Institute for Sanitary Engineering, Water Quality and Solid Waste ...

Biological Air Purification ALR
di-tert-butylperoxide, di-tert-amylhydroperoxide and
di-tert-butylhydroperoxide for example belong to this
group. The feasibility of biodegradation of these peroxides
occurring as waste air compounds in air streams
generated in the production of these peroxides was
determined in cooperation with consulting engineers.
In literature different peroxidases able to cleave peroxides
in general are described. Most of them are specialised
in the degradation of hydrogen peroxides. Only
some of them like horseradish peroxidase are adapted
for the degradation of organic peroxides. Experimental
studies, focused on the di-tert-butylperoxide, showed
a poor biodegradability of this compound caused by its
low solubility in water and a high sterical shielding of
the ternary carbon atoms.
Development of a capable waste air treatment
concept to fulfill limit values of the TA-Luft 2002
for emissions out of sewage sludge during sludge
dehydration in belt drying systems.
Even though using state of the art techniques and
optimising them, in most cases TA-Luft limit values
cannot be passed. In cooperation with the industrial
partner state of the art techniques were compared and
most promising ones were tested under realistic waste
air conditions. Adapted techniques were identified and
core of further optimisation especially in the view of
temperature effects, condensation effects, maintenance
intervals (quick stops, maintenance stops) and
elimination of odorimetric loadings.
Advisor: Dr.-Ing. D. Dobslaw
Advisor: Dr.-Ing. D. Dobslaw
Independent Studies, Master- and Diploma Thesis
The bacterial degradation of Isophorone
Isophorone is a major product of the chemical industries.
In this work bacterial straines were enriched,
which could use isophorone as sole source of carbon
and energy. The yielded straines were identified, their
degradation kinetics were examined and the best performer
was selected for further experiments.
To reveal the degradation pathway a transposon mutagenesis
was performed. Some knock-out mutants
were identified. They were incubated with Isophorone
and another carbon source (their isophoron-degradatio
pathway was now defective – see figure), and the
produced metabolites were analyzed with the GC-MS.
Thilo Hurler (technische Biologie) 2009
Supervisor: Dr. N. Strunk
Independent Study
Transposon mutagenesis:
Upper row: One substrate (blue) is transformed by
4 enzymes (red) to a product (pink). Three metabolites
(green) appear in the reaction chain. The enzymes are
coded by structural genes (orange), they lie all in the
same operon.
Lower row: One of the structural genes is damaged
by a transposon (cyan). Gene 2 is disrupted, enzyme
2 is defective. Therefore only one metabolite (green)
is produced, which could be extracted and analyzed
Isophoron (C 9
H 14
O)
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