September 2009
On the change in bacterial size and magnetosome features for Magnetospirillum magnetotacticum (MS-1) under high concentrations of zinc and nickel
S. Kundu et. al., Biomaterials, 30, 4211 (2009)
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Biophysics Lab III
In the forthcoming decade, the
ability to sense and detect the state of biological system and living organisms optically, electrically
and magnetically will be completely transformed by developments in material physics. Optical tweezer is a
powerful research tool in different areas such as biomaterials, biophysics, molecular biology and
nanomaterials. It provides an opportunity to manipulate, detect and apply optical forces on different
types of plant and animal cells, bacteria, viruses and even on single biomolecules. The new generation
optical tweezer coupled with force calibration system is being used for nano-positioning and force
measurement even at piconewton level.
The optical tweezers technique has applications in various areas including cell bio-sensors and cell
micro-chip. Different mechanical aspects of single DNA molecules are studied by the controlled light force
in optical trap. The ability to apply piconewton level forces to micron size particle is now routinely
used to study molecular motion at the single molecular level. Rotation of RBC, bacteria such as E.coli, rotation of metal oxide microscopic particles inside the optical
trap is being investigated.
The characteristic size, shape and specific alignment of magnetite crystals synthesized by magnetotactic
bacteria is a highly coordinated process with precise control over magnetosome vesicle formation,
uptake and transport of Fe, and magnetite biomineralization. Magnetosome membranes along with some
specific membrane proteins regulate crystal nucleation and morphology of magnetite.