Bioremediation of n-hexadecane by mixed culture TN-4 and pure culture Rhodococcus erythropolis NTU-1
Date Issued
2005
Date
2005
Author(s)
Lin, TzeKhai
DOI
zh-TW
Abstract
Petroleum is one of the world’s major resources of energy. Nevertheless, continual exploitation of petroleum hydrocarbon has severely polluted our environment and threatened the well being of human life. The major purpose of this research was to investigate n-hexadecane biodegradability and bioflocculate formation performed by a mixed culture TN-4 and a pure culture Rhodococcus erythropolis NTU-1. Two key abiotic factors (1) n-hexadecane concentration and (2) initial acidity of culture medium, were altered to carry out the research work.
It was discovered that the growth of TN-4 increased as the concentration of n-hexadecane rises even though the alkane consumption ability performed was fairly alike especially under high substrate concentration. However, both growth and biodegradability of NTU-1 was not affected for culture under different concentration of n-hexadecane. In addition, TN-4 and NTU-1 attained the best alkane removal efficiency when the initial acidity of culture medium was adjusted to pH 7.5. Both strains successfully removed almost 100% of n-hexadecane (up to 1470 ppm) after incubation for 66 hours.
The bioremediation process was accompanied by formation of bacterial pellets (bioflocculate), with size ranging from 0.1 to 2 cm in diameter. This flocculation mechanism had provided high removal efficiency as most of the residual n-hexadecane was engulfed by the bacterial pellets and being consequently biodegraded. Aggregates formed by TN-4 are yellowish, round in shape and relatively firmer. Aggregates formed by NTU-1 are white in color and much incompact in comparison. Furthermore, it was also discovered that further addition of hexanoic acid into the culture could have possibly modified the surface properties of the cell because the flocs formed during incubation tended to attach to each other furing incubation. Besides that, due to the comparable results shown by these two strains, it was postulated that NTU-1 played a primary role of n-hexadecane degradation as well as bioflocculate formation throughout the process.
Last but not least, development of bioflocculate was non trivial due to its importance in the enhancement of alkane mediation as well as easy removal of suspended solids in wastewater treatment.
Subjects
生物降解
正十六
烷細菌結塊
bioremediation
n-hexadecane
bioflocculate
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-94-R92524091-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):e37416d86796ddeaf1bbb2780e117de7