Tuesday 27 October 2015

ISOLATION OF MICROALGAE

Practical 2

ISOLATION OF MICROALGAE

Introduction

Microalgae culture is so important have lot of benefit. But it is hard to have a pure culture of algae because there will be a lot of species in one culture. To have a single species culture, isolation of microalgae is needed. There is a few techniques to isolate a microalgae such as,

a)    Single cell isolation by using micropipette
b)    Streaking samples on agar plates
c)     Isolation by dilution

Material and methods

Single cell isolation by using micropipette

Materials: Culture Water, Bunsen burner, lighter, microscopic glass slide, Pasteur pipette, forceps, compound microscope


Methods:

1)    Pasture pipette is placed over the flame of the Bunsen burner.
2)    Using forceps, the tip of Pasteur pipette became soften and being pulled to make it longer and small hole.
3)    The ends of the pipette should be smooth to prevent it from destroying algae cell.
4)    The pipette was then connected to a rubber hose/tubing.
5)    A drop of sample was dropped on glass slide and was placed under the compound microscope, the micropipette was used to pick up cells different cells and then dropped on to the side of the glass slide.
6)    Finally, the single cell is transferred to the media in one of the well in a 96-well plate.


     
Figure 1: softening pasture pipette                   Figure 2: using micropipette isolation


Streaking samples on agar plates

Materials: f/2 agar plates, f/2+si agar plates, inoculation loop, Bunsen burner, centrifuge, Epperndorf tubes.

Methods:

1)    1 mL of sample was insert into an Epperndorf tube and being centrifuged at 5000rpm for 10minutes.
2)    Inoculation loop were sterile by putting the loop tip on the flame of Bunsen burner and let it cool down for 15 sec.
3)    The cell pellets at the bottom of Epperndorf tube were picked up with a inoculation loop and was streaked on the agar which is two type of agar, f/2 and f/2 + si.
4)    The plates were then incubated under room temperature with the presence of fluorescence light.
5)    Observation on the streaking plate being done after two weeks.


Figure 3 : Streaking sample on agar technique


Isolation by dilution

Materials: 10 test tubes, seawater, micropipette, stock culture

Methods:

1)    10 test tube being filled up with 9ml of water.
2)    Then 1ml of stock culture being inserted into test tube 1 and being mixed using micropipette.
3)    1ml of mixed culture in test tube 1 being transferred into test tube 2 and being repeated until test tube 10.
4)    The test tubes were then kept under room temperature and under the presence of light.
5)    The growth of algae was observed daily. It is indicated by the changing color of the media.

Figure 4 : Test tube use for isolation by dilution


Result

a)   Single cell isolation by using micropipette

None species was successfully being isolated using this method.

b)   Streaking samples on agar plates
c)   Isolation by dilution

This method was not successful because there is no bacteria growth.


Discussions

All method to isolate microalgae has their difficulty and successful rate. For single cell isolation using micropipette, high skill is needed to isolate one species of microalgae from one drop of water. Lot of time needed to search one cell of microalgae and will be difficult to isolate moving microalgae.
For streak plate method, this method is easy and can be practiced by everyone. But the result for streak plate method cannot be expected because of the sample that was taken might have several species or the agar plate being contaminated by other bacteria.
For dilution method, stock culture is needed because serial dilution is needed in this method. Dilution will be done for 10 times using 10 test tubes. Dilution is needed to decreased the number of microalgae cell in culture stock.


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