Lect 29 - microbial population growth - from one to many cells & how we can study them

Flashcards covering microbial growth, nutritional needs, trophic groups, and culture methodologies.

What is binary fission?

Prokaryotes reproduce asexually through this process, resulting in two genetically identical cells.

What is a 'closed' batch culture system?

A closed system with a limited amount of nutrients where cells eventually stop proliferating.

What is the exponential (log) phase?

The phase where cells are actively dividing and resources are not limited.

What is cryptic growth?

Organisms survive by consuming lysed cell constituents of dead cells.

What happens during the death phase of microbial population growth?

Equilibrium between growing and dying cells shifts towards cell death.

What is the role of a carbon source for prokaryotes?

Building blocks for macromolecular synthesis.

What is defined as reducing power in the context of prokaryotes?

Carriers of energy and electrons, such as NAD+ and NADP+.

What is ATP in prokaryotes?

The most common energy currency in cells.

What are photoautotrophs?

Energy source: light; Carbon source: carbon dioxide.

What are chemoheterotrophs?

Energy source: chemical compounds; Carbon source: organic compounds.

What is cross feeding (syntrophy)?

Allows for the survival of auxotrophs by harvesting resources generated by other organisms

What is a microbiome?

The complete collection of microorganisms, and their genes, within a particular environment.

What is microbiota?

Individual microbial species in a biome.

What are the pros of using culture dependent methods?

Allows access to phenotype, can study one organism at a time, and can manipulate conditions to see response of an organism.

What are the cons of using culture dependent methods?

Not all organisms can be cultured, there are too many species to grow them all, and there is no pure culture, so no ability to manipulate.

What are the pros of using culture-independent methods?

Allows access to genotype, can study many organisms at a time, shows communities as they are in nature, can target non-culturable organisms, and provides access to unknown information/species.

What are the cons of using culture-independent methods?

Culturing requires precise conditions to match microbes needs, it does not match real world conditions, and uses expensive and complex methods.