Microbiology in Agriscience and Production Agriculture

1. Microbiology in Agriscience and Production Agriculture Competency 11.00

2. What is a virus? • A virus is an organism composed of a DNA or RNA core surrounded by a tough protein outer coat. • NOT CLASSIFIED AS A TRUE LIVING ORGANISM • Cannot reproduce sexually, only through division in a HOST (viruses are parasitic) • Reproduce quickly, mutate often, and can survive harsh environmental conditions

3. Viruses • Responsible for some of the most dangerous human ailments • Can be destroyed by altering DNA HIV Virus

4. Viruses • Often used as a vector to transport genes into organisms when genetically modifying organisms.

5. Types of Viruses • Tobacco Mosaic Virus (TMV)-often used as a vector for genetic engineering in plants-1 long RNA molecule • Bacteriophage-DNA packaged tightly in a protein head-often used in genetic engineering

6. Types of Viruses • Common viruses • Human Immunodeficiency Virus(HIV) • Influenza • Common Cold • Measles • Norwalk • Hepatitis • Rabies Measles

7. Prokaryotic Organisms

8. What is a prokaryotic organism? • A single celled organism that has no membrane bound organelles and no distinct nucleus. • Usually have very short life spans

9. Characteristics of Prokaryotic Organisms • Contain free-floating DNA • Can be autotrophic (produce their own energy) or heterotrophic (consume other things for energy) • Also reproduce quickly and mutate often, but are not as tough as viruses

10. Examples of Prokaryotic Organisms • Bacteria • Cyanobacteria • Blue-green algae Blue-green Algae

11. Bacteria

12. Characteristics of Bacteria • Can be beneficial or harmful to humans • Unlike viruses, bacteria are not PARASITES, and do not need a host • Molds and funguses including yeast are not bacteria

13. Beneficial Bacteria • Provide a benefit to human activity through normal function or manipulation through biotechnology techniques • Examples: • Nitrobactus alkalikus • Lactobaccillius sp.

14. Nitrobactus alkalikus • Bacteria occurring naturally in soil on the roots of legumes, that change nitrogen in the air to a form useful for plants • Nitrogen fixing

15. Lactobaccillus sp. • A genus of microorganisms that have been introduced to foods (often dairy products) to aid in digestion

16. Harmful Bacteria • Affect agriscience products and processes in a negative manner, affecting both plants and animals • Example: • Eescherichia coli (E. coli) • Clostridium boutlinum • Salmonella enteriditus • Pythium spp.

17. Destroying Harmful Bacteria • Sterilization-kills all living organisms in a or on a substance • Pasteurization-kills most harmful microorganisms, leaving some beneficial organisms surviving

18. Multiform Bacteria • Can either be beneficial or harmful to plants under different circumstances and conditions • Example: • Agrobacterium tumefaciens-naturally occurring bacteria that penetrates plant cells transmitting its own DNA to the cells and causing the growth of a gall (tumor like mass) • Used in genetic engineering to transmit genes

19. Agriscience Uses of Bacteria • Pharming • Bioremediation • Biocontrol • Biofuels

20. Example of Pharming • Inclusion of cholesterol consuming bacteria in milk products to lower human cholesterol

21. Bioremediation • Use of bacteria that consume contaminants in soil and water • Example- bacteria used to “eat” oil from tanker spills, or excess organic nutrients from animal waste

22. Biocontrol • Use of beneficial bacteria in horticulture to kill harmful bacteria in soil, water and on plant surfaces.

23. Biofuels • Very few applications in renewable energy or biofuels now, but lots of potential applications

24. Eukaryotic Cells

25. What is a Eukaryotic Cell? • Advanced cells characterized by the presence of membrane bound organelles and a distinct nucleus. • Usually occur in multicellular organisms, but also include a few single celled Protists.

26. Eukaryotic Cell Structures • Cell membrane • Golgi apparatus • Mitochondria • Nucleus • Ribosomes • Vacuoles

27. Cell Membrane • Selectively permeable membrane surrounding all eukaryotic cells. • Protects the cell and controls the movement of substances into and out of the cell.

28. Golgi Apparatus • Center for the distribution of proteins, enzymes, and other materials through the cell • Like the post office

29. Mitochondria • Structures inside the cell that convert simple sugars to a useful form of cellular energy through the process of respiration

30. Nucleus • A large central segment of the eukaryotic cell that contains the cell’s genetic information (DNA)

31. Ribosomes • Small structures in the cytoplasm of the cell that utilize RNA to produce proteins for cell functions

32. Vacuoles • Specialized “bubbles” in cells used for storage, digestion, and excretion. • Much larger in plant cells

33. Special Plant Cell Structures • Chloroplasts-use chlorophyll to capture light energy for conversion to chemical energy • Cell wall-structure outside the cell membrane that helps support and protect cells. • Not semi-permeable

34. Specialized Eukaryotic Cells • Diploid Cells • Haploid Cells • Stem Cells

35. Diploid Cells • Includes all single celled eukaryotes and every non-reproductive cell in multicellular eukaryotes (plants and animals) • Examples: Skin cells, muscle cells, nerve cells

36. Haploid Cells • Specialized reproductive cells in eukaryotes that contain ½ the amount of genetic material of normal (diploid) cells • Also called gametes or sex cells • Haploid cells combine during sexual reproduction to create a fertilized egg • 4 distinct types • Male-sperm or pollen • Female-egg or ovum

37. Stem Cells • Produced from the union of haploid cells • Special cells that differentiate into all diploid cells in the body.

38. Culturing Bacteria

39. Ideal Bacterial Environments • Most bacteria prefer warm moist environments, though specific species require different culturing conditions • Bacteria thrive in the harshest environments on earth • Deep sea ocean vents with no sunlight and little useable oxygen

40. Bacteria Testing Methods • Swabbing-method used to test surfaces for bacteria • A sterile cotton swab is dipped in a dilution solution and rubbed across the surface to be tested. • The end of the swab is cut and dropped into the solution • The infested solution is swirled at .1 ml extracted for plating

41. Plating • The process of physically spreading bacteria on an agar based culture media

42. Plating Process • To produce agar plates, heat a clear solution in a water bath. Next, proceed to pour the solution into Petri dishes and immediately seal. • Bacteria can be spread using an inoculating loop or glass “hockey stick” • Plates should be sealed and incubated at 30 degrees Celsius to avoid the growth of most bacteria harmful to humans (35-37 degrees for Salmonella)

43. Identifying/Counting Bacteria • Different agar mixes can be used to culture specific types of bacteria. • Gram staining is used to broadly identify certain types of bacteria. • Identifying individual strains is much more difficult.

44. Cleanup After Culture of Biological Labs

45. Cleanup of Labs • Cultures should be placed in a biohazard bag for sterilization in an autoclave set at 121 degrees Celsius and 15 pounds per square inch (psi) for 15 minutes. • Agar should be disposed of according to lab protocol-not poured down sinks, as liquid agar can quickly solidify and clog drains.

46. Cleanup of Labs • Individuals should always wear latex gloves and immediately dispose of them after use. • This is due to the hands being the most common point of contact.