Identifying Bacterial Growth

Keywords: bacterial progress experiment, bacterial progress genus


This test was about isolating an individual bacterial colony from a earth test and identifying which genus it belongs in. That is especially important for functions such as agriculture, as knowing whether a specific soil has a higher concentration of nutritional producing bacterium is essential to being able to harvest good crops. Another key element of ground bacterium, is that they have a tendency to be saturated in nutrient recycling organisms. As well there tends to be a high amount of differing phylum in garden soil bacterium that once was unknown, just as 2003 Joseph et al. were able to isolate 350 different bacterium that have been allocated into 9 different phyla. As well about 27% of the isolated bacterium belonged to unnamed people, and were positioned in very poorly researched phyla. (Joseph et al. 2003)


The experiment began by subculturing a bacterial colony recognized from an array of soil bacterium isolated in an agar dish. Then this bacterial colony was observed by having a microscope, as well as tested for whether it was gram positive or gram negative. Then your bacterium was re-cultured into differing answers to test for specific nutrient use. First it was subcultured onto an agar dish abundant with starch, incubated, and examined for starch hydrolysis via the use of lugol's iodine, to see if there was starch left over in the area of the bacterial colony. A deep abundant with sulfur was inoculated with the bacterium, and noticed for whether motility was exhibited, or whether hydrogen sulphide was produced. Then your bacterium was inoculated in a peptone broth, to check for development of ammonia, through the addition of Nessler's Reagent, an ammonium sulphate broth and a nitrite broth, to test for the ability to nitrify materials using Nessler's reagent; Trommdorf's Reagent; diphenylamine; and Sulfuric acidity, and a nitrate broth to test for the capability to denitrify substances using indicated reagents. Then the bacterium was located into a thioglycollate medium to check the air tolerance of the bacterium. Next the bacterium was subcultured onto a standard agar plate, to check for the presence of catalase and oxidase. Finally the bacterium was subcultured on plates with differing NaCl concentrations, and inoculated in tubes of differing pH's and pipes with varying conditions. (Robertson and Egger, 2010)


In this laboratory our obtained data was gathered and summarized (Desk 1). This was then used to secure a possible bacterias genera from the accumulated data, based on a content material of classifications. These include referrals for whether a microbe genera happens to truly have a specific enzyme, to which types of electron donors it utilizes throughout its ATP creation phase, whether it be in oxidative phosphorylation, or substrate level phosphorylation, or even a form of fermentation.

The information collected in desk in is well correlated in the assigned manual, which is indicative of the genera Bacillus, which is well known for its Rod-like form, and the ability of the specific genera to expand across a vast array of nutritional types. (Sneath, 1986) Other signals of the particular Genus, are that Bacilli have a tendency to grow most predominantly within a heat range characterized by mesophilic organisms, and have a wide range of osmotic pressure, or sodium concentration tolerances. Another sign of the bacillus genera, is the fact that this unfamiliar bacteria tested positive on the gram test, as most people of the bacillus genera are gram-positive bacteria.


The bacterium is of the genus bacillus, because of the idea that it fits into the category of being able to survive in most conditions. (Sneath, 1986) The primary characteristics that helped identify this bacterium were the fact that it's gram positive, that it's rod-shaped, and the perseverance through chemical screening that this can utilize multiple nutritional types to expand, and reproduce. These characteristics directed definitively to the bacterium bacillus, and additional investigation revealed them to many likely be either Bacillus cereus, or Bacillus licheniformis. These bacterium share almost all in keeping with the isolated bacterium in terms of substance use, and similar cosmetic. This bacterium might have been further recognized through other lab tests, such as looking for other enzymes which may be present, and performing tests to determine the exact make-up of the cell wall structure. The other assessments that might be performed, could be to detect for the presence of chemicals known to be associated with fermentation, such as lactic acid solution. The limits of the checks that have been performed, are that they have a tendency to test for the same type of thing. For instance if something testing positive for nitrification, they might not test positive for ammonification since it is all altered right to a nitrate form.

The Bacillus tension plays many various roles in nature, predicated on its great adaptability, and the variance of locations it is situated in. For instance, it ranges from residing in soil, to water, from pets or animals, to plant life. The Bacillus is even found in a pathogenic form, as Bacillus anthracis in humans, and in multiple varieties in insects and pets or animals. (Sneath, 1986) This means that the Bacillus anthracis pressure is of a particular interest to experts, as it is a reason to research antibiotics, and a reason to research different strains of this bacterium to see how many other pathogenic assignments this bacterium can cause in living creatures.

This lab includes many possible sources of error, the primary one being combination contaminants. As the bacterium was recultured so many times, each time symbolizes a possible case where another bacterium was put into the combine, or substituted for the bacterium being isolated. Also during testing different bacteriums could have been found and added to the testing that could have triggered a change in results, or an increase in the number a specific final result is in. Another way to obtain error, is that there was what appeared to be a subculture of yeast intermixed with one of the bacterium subcultures obtained during trials. As this fungus subculture was at onetime on the same dish as the bacterium that was isolated and analyzed for, it might are also located in our sample tossing our specific results off. These specific problems could inevitably cause the info gathered to indicate the wrong bacterium genus and business lead to misclassification. This may be corrected for by taking multiple subcultures of the bacterium, and watching each subculture carefully to ascertain if there is any existence of different bacterial strains.

In the end, the objectives of this experiment were properly found, as a bacterial sample was subcultured from a land test, and the bacterium was sufficiently identified by using a myriad of checks and strategies. Since these targets were fulfilled the experiment could be looked at to reach your goals, especially as it taught me about different subculturing techniques as well as the techniques a microbiologist uses to find out bacterial identification.

Literature Cited:

Joseph, S. J. , Hugenholtz, P. , Sangwan, P. , Osborne, C. A. , Janssen, P. H. (2003) Lab Cultivation of Widespread and Previously Uncultured Soil Bacterias. Applied and Environmental Microbiology. 69: 7210-7215

Robertson, S. , Egger, K. (2010) Recognition of Soil Bacteria. Biology 203 Microbiology Lab Manual. 4-33

Sneath, P. H. A. Ed. Bergey's Manual of Systematic Bacteriology Volume 2. 1986. Lipincott, Williams, & Wilkin's. Baltimore, Maryland.

Also We Can Offer!

Other services that we offer

If you don’t see the necessary subject, paper type, or topic in our list of available services and examples, don’t worry! We have a number of other academic disciplines to suit the needs of anyone who visits this website looking for help.

How to ...

We made your life easier with putting together a big number of articles and guidelines on how to plan and write different types of assignments (Essay, Research Paper, Dissertation etc)