Unknown Lab Report

Unknown Lab Report
Mikee Lianne Gonzales
Biol 351- 1005
Holly Martin
Unknown: # 76

Abstract This report is about identifying the respective genus of the given unknown organism. The goal is to show and prove the student’s understanding of microbiology and laboratory learned experimental techniques. The student is to use studied tests to eliminate possible generas and to isolate the correct genus and identify it to the given unknown. This proves the diversity of microorganisms and their uniquely varying traits. The resulting data obtained in class will enhance students’ laboratory skills and knowledge regarding microbial laboratory.

Introduction The purpose of this study is to identify the genus and species

Selective medium involves medium with environmental conditions that specifically grows some microbes while inhibiting others. Differential medium is used to identify and differentiate (as the title says) closely related microbes based on growth responses and physical indicators. It is imperative to use laboratory positive and negative controls in identifying the unknown because it confirms and compares the results of the unknown’s response to the definite guide. While performing the procedures in this report, students had to keep the bacterial and biological species concepts in context. The bacterial species concept is the identification and naming of microbes based on relating physical and physiological features of the unknown to the fitting taxa. This concept created a guide on naming all Bacteria and Archaea. The biological species concept on the other hand, does not take physical appearance into account on comparing and contrasting organisms but defines a species as part of populations that potentially interbreeds in nature. Students cannot classify microbes within the guidelines of a

An endospore is a dormant of a bacterial cell. It is a non-reproductive structure that ensures survival of a bacterium through stressful environmental conditions. Unknown #76, using aseptic technique, was inoculated to a nutrient sporulation medium (NSM) plate. This concerns a selective medium that increases the initiation of endospore production. A spore-former would have green-pigmented endospore cells when looked at under the microscope. From the growth on the NSM, I smeared it aseptically to a wet slide. Slide was then left to be air-dried for about 10 minutes. It was important to heat fix the slide using a micro incinerator. The succeeding steps had to be taken with caution because the primary stain, malachite green, is toxic. Under the hood, the slide was covered with a properly cut size of paper towel. The slide was then stained and left to steam with malachite green. It was continuously followed up by applications of the stain so it may remain moist for 10 minutes. The slide was then rinsed and safranin was again used as a counterstain. Using oil immersion objective lens of the microscope, unknown #76 had only reddish-pink cells without any signs of spore formation. Thus the given unknown is a non-spore former. Bacillus subtilis was used for positive control and Escherichia coli for negative control for endospore