Biology Investigatory Project 45472e

ACKNOWLEDGEMENT In the accomplishment of this project successfully, many people have best owned upon me their blessings and the heart pledged , this time I am utilizing to thank all the people , this I am utilizing to thank all the people who have been concerned with project. Primarily I would thank god for being able to complete this project with success. Then I would like to thank my biology teacher Mrs. Manna Milan, whose valuable guidance has been the ones that helped me patch this project and make it full proof success with suggestions and his instructions has served as the major contributor towards the completion of the project. Then I would thank my parents and friends who have helped me with their valuable guidance have been helpful in various phases of the completion of the project. Last but not the least I would like to thank my classmates who have helped me a lot.

CERTIFICATE This is to certify that DIVYENDU SEKHAR SAHOO, a student of class X1-A has successfully completed the research on the below mentioned project under the guidance of Mrs. Manna Milan (subject teacher) during the year 2016-17 in partial fulfilment of biology practical examination conducted my DAV Public School.

Signature of chemistry teacher

INVESTIGATORY PROJECT ON EFFECT OF ANTIBIOTICS ON MICROBES NAME- DIVYENDU SEKHAR SAHOO CLASS- XI A ROLLNO – 13 SCHOOL-DAV PUBLIC SCHOOL

INDEX CONTENTS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

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INTRODUCTION Antibiotics are the organic secretions produced by micro organisms, which in low concentrations are antagonistic to the growth of other micro-organisms (mostly pathogens). Anti-biotics have proved very useful in combating several bacterial diseases in man and animals. Antibiotics are commonly obtained from actinomycetes and some bacteria. Some of the important anti-biotics are streptomycin, aureomycin, terramycin, chloromycetin, erythromycin, neomycin etc. Soil is a natural medium which harbours several types of micro organisms. These micro-organisms can be grown on culture media. The effect of different types of antibiotics can be studied on the growth of micro-organisms growing in culture media. This is an important subject; therefore study of effect of antibiotics on microorganism has been taken for the present project. Antibiotics act as an ecological factor in the environment that could potentially affect microbial communities. The effects include phylogenetic structure alteration, resistance expansion, and ecological function disturbance in the micro-ecosystem. Numerous studies have detected changes of microbial community structure upon addition of antibiotics in soil and water environment.

AIM OF THE EXPERIMENT- To study the effect of Anti-biotics on Micro-organisms MATERIALS REQUIRED- Potato, agar, dextrose, beef, peptone, NaCl, Sodium bicarbonate, distilled water, five different types of antibiotics (such as penicillin, streptomycin, aureomycin, terramycin and chloromycetin), syringe, oven sterilized petridishes, flasks, beakers, pipettes, garden soil, glass marker pen etc. EXPERIMENTAL PROCEDURE A. Preparation of cultured medium 1. Potato Dextrose Agar (PDA) Medium: Take 200 g of peeled potato chips. Boil them with 500 ml of water in a beaker for 15 minutes. Squeeze the potato pulp thus obtained through a muslin cloth and keep it in a flask. Take 20 g of agar in a beaker and warm it with 500 ml of water. Mix both the solutions of potato and agar and add 20 g dextrose to it. Thus one litre of PDA medium is prepared. Autoclave the medium at 15 pounds pressure for 15 minutes.

2. Meat Extract Agar Medium:

Weight 3 g beef extract, 10 g peptone, 5 g NaCl and mix these in 1 litre of distilled water. Heat the mixture to 65 degree Celsius stirring until the materials are completely dissolved. Filter the mixture through filter paper and adjust the pH to 7.2 to 7.6 by adding a bit of sodium bicarbonate. Now, add 20 g to the broth and autoclave the medium to 15 pounds pressure for 15 minutes. B. Effect of antibiotics on soil micro-organisms 1. Take 2 g of soil and dissolve it in 10 ml of water in a beaker. Let the soil particle settle down. 2. Take 6 oven sterilized petridishes and pour 1 ml of soil suspension in each of the plates. Now pour 1 ml of five antibiotics separately in five petridishes with the help pf syringe, and mark them with marker pen. Leave the sixth petridish without antibiotic to serve as control. 3. Pour PDA or Meat extract agar in each of the petridishes and mix the suspension by rotating the petridishes undisturbed at a warm place for a week.

OBSERVATIONS

PRECAUTIONS 1. Do not expose the culture of the petridish to the atmosphere. 2. Sterilise the petridishes properly in the oven before use. 3. Use proper kind of strains for different micro-organisms.

BIBLOGRAPY www.wikipedia.com www.technopedia.com