chapter 19 Flashcards
What is enrichment in culture-dependent analysis?
Enrichment is a process that increases the number of specific microorganisms in a sample by providing favorable growth conditions for them
What are classical procedures in culture-dependent analysis?
Classical procedures involve isolating and growing microorganisms in a lab using solid or liquid media to study their characteristics.
What is single-cell isolation?
Single-cell isolation is a technique where individual microbial cells are separated and cultured to obtain pure cultures for study.
What is enrichment in culture-dependent analysis?
Enrichment selects for desired organisms by manipulating the medium and incubation conditions.
What does enrichment prove about an organism in an environment?
Enrichment can prove the presence of an organism in a habitat but cannot prove that the organism does not inhabit the environment.
What does the ability to isolate an organism from an environment tell us?
Isolating an organism says nothing about its ecological significance in that environment.
What is enrichment bias in microbial culture?
Enrichment bias occurs because lab cultures often favor minor components of the ecosystem due to high nutrient levels.
Why do rapidly growing weed species appear in enrichment cultures?
These species grow fast in the lab due to nutrient levels that are much higher than in nature.
How is enrichment bias minimized?
By diluting the inoculum to reduce the growth of rapidly growing, insignificant species.
What is a pure culture in classical methods?
A pure culture is obtained by streaking a sample to isolate a single colony.
How can pure cultures be observed?
Pure cultures can be observed through colony inspection or microscopy.
What is the most probable number (MPN) method?
MPN estimates the concentration of viable microorganisms in a sample using statistical methods.
What is the goal of single-cell isolation?
To separate the fundamental niche from the realized niche.
What is a fundamental niche?
The fundamental niche is the potential environment where an organism could live.
What is a realized niche?
The realized niche is the actual environment where an organism does live, due to resource limits and competition.
What are laser tweezers used for in single-cell isolation?
Laser tweezers use focused laser beams to manipulate and isolate individual cells.
What is flow cytometry in single-cell isolation?
Flow cytometry uses a laser to sort cells based on their size, complexity, and fluorescence.
How do microfluidics assist in single-cell isolation?
Microfluidics uses tiny channels to manipulate and isolate cells in a controlled environment.
What is high throughput in the context of single-cell isolation?
High throughput refers to processing large numbers of cells rapidly for analysis or isolation.
What is staining used for in culture-independent analysis?
Staining uses dyes to highlight specific organisms or cell structures, allowing identification under a microscope.
What does Fluorescence In Situ Hybridization (FISH) do?
FISH uses fluorescent probes to bind to specific DNA sequences in cells, allowing for detection of particular microbes.
What is DAPI, Acridine Orange (AO), and SYBR Green I used for?
These fluorescent stains bind to nucleic acids and are used for enumerating microorganisms under UV light.
What are the limitations of DAPI, AO, and SYBR Green I?
They are nonspecific and cannot differentiate between live and dead cells.
What do viability stains differentiate between?
They differentiate between live and dead cells.
How do viability stains work?
They use two dyes based on cell membrane integrity—green for live cells and red for dead cells.
What is a limitation of viability stains in environmental samples?
Nonspecific staining can be an issue
What is the purpose of FISH?
To identify microbial populations using nucleic acid probes complementary to target gene or RNA sequences.
What does the FISH method typically detect?
rRNA sequences using fluorescing nucleotides.
What applications does FISH have?
It’s used in microbial ecology, food industry, and clinical diagnostics.
Can FISH use multiple probes?
Yes, multiple probes can be used.
What is PCR used for in culture-independent genetic analysis?
To amplify specific DNA sequences for microbial identification and analysis.
What are microarrays used for in microbial analysis?
to detect and quantify gene expression across large sets of genes.
What does Environmental Multi-omics integrate?
It combines genomics, transcriptomics, proteomics, and metabolomics to analyze microbial communities.
How do microarrays work in microbial analysis?
Known short DNA sequences on a slide bind with community DNA, causing a fluorescent signal when complementary sequences match.
What is Environmental Multi-omics?
Powerful tool for assessing the phylogenetic and metabolic diversity of an environment
Environmental Multi-omics Can detect
genes that are not amplified by
current P C R primers
in Environmental Multi-omics DNA is cloned from microbial community and
sequenced to Detect
as many genes as possible
Environmental Multi-omics Yields picture of
gene pool in environment
