1. ADNAN MENDERES UNIVERSITY Department of Food Engineering FE 206 Food Microbiology I Lecture #1 Cisem Bulut Albayrak, Ph.D.

2. FE 206 Food Microbiology I Section I Tuesdays Lecture 08:30-10:15 Lab 10:30-12:15 Section II Thursdays Lecture 08:30-10:15 Lab 10:30-12:15 FE206 Food Microbiology I2

3. Textbook Doyle and Buchanan, Food Microbiology: Fundamentals and Frontiers, 2013, 4 th ed. ASM Press, ISBN: 978-1555816261 Available in University Library as e-book FE206 Food Microbiology I3

4. Grading GradeLetter 90-100AA 85-90BA 75-84BB 70-74CB 60-69CC 55-59DC 50-54DD 0-49FF Grades will be determined as follows: Laboratory grade: 20% Quizzes: 10 % Homeworks: 10% Midterm: 20% Participation: 10% Final exam: 30% Total: 100% Laboratory will be graded by: Laboratory reports: 70 % Lab Exam: 30 % FE206 Food Microbiology I4

5. Attendance Student attendance is mandatory and students must attend all sessions Small tolerance may be shown At least 70 % attendance in lectures and 80% in labs are expected FE206 Food Microbiology I5

6. Binomial nomenclature Saccharomyces cerevisiae Escherichia coli Homo sapiens FE206 Food Microbiology I6 S. cerevisiae E. coli H. sapiens Saccharomyces cerevisiae Escherichia coli Homo sapiens

7. Types of Microorganisms in Food Important Microorganisms in Foods – Fungi – Bacteria – Parasites – Viruses – Algae – Prions FE206 Food Microbiology I7

8. Fungus - Fungi Chytridiomycetes-Members are found in soil, fresh water, and saline estuaries. Zygomycetes- fungi that reproduce sexually by forming zygospores Ascomycetes Basidiomycetes Deuteromycetes (Fungi Imperfecti): No known sexual growth FE206 Food Microbiology I8

9. Fungus physiology and structure Most fungi are multicellular, forming a network of hyphae (sing. hypha) Hyphae that extend above the surface can produce asexual spores called conidia (sing. conidium) – Conidia are often pigmented and resistant to drying Hyphae form compact tufts called mycelia Most fungal cell walls are made of chitin FE206 Food Microbiology I9

10. Conidiophore Aerial hyphae Subsurface Hyphae Conidia (spores) Germination FE206 Food Microbiology I10 Conidium (spore) Hypha

11. FE206 Food Microbiology I11

12. Fungal Diseases Fungi can cause disease (mycosis) in plants and animals – Mycoses in humans range in severity from "athlete's foot" to histoplasmosis FE206 Food Microbiology I12

13. Fungal Reproduction and Phylogeny Asexual reproduction in three forms – Growth and spread of hyphal filaments – Asexual production of spores – Simple cell division (budding yeasts) Some fungi produce spores as a result of sexual reproduction – Sexual spores can originate from the fusion of two haploid cells to form a diploid cell (ascospores, basidiospores, zygospores) – Spores are resistant to drying, heating, freezing, and chemicals FE206 Food Microbiology I13

14. Ascomycetes Key genera: Saccharomyces, Aspergillus, Penicillium, Microsporum, Morchella Around 50,000 species of molds, yeasts, an plant parasites Also known as (aka) Sac fungi FE206 Food Microbiology I14

15. FE206 Food Microbiology I15 Saccharomyces cerevisiae budding Time-lapse movie https://www.youtube.com/watch?v=FcV1ydls9hg Budding Yeast

16. Basidiomycetes Key genera: Agaricus, Amanita Over 30,000 described species Many are recognizable as mushrooms and toadstools – Also yeasts and pathogens of plants and humans Undergo both vegetative and sexual reproduction FE206 Food Microbiology I16

17. Gills FE206 Food Microbiology I17

18. Zygomycetes Key genera: Rhizopus, Mucor, Encephalitozoon – Known primarily for food spoilage – Commonly found in soil and decaying plant material – All are coenocytic (multi nuclei) – Sexual spores are called zygospores Rhizopus stolonifer (black bread mold) is representative Microsporidia: unicellular, obligate parasites – Often infect immune-compromised individuals FE206 Food Microbiology I18

19. FE206 Food Microbiology I19 Rhizopus stoloniferMicrosporidia

20. Important Bacterial Groups Lactic acid bacteria (LAB) – Gram (+), non-sporulating rods/cocci, produce lactic acid – Lactobacillus, Lactococcus Acetic acid bacteria – Gram (-), obligate aerobic, chemoorganotrophic – Acetobacter Butyric acid bacteria – Spore forming anaerobes – Clostridium butyricum FE206 Food Microbiology I20

21. Important Bacterial Groups Proteolytic bacteria Lipolytic bacteria Thermophilic bacteria Psychrophilic bacteria Halophilic bacteria Sporeformers FE206 Food Microbiology I21

22. Sources of Microorganisms in Foods Water – Water used in production – Washwater Plants and Plant Products – Human pathogens from contaminated soil, water – Mold from soil FE206 Food Microbiology I22

23. Sources of Microorganisms in Foods Food Utensils and Packaging Materials – Open served foods Intestinal Tract of the Human and Animals – Pathogens – E. coli, Salmonella – Candida – Enteroviruses FE206 Food Microbiology I23

24. Sources of Microorganisms in Foods Food Handlers – Personal hygiene Food Ingredients – Chemicals – Spores Sewage!!! FE206 Food Microbiology I24

25. Sources of Microorganisms in Foods Animals, Birds, and Fish – Natural flora of animals Air, Dust, and Soil – Bacterial spores – Fungus spores Miscellaneous Sources Animal feeds, Rodents, Insects FE206 Food Microbiology I25

26. Primary Sources of Microorganisms Pathogenic Escherichia coli – intestine Salmonella – intestine, poultry, eggs Campylobacter jejuni – poultry Staphylococcus aureus – nasal cavity Streptococcus pyogenes – nasal cavity Listeria monocytogenes – cheese, milk, fish Bacillus cereus – starchy foods, rice, pasta Brucella – raw milk and products Clostridium perfringens – soil FE206 Food Microbiology I26

27. Resources Brock Biology of Microorganisms, Pearson FE206 Food Microbiology I27