The Effect of Environmental Factors Such as Temperature, Osmotic Pressure, Oxygen Concentration and Ph on Microbial Growth and Survival
The effect of environmental factors such as temperature, osmotic pressure, oxygen concentration and pH on microbial growth and survival
Abstract:
Microbial growth can be affected by different environmental factors such as temperature, osmotic pressure, oxygen concentration and pH. Six experiments were carried out in this report testing for microbial growth against different environmental factors. Good aseptic techniques were used to prevent contamination, resulting in a uniform set of results that are in line with the literature.
Introduction
Bacteria vary greatly in terms of their characteristics and morphology. Colonies can be classified according to their colour, form, elevation, margin and size. Pure cultures of microorganisms are those that are uniform and are of the same descendants of the same organism. The isolation of colonies by streak plate technique allows the obtainment of pure cultures which can be studied further. Good quality aseptic technique and proper sterilisation are a required to ensure that all samples produced are free from unwanted organisms that can lead to contamination of microbial cultures.
Environmental factors such as temperature, osmotic pressure, oxygen concentration and pH can affect both the growth and survival of microorganisms. Microorganisms are versatile enough to adapt to different environments that they occupy that would otherwise threaten the survival of other species.
The method of isolating pure cultures of microorganisms on to a solid media was developed by Robert Koch in 1883. He added a solidifying agent to a liquid nutrient broth which supports the growth of a wide variety of microorganisms whilst the agar function is the solid media onto which the bacteria can be isolated as independent colonies which are representatives of different bacterial species.
Controlling microbial growth is necessary in numerous situations and is greatly significant in areas such as medicine. Growth of microorganisms is
Abstract:
Microbial growth can be affected by different environmental factors such as temperature, osmotic pressure, oxygen concentration and pH. Six experiments were carried out in this report testing for microbial growth against different environmental factors. Good aseptic techniques were used to prevent contamination, resulting in a uniform set of results that are in line with the literature.
Introduction
Bacteria vary greatly in terms of their characteristics and morphology. Colonies can be classified according to their colour, form, elevation, margin and size. Pure cultures of microorganisms are those that are uniform and are of the same descendants of the same organism. The isolation of colonies by streak plate technique allows the obtainment of pure cultures which can be studied further. Good quality aseptic technique and proper sterilisation are a required to ensure that all samples produced are free from unwanted organisms that can lead to contamination of microbial cultures.
Environmental factors such as temperature, osmotic pressure, oxygen concentration and pH can affect both the growth and survival of microorganisms. Microorganisms are versatile enough to adapt to different environments that they occupy that would otherwise threaten the survival of other species.
The method of isolating pure cultures of microorganisms on to a solid media was developed by Robert Koch in 1883. He added a solidifying agent to a liquid nutrient broth which supports the growth of a wide variety of microorganisms whilst the agar function is the solid media onto which the bacteria can be isolated as independent colonies which are representatives of different bacterial species.
Controlling microbial growth is necessary in numerous situations and is greatly significant in areas such as medicine. Growth of microorganisms is
References: 1. R. S. Horvath and M. E. Ropp. 1974 “Mechanism of Action of Eosin-Methylene Blue Agar in the Differentiation of Escherichia coli and Enterobacter aerogenes”.International journal of systemic bacteriology. April 1974, p. 221-224 2. Dagny Jayne Leininger, Jerry Russel Roberson, Franc¸ois Elvinger. 2001 “Use of eosin methylene blue agar to differentiate Escherichia coli from othergram-negative mastitis pathogens”. J Vet Diagn Invest 13:273–275 3. Hiroshi Fujikawa, 1994. “Diversity of the growth patterns of Bacillus subtilis colonies on agar plates”. FEMS Microbiology Ecology 13: 159-167 4. Anna Csillag, 1972. “Appearance of acid-fast rods in cultures of mycococcus luteus”. Tubercle and Lung Disease 53: 221-225 5. James A. Bastock, Michelle Webb and Jane A. Grasby, 2007. “The pH dependence of the Escherichia coli RNase HII-catalysed Reaction Suggests that an Active Site Carboxylate Group Participates Directly in Catalysis”. Journal of microbiology 368: 421-433 6. Lloyd D. Witter, 1961. “Psychrophilic Bacteria—A Review”. Journal of dairy science 44:983-1015 7. D. Mora, M.G. Fortina, G. Nicastro, C. Parini and P.L. Manachini, 1998. “Characterization of thermophilic bacilli: A study on new soil isolates and several reference strains”. Research in microbiology 149:711-722 8. Rosario Lagunas, 1982. “What is meant by facultative anaerobes?” Biochemical education. 10: 141-142