The Influence Of Environmental Factor To The Microbial Growth” 6a3q2z

APPROVAL SHEET The complete report of experiment Basic Microbiology with title “The Influence of Environmental Factor to the Microbial Growth” created by Name

: Mutmainna Ekawati

Reg. No

: 071404189

Group

: IV (Forth)

Have been checked and consulted by assistant and assistant coordinator and this report is accepted. Makassar, January 2010 Assistant Coordinator,

Assistant,

Rezky Amelia Waji, S. Si.

Sulfianto 061 414 025

Known by Lecturer of responsibility

Prof. Dr. Ir. Yusminah Hala NIP: 1961 12 12 1986 01 20 02

CHAPTER I INTRODUTION A. Background A simple and specific medium consisting of chitosan, trypticase, Tween-80 and agar is devised to isolate the organisms directly from the clinical specimens and to produce germ tubes. The isolation of independent bacterial species from various environmental sources is important in all branches of microbiology since bacteria are ubiquitous and live in microbial communities of mixed populations. Populations in microbial communities or ecosystems may interact and cooperate in their efforts to obtain nutrients from the environment with the waste products from one group of microorganisms serving as nutrients for another. Alternatively, the metabolic wastes from fermentation processes of some bacteria in a population (for example acid production) may provide a favorable ecological niche for bacteria that prefer to grow at low pH. New appreciation of the importance of cellular heterogeneity, coupled with recent advances in technology, has driven the development of new tools and techniques for the study of individual microbial cells. Because observations made at the single-cell level are not subject to the "averaging" effects characteristic of bulkphase, population-level methods, they offer the unique capacity to observe discrete microbiological phenomena unavailable using traditional approaches. As a result, scientists have been able to characterize microorganisms, their activities, and their interactions at unprecedented levels of detail. All living things need nutrient to their growth and development. Nutrient is main material that is used to build new cellular components and to produce energy that is needed in the cell life process. To stimulate the microbe’s growth the media that is used must contain components that are needed by those microbes. Growth and death rates of microorganisms are greatly influenced by number of environmental

factors such as solutes and water acidity, temperature, oxygen requirement, pH, pressure and radiation. To prove that statement we must to do this experiment. B. Purpose This experiment was done to know the influence of environmental factors to the microbial growth. C. Benefit The benefits of this experiment are: 1.

As literature reference to the next observation.

2.

As materials to the next scientist.

CHAPTER II PREVIEW OF LITERATURE Bacteria live within the widest temperature range in all organisms. Some species live at ocean depths of 27m3 meters where the temperature is close to 350ºC. They have been found growing in Artic ice in the atmosphere. Bacteria are present in the nose, intestines, skin, and in the air you breathe. One reason bacteria can survive in so many environments is that some bacteria do not require oxygen. Most species of bacteria need oxygen to live. They are called aerobic bacteria. Bacteria that do not need oxygen to live are called anaerobic (Daniel, 1987: 94). Microbial growth is greatly affected by chemical and physical nature of their surroundings instead of variations in nutrient levels and particularly the nutrient limitation. For successful cultivation of microorganisms it is not only essential to supply proper and balanced nutrients but also it is necessary to maintain proper environmental conditions. Thus, understanding of environmental influences on the growth of microorganisms becomes mandatory. As bacteria shows divers food habits, it also exhibits diverse response to the environmental conditions. Growth and death rates of microorganisms are greatly influenced by number of environmental factors such as solutes and water acidity, temperature, oxygen requirement, pH, pressure and radiation (Anonima, 2010). Bacterial growth usually refers to an increase in the number of bacteria, rather than to an increase in the size of an individual cell. A colony is a large group of bacteria, such as that grown on a nutrient plate in a laboratory. All the of a colony are descendants of a single bacterium. All bacteria need food and water and many need oxygen. Other factors that influence growth are temperature, sunlight, and chemicals. Limiting these growth factors helps prevent food spoilage due to bacterial action (Graham, 1986: 302-303). According to Anonimb (2010), knowledge of the factors that favor or inhibit the growth of the microorganisms is important in understanding the principles

of food six major factors: 1. Moisture 2. Oxygen¬spoilage and preservation. 3. Temperature 4. Acidity, pH 5. Nutrients 6. Growth inhibitors 1. Effect of moisture on microbial growth, water is essential for the growth of all living organisms. Has many important functions in the growth of microoranisms and in enzyme activity.

Preserving techniques such as dehydration,

concentration, freezing¬ Mainly¬are based on making water unavailable for the microorganisms.

3 methods for making water unavailable: 1. Increasing the

solute concentration; removing water, adding of solutes (salt, sugar) 2. Addition of hydrophilic (water-binding) colloids (gels, pectins, gums) 3. Bringing water to a solid phase (freezing) 2. Osmotic Effect, water is transported into and out of the¬ microbial ¬cell through the semi-permeable cell membrane (wall) by osmosis. If solute¬Water es from the less dense medium to the more dense. Concentration of the food (growth medium of microorganisms) is increased water flows from the microbial cell to its surrounding. Microbial cell shrivels (shrinks) when osmoregulatory capacity of the cell is exceeded (plasmolysis). Shrinking of cells retards the metabolic activity. 3. Existance of water in foods, bound water: An integral part of the living tissue, vital to all Free water: Exists in and around¬processes associated with the cell. The tissue or cell. Important for metabolism and survival of Amount of water available for microorganims is¬microorganisms. Expressed in of water activity. aw = Po/Pow (ERH) at a given T, 0.0 < aw < 1.0 Temperature, especially on land, is an important ecological factor. Bacteria can live within the greatest temperature range. Some bacteria form endospores and can withstand temperatures above the boiling point and far below the freezing point of water. For this reason, bacteria are found almost everywhere. Some sores and seeds can survive temperatures that would kill a mature plant. In this way, the species survives extreme temperatures (Oram: 1986: 648).

CHAPTER III OBSERVATION METHOD

CHAPTER IV OBSERVATION RESULT AND DISCUSSION

B. Discussion In our experiment we just use 3 environmental factors; they are temperatures, acidity (pH), and toxic chemist compound. 1. The influence of temperature Based on our group data, seemed that in the temperature 5ºC, the Nutrient Broth that contaminated with Escherichia coli still transparent, found thin sediment and sheath, and there is not found foam. In the temperature 30 ºC the medium change to turbid, has no foam, has thick sediment, and still has sheath. While in the temperature 50 ºC the medium become transparent, has no sediment and foam. From the explanation above, we can see the turbidity of the medium is always changing. In the 5 ºC, the medium is transparent because the microbe is in desired condition. The enzyme is still in inactive condition, it can be seen by the sediment that found in the top of tube. In the 30 ºC, the medium become turbid. It signs that the enzymes start to active. In the temperature 50 ºC, the medium become transparent. It signs that the denaturation of enzyme is has done. Most of the others group has similar data wit us. Environmental temperature is one of the most important factors affecting the growth rate of microbes. There is a minimum temperature, below which growth does not occur. As we rise above the minimum, rate of growth increases in accordance with the laws governing the effect of temperature on the chemical reactions that make up growth. These reactions are mostly enzyme catalysed. However, a point is reached the optimum temperature when there is also a very rapid increase the rate of inactivation of heat sensitive cell components, like enzymes, ribosomes, DNA, membranes etc. Above an optimum temperature, this heat denaturation will occur so rapidly that there is a corresponding rapid drop in the rate of growth to give a maximum temperature for growth for that particular microorganism. Most microbes are capable of growth in a temperature range of 203O"C. Most microorganisms have a growth optimum between 20 and 40°C and are

called mesophilic. Those inhabiting cold environments such as polar areas can prow at much lower temperatures (Anonima, 2010). 2. The Influence of Acidity (pH) In this experiment we use pH 3, 7, and 9 to determine the microbe that can be found. In the pH 3, the NB is transparent, has no sediment and foam. In the pH 7, the medium become turbid, much sediment has sheath and has no foam. While in the pH 9 the medium become rather turbid, little sediment, has sheath and has no foam. Increasing the acidity of foods, either through fermentation or the addition of weak acids, has been used as a preservation method since ancient times. In their natural state, most foods such as meat, fish, and vegetables are slightly acidic while most fruits are moderately acidic. A few foods such as egg white are alkaline. It is well known that groups of microorganisms have pH optimum, minimum, and maximum for growth in foods. As with other factors, pH usually interacts with other parameters in the food to inhibit growth. The pH can interact with factors such as aw, salt, temperature, redox potential, and preservatives to inhibit growth of pathogens and other organisms. The pH of the food also significantly impacts the lethality of heat treatment of the food. Less heat is needed to inactivate microbes as the pH is reduced (Anonimc, 2010). Same with the range of temperature, the pH also has role to the bacterial growth. It can be seen from the sediment that found. In the neutral condition, the enzyme of bacterial is work optimally so we can see in the pH 7 the medium become turbid. It condition also found in the others group. 3. The influence of toxic chemist compound In this experiment, we use many kinds of materials like soap, sulfur soap, medicines, and tooth paste. But in this case, we just found 4 data, and the others can be said failed. For the first, the paper dish was submerging to the Amoxylin (material). This material has different dilution there are 30%, 50% and 100%. After 60 minutes, the paper dish was taken in the surface of medium. We used 2 methods (pour and

spread method). After incubated for 24 hours, we found the zone area. In the spread method, especially in the dilution 30% the shortest zone is 2.1 cm while the longest is 3.4 cm, in the dilution 50%, the shortest zone is 2 cm while the longest zone is 2.9 cm. in the 100% solution, the shortest zone is 1.8 cm while the longest zone is 2.5 cm. while if each of them are decreased with the diameter of paper dish, so the result in order from 30%, 50% and 100% are 2.6 cm, 2.3 cm and 2.2 cm. In this, the pour method is failed.

The Amoxylin form zone area in the medium (pour method) that contaminate with Stapylococcus aureus.

The next is using Resik V and Candida albicans. The paper dish is also submerged in the Resik V for 60 minutes. After incubated for 24 hours, we found the zone area. In the spread method, especially in the dilution 30% the shortest zone is 2.0 cm while the longest is 3.0 cm, in the dilution 50%, the shortest zone is 1.5 cm while the longest zone is 2.0 cm. in the 100% solution, the shortest zone is 2.0 cm while the longest zone is 2.5 cm. while if each of them are decreased with the diameter of paper dish, so the result in order from 30%, 50% and 100% are 2.35 cm, 1.6 cm and 2.1 cm. In the pour method, in the dilution 30% the shortest zone is 1.7 cm while the longest is 3.2 cm, in the dilution 50%, the shortest zone is 1.0 cm while the longest zone is 2.3 cm. in the 100% solution, the shortest zone is 2.0 cm while the longest zone is 2.5 cm. while if each of them are decreased with the diameter of paper dish, so the result in order from 30%, 50% and 100% are 2.3 cm, 1.5 cm and 2.5 cm. this data indicate the pour and spread method just has little different.

In the tooth paste (pepsodent) we also found zone area. In the 50% the shortest zone is 1.5 cm while the longest zone is 2.2 cm. in the 100% solution, the shortest zone is 1.5 cm while the longest zone is 2.0 cm. while if each of them are decreased with the diameter of paper dish, so the result in order from 50% and 100% are 1.7 cm and 1.6 cm. in this the spread method is failed. From the picture seem the zone is entered by microbial, it can be happened because there is another microbe except the Staphylococcus aureus that contaminate with the medium.

Halogen is group of chemist compound that mostly used as preventive materials for microbes. Halogen is strong oxidation, so finally this character very effective in damage the important compound in the microbial cell. Iodine is one of microbial preventive that nice to use (Hala, 2009: 54). Added

antimicrobial

compounds

can

have

an

interactive

or

synergisticeffect with other parameters of the formulation. One example is the interaction with pH. Many preservatives have an optimum pH range for effectiveness. Other factors include aw, presence of other preservatives, types of food constituents, presence of certain enzymes, processing temperature, storage atmosphere, and partition coefficients. The effective use of combinations of preservatives with other physicochemical parameters of a food formulation can stabilize that food against spoilage organisms or pathogens. Leistner systematically developed the “hurdle concept” to describe these effects. The hurdle concept states that several inhibitory factors (hurdles), while individually unable to inhibit microorganisms, will, nevertheless, be effective in combination. A classic example of applying the hurdle concept is the antibotulinal stability of certain shelf-stable processed cheese formulations. Combinations of moisture, total salt, and pH have been shown to allow

for the safe storage of these products at room temperature for extended time even though the individual factors, taken singly, would not that practice. In combination products, the effectiveness of an antimicrobial may be altered by other factors including the potential for migration of the antimicrobial to other components of the food and the different food parameters at the interface areas (Anonimc, 2010). Many chemical compounds selectively inhibit microbial activity These compounds act either by inactivating a necessary enzyme needed¬ for growth, by denaturing the protein portion of a cell or by causing physical damage to certain parts of the cell like breaking the cell A microrganism growing in food may produce substances¬wall. inhibitory to other organisms or to destroy compounds inhibitory to its growth. Basis for production of antibiotics. Example: Pencillin is produced by moulds (aspergillus) and retards growth of bacteria (Anonima, 2010)

CHAPTER V CONCLUSION AND SUGGESTION A. Conclusion Based on the observations that have done, we can conclude that the microbial growth can be influenced by the environmental factors like the temperatures, acidity (pH) and the toxic chemist compound. B. Suggestion . 1. Ought to all assistant come at the practice day, so can guide the practical for each groups. 2. Ought to the practical came in the laboratory no late, must be discipline. 3. Ought to keep the cleaning the laboratory and ought to comply the rule, when after equable and difficult for using the tools, in order that observation, the tools when has used is cleaned and saved for it’s place.

BIBLIOGRAPHY

Anonima. 2010. Factors that Influence Microbial Activity. http://www.idoub.com/doc/17275885/5268-Factors-That-InfluenceMicrobial-Activity. Accessed on January 02nd 2010. Anonimb. 2010. The Influence of Environmental Factors on Growth. http://www.studentsguide.in/microbiology/microbial-nutritiongrowth/the-influence-of-environmental-factors-on-growth.html. Accessed on January 02nd 2010. Anonimc. 2010. Factors that Influence Microbial Activity. http://www.publichealthgreybruce.on.ca/FoodSafety/Temperature_Etc/ MicrobialGrowthInfluences.html. Accessed on January 02nd 2010. . Daniel, Lucy. 1987. Focus on Life Science. Merrill Publishing Company. United States of America. Graham, Linda. 1986. Biology. Harcourt Brace Jovanovich. New York. Hala, Yusminah. 2009. Penuntun Praktikum Mkrobiologi Dasar. Laboratorium Mikrobiologi Jurusan Biologi UNM. Makassar Oram. 1986. Biology Living Systems. Merrill Publishing Company. London.

Ini adalah tembolok Google' untuk http://www.idoub.com/doc/17275885/5268-Factors-That-InfluenceMicrobial-Activity. Gambar ini adalah jepretan laman seperti yang ditampilkan pada tanggal 24 Des 2009 17:09:26 GMT. Sementara itu, halaman tersebut mungkin telah berubah. Pelajari Selengkapnya Factors that influence microbial activity ¬ A knowledge of the factors that favor or inhibit the growth of the microorganisms is important in understanding the principles of food Six major factors: 1. Moisture 2. Oxygen¬spoilage and preservation. 3. Temperature 4. Acidity, pH 5. Nutrients 6. Growth inhibitors Effect of moisture on microbial growth ¬ Water is essential for the growth of all living organisms. Has many important functions in the growth of microoranisms and in enzyme activity. Preserving techniques such as dehydration, concentration, freezing¬ Mainly¬are based on making water unavailable for the microorganisms. 3 methods for making water unavailable: 1. Increasing the solute concentration; removing water, adding of solutes (salt, sugar) 2. Addition of hydrophilic (water-binding) colloids (gels, pectins, gums) 3. Bringing water to a solid phase (freezing) Osmotic Effect Water is transported into and out of the¬ microbial ¬cell through the semi-permeable cell membrane (wall) by osmosis. If solute¬Water es from the less dense medium to the more dense. concentration of the food (growth medium of microorganisms) is increased water flows from the microbial cell to its surrounding. Microbial cell shrivels (shrinks) when osmoregulatory capacity of the cell is exceeded (plasmolysis). Shrinking of cells retards the metabolic activity. (0.85% salt) Existance of water in foods ¬ Bound water : An integral part of the living tissue, vital to all Free water : Exists in and around¬processes associated with the cell. the tissue or cell. Important for metabolism and survival of Amount of water available for microorganims is¬microorganisms. expressed in of water activity. aw = Po/Pow (ERH) at a given T, 0.0 < aw < 1.0 Effect of oxygen on microbial growth Essential element for the metabolic¬ activity Free atmospheric oxygen in air. Some organisms can utilize oxygen in¬ Microorganisms are classified according to their oxygen¬C-H-O requirements: aerobic : grow in the presence of atm. oxygen anaerobic : grow in the absence of atm. oxygen facultatively anaerobic : grow either in absence or presence of oxygen microaerophilic : grow in the presence of limited oxygen In the presence of atmospheric oxygen¬ microbial activity leads to a slow oxidation of foods: Carbohydrates → CO2 and H2O Amino In the¬acids → NH3 , CO2 and H2O Fats → free fatty acids, CO2 and H2O presence of limited oxygen oxidation results in intermediary products; alcohol, lactic acid, acetic acid, formic acid. C6H12O6 + 6O2 → 6CO2 + 6H2O + 674 calories C6H12O6 → 2C2H5OH + 22 calories Effect of temperature on microbial growth Optimum, minimum and maximum temperatures for¬ microbial Microorganisms are classified w.r.t. their¬growth. min. T. : refrigeration, freezing max. T. : heat processing temperature requirements. Dependence of growth of microorganisms on¬ temperature Three different effects of¬is largely related to activation and inactivation of enzyme systems in microorganisms. temperature contribute to the death of microbial cells: 1. Denaturation of proteins (enzymes) by heat 2. Intoxication due to accelerated metabolic reactions 3. Changes in essential lipids. Melting points of the fats found in the organisms and temperature ranges of death are related. Effect of acidity on microbial growth Microorgisms¬ affected by pH of foods, since they do not have any mechanism to adjust Microorganisms have different minimal, maximal and¬their internal pH. optimal pH-levels for growth: optimum Bacteria Molds Yeasts 6.5-7.5 4.0-6.8 4.5-6.5 maximum 9.0 8.0-11.0 8.0-8.5 minimum 4.5 1.5-3.5 1.5-3.5 Acid foods : pH¬ < Pasteurization (heat treatment below boiling¬4.5 . Pathogenic micro-organisms cannot survive. temperature) For pH¬is sufficient for acid foods. > 4.5, sterilization (severe heat treatment above boiling temperatures) is needed to destroy pathogenic microorganisms and their toxins. pH ranges for major foods Fruits ¬: 3.0 – 4.5 Vegetables : 4.6 – 6.6 Meat : 5.5 – 6.8 Milk : 6.0 – 6.8 Acetic-,¬Pickling : Production of acids in foods by fermentation. citric-, lactic-, propionic-, benzoic-, and sorbic acids added to foods pH also affects resistance of¬for preservation (acidulants) microorganisms to destruction during heating, drying and other processes

Effect of nutrients on microbial growth ¬ ¬Microorganisms depend on nutrients for both energy and growth. Different microorganisms possess different enzyme systems which are ¬specific in breakdown of certain nutrient compounds. Microbial growth can be enhanced by enriching the growth medium with specific Creating¬nutrients and it can be retarded using growth inhibitors. specific nutrient media is a very useful tool both in laboratory work and in industry for isolation and growth of certain microorganisms. Growth inhibitors Many chemical compounds selectively inhibit¬ microbial activity These compounds act either by inactivating a necessary enzyme needed¬ for growth, by denaturing the protein portion of a cell or by causing physical damage to certain parts of the cell like breaking the cell A microrganism growing in food may produce substances¬wall. inhibitory to other organisms or to destroy compounds inhibitory to its growth. Basis for production of antibiotics. Example: Pencillin is produced by moulds (aspergillus) and retards growth of bacteria. Antibiotics used to control microbial growth 1. 2. 3. Cell wall inhibitors Protein synthesis inhibitors DNA replication inhibitors Ini adalah tembolok Google' untuk http://www.studentsguide.in/microbiology/microbial-nutrition-growth/theinfluence-of-environmental-factors-on-growth.html. Gambar ini adalah jepretan laman seperti yang ditampilkan pada tanggal 18 Des 2009 20:24:39 GMT. Sementara itu, halaman tersebut mungkin telah berubah. Pelajari Selengkapnya The Influence of Environmental Factors on Growth Microbial growth is greatly affected by chemical and physical nature of their surroundings instead of variations in nutrient levels and particularly the nutrient limitation. For successful cultivation of microorganisms it is not only essential to supply proper and balanced nutrients but also it is necessary to maintain proper environmental conditions. Thus, understanding of environmental influences on the growth of microorganisms becomes mandatory. As bacteria shows divers food habits, it also exhibits diverse response to the environmental conditions. Growth and death rates of microorganisms are greatly influenced by number of environmental factors such as solutes and water acidity, temperature, oxygen requirement, pH, pressure and radiation Ini adalah tembolok Google' untuk http://www.publichealthgreybruce.on.ca/FoodSafety/Temperature_Etc/MicrobialGrowthInfluences.htm. Gambar ini adalah jepretan laman seperti yang ditampilkan pada tanggal 27 Des 2009 20:04:06 GMT. Sementara itu, halaman tersebut mungkin telah berubah. Pelajari Selengkapnya Chapter III Factors that Influence Microbial Growth Increasing the acidity of foods, either through fermentation or the addition of weak acids, has been used as a preservation method since ancient times. In their natural state, most foods such as meat, fish, and vegetables are slightly acidic while most fruits are moderately acidic. A few foods such as egg white are alkaline. Table 3–3 lists the pH ranges of some common foods. Added antimicrobial compounds can have an interactive or synergistic effect with other parameters of the formulation. One example is the interaction with pH. Many preservatives have an optimum pH range for effectiveness. Other factors include aw, presence of other preservatives, types of food constituents, presence of certain enzymes, processing temperature, storage atmosphere, and partition coefficients. The effective use of combinations of preservatives with other physicochemical parameters of a food formulation can stabilize that food against spoilage organisms or pathogens. Leistner systematically developed the “hurdle concept” to describe these effects (Leistner 1995). The hurdle concept states that several inhibitory factors (hurdles), while individually unable to inhibit microorganisms, will, nevertheless, be effective in combination. A classic example of applying the hurdle concept is the antibotulinal stability of certain shelf-stable processed cheese formulations. Combinations of moisture, total salt, and pH have been shown to allow for the safe storage of these products at room temperature for extended time even though the individual factors, taken singly,would not that practice (Tanaka and others 1986). In combination products, the effectiveness of an antimicrobial may be altered by other factors including the potential for migration of the antimicrobial to other components of the food and the different food parameters at the interface areas.There are a number of food formulations that, either by addition of preservatives or through the application of the hurdle concept do not require refrigeration for microbiological stability or safety. However, in the absence of a well defined and validated microbiological model, it is usually difficult to evaluate the microbiological safety of these products. In the majority of these cases, the application of appropriate microbiological challenge testing is the most effective tool for judging the suitability of these formulations for nonrefrigerated storage.