Workshop 1 - Microbial Ecology

Microbial Diversity

Microbes are diverse organisms that can adapt and thrive in various environments.

Species Richness

The number of different species present in a particular environment.

Species Evenness

The relative abundance of each species in a community.

Culture-Independent Methods

Techniques like 16S rRNAs, OTUs, and metagenomics used to study microbial communities

Culture-Dependent Methods

Methods that rely on culturing microbes to study microbial communities.

Microbiome

collection of microorganisms living in a particular environment, such as the gut of an organism. Key roles in host physiology, development, immune function/defence, and nutrition.

worker honey bee core gut microbiome

contains 9 distinctive species with a characteristic distribution in the hindgut, each species with different metabolic capabilities.

Shannon Index (H)

measure of diversity where a higher value indicates a more diverse community.

H = 0

only one species present

Colony Forming Units (cfu)

An estimate of the number of viable cells in an original sample. Calculated using serial dilutions

cfu/mL =

number of colonies counted/(dilution factor x volume plated)

Winogradsky Column

An artificial microbial ecosystem used to study microbial interactions and growth patterns.

Top of Winogradsky column

iron oxidising bacteria which require oxygen to oxidise Fe (II) to Fe (III).

2nd from top in Winogradsky column

cyanobacteria, produce oxygen by photosynthesis.

3rd from top in Winogradsky column

purple and green non sulphur bacteria which usually carry out anoxygenic photosynthesis. May be able to fix nitrogen.

2nd from bottom of Winogradsky column

green sulphur bacteria, obligate anaerobes which carry out anoxygenic photosynthesis using H2, H2S and S as electron donors.

Bottom of Winogradsky column

sulphur reducing bacteria. Obligate anaerobes which produce sulphide.

3rd from bottom of Windogradsky column

purple sulphur bacteria, photosynthesise using sulphide or thiosulphate as an electron donor.