Environmental Engineering Reference
In-Depth Information
bioilm formation. Though an excellent technique, the major disadvantage is the
requirement for speciic deoxyribonucleic acid (DNA) fragments complementary to
speciic bacterial DNA sequences from target microorganisms [49].
Another popular molecular identiication technique is PCR for identifying bioilm
organisms. Total polysaccharides, total carbon content, protein and lipid estimation,
water content, adenylate activity (content of ATP or total adenylate content),
hydrolytic activity (activity of hydrolytic enzymes such as glucosidases, lipases and
aminopeptidases) can be used to quantify biological activity in a bioilm [49].
Although these assays and molecular techniques give lots of information, the main
disadvantage is that all these methods are time consuming, and are static assays so
yield qualitative or semi-quantitative data. Also they are not
in situ
techniques and
do not provide information on the full picture of the bioilm attached to the surface.
Also the cost involved is high.
The new approaches to analyse bioilms should give us more quantitative data, be
online monitored,
in situ
and should be non-destructive. The sensors and probes,
which could be used to analyse bioilms online and
in situ
, although they are in use,
still need more research and development so that more accurate and reliable results
are obtained and they must be cost effective.
6.1.3 Mathematical and Molecular Models
The mechanism of bacterial adhesion, its interaction with the surface and its inluence
on the surface and the impact of the environmental parameters on this process
are very complicated. The environmental cues affecting the bioadhesion are also
dynamic. Experimental estimation of bioilm formation, and its impact on the surface
are extremely complex. Polymers used for these studies also undergo chemical and
physical modiications that are not systematic and are because of factors other than
microbial adhesion. Thus, bioilm formation, and its effect on the substratum require
mathematical models that are not only used to conirm experimental results, but also
to provide qualitative and quantitative predictions that serve as guidelines for the
design of new polymers to resist bioilm formation.
6.1.3.1 Modelling of Bioilms
Bioilm formation is a complex process governed by various physical, chemical
and biological cues and environmental conditions. The types of microbe inside the
bioilm also play an important role in the formation and development of the bioilm.
