Gram-positive bacteria include many well -known genera like Streptococcus and Bacillus.
Most pathogenic bacteria in humans are Gram-positive organisms and these are used to manufacture antibiotics.
Bacillus subtilis, also known as the hay bacillus or grass bacillus is a Gram- positive bacterium, which is mostly found in soil. Bacillus subtilis is not a human pathogen and it can contaminate food but rarely causes . Bacillus subtilis spores can survive the extreme heat during cooking and Bacillus subtilis is responsible for causing a sticky, stringy consistency in spoiled bread dough.
Antibiotics are among the most frequently prescribed medications in modern medicine.
They cure disease by killing or injuring bacteria. The first antibiotic was penicillin, discovered accidentally from a mold culture. Penecillium fungus produces penicillin to kill bacteria. Today, over 100 different antibiotics are available to cure minor discomforts as well as life-threatening infections.
Antibiotics are produced by microorganisms to kill or control the growth of other organisms. Inappropriate antibacterial treatment and have contributed to the emergence of antibacterial-resistant bacteria. It is important to know that antibiotics only treat bacterial infections, not viral (e.g. common cold) or fungal infections.
The different antibiotics, which are placed in the Petri dishes with the Bacillus subtilis.
E- Erythromycin, 5ug
FE-Fluidic Acid, 10ug
NO- Novobiocin, 5ug,
PG- Penecillin G, 1 unit
S- Streptomyan, 10 ug
T- Tetracyline, 25ug
The zone of inhibition (of killed bacteria) in mm (+/- 0.5mm). Measured with a ruler.
The following is a table to show how large the zone of inhibition for each antibiotic is in mm. The Petri dishes were left for 24 hours at a temperature of 30°C. (+/-0.5°C).
As seen in my result table the antibiotics Chloramphenicol, Erythromycin, Fusidic Acid and Oxacillin show the biggest effect on the bacteria. The zone of inhibition for these antibiotics is the largest. The different types of penicillin show very similar results in all five repeats and P1 has the smallest zone of inhibition, whereas P10 has the largest. Overall the table shows that Oxacillin has the largest average zone of inhibition with 22.6 mm. Looking at the table carefully the size of the zone of inhibition increases steadily from an average of 13.4mm until it reaches Oxacillin at an average of 22.6mm and then it decreases again. Only Tetracycline has a higher size of the zone of inhibition again. This shows that different antibiotics have differently strong effects on the same bacteria. Therefore it must be considered well which antibiotics to take against which infection.
Here's what a teacher thought of this essay
**** A very good, interesting scientific study. Although not complete the foundation for an excellent investigation is present. The method needs to be provided which would allow the reader to repeat the experiment. The data collection is excellent and answers the aim of the investigation well. The conclusion does not put enough emphasis on the central question of which antibiotic is most effective and offer a scientific explanation of why this might be.