Lab Report in Food Microbiology

Question: Discuss about theLab Report in Food Microbiology. Answer: Introduction Safety Regulations When orking in a microbiology laboratory, there are a set of safety regulations that need to be adhered to ensure the safety of the researcher as well as other laboratory personnel. For instance, all microorganisms should be treated as potential pathogens. This is because there has there are microbes which are nonpathogenic have the ability to be pathogenic and cause harm to humans (Aziz et al., 2014). All the materials being used in the laboratory such as pipettes, media, plateau and some more should be sterilized by use of the appropriate sterilizing chemicals. However, there are commercially sterilized materials which can be purchased for use. Before beginning any microbial work in the laboratory one should disinfect all the surfaces; same cases after use. The most common chemicals for disinfection are 70% ethanol and 10% bleach. Upon completion of a laboratory session, the user should wash hands with soap and water. Gloves should always be worn when working with microorganisms to avoid contamination. It is important also to not that it is illegal to eat or drink in the laboratory to avoid contamination. In case a lab user has some cut, they should cover them immediately. In order to make work easier the researcher should label all reagents appropriately labeled so as to reduce the time wasted while locating them. In a microbiology laboratory after the end of every session, all materials such as gloves, needles, culture plates and tubes should be autoclaved. Isolation of Pure Cultures In nature, the microorganism say in a food sample exists as a mixed population. In order to isolate and characterize a microbe on it's, the methods of isolating pure cultures are used. This means the organisms should be separated such that they share the same descendants. In the streak method, bacteria cells are separated on an agar. A colony is picked from a culture plate by use of a loop (Cox et al., 2016). The loop is then streaked in a new agar and plate across the surface by use of a certain pattern. As the loop moves, more bacteria are rubbed off until individual organisms are produced. When the plate is incubated, the region where the loop started has a very high density of microbes. As the loop moves, the density reduces and individual bacterial colonies can be seen. In the pour plate method, the bacteria mixture in a sample is mixed with molten agar. Once it is distributed evenly, it becomes separated and it is poured into a sterile unused plate (Faraji et al., 2014). And given some time to solidify. Upon incubation, the bacterial colonies can be counted individually. Colonies Calculation The viable bacterial cells say in a food sample are reported in colony forming units. For liquid samples, it is reported as colony forming units /mL or per gram (Da Silva et al., 2013). A simplified equation for bacterial counting is: cfu/ml = (no. of colonies x dilution factor) / volume of culture plate. Since not all bacteria form colonies, bacteria are counted and reported in colonies per mL or per gram. If the colonies are above 250, the colonies are said to be too many while those below 25 are the most preferable for counting. The counting of colonies can be done manually, by use of a microscope and use of a colony counter instrument. References List Faraji, S., Fazlara, A., Hashemi Ravan, M., Faraji, N. and Taheri, S., 2014. Comparison of impedance splitting method to pour plating method for the estimation of bacterial count in mayonnaise. International Food Research Journal, 21(6). Cox, N.A., Richardson, L.J., Cosby, D.E., Berrang, M.E., Wilson, J.L. and Harrison, M.A., 2016. A four?quadrant sequential streak technique to evaluate Campylobacter selective broths for suppressing background flora in broiler carcass rinses. Journal of Food Safety. Aziz, N., Zhao, Q., Bry, L., Driscoll, D.K., Funke, B., Gibson, J.S., Grody, W.W., Hegde, M.R., Hoeltge, G.A., Leonard, D.G. and Merker, J.D., 2014. College of American Pathologists' laboratory standards for next-generation sequencing clinical tests. Archives of Pathology and Laboratory Medicine, 139(4), pp.481-493. Da Silva, N., Taniwaki, M.H., Junqueira, V.C.A., Silveira, N. and GOMES, R.A.R., 2013. Microbiological Examination Methods of Food and Water. CRC Press.