Lecture 3 Flashcards
The great plate count anomaly
Most microbes can’t be grown under lab conditions
Direct measurement for microbial growth
Counted using petroff-houser chamber
-grid with 25 large squares
Known depth below plate and area of square
Cells are counted in squares
Flow cytometry
16s ribosomal rna
Initiation of protein synthesis
Stabilization of correct codon anticodon pairing
Classifying microorganisms
Not easy based on behaviour or appearance
DNA amplification and sequencing helped a lot
How is the phylogenetic relationships determined
By sequencing 16s and 18s robisomal rna
98.7 percent cutoff
Ani
Average nucleotide identoty
Classifying microorganisms
Comparing ani with 95 percent cutoff
Sequencing of 16s and 18s rrna,
98.7 cutoff
Transcription vs translation
DNA copied to rna
Rna used to produce proteins
Genotyping characterization using 16s
Culture
Purify dna
Pcr amplify- 16s rna gene
Primers
Analyze- agarose gel
DNA sequence pcr product
Create consensus sequence
Compare consessus sequence to gene bank database
Analysis
Pcr
Genotyping characterization of cultivable bacteria (7)
Get samples- environmental
EXTRACT dna
Genomic dna
Pcr and sequencing
16s rrna sequencing
Sequence comparison
Phylogenic trees
Marine microbiology diversity- current lab methods
Prep of instruments
Sample collection
Sample preparation
Sample processing
-microscopy
-dna extraction
Phenotypic characterization
Gram stain (membrane
Flagella
Pili
Capsule
Enzymatic profile
Genotypic characterization
Analysis of genes encoding rna
Analysis of multiple genes or whole genome
