Genetic engineering for trichloropropane degradation
PhD ceremony: Ms. G. Samin, 11.00 uur, Academiegebouw, Broerstraat 5, Groningen
Dissertation: Genetic engineering for trichloropropane degradation
Promotor(s): prof. D.B. Janssen
Faculty: Mathematics and Natural Sciences
A genetically modified organism is constructed by Ghufrana Samin for the degradation of a toxic compound and applied successfully in a lab-scale bioreactor to remove 1,2,3-trichlororpropane (TCP)-contaminated groundwater.
TCP is a toxic compound that has caused serious groundwater pollution at chemical waste disposal sites. The availability of a bacterium that can degrade this compound would allow the development of bioreactors for TCP removal from contaminated groundwater. A possible degradation pathway would start with hydrolytic dehalogenation of TCP to 2,3-dichloro-1-propanol (DCP), followed by further oxidative metabolism. In the first part of her study, Samin isolated a strain of Pseudomonas putida from contaminated soil on basis of its capacity to utilize DCP as growth substrate. To transform TCP into DCP, she expressed an engineered haloalkane dehalogenase (DhaA31) constitutively under control of the dhlA promoter and introduced into the genome of the DCP-degrading bacterium by using a transposon delivery system. The transposon-located antibiotic marker was subsequently removed. Growth of the engineered bacterium on TCP was indeed observed. The genetically engineered TCP-degrading strain is stable, free of any additional plasmid-encoded antibiotic resistance marker and has the ability to completely mineralize TCP with quantitative stoichiometric release of inorganic chloride.
The application of the strain in lab-scale bio-reactors was also investigated by Samin. Her results indicate that with the constructed strains, the reactor removed TCP (80-98%) at various residence times (116 h and 23 h). During the construction of the genetically engineered bacterium, she found that haloalkane dehalogenase was exported to the periplasm even though no signal sequence was present. The results indicate the potential use of DhaA as a tag for the periplasmic export of heterologously expressed proteins.
Last modified: | 13 March 2020 01.01 a.m. |
More news
-
17 July 2024
Veni-grants for ten researchers in Groningen
The Dutch Research Council (NWO) has awarded a Veni grant of up to €320,000 each to ten researchers of the University of Groningen and the UMCG. The Veni grants are designed for outstanding researchers who have recently gained a PhD.
-
15 July 2024
Funding for RUG researchers from National Growth Fund programme Circular Plastics NL
For research on making plastics circular, Professors Patrizio Raffa and Katja Loos together receive about 1.2 million euros from the National Growth Fund programme Circular Plastics NL.
-
09 July 2024
NWO Open Technology funding for improving quality 3D printing technology
Dr. Liangliang Cheng receives a NWO OPT grant of EUR 950,000 for research on safer application of metals in 3D printing technology.