Nisin is an antibacterial peptide, which when adsorbed
on a surface can inhibit bacterial adhesion and viability.
The ability of noncovalently immobilized nisin to withstand
exchange by the milk proteins bovine serum albumin, ��-lactoglobulin, ��-lactalbumin, and ��-casein on surfaces that
had been silanized with dichlorodiethylsilane to exhibit
high and low hydrophobicities was examined using in situ
ellipsometry. Kinetic behavior was recorded for nisin
adsorption for 1h and 8h, followed in each case by rinsing
in protein-free buffer solution, and sequential contact with
a single milk protein for 4h. Concerning nisin adsorption to
each surface, a higher adsorbed mass was consistently
recorded on the hydrophilic relative to the hydrophobic
surface, independent of adsorption time. While desorption
was greater from the hydrophilic surface in the 1h test, the
amount desorbed was quite similar on each surface in the 8h
tests. The sequential data were consistent with the
assumptions that nisin organization at the interface
involved adsorption in at least two different states,
possibly existing in more than one layer, and that in the
absence of exchange, upon addition of the second protein
adsorbed mass would increase by an amount equivalent to its
experimentally observed monolayer coverage. The Mass of
nisin exchanged was generally higher on the hydrophobic
compared to the hydrophilic surface presumably because of
the presence of a more diffuse outer layer in the former
case. ��-casein was the most effective eluting agent among
the proteins studied, while ��-lactalbumin was the least
effective, apparently adsorbing onto the nisin layers with
little exchange. Both bovine serum albumin and ��-lactoglobulin were moderately effective in exchanging with
adsorbed nisin, with the amount of nisin removed by bovine
serum albumin being more substantial, possibly due to its
greater flexibility. / Graduation date: 1995
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/35183 |
| Date | 20 December 1994 |
| Creators | Muralidhara, Lakamraju |
| Contributors | McGuire, Joseph |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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