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Microbial biosensors generally offer an attractive alternative to the existing methods of water analysis.
One particular advantage of those systems is the ability to measure direct
effects on living cells, e.g., their respiratory activity and its alteration caused by environmental
pollutants. It is true that microbial sensors, often do not provide the optimum solution for the
determination of individual analytes when compared to established physico-chemical analysis methods.
However, these biosensing devices are predestined for the summary determination of environmentally
relevant compounds and their complex effects, respectively. For this reason, microbial sensors allow
an integral evaluation of the degree of environmental pollution including the interaction of various compounds.
Moreover, in some cases specific metabolic pathways in microorganisms are used, resulting in the development
of microbial sensors for the more selective analysis for those compounds or pollutants, which cannot be
measured by simple enzyme reactions, e.g., the determination of aromatic compounds and heavy metals.
Pharmacom has great interest of developing microbiological biosensors on respiratory basis for the measurement of the
following environmentally relevant compounds: inorganic N-compounds, heavy metals, organic xenobiotics and the
estimation of sum parameters or so-called complex parameters such as BOD, ADOC, N-BOD, and the inhibition of
nitrification
We intend to prototype a microbial system for the
point-of-care and diagnostics market. The microbial biosensor consists of a transducer in conjunction with
immobilised viable or non-viable microbial cells. Non-viable cells obtained after permeabilisation or whole
cells containing periplasmic enzymes have mostly been used as an economical substitute for enzymes. Viable
cells make use of the respiratory and metabolic functions of the cell, the analyte to be monitored being either
a substrate or an inhibitor of these processes. Bioluminescence-based microbial biosensors can also be developed
using genetically engineered microorganisms constructed by fusing the lux gene with an inducible gene promoter for
toxicity and bioavailability testing.
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