lab 6

ABSTRACT

Microorganism or parasite are mainly organism that can only be detectable with the aid of equipment called microscope, which designed for high magnifications. A process called mitosis process is their reproduction that involves duplication of nucleus through cell division of the cell. The objective of this experiment are to study/observe the growth of  inetics inetics of microorganism microorganism in shae flas experiment, to construct construct a growth growth curve including including lag, log, stationary and death phases and to determine the Monod parameters of maximum growth rate !"max#, mass doubling doubling time !td# and specifc growth rate (µnet).  $rlenmeyer  flas is used in this experiment experiment to grow microorgani microorganisms. sms. Escherichia  Escherichia coli ! coli ! E.Coli#  E.Coli# is grown in Terrific %roth !T%# medium at &'( rpm and &)*+. They were fermented in incubator  shaer for - hours. Throughout every  hours, cell is taen out to obtain the value of  abso absorb rban ance ce by usin using g spec spectr trop opho hoto tome mete terr. +ell +ell dry dry is then then obta obtain ined ed afte afterr the the mass mass concentration inside the flas is dried overnight. As for the optical density analysis, the abso absorb rban ance ce read readin ing g from from the the spect spectro roph phot otom omete eterr is tae taen. n. The The cell cell dry weigh weight, t, in the the other hand, is taen after the mass concentration is being dried overnight in the oven. The weight of the tube which contains the biomass before and after the drying process is recorded to get the cell dry weight. Then, all obtained value are turned into a graph to observe the changes in growth inetics of the cell.

1

INTRODUCTION

Microorganism or parasite are mainly organism that can only be detectable with the aid of equipment called microscope, which designed for high magnifications. The nature of  the microorganisms are algae, bacteria, moulds, protooa, viruses and yeast are normally considered by scientists to as a nonliving entity. Microorganisms can be present everywhere in our environment lie air we breathe, soil, water, various parts of our bodies and the food that we tae. A process called mitosis  process is their reproduction that involves duplication of nucleus through cell division of the cell. 0eproduction of microorganisms can also occur when a haploid nuclei unit to form a diploid cell, changing further to bring about sexually produced offspring. Microorganisms are lie any other living things that needs a favourable circumstances for growth, which can be slightly varied with microorganisms. 1ome of these circumstances commonly considered as factors that influencing the growth of these entities. The factors that can influenced the growth of microorganisms are p2, nutrition, moisture, oxygen, temperature and time. %acterial population growth studies require inoculation of viable cells into a sterile  broth medium and incubation of the culture under optimum temperature, p2, and gaseous conditions. 3nder these conditions, the cells will reproduce rapidly and the dynamics of the microbial growth can be charted by means of a population growth curve, which is constructed  by plotting the increase in cell numbers versus time of incubation and can be used to delineate stages of the growth cycle. 4t also facilitates measurement of cell numbers and the rate of growth of a particular organism under standardied conditions as expressed by its generation time, the time required for a microbial population to double. There are many ways to carried out 5ermentation process such as batch, continuous and fedbatch processes. 4n this experiment, we decided to use the shae flas fermentation. The shae flas fermentation is an example of batch fermentation. 4n shae flas, the culture flas usually $rlenmeyer flas is being used to place and growing the microorganisms. 4t is a small scale equipment which equivalent to stirred tan bioreactor and it is also the cheapest and easiest way to culture microorganism aerobically, in small volumes of nutrient broth. 3sually, complex media are used for shae flas cultures. 2owever, to enhance the growing the synthetic medium is being devised for the fermentation process. 1tudies on

2

inoculum sie, temperature, agitation, nutrition are initially done using these cultures to monitor their influences on growth and product formation. There are many specific media for certain microorganisms lie 6uria %ertani !6ennox# and Terrific %roth media. %acterial  E.coli growth media7 6% Miller broth/6% 6ennox broth is the most commonly used medium in molecular biology for  E.coli cell culture. 6% broth contains the enymatic digestion product of casein commonly nown as  peptone !some vendors term it Tryptone#, yeast extract, and sodium chloride. 8eptone is rich in amino acids and peptides. 4ts amino acid and peptide compositions reflect those of casein. 4n addition to amino acids and peptides, yeast extract also contains nucleic acids, lipids and other nutrients which are needed for bacterial growth. !6% Miller, 6ennox#. 9ther media is %acterial $. coli growth medium T% or Terrific %roth T% or Terrific  broth is a phosphate buffered rich medium. 4n addition to (: more peptone and &;(: more yeast extract than 6% broth, T% also has an added (.-: glycerol as an extra carbon source. All these nutrients in T% can support $. coli growth to 9