General Microbiology: Classification and Survey of Microorganisms

This flashcard set covers the history of classification, characteristics of fungi and algae (including food industrial roles and toxins), protozoa groups and pathogenicity, and the fundamental properties and replication of viruses as presented in the General Microbiology lecture notes.

Artificial classification

Classification based upon the expressed characteristics or phenotype of microorganisms.

Natural or Phylogenetic classification

Classification based upon the suggested evolution of the organism from a common ancestor.

Linnaeus (1735)

Developed a classification system consisting of 2 kingdoms: Vegetabilia and Animalia.

Whittaker (1969)

Proposed a 5-kingdom system: Monera, Protista, Fungi, Plantae, and Animalia.

Woese et al. (1990)

Established three domains for classification: Bacteria, Archaea, and Eucarya.

Fungi Cell Wall

A rigid wall primarily made of chitin, the same substance found in insect exoskeletons.

Septa

Holes in some fungi that allow organelles and cytoplasm to pass between cells, making cellular boundaries less clear.

Mycelium

An underground network of interconnected cells in fungi, often found in decaying organic matter.

Yeasts

Unicellular forms of fungi, as opposed to the more common filamentous forms.

Chemoheterotrophic (chemo-organotrophic)

The nutritional mode of all fungi, indicating they obtain energy and carbon from organic compounds.

Chytridiomycota

A major fungal group characterized by having flagellated, motile sexual and asexual spores.

Zygomycota

Fungi that produce thick-walled resting sexual spores called zygospores and asexual spores in a sporangium.

Ascomycota

Fungi known as sac fungi where sexual spores are borne internally in an ascus and asexual spores as conidia.

Basidiomycota

Club fungi where sexual spores are borne externally on a club-shaped structure called a basidium.

Saprophytes

Fungi that act as decomposers by breaking down organic matter and recycling nutrients in ecosystems.

Mycorrhizal Symbionts

Fungi that form mutualistic relationships with plant roots to aid in nutrient and water absorption.

Endophytes

Fungi that live inside plants, often enhancing growth and resistance to stress.

Mycotoxins

Toxins released by fungi, such as aflatoxins from Aspergillus flavus, which contaminate food.

Algae

A large, diverse group of eukaryotic, photosynthetic organisms including seaweeds and unicellular life forms.

Chlorophyta

The major group of algae known as Green algae.

Rhodophyta

The major group of algae known as Red algae.

Phaeophyta

The major group of algae known as Brown algae.

Bacillariophyta

Unicellular algae known as Diatoms, characterized by a silica-based cell wall.

Dinophyta

An algal group commonly referred to as Dinoflagellates.

Nori

Edible red algae (Porphyra umbilicalis) used in sushi wraps; high in protein, vitamins, and iodine.

Spirulina

A blue-green algae (Arthrospira platensis) used as a superfood containing approximately 60% protein.

Agar

A red algae extract (Gelidium amansii) used as a gelling agent and vegan alternative to gelatin.

Carrageenan

Extracted from red algae (Kappaphycus alvarezii) and used as a stabilizer and thickener in dairy and meat products.

Red Tide

Algal blooms caused by dinoflagellates like Karenia brevis that produce brevetoxins and saxitoxins.

Ciguatera Fish Poisoning

Caused by toxins from Gambierdiscus toxicus accumulating in reef fish like barracuda and snapper.

Sarcocystis

A protozoan parasite forming cysts in the muscles of wild animals; can infect humans through undercooked meat cooked below $74\,^\circ\text{C}$.

Amoebozoa

Protozoa that move via pseudopodia (extensions of cytoplasm) and feed by phagocytosis.

Ciliophora

Protozoa that move using cilia and possess two types of nuclei: a macronucleus and a micronucleus.

Apicomplexa

Non-motile parasitic protozoa, such as Plasmodium, featuring an apical complex for host invasion.

Euglenozoa

Protozoa that move via flagella; examples include Trypanosoma and some photosynthetic species like Euglena.

Virus

A non-living, obligate intracellular parasite composed of genetic material (DNA or RNA) enclosed in a protein coat.

Capsid

The protein coat that protects the genetic material of a virus.

Viral Size

Typically ranges from $20\text{--}300\,nm$, making them only visible under an electron microscope.

Bacteriophage

A type of virus that specifically infects bacterial cells.

HACCP

Hazard Analysis Critical Control Points; a system implemented by food technologists to identify and minimize viral risks in food production.