Journal of Xi'an University of Architecture & Technology ISSN No : 1006-7930 Growth Characteristics of Escherichia coli and Staphylococcus aureus Bacteria on Alternative Medium Leaves of Lamtoro (Leucaena leucocephala) Meidawati Suswandari*, Department of Primary School, Faculty of Teacher Training and Education, Universitas Veteran Bangun Nusantara, Sukoharjo, Indonesia Lamtoro leaf has a high protein content. The protein content is very suitable for bacterial growth. Because of the high cost of bacterial growth media for educational and research institutions, lamtoro leaves can be used as an alternative medium for bacterial growth in general. The purpose of this study was to determine the potential of lamtoro leaf as an alternative medium for bacterial growth in general. This research is descriptive. Alternative mediums of lamtoro leaf were tested for the growth of Escherichia coli and Staphylococcus aureus. Escherichia coli bacteria grow on three alternative medium plates. After final identification, there are Escherichia coli bacteria. Whereas the Staphylococcus aureus bacterium did not grow on seven plates of alternative medium despite being incubated for 48 hours. Lamtoro leaf has less potential as an alternative medium for bacterial growth in general. The lamtoro leaf medium can only be used as a growth medium for gram-negative bacteria. While the growth of gram-positive bacteria there is no growth due to the presence of active substances in lamtoro leaves. Key words: Leaves of Lamtoro, Alternative Media, Escherichia coli, Staphylococcus aureus Introduction Bacteria are single-celled creatures that are very small or microscopic. Hans Christian Gram divides bacteria based on the characteristics of cell walls through the Gram staining system, namely Gram Positive and Gram Negative bacteria (Elferia, et al, 1996; Elliot, 2013; Harvey, 2001; Clausen, Gildberg, and Raa, 1985). Gram-positive bacteria have a thick layer of peptidoglycan and a thin lipid layer on the cell wall, so after Gram staining, Gram-positive Volume XII, Issue VI, 2020 Page No: 1550 Journal of Xi'an University of Architecture & Technology ISSN No : 1006-7930 bacteria will be colored purple by violet crystal dye. Examples of Gram-positive bacteria include Clostridium tetani, Staphylococcus sp., Staphylococcus sp., Etc. While Gram-negative bacteria have a thin layer of peptidoglycan and a thick lipid layer on the cell wall, then after Gram staining, Gram-negative bacteria will turn red by safranin coloring. Examples of Gram- negative bacteria include Bacillus cereus, Clostridium botulinum, Escherichia coli, and so on (Elferia, et al, 1996). Bacteria can live in nature, are grown and developed on a substrate, called a medium. Most bacteria will grow on an artificial medium. Under the right conditions (nutrition, temperature, and atmosphere), a bacterium will grow in size and then divide through the process of binary fission into two identical cells. Both of these cells are able to grow and divide at the same speed as stem cells provided that their environmental conditions remain stable (Elliot, 2013; Harvey, 2001). Besides requiring suitable conditions, bacteria also need nutrients for growth in the medium. Nutrition in growth must contain all the elements needed to make a new organism biologically (Clausen, Gildberg, and Raa, 1985). The required elements include carbon sources, nitrogen sources, sulfur sources, and mineral sources. Carbon sources can be organic carbon, carbon dioxide or carbohydrate groups because carbohydrates are composed of carbon atoms, hydrogen and oxygen. The carbon source is used to support the growth of fermentation or respiratory growth in many organisms. For the growth process, bacteria also need nitrogen because nitrogen is a major component of protein and nucleic acids, generally about 10% of the bacterial dry weight (Thomas, Keat, Walker, and Mackinnon, 2013). Like nitrogen, sulfur is a component of many organic materials in cells. While the mineral source is needed by bacteria for enzyme function (Elferia, et al, 1996). From the classification of types of medium based on their form and function, the type of medium that is often used in educational, research and health service institutions is a general growth medium, for example, medium Nutrient Agar, Plate Count Agar and Nutrien Broth. Nutrient Medium Agar is a type of general medium with a solid form that is widely used because many bacteria can grow on the medium and the growth of the colony can be seen macroscopically. In educational institutions in general or for research activities, the need for a general growth medium must be fulfilled. However, in order to provide this common growth medium, it sometimes encounters cost constraints. Another obstacle is the place that provides the growth medium, most of the distributors are located in big cities, so that the general growth medium such as Nutrients is difficult to obtain even more so if the inspection site is located in rural areas or places with difficult to access locations while the availability of the medium very needed. Then an alternative medium is needed to replace the Nutrient Agar medium as a medium for bacterial growth. According to Leveau and Lindow (2005) and Willey, Sherwood, and Woolverton (2014), the best food base for bacterial growth is a medium that contains organic substances such as meat stew, vegetables, food scraps or herbs made by humans. Indonesia as an agricultural country has many sources of raw materials, including Lamtoro (Leucaena leucocephala) (Jones, 1979; Bairagi, Ghosh, Sen, and Ray, 2004). So far, lamtoro is often used by the community as a food supplement and as medicine. However, compared to lamtoro seeds, people often use lamtoro trees as reforestation, shade trees, prevent erosion or use wood sources of lamtoro trees as furniture. Volume XII, Issue VI, 2020 Page No: 1551 Journal of Xi'an University of Architecture & Technology ISSN No : 1006-7930 In terms of its function, many people use lamtoro seeds and trees for household or furniture industry needs. Whereas lamtoro leaf is only used by the community for animal feed. Although it can be used as animal feed, according to research conducted by Askar (1997) on ruminant animals and by Yurmiaty (2007) on rabbits, the results show that animal feed from fresh lamtoro leaves causes health problems in animals because there are anti-nutrient substances that are affect the work of enzymes in farm animals. So to overcome this problem, lamtoro leaves are used in other fields. According to Poedjiadi dan Supriyanti (2005), in 100 g lamtaro leaves contain 12.4 g carbohydrates, 6.5 g fat, 12.0 g protein, 128 g calories, 1500 mg calcium ions, 100 mg phosphorus ions and 2.5 mg iron ions . Seeing the presence of protein and carbohydrate content in lamtoro leaves, the lamtoro leaves have the potential as a medium for bacterial growth, because to support the growth of bacteria needed growth factors in the form of carbon and nitrogen sources found in lamtoro leaves in carbohydrate and protein content. In addition, the use of lamtoro leaves as an alternative medium for bacterial growth can also be a solution and a substitute for synthetic medium in the form of Nutrient Agar medium, which now has a quite expensive price for educational institutions and researchers. Research Method This type of research is a descriptive study to describe the growth of Escherichia coli and Staphylococcus aureus bacteria on an alternative medium of lamtoro leaf. This research was conducted data collection to obtain information by presenting and analyzing data that has been collected or deliberately collected (Luknis, 2014). Identification of Escherichia coli and Staphylococcus aureus Bacteria on Agar Nutrient Medium According to Waluyo (2008), identification of Escherichia coli bacteria can be done by carrying out a biochemical, confectionery and growth test on the Mc Conkey medium. The ose needle is fixed by spreading it to the flame. Pure bacterial inoculants in the test tube were fixed by passing the test tube mouth to the fire. Escherichia coli bacterial inoculants were taken using ose needles and dipped or wiggled ose needles on indole, MR, VP medium and aseptic test sugars. Whereas in Simon Citrat and Mc Conkey medium, bacterial inoculants that have been taken are stripped on the surface of the medium aseptically. The test medium is labeled with the name of the bacterial species that has been cultured. The new culture was incubated in an incubator at 37 °C for one night Catalase, coagulase and culture tests on MSA medium The ose needle is fixed by spreading it to the flame. Pure bacterial inoculant medium is fixed by passing the test tube mouth to the fire. Staphylococcus aureus bacterial inoculants were taken using an ose needle and cultured or scratched on MSA medium on the surface of the medium. The medium was labeled and incubated 24 hours. In the catalase test, inoculant bacteria Staphylococcus aureus was etched on the slide and then added 1-2 drops of H2O2. On the slide the object is noticed that there are small bubbles generated from the preparation. Whereas in the coagulase test, plasma citrate was dropped on a slide as much as 1 drop, then inoculant bacteria Staphylococcus aureus were taken one ose on the different ose and glass Volume XII, Issue VI, 2020 Page No: 1552 Journal of Xi'an University of Architecture & Technology ISSN No : 1006-7930 objects that had been labeled. Plasma citrate and bacterial inoculants were homogenized and the presence of fine lumps in the preparations was noted. Making Medium Nutrient Agar According to the quality control procedure contained in the Nutrient Agar packaging with the Oxoid brand, the making of the Nutrient Agar medium can be done by dissolving as much as 2.8 g of Nutrient Agar into 100 ml of distilled water in the Erlenmeyer flask while being heated on fire. During the heating process, the solution continues to stir until it boils.