ADOPT A MICROBE

By SITI NOOR FADHILAH MOHAMAD

168966

Prototheca zopfii

Prototheca zopfiiFirst isolated from slime flux of trees in 1894, it was thought to be a type of fungus

• In taxonomy, Prototheca is a genus of algae, specifically of the Chlorellaceae.• Some species can cause the disease protothecosis.

• low pathogenicity and generally infect during wound contamination.

Prototheca zopfii

TAXONOMY

Identification of species in the genus Prototheca.

Morphology:

• yeast like colonies, smooth surface and  smooth margin

• beige or ocher colored.

• Its size varies from 2 to 15 micrometres

Microscopic image

Histologic stain of a Prototheca zopfii infection in a dog

DIAGNOSTICS

• Plate culture on fungi media, e.g. Sabouraud-glucose-agar, Kimmig-agar

• subsequent microscopical examination of smears with lactophenole cotton blue or with PAS-staining or Immunofluoreszence (pathohistology)

• Grew well on hydrocarbon mixture at 35-38 °C.

• Differentiation between P. zopfii and P. wickerhamii by assimilation of Trehalose.P. wickerhamii utilize trehalose; P. zopfii does not.

Infections:

• Human protothecosis• Canine protothecosis• Bovine protothecosis -etiological agents of intramammary infections (IMI) in cows. Prototheca generally behave as environmental mastitis pathogens, but can also be spread between cows during milking.

Comparison to Chlorella

• Prototheca has been thought to be a mutant of Chlorella, a type of single-celled green alga.

• However, while Chlorella    contains Galactose and    galactosamine in the cell wall,    Prototheca lacks these.

• Also, Chlorella obtains its energy through photosynthesis, while Prototheca is saprotrophic, feeding on dead and decaying organic matter.

The image of Chlorella

BIOREMEDIATION• Prototheca zopfii is an achlorophyllous alga which degrades oil.

• It has been found to degrade 10 and 40% of a motor oil and crude oil, respectively, when tested under appropriate conditions.

MECHANISM• capable of using hydrocarbons as sole carbon and energy source.

• Using pathway:- subterminal oxidation pathway

Figure: Degradation of oil

Subterminal oxidationinvolves the hydroxylation at a middle carbon in an n-alkane

a secondary alcohol being generated that is then oxidized by an alcohol dehydrogenase to the corresponding ketone.

The ketone is converted to an ester by a Baeyer-Villiger monooxygenase that is then cleaved into a primary alcohol and a fatty acid by an esterase.

The primary alcohol is oxidized to the corresponding fatty acid and then enters the B-oxidation pathway.

COMPARISON

• Degradation of the crude oil observed in this study compares well with the amount of degradation accomplished by bacteria.

• P. zopfii was found to degrade a greater percentage of the aromatic hydrocarbons in motor oil than of the saturated hydrocarbons and a greater percentage of saturated hydrocarbons in crude oil than of aromatic hydrocarbons.

CONT.’• Resins and asphaltens were produced during degradation of motor oil, whereas these fractions in crude oil were degraded.

• P. zopfii did not demonstrate preferential utilization of lower homologues of cycloalkanes and aromatics.

• Interestingly, in the crude oil, 38-60% of the saturated aliphatic hydrocarbons and 12-41% of the aromatic compounds were degraded.

• whereas in the motor oil, 10-23% of the saturated aliphatic hydrocarbons and 10-26% of the aromatic compounds were degraded.

Motor oil

• This suggested that the alga was capable of degrading different oils to varying levels.

Inhibition of P. zopfii• Since this algae can cause diseases, irradiation of cells of Prototheca zopfii with blue light and ultraviolet radiation inhibited the respiratory capacity of the cells.  

• The inhibition of respiration was correlated with a photodestruction of cytochrome c(551), cytochrome b(559), and cytochrome a3. 

RESEARCH ON

1975

RESEARCH ON

1999

RESEARCH ON

2006

RESEARCH ON

2013

MY THOUGHT ON THIS TASK:• This task is interesting, because we were asked to find information or ‘adopting’ a microbe that of interest. 

• So, I am interested on the microbe that involve in bioremediation. This microbe is helpful in cleaning up our polluted environment. Thus, it is time to start appreciating this little microbe. Even though they cause destruction, but they are good bioremediaters too.

My self• My name is Siti Noor

Fadhilah Mohamad• I am the second year of

Bsc. Microbiology• My principle of life is:

Never give up.