UNIVERSITY OF DAR –ES-SALAAM
COLLEGE OF NATURAL AND APPLIED SCIENCES
DEPARTMENT OF MOLECULAR BIOLOGY AND BIOTECHNOLOGY
MC206: FOOD MICROBIOLOGY PRACTICALS
MICROORGANISMS IN THE ENVIRONMENT
NAME: DUSENGEMUNGU Léonce
REG #: 2011-04-07086
COURSE INSTRUCTOR: Dr Mugassa S.T Rubindamayugi
DATE OF SUBMISSION: November ,2012 ABSTRACT
This practical was regarding microorganisms in the environment as we know microorganisms are everywhere ,this session was divided in three parts where in part A of the practical we planted microorganisms on different petri dishes in order to verify if the microorganisms are really everywhere The necessity and value of collecting, identifying, and analyzing the various microbes regularly encountered in the daily human environment becomes quite apparent .when one gains even a very basic knowledge of how diseases are acquired and spread. The purpose of this lab was to collect and observe microbes from environmental and human body samples by culturing them on the appropriate media using aseptic transfer techniques. And also regard different effect of temperature on microbial growth in Part B ,and looking also the resistance of Bacteria to heat ,the result on was quite visible ,in part A of this practical we noticed the extremely growth of microbes on different petri dishes and the growth was differing according to the way we inoculated the petri dishes ,and in Part B we saw that the Temperature was really affecting the growth of Microbes as well as in part C where we saw that some Microbes are really resisting to heat .I was impressed by the way that microorganisms are everywhere regarding the way we contaminated the petri dish,the effect of temperature was also remarquable as it was been experienced by other big person in Microbiology ,Briefly I have got the expected result in each part of this practical . ( http://www.studymode.com/ /Environmental-Microbiology)
The natural environment is populated with many microorganisms suspended in the air, in water, and associated with other organisms (e.g., humans). All surfaces in the lab and in the environment are potential sources of contamination. The ease in which microorganisms may be dispersed in the environment has significant consequences on the quality of laboratory measurements that may wish to examine a particular cell.
In order to examine microorganisms thoroughly without the use of a microscope, they must be given the proper conditions and nutrients and allowed to flourish into colonies. In this experiment, microorganisms were taken and cultivated from six different sources. For each of these six sources, there were one media types used – nutrient agar, The intent was to determine the differences between the growth of microorganisms from different sources used and the different colony counts observed, while at the same time appreciating the need for sterile techniques to combat contamination. We walked also on effect of Temperature on growth of Microorganisms ,Temperature is probably the most important environmental factor affecting growth ,if temperature is too hot or too cold microorganisms will not grow. The minimum and maximum temperatures for microbial growth vary widely among microorganisms and is usually a reflection of the temperature range and average temperature of their habitat . each type of bacteria i.e Psychrophile ,mesophile,or thermophiles ,has a minimum,maximum ,and optimum growth temperature .,all these alre shown in the diagram below
It may be seen that as the temperature of incubations rises so does the growth rate (rate of...
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