Research Interests:
Anaerobic thermophiles: Ongoing
research includes the isolation and classification of new strains
exhibiting special
features of industrial or academic interest. Thermophilic anaerobes
have a potential for use in industrial applications due to several
features, including their thermostable enzymes. We have described
several new thermophilic anaerobes, some of which have been patented,
e.g. for ethanol production, others constitute a new group of
exciting extremophiles, e.g., the alkali-thermophilic anaerobes,
which grow optimally above pH 9.0 and 65°C with doubling
times as short as 10 min. Previously it was assumed that such
conditions are too hostile for optimal growth of bacteria. Our
physiological studies include answering nutritional questions,
regulation studies and the isolation of enzymes (e.g. xylosidases/xylanases)
of industrial and academic interest. The ecological studies deal
with distribution and diversity of anaerobic thermophiles in
both moderate and extreme environments. To be able to manipulate
our strains for industrial applications we are developing genetic
systems for thermophilic clostridia and related bacteria.
Anaerobic degradation of chlorinated
aromatic compounds: Our research focuses on the sequential degradation
of chlorinated phenols and polychlorinated biphenyls
(PCBs) by anaerobes in mesobiotic sediments from polluted sources. We study
the effects of environmental parameters e.g., temperature and
pH on the interactions
within the participating bacterial community in an environment. We isolate
and characterize the various organisms to elucidate the degradative
pathways and
isolate and characterize novel key enzymes such as the hydroxybenzoate decarboxylases
and the aryldehalogenase. The work on PCB dehalogenation is geared toward obtaining
data for designing bioremediation processes as well as isolating PCB-dechlorinating
anaerobes, organisms which have never been isolated, so far.