Introduction to Microbiology Part - 1 Sharini Samaranayake MSc ( Reading, UOC ), BSc ( Hons ) Microbiology ( UOK ) What are Micro - organisms? • Micro organisms also known as microbes, • A form of life • T hat can’t be seen with the naked eye. • They are very diverse in form and function. • I nhabit every environment on earth. • M ost of them are uni - cellular. • Some can form complex structures, and some are even multicellular. • Microorganisms typically live in complex microbial communities , and their activities are regulated by interactions with each other, with their environments, and with other organisms. 2 W hat is Microbiology? • Microbiology is the study of all living organisms that are too small to be visible with the naked eye. • This includes bacteria, archaea, viruses, fungi, prions, protozoa and algae, collectively known as 'microbes'. 3 W hy is it so important ? • Importance of Microbiology in the Pharmaceutical Industry • Importance of Microbiology in Medicine and Science • Importance of Microbiology in the Field of Biotechnology • Importance of Microbiology in the Food Industry • Importance of Microbiology in the Environment • Importance of Microbiology in Chemical Substances 4 Scope of Microbiology 5 K ey terms in microbiology • A microbial culture is a collection of cells that have been grown in or on a nutrient containing medium. • A medium (plural, media) is a liquid or solid nutrient mixture that contains all of the nutrients required for a microorganism to grow. 6 • In microbiology, the word growth to refer to the increase in cell number as a result of cell division. • O n a solid – colony • I n the liquid - turbidity 7 K ey terms in microbiology • A single microbial cell placed on a solid nutrient medium can grow and divide into millions of cells that form a visible colony The formation of visible colonies makes it easier to see and grow microorganisms. 8 K ey terms in microbiology Classifications of Microorganisms • Have been divided into two groups – according to the cellular organization and biochemistry • Prokaryotes – (ex - Bacteria and Archaea) • Eukaryotes – (ex - Fungi, Algae, Slime molds, Protozoa) 9 D ifferences between prokaryotes and eukaryotes 10 Character Prokaryotes Eukaryotes Nucleus Membrane - bound organelles Chromosomes Absent, No nuclear envelope Absent Single coiled chromosome in cytoplasm ‘nucleoid’ region in association with ‘histone - like’ proteins Present (with nuclear envelope and nucleus) Present (mitochondria, chloroplasts, Golgi apparatus, endoplasmic reticulum ) Multiple linear chromosomes with histone proteins 11 Character Prokaryotes Eukaryotes Cell wall Mitotic division Ribosomes Flagella Present Absent 70S. Free in cytoplasm when present, consist of protein flagellin Present (No cell wall in animal cells) Present 80S. Both free in cytoplasm and attached to rough E.R.70S in mitochondria and chloroplasts consist of 9+2 arrangement of microtubules 12 13 P hylogenic tree of life 14 • Carl Woese (1978) • The system of nomenclature (naming) for organisms in use today was established in 1735 by Carolus Linnaeus. • Scientific names are latinized because Latin was the language traditionally used by scholars. 15 N omenclature of Microorganisms • Scientific nomenclature assigns each organism two names, • the genus (plural: genera ) is the first name and is always capitalized; • the specific epithet ( species name) follows and is not capitalized. • The organism is referred to by both the genus and the specific epithet, and both names are underlined or italicized. 16 N omenclature of Microorganisms O bserving through a Microscope • S ince microbes are too small to observe with a naked eye, they must be observed with a microscope. 17 18 O bserving through a Microscope 19 O bserving through a Microscope 1 - Barrel 2 - Nosepiece 3 - Objective lenses 4 - Stage clips 5 - Stage 6 - Condenser 7 - Light 8 - Eyepiece 9 - Arm 10 - Core adjustment 11 - Fine adjustment 12 - Base • Most microorganisms appear almost colourless when viewed through brightfield microscopy. • So we must prepare them for observation. • One way is to stain ( color ) the specimen. 20 O bserving through a Microscope