VM1G2T1: Cupriavidus metallidurans by Farhanna Abd

My Findings

farhanna_abd_ghani_97 — 2017-03-14 14:01:32 UTC

So hey guys, Before I went deeper in searching for C.metallidurans, I search via Microbe Wiki first.
SO have a tour and comment about it below :D

1st video discussion

farhanna_abd_ghani_97 — 2017-03-14 15:10:56 UTC

Do you think there is any improvement that is needed to be done if there is another video discussion to come?

Biochemical Test further readings

pretty_priyaa97 — 2017-03-15 14:20:03 UTC

1. 284 medium or a modified version of the 284 medium with MOPS and Beta-glycerophosphate to study the metal resistance of Cupriavidus Metallidurans CH34

2. Viable, inactive, and dead C. metallidurans CH34 cultures were incubated in the presence of 50 μM Au(III)-complexes at pHs of 5.0 to 8.0 for 6 h and 144 h, and Au uptake was measured using ICP-MS.

3. When placed in an environment containing aqueous Gold (III) chloride, this bacterium reduces the complex – by a mechanism yet to be fully understood – leading to the precipitation of solid gold nanoparticles within or outside the cell.

Biochemical test

aariswary2010 — 2017-03-15 14:28:24 UTC

1) Kinetic experiments with metabolically active cells [incubated with 50 μM Au(III), 1 min to 144 h, pH 7.0] confirmed a two-stage reduction for Au(III)-complexes .

2) The distribution of Au and other elements (i.e., S, Ca, Fe, Cu, Zn, Mn; was mapped in individual cells using synchrotron μ-X-ray fluorescence (μXRF) .

3) Heavier elements expected in bacterial cells were successfully mapped. Calcium, Zn, and Cu, which can make up to 0.5 wt%, 0.03 wt%, and 0.005 wt% of the dry weight of bacterial cells, respectively , are shown in overlays with Au to assess the location of Au associated with cells. After 1 min of exposure to Au(III), cells had taken up 1.82 ± 0.19 ng cm⁻² of Au, and accumulated Au was distributed throughout the cells. The concentrations of accumulated Au in cells increased to 2.79 ± 0.31 ng cm⁻² after 6 h and to 12.2 ± 1.3 ng cm⁻² after 72 h. After 72 h, zones containing up to 34.6 ± 2.4 ng cm⁻² Au were detected. After 144 h of exposure, Au concentrations in the cytoplasm decreased to 2.25 ± 0.79 ng cm⁻²; in contrast, regions of the cell envelope containing high Au concentrations were more numerous and larger .

4) Cells actively removed Au from the cytoplasm and precipitated it as nanoparticulate Au⁰ in the periplasm, as confirmed by transmission electron microscope (TEM) . This suggests that a combination of several mechanisms may be used by C. metallidurans to detoxify Au(III)-complexes and points to energy-dependent efflux as well as intra- and extracellular reductive precipitation.

Characteristics of Cupriavidus metalidurans

muhamadazri95 — 2017-03-19 08:51:06 UTC

This bacterium is able to
survive in these
environments due to the
abundance of metal-
resistance genes dispersed
throughout its genome which
code for heavy metal
exporters, regulators,and
potential metal-binding
proteins used to detoxify the
cell.
These abilities have earned C. metallidurans some fame.
When placed in an environment containing aqueous Gold (III)
chloride, this bacterium reduces the complex by a mechanism yet to be fully understood leading to the precipitation of solid gold nanoparticles within or outside the cell.

This bacterium is able to
survive in these
environments due to the
abundance of metal-
resistance genes dispersed
throughout its genome which
code for heavy metal
exporters, regulators,and
potential metal-binding
proteins used to detoxify the
cell.

These abilities have earned C. metallidurans some fame.
When placed in an environment containing aqueous Gold (III)
chloride, this bacterium reduces the complex by a mechanism yet to
be fully understood leading to the precipitation of solid gold
nanoparticles within or outside the cell.

C. metallidurans is 
normally found an ç
industrial sediments or
wastes which contain high
heavy metal  - 
concentrations. 
C. metalliduranswas initially isolated from the wastewater of a zinc factory ii
Liège, Belgium.
Later, this bacterium was found in another unusual place. It was the
dominant organism present in biofilms on gold grains found in the
Prophet gold mine in Queensland, Australia.

C. metallidurans is a facultative anaerobe that can undergo
regular oxidative phosphorylation, but when there is limited
access to oxygen in the environment. C. metallidurans is also
able to reduce nitrate, but not nitrite.
C. metallidurans is unable to grow on glucose, fructose, or
galactose because it lacks sufficient glucose uptake systems.
It can, however, produce energy by assimilating some acidic
sugar-derivatives which, via a chain of pathways, will end up
producing two molecules of pyruvate each to feed in to the
TCA cycle or other related cycles.

C.Metallidurans have symbiotics relationship with Delftia Acidovoran which is there has
share genes that make them resistant to the toxic effects of heavy metals

blendspace link to CLICK

farhanna_abd_ghani_97 — 2017-03-28 03:36:21 UTC

https://www.tes.com/lessons/GjosCCWljvmjEQ/collab/PYAIKhsWGiYfbNsCIYJLabFzpOqIMHQx/register

Applications to Biotechnology

umimaisyarah2 — 2017-03-28 06:21:24 UTC

The metabolic and heavy-metal resistant capabilities of C. metallidurans make it an excellent candidate for many biotechnological applications in which nutrient sources are limited and conditions are unfavorable for most organisms.

While the ability of C. metallidurans to precipitate pure gold is a fascinating one, it is not economical on a large scale; considering one requires gold to make gold (III) chloride, there is no real benefit.

Another application of C. metallidurans is in biosensing. Biosensors are devices that use biological systems to detect specific compounds; the binding of the sensor, which is usually an enzyme, results in a measurable change. Due to the specificity of multiple gene products that are up-regulated in C. metallidurans when exposed to gold, this bacterium is a promising candidate for use as a biosensor. One could theoretically utilize these gold-specific proteins to immediately detect and quantify gold concentrations in environmental samples. This would save much time and money, and be of significant benefit in the gold mining industry

Diagram of sand filtration showing the decontamination of heavy metal waste water.

umimaisyarah2 — 2017-03-28 06:24:41 UTC