Biomedical Engineering Reference
In-Depth Information
A
B
C
D
E
F
FIGURE 9.1
Electron.micrographs.of.crystal.morphologies.and.intracellular.organization.of.magnetosomes.found.in.vari-
ous.magnetotactic.bacteria..Shapes.of.magnetic.crystals.include.cubo-octahedral.(A),.elongated.hexagonal.pris-
matic.(B,.D-F,).and.bullet-shaped.morphologies.(C)..The.particles.are.arranged.in.one.(A-C),.two.(E),.or.multiple.
chains.(D).or.irregularly.(F)..(Bar.equivalent.to.100.nm)..(From.Schuler,.D.,.and.Frankel,.R.B.,.
Appl. Microbiol.
Biotechnol.
,.52,.464,.1999.).With.permission.
nanoparticles.with.very.good.monodispersity.have.been.produced,.and.the.nanoparticles.
were.stable,.even.after.up.to.4.months.incubation.at.25°C..This.is.an.important.aspect.of.
nanoparticle. synthesis,. since. the. lack. of. suficient. stability. of. many. nanoparticle. prepa-
rations. has. to. some. extent. impeded. the. development. of. applications. of. nanomaterials..
Similarly,. Ahmad. and. co-workers
32
. used. the. alkalotolerant.
Rhodococcus
. sp.. for. intracel-
lular.synthesis.of.good.quality.monodisperse.gold.nanoparticles.
9.2.4 The Use of Fungi in Nanoparticle Synthesis
One.of.the.irst.works.deining.the.use.of.fungi.for.nanoparticle.synthesis.was.carried.out.by.
Mukherjee.and.colleagues.for.the.production.of.gold.nanoparticles.using.
Verticillium
sp.
33
.
Gold. nanoparticles. of. around. 20. to. 25. nm. in. diameter. were. formed. intracellularly.. The.
particles.were.mostly.spherical,.but.there.were.also.a.few.triangular.and.hexagonal.par-
ticles. present.. They. concluded. that. compared. to. bacteria,. fungi. could. be. a. good. source.
