are three types of microorganism that found in activated sludge treatment which
is bacteria (95%), protozoa (4%) and metazoan(1%).Basically, three are three
types of agar that used to grow the microorganism because this sample was an
unknown source. (Luo et al., 2014).The agar was used is nutrient agar,
MacConkey agar, and PDA.(Glymph et al., 2012). In figure 4.8,4.9 and 5.1 was
shown under the microscopic and from that was identify the types of shapes for
this three types of microorganisms was bacteria according to the shape.
microorganisms, A in figure 4.8 is bacillus(rod) and this microorganism was
grown on MacConkey agar. MacConkey agar is a selective and differential culture
media commonly used for the isolation of enteric Gram-negative bacteria and the
gram staining analysis was already which the result obtained was gram negative.
Gram-negative enteric bacteria that grow on MacConkey agar are differentiated
by their ability to ferment lactose. If the lactose is fermented by the
bacteria, the production of the acid drops the pH of the media. The drop in pH
is indicated by the change of neutral red indicator to pink. (Jianlan et al., 2015). So, can prove that these
microorganisms which are A were bacteria.
While in figure
4.9 was illustrated as microorganisms B
and in figure 5.1 was shown as the microorganism B.Then, the image was
obtained under the microscope with 1000x of magnification and it can identify
the shape of this microorganism which is for both microorganisms B and C is
coccus sphere. From this characteristics, can assume that both of this
microorganisms are bacteria. (Luo et al., 2014).For microorganisms B, nutrient
agar was used as a medium for this microorganism. Nutrient Agar is a general
purpose, nutrient medium used for the cultivation of microbes supporting the
growth of a wide range of non-fastidious organisms. Nutrient agar is popular
because it can grow a variety of types of bacteria and fungi, and contains many
nutrients needed for the bacterial growth.
Then, in figure
5.1 as the microorganisms, C has used PDA agar as a medium to grow.Potato
Dextrose Agar (PDA) is used for the cultivation of fungi. Potato Dextrose Agar
(PDA) is a general purpose medium for yeasts and molds that can be supplemented
with acid or antibiotics to inhibit bacterial growth but for this study, the
antibacterial was not added, so it possible the microorganisms that grow at PDA
was bacteria. (Luo et al., 2014).It is because the main characteristic of fungi
is has a spore.In this study, the microorganisms that grow in PDA does not have
any spore.So, it was assumed that microorganisms C also the bacteria.