Unit 4 Chapter 6 Microbiology

Bacteria Characteristics of bacteria: Microscopic Unicellular (single-celled) Prokaryote Classified according to their shape: Rod, spherical (cocci) and spiral Reproduce by binary fission. © Edco

Structure of a bacteria © Edco

Common diseases caused by bacteria in cattle and sheep © Edco

Respiration Mycobacterium bovis, the bacteria responsible for TB in cattle, is an aerobic bacteria. It can release energy from sugars in the presence of oxygen. Lactobacillus bacteria can release energy from sugars in the absence of oxygen. This is called anaerobic respiration or fermentation. © Edco

Reproduction Bacteria can reproduce asexually by binary fission. The bacteria cell replicates its genetic information and then divides in two. © Edco

Rhizobium Rhizobium is a rod-shaped bacterium that has a symbiotic relationship with clover. A symbiotic relationship occurs when two organisms have a close relationship that benefits both organisms. The bacteria live in the root nodules of clover where they fix atmospheric nitrogen into nitrates. © Edco

Experiment: To isolate and grow Rhizobium bacteria from the root nodules of clover © Edco

Experiment: To isolate and grow Rhizobium bacteria from the root nodules of clover © Edco

Experiment: To isolate and grow Rhizobium bacteria from the root nodules of clover © Edco

Experiment: To isolate and grow Rhizobium bacteria from the root nodules of clover © Edco

Fungi Characteristics of fungi: Eukaryotic Lack chlorophyll, so they are unable to undergo photosynthesis Fungal cell walls contain the carbohydrate chitin Majority of fungi produce filaments called hyphae, some fungi, e.g. yeast, are single-celled Can reproduce both asexually (spores) and also sexually (zygospores) Heterotrophic. © Edco

Basic structure of a fungi © Edco

Fungal diseases of plants and animals © Edco

Advantages/disadvantages of bacteria and fungi © Edco

Viruses Characteristics of viruses: Simple structure (capsid containing genetic material) Genetic material of either DNA or RNA All viruses are parasites Viruses lack a cellular structure and do not contain cell organelles. © Edco

Notifiable diseases A notifiable disease is a disease that must be immediately reported. Characteristics of notifiable diseases: Spread quickly Cause significant economic loss Decrease productivity Cannot be easily treated or controlled. © Edco

Non-infectious diseases A non-infectious disease is a disease that is not caused by a pathogen (micro-organism). Milk fever and grass tetany are examples of diseases caused by a deficiency of a mineral in the diet of an animal. © Edco

Biosecurity Farmers try to prevent entry of disease onto their farms by Maintaining a closed herd Quarantining all bought-in stock Providing good fencing to prevent contact of stock with neighbouring stock Limiting access to the farm Controlling vermin and ensuring that wildlife do not have contact with animal feeds Ensuring all newborn animals receive colostrum from their mothers. © Edco