Pure Culture Methods and Gram Staining

Pure Culture Methods and Gram Staining Individual and well separated colonies are crucial when working with bacterial cultures. Pure culture method involves the step of taking a small and well isolated colony and transferring it to a sterile growth medium in a suitable culture vessel (Ryan Ray, 2010). There are three types of commonly used methods to produce pure cultures. They are the streak plate, spread plate and pour plate. All these methods require the use of aseptic technique. Streak plate is suitable for the direct plating of media that contains a large number of cells. To prepare a streak plate, a colony or a loopful of bacteria culture will be taken using a sterile inoculating loop and then the sample will be streaked several times over the surface of the solid growth media. Single cells are obtained along the streak as each streak represents a dilution process. The bacteria will grow into a separate colony and to be used for pure culture after being incubated at optimum condition (Carter Wise, 2004). Another alternative to obtain pure culture is the spread plate method where a small volume of suspension is spread evenly over the surface of an agar plate. The bacteria colonies will be evenly distributed over the surface of the agar plate after incubation. Larger colonies are the colonies that are well isolated. Pure culture can also be done by using the pour plate method. The diluted sample is suspended in agar growth at about 50 à ¢Ã‚ Ã‚ °c. The mixture is then poured into a suitable vessel and incubated. The bacteria colonies will grow throughout the agar plate. The colonies within the agar will be very tiny and difficult to see and count as compared to those which grow on the surface of the agar. Objectives: The purpose of conducting this experiment was to understand the principles and aim of obtaining pure cultures, to compare the separation of bacterial colonies using streak plate, pour plate and spread plate techniques and to observe and compare the colonial features of isolated bacterial colonies on solid nutrient media as well as the morphological cellular features of isolated bacterial colonies using the gram stain method. In addition, the experiment explained about the principles of gram stain method and allowed the interpretation of each of the steps in gram staining. Method: Refer to lab manual page 32-36. Results: In this experiment, mixture of Bacillus cereus, Escherichia coli and Staphylococcus aureus was used to prepare pure culture using the three methods which are the streak plate, spread plate and pour plate. The plates were incubated and the colony morphology of the plates was observed. The cellular morphology of the bacteria was determined using the gram stain method. The results were recorded and tabulated in a table. Table 1: colony morphology and cellular morphology of different organisms. Organism Colony morphology Cellular morphology Gram stain Shape Arrangement Bacillus cereus Irregular, opaque and cream in colour, flat Positive (purple colour) Rod Chain Escherichia coli Circular, center, smooth, translucent, white (small), raised (Cham Tan, Group 1). Negative (pink colour) Rod Cluster Staphylococcus aureus Circular, smooth, some yellow, some white, convex. Positive (purple colour) Cocci Cluster Discussion: 1) Bacillus cereus was obtained from the big bacteria colony. When observed from the agar plate, it appeared to be irregular in shape, flat, opaque and cream in colour. It is a gram positive bacteria. So when gram stain was performed, the bacteria appeared purple in colour under the microscope. Bacillus cereus is of rod shape and the arrangement is in the form of chain. It has ÃŽÂ ²- capsule and is non motile. For Escherichia coli, it was obtained from the medium colony. When observed from the agar plate, it appeared to be circular in shape and mostly was located at the center of the agar. The bacteria colony appeared to be smooth, translucent, and some were white in colour (Cham Tan, Group 1). Escherichia coli is a gram negative bacteria. Therefore, it was pink in colour under the microscope. It has rod shape and its arrangement is in cluster form. It is motile and is a type of non spore forming bacteria. Staphylococcus aureus was from the small bacteria colony. It is circular, smooth, convex and some are yellow in colour while some are white in colour. It is a gram positive bacteria where it showed purple colour when under the microscope. The shape for Staphylococcus aureus is cocci and it is in cluster form. It is a non spore forming bacteria and is non motile. The cells seen in the original mixture matched with those obtained in the pure culture. Streak plate method is suitable for the direct plating of media that contains a large number of cells and as for spread plate method, a small volume of suspension is spread evenly over the surface of an agar plate. On the other hand, bacteria are suspended and grow throughout the agar plate for pour plate method. 2) Spread plate will be more suitable to produce well isolated single colonies from a broth culture that contains a mixture of organisms as the bacteria will be on the surface or the agar and not suspended. This way, the isolated colony can be counted and also be obtained easily compared to streak plate and pour plate method. When the bacteria is taken from a mixed broth culture, the colonies will grow and overlapping each other after being incubated. When the bacteria is incubated using pour plate method, the bacteria grown will be smaller and it will be harder to obtain a well isolated colony as they grow throughout the media. Agar has a higher melting temperature than gelatin. Gelatin will melt and becomes soft when bacteria is being incubated on gelatin media at their optimum temperature which is 37 à ¢Ã‚ Ã‚ °c. 3) Agar is used in preference to gelatin for making solid media as agar will remain solid at the optimum temperature for the growth of most bacteria. Therefore, the property of agar makes it to be more effective than gelatin as a solidifying agent (Muir Ritchie, 1953). 4) Bacteria that are well separated grow as isolated colonies without affecting the growth process as these bacteria cell do not merge or overlap with other bacteria cells in compete for sources. The growth of isolated bacteria will not be limited by the depletion of the nutrients (Cruickshank, 2005) 5) Individual colony does not always consist of one type of bacterium as the bacteria could be from a mixed culture of different organisms. Therefore, an individual colony does not always originate from a single parent cell. Before staining process, bacteria culture has to be dried and fixed. Heat fixation is convenient and it retains the cell wall structure. 6) Smear preparation has to be heat fixed through the Bunsen burner flame to kill the bacteria and make them adhere to the slide. Besides, it will also allow the cells to stain better during the staining process. A good smear preparation will allow a better microscopic view of the bacteria cellular features. Correct techniques in preparation of smear are important. 7) If the whole colony is used to make the smear, the smear will be too thick. Thick smear will cause the difficulties in distinguishing individual cell. In addition, the stain might not be completely washed out. If the bacteria used is gram negative, the cells will appear purple in colour giving gram positive results which is wrong. If the bacteria is gram positive, the intensity of purple colour will be so high that it will not be easy to differentiate the cellular features of the cell. 8) Cell wall determines the shape of a cell. Cells that lose their cell wall will change its shape. However, changing the shape of the cells will not affect the reaction to gram stain. Hence, there will be no association between cell shape and reaction to gram stain The cell wall structure of gram positive bacteria is different from the cell wall structure of gram negative bacteria. The cell wall of gram positive bacteria has a thick peptidoglycan layer while the peptidoglycan layer in the cell wall of gram negative bacteria is thinner. The thick peptidoglycan layer of the cell wall of gram positive bacteria retain the crystal violet dye and stain purple even after decolourisation but for gram negative bacteria, it is decolourised by the decolourising agent. Gram negative bacteria retain the second dye and stain pink. 9) The cell wall structure of a bacterial cell is important to determine its gram reaction. 10) The third step which is the decolourisation step of the gram staining procedure is important to determine the outcome of the result. The time taken should not be too long or too short as over-decolourising will cause the cell not able to retain the crystal violet dye and appear colourless. If the decolourising time is too short, the gram negative cells will remain purple giving a gram positive result. Conclusion: In conclusion, pure culture can be obtained by using several methods which are the streak plate method, spread plate method and pour plate method. Using the pure culture, the separation of bacterial colonies, the colonial features and cellular features can be compared. Aseptic technique should be followed all the time to prevent introducing new contaminants to the environment.

Thermodynamics of the Dissolution Borax

Thermodynamics of the Dissolution of Borax Lina Jawadi Objectives: * Study a system of salt and water solution. * Determining a variety of important thermodynamics quantities from the solubility information at various temperatures. Background: The salt and water solution in this experiment has relatively simple solubility equilibrium of borax in water. Na2B4O7 . 10 H2O 2Na + + B4O5(OH)42- + 8H2O This reaction is an equilibrium process and 8 water molecules from the hydrated salt are lost to the reaction medium. The equilibrium constant expression for this reaction is:K = [Na+]2 [B4O5(OH)42-] [H2O]8 [Na2B4O7 . 10 H2O] In this experiment we will always make sure there is some solid borax remaining in the sample mixture before removing some of it to analyze it. Therefore, we can assume that the concentration of solid borax is constant. In addition, the water molecules which were originally part of the borax’s crystalline matrix is lost to the sample mixture; however, it doesnâ₠¬â„¢t significantly affect the concentration of the water. The equilibrium constant expression can now be simplified to become: K = [Na+]2 [B4O5(OH)42-]The first equilibrium expression and the balanced solubility equilibrium reaction allow us to express either borate ion or sodium ion in terms of the other. So, it is possible to determine the constant in terms of either ion. After substituting borax ion in place of the sodium ion, ([Na+] = 2 [B4O5(OH)42-] , K = (2 [B4O5(OH)42-] )2 * [B4O5(OH)42-] ) we get: K = 4 [B4O5(OH)42-]3 . Finding the concentration of borate ion in any sample at any given temperature gives us the solubility product at that temperature. Equipment: * 5mL pipet * Test tubes * Marker * Hot plate * 250 mL beaker * Flask Electric balance Procedure: 1. Using the pipet add 5mL of distilled water to 10 test tubes. 2. Mark the level with the marker and pour the water out. Mark the test tube with the assigned temperature. 3. Weigh 30-32g of solid sodium borate decahydrat e (borax) in a 250 mL beaker and then add 150 mL of water. 4. Place the mixture on a hot plate, but don’t allow its temperature to exceed 50oC. 5. After all the borax dissolves, add more and let the temperature reach 45oC. 6. Once it starts slightly exceeding 45oC, remove it from the hot plate and place instead a beaker filled with 150 mL of distilled water. . Continue stirring the mixture until it reaches the desired temperature. 8. Quickly pour 5 mL of the mixture in two test tube without transferring any solid borax. (record the temperature before and after the transfer. ) 9. When the water bath reaches 45oC, place the test tube in it until precipitation of borax has dissolved. 10. In a flask with 50-75 mL of water and 10 drops of bromocresol green indicator, add 125 mL of the borax solution. 11. Before titrating the borax with acid make sure that it has a blue color.Using buret filled with 50 mL oh HCl, add the acid to the borax until it reaches the endpoint, which is whe n the solution turns from a blue color to a yellow. Record the initial and final volume. (For calculations: find the moles of borax using the volume of HCl and its molarity. Then find the solubility product constant and plot the ksp vs. (1/t) graph and from it obtain the values of ? H and ? S. Make sure the temperature is in kelvin when doing the calculations. Finally, find the value of ? G using both equations and plot the ? G vs. time graph. )

Cross-Cultural Determinants of Employee Motivation in Starbucks Company

Introduction Starbucks has served as a milestone in the coffee industry and is a massive organization in terms of people employed and stores owned. At the current time it has revenue of $10.7 billion and owns 16,850 shops in 40 countries. Starbucks is clearly the world’s top coffee retailer, it employs 137,000 employees or â€Å"partners† as it likes to call them. Howard Schultz, the CEO of Starbucks, considers that ‘the tip of success in Starbucks is not coffee but employees’. He constantly builds upon the working experience of employees, providing chances of promotion, and treating workers as working partners is their way to operate sustainability. He firmly believes that the spirit of Starbucks is employees and feels honored about the value of Starbucks employees. Many theorists believe that â€Å"it is necessary to have a perfect education and training policy for better performance in a company† (Michelli, 2006). Despite serving in many countries, Starbucks h as a similar organizational structure; as a result, it does not take into account the cross cultural determinants. It has been criticized for its approach; also because, employees of some countries like UK are not as satisfied as employees from Poland and Germany, thus Starbucks must make use of cross-cultural determinants in order to improve its management methords. One of the most proficient theory, the Hofstede theory states that the motivational factors of every country are different and thus must be looked into before a company, such as Starbucks sets its motivational methods. Along with Hoftsede it talks about Management and Motivation in reference to the Grid/Group Theory by Douglas, which strives to classify different cultures in relation to being hierarchist, individualist, egalitarian and fatalist. It also talks about the ‘Cultural Theory’ and ‘Organizational Theory’ in relation to Starbucks. This research attempts to access these theories in ref erence to Starbucks, and its motivational methods across nations. It looks at a comparison between the way Starbucks company treats or must treat its employees across UK, Poland and Germany. Brief Overview The Starbucks Company is a vast and well constructed multi-national, which serves in 40 countries. It has to keep in mind various cross-cultural determinant while bringing in its motivational schemes. However, it has been criticized for not taking into account, cross-cultural determinants when building its management cultural across countries. It is often assessed, that the employees of countries like UK, seem to be less motivated than employees from Poland and Germany. This paper talks about all possible schemes in relation to motivational theories, that can be adopted by Starbucks,chiefly the Hofstede theory. The factors of this theory are highly relevant and can be implemented in various ways to improve performance. The first factor, Power distance can be defined as â€Å"the extent to which the less powerful members of institutions and organizations within a country expect and accept that power is distributed unequally† (Hofstede 1991, p. 28). UK and Germany, are ranked as a low power distance society, where the relationship between bosses and subordinated is of interdependence, treating each worker equally and calling them ‘partners’. There, the managers of Starbucks are likely to place a greater importance on labors’ rights as compared to managers in Poland, which ranks as a high power distance country. However, in Poland there is a hierarchical social system, thus, it is said that their ‘ideal boss is a benevolent autocrat’. Another factor of the Hofstede theory is Masculinity, the dominant values in society being material success versus femininity, caring for others and the quality of life. UK, Poland and Germany, are Masculine societies, driven by competition, achievement and financial success. In these countries, people’s performance is highly valued and people ‘live in order to work’. Starbucks too, beliefs in monetary based appraisals, it spends $300 million, on their employees’ welfare, much more than ‘they do on coffee beans’. Starbucks even gave its UK staff shares worth around ?4 million in their employee share scheme ‘Bean Stock’, followed by a Christmas cash bonus to staff worth ?1.5 million. Uncertainty Avoidance, is another of Hofstede’s theories, it classifies countries into being high in Uncertainty Avoidance; having strict rules and resistance to changes like Germany and Poland and low in Uncertainty Avoidance; having fewer rules and being welcome to changes like UK. This is an important factor to look into a country when bringing in new innovations, and the planning of how the change has to be implemented. Managers of UK can bring in new ideas easily and with more enthusiasm while managers in Germany and Poland have to bring in changes subtely because people resist from breaking orthodox norms uneasy. Starbucks went through many changes when it merged with Giornale, it was welcoming to his employees’ involvement and included them in every change, by 1987, and employees at Starbucks had begun buying into the changes. The theory includes a comparison between countries which have more, individualism everyone is expected to look after themselves and their immediate family against collectivism, and cultures in which people are bound into strong and cohesive groups. UK, Germany and Poland, are individualistic societies, where the route to happiness is through individual accomplishment. Here the company, in order to motivate its employees has to come up with schemes to provide them and their families’ advantages. The culture in Starbucks is of mutual advantage, thus workers usually do a fruitful job but all these factors must be kept in mind. Understanding all the cross-cultural determinants including these is crucial for a company which serves such a wide range of cultures; their observation along with development on these lines, must all be looked into, in order to bring out the best results. Another theory is the Cultural Theory’ which talks about the importance of culture, stating that is is too ‘important to be left undefined and unrefined, and analysts need a deeper awareness of the anthropological and sociological frameworks’ when refining their management attitudes. It outlines the effect on culture in relation to common objectives, employee motivation and loyalty. Setting of roles, leadership, innovation, setting incentives, tolerance and accountability. The setting of the corporate cultural is extremely subjective of the countries cultural as a whole. The Grid/Group theory is another theory based on cultural determinants, created by Mary Douglas, in 1996. It strives to study cultural relativism, which can be increased through a classification system taking into account ‘moral system, worldviews and ideologies’. This classification is built into two axes, based on individualism versus collectivism, including isolate/fatalist, hierarchist, individualist and sectarian groups. Each type is based on different classifications, power paradigms, moral values and individuality. In this paper, it is used to analyze, the classification of different cultures, such as UK, Germany and Poland into these categories, observing where their general workers fall, taking into account their employee, culture, market and forms of hierarchy. The paper also talks about Organizational Culture Theory which is based on performance, ‘organization effectiveness, employee commitment, employee satisfaction, culture type, culture strength and culture congruence’. This theory is talked about in relation to Poland, Germany and UK; assessing them based on all these assesses their management and motivational factors. Even though Starbucks operates in different countries, its organization culture is often the same. This can be a harmful strategy, as due to differing cultural determinants, the company must change its strategies relatively. If this is not done, the motivation of employees can be lowered and the management can fail to do its job. Thus, this paper talks about all these theories and the possibilities that they provide to Starbucks, in modifying its strategies based on varying cross-cultural determinants. Objective This paper is set to analyze and evaluate the cross cultural determinants of Poland, UK and Germany, in order to find out the best ways to motivate the employees of those countries. It attempts to Find out the cross cultural determinants of these societies and the way the employees of these countries are treated. Methodology The Prime methodology used will be questionnaires that will be filled out by Starbucks employees across these countries. The questionnaire will be based on the Organizational Energy Questionnaire from ‘fully charged’ written by Heike Bruch, which is an instrument to measure a company’s energy state. The questions will include if the employees like what they do, do not have much drive feel relaxed in their job, feel angry in their job, feel enthusiastic in their jobs, have no desire to make something happen, speculate about the real intentions of management, have real care about company’s fate, are efficient in conducting work, behave in destructive manner, go out of their way to make company succeed and if they feel discouraged in their jobs. All these questions will convey about the general state of employees and their will be a separate questionnaire to observe the importance of cross-cultural determinants. References Heike Bruch and Bernd Vogel (2011). Fully Charged. United States of America: Harvard Business School Publishing. HOFSTEDE THEORY- Poland, (2011) [online]. [Accessed 2012]. Available from: . Penny Bassett (2004). CHINESE AND AUSTRALIAN STUDENTS’ CULTURAL PERCEPTIONS: A COMPARATIVE STUDY, Victoria University. Jim Boyer (2009). Understanding Hofstede’s Theory to Motivate Cross Cultural Employees. Business Insider [online]. (2011) [Accessed 6 May 2012]. Available from: Nicholson, N (1998) Encyclopedic Dictionary of Organizational Behavior Blackwell, pp 215 Hoovers [online]. [Accessed 2012]. Available from: . Starbucks Coffee [online]. [Accessed 2012]. Available from: . V S RAMA RAO (2009). The Hofstede Studies [online]. [Accessed 2012]. Available from: . Cultural Dimensions Theory [online]. (2010) [Accessed 2012]. Available from: . Zoe Wood (2010). Starbucks’ staff set to get free shares in incentive scheme. 19 December 2010. Starbucks [online]. [Accessed 2012]. Available from: . Employee Benefits [online]. (2011) [Accessed 2012]. Available from: . Projects [online]. (2011) [Accessed 2012]. Available from: . York Universit y [online]. (2011) [Accessed 2012]. Available from: .

The Exciting and Interesting Life of Mark Anthony in the...

Throughout the play of Julius Caesar, Mark Antony has shown multiple times the sides of him more in history and sometimes more of just a character. Mark Antony has had a very exciting and most interesting life. He has been through the thick and thin; the deaths of friends, loved ones, spouses, and so much more. It is pretty amazing that one person could conquer so much in a single lifetime. The history of Mark Antony is one of the most important parts of the history of Rome. Mark Antony was one of the most important characters of the Roman Empire. Born to Marcus Antonius Creticus and Julia Antonia in 83 BC, Antony was one of the bravest Roman generals who worked under Triumvir and Julius Caesar during 43-30 BC. â€Å"In your bad strokes, Brutus, you give good words;/ Witness the hole you made in Caesars heart,/ Crying â€Å"Long live! Hail, Ceasar!† Antony received his first overseas experience in the western portion of the Roman Empire during 57 to 55 BC. He served with the Roman governor of Syria, which was a province of Rome. Caesar conquered Gaul for Rome, and Antony assisted him in suppressing local rebellion against the Romans. In 50 BC after returning to Rome, Antony was elected a tribune, an office that represented the peoples interests. Antony came into the office at a critical time. Caesars command in Gaul was coming to an end, and a group in the Senate was set on bringing Caesar to trial for what they saw as his misuse of his power. Caesar depended upon the tribunes toShow MoreRelatedANALIZ TEXT INTERPRETATION AND ANALYSIS28843 Words   |  116 Pagesaction and the resolution are dispensed with altogether. Exposition and complication can also be omitted in favour of a plot that begins in medias res (â€Å"in the midst of things†). In much modern and contemporary fiction the plot consists of a â€Å"slice of life† into which we enter on the eve of crisis, and the reader is left to infer beginnings and antecedents – including the precise nature of the conflict – from what he or she is subsequently able to learn. Some stories are sometimes referred to as â€Å"plotless†