.High CPI values of geological records therefore indicate the arid paleoclimate.Though long-chain n-alkanes in soil are derived mainly from leaf wax of terrestrial vascular plants,the regular latitudinal variations of soil CPI might not be caused by the change of vegetation.We speculate that increased long-chain n-alkanes from microbes and/or enhanced biodegradation in the humid climate lead to the decrease of soil CPI.
