Bio 230 - Microbiology - Spring 2012

Study Guide 17

http://thebreakthrough.org/blog/images/Energy_cartoon.jpg

The myxobacteria ("slime bacteria") are

a group of bacteria that predominantly live

in the soil. The myxobacteria have very

large genomes, relative to other bacteria,

e.g. 9-10 million nucleotides. Sorangium

cellulosum has the largest known (as of

2008) bacterial genome, at 13.0 million

nucleotides. Myxobacteria are included

among the proteobacteria, a large group of

Gram-negative forms.

http://star.tau.ac.il/~eshel/Bio_complexity/11.%20Swarming%20Intelligence/Myxobacteria_files/chondromyces.gif

Myxobacteria : a group of gram negative

eubacteria, belonging to the delta group of the

proteobacteria.

They were originally

isolated in 1892 by Roland

Thaxter who recognized

them as a distinct and

unusual group of bacteria.

http://myxobacteria.ahc.umn.edu/

http://www.nd.edu/~mcbg/nov10/nov10.2.gif

S-motility

The pilus extends ahead of a cell,

adheres to the fibrils on the cells ahead

of it and then retracts, pulling the leading

end of the piliated cell forward.

A-motility

Cell is pushed by slime secretion.

COUPLING CELL MOVEMENT TO

MULTICELLULAR

DEVELOPMENT IN

MYXOBACTERIA by Dale Kaiser

Nature Reviews Microbiology 1, 45-54

(2003)

Streptomyces is the largest genus of

Actinobacteria and the type genus of the

family Streptomycetaceae. Over 500 species

of Streptomyces bacteria have been

described. As with the other Actinobacteria,

streptomycetes are gram-positive, and have

genomes with high GC-content. Found

predominantly in soil and decaying

vegetation, most streptomycetes produce

spores, and are noted for their distinct

"earthy" odor which results from production

of a volatile metabolite, geosmin.

The complete genome of

one of the strain, "S.

coelicolor" A3(2), was

published in 2002. At the

time, the "S. coelicolor"

genome was thought to

contain the largest number

of genes of any bacterium.

The chromosome is

8,667,507 bp long with a

GC-content of 72.1% and

is predicted to contain

7,825 protein encoding

genes.

http://www.essex.ac.uk/BS/biophysics/Images/Worrall%20Streptomyce%201.jpg

http://upload.wikimedia.org/wikipedia/commons/d/de/Streptomyces_sp_01.png

ANTIBIOTICS AND BIOACTIVE COMPOUNDS ARE

PRODUCED BY STREPTOMYCETES

Antibiotics

streptomycin (Streptomyces griseus)

rifamycin (Amycolatopsis mediterranei)

erythromycin (Saccharopolyspora erythraea) oleandomycin

(Streptomyces antibioticus).

Bioactive compounds

avermectin (Streptomyces avermitilis),

bleomycin (Streptomyces verticillus), and

daunomycin (Streptomyces peuceticus) as antitumor compounds

FK506 (Streptomyces tsukubaensis) as an immunosuppressant

validamycin (Stereptomyces hygroscopicus var. limoneus) as a

treatment of rice sheath blight disease.

http://home.hiroshima-u.ac.jp/mbiotech/hosenkin_lab/Strepto-E.html

http://home.hiroshima-u.ac.jp/mbiotech/hosenkin_lab/Strepto-E.html

Aquifex fix carbon dioxide from the environment to get the carbon

that they need. They are chemolithotrophic, which means that they

draw energy for biosynthesis from inorganic chemical sources.

The enzymes this organism uses for aerobic respiration are similar

to the enzymes found in other aerobic bacteria (Deckert et al.

1998). A. aeolicus requires oxygen from the air as an electron

acceptor to oxidize hydrogen gas: 2 H2 + O2 → 2 H2O

Aquifex means water-maker in Latin, and refers to the fact

that its method of respiration creates water.

Aquifex is a genus of bacteria, one of the few in the

phylum Aquificae. The two species generally classified in

Aquifex are A. pyrophilus and A. aeolicus.

Both known species of Aquifex are rod-shaped bacteria

with a length of 2 to 6 µm and a diameter of around 0.5

µm. They are non-sporeforming, Gram negative

autotrophs. Aquifex tend to form cell aggregates composed

of up to 100 individual cells.

http://microbewiki.kenyon.edu/images/6/6d/Upstream_of_aquifex_environment.jpg

Aquifex is highly thermophilic, growing best in water temperature

of 85 °C to 95 °C. They are true bacteria as opposed to the other

inhabitants of extreme environments, the Archaea.

http://www.geocities.com/awjmuller/jpg_files/reykfig5.jpg

A. aeolicus genome is 1,551,335 bp in length, is densely packed and

contains genes that overlap others. In addition, no introns or protein

splicing elements have been found.. This, along with a reduced

metabolic flexibility, is probably due to the limited genome size; the

genome of this complex organism is only one-third of the E. coli

genome. Comparison of the Aquifex genome to other organisms

showed that 16% of it genes originated from archaea bacteria.

Deinococcus radiodurans

Initially it was placed in the genus Micrococcus. After

evaluation of ribosomal RNA sequences and other

evidence, it was placed in its own genus Deinococcus,

which is closely related to the genus Thermus of heat-

resistant bacteria; the group consisting of the two is

accordingly known as Deinococcus-Thermus.

The name Deinococcus radiodurans means "strange

berry that withstands radiation". The species was

formerly also called Micrococcus radiodurans and

Deinobacter radiodurans.As a consequence of its

hardiness it has been nicknamed "Conan the Bacterium"

The branches in red are those in which ionizing-radiation-

resistant taxa have been described. The scale bar represents 10

inferred nucleotide substitutions per 100 nucleotides.

http://www.salinesystems.org/content/figures/1746-1448-1-3-1-l.jpg

When older colonies of D. radiodurans are used, their survival

extends much farther, to around 17kGy (1.7 million rads).

Scientists believe this extreme radiation resistance may be a side

effect of D. radiodurans' ability to survive severe dehydration,

which also fragments DNA. [Nature Biotechnology 18, 85-90

(January 2000)]

http://trishul.sci.gu.edu.au/~bharat/images/Deinococcus.jpg At >30 Gy humans die in 48 hrs

Trends in Microbiology, Volume 7, Issue 9, 362-365, 1 September 1999

The nucleoid in each compartment is highly condensed and maintains

its overall architecture after irradiation. High levels of Mn(II) might

contribute to the recovery from DNA damage. A wide range of

enzymes probably also contribute to genome reconstitution.

Deinococcus

radiodurans —

the consummate

survivor

Michael M. Cox

and John R.

Battista

Nature Reviews

Microbiology 3,

882-892

(November 2005)

A mechanism of error-free double-strand-break repair that is initiated by creating 3' overhangs from the ends

of the broken DNA duplex (green in the figure). One of these 3' ends invades a homologous region on an

undamaged sister duplex (blue in the figure), priming DNA synthesis and creating a D-loop that acts as a

template or DNA synthesis primed by the other 3' end. If displaced, the newly synthesized DNA can anneal,

closing the double-strand break. Newly synthesized DNA is coloured red.

Lyme Disease

http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/17244.jpg

Tertiary Lyme disease is a late, persistent inflammatory disease

characterized by skin changes, neurological and musculoskeletal

symptoms caused by the bacterium Borrelia burgdorferi transmitted

by the bite of a deer tick. Tertiary Lyme disease is indicated by

chronic arthritis.

http://www.wadsworth.org/databank/hirez/hechemy2.gif

Borrelia cells average 0.2 to 0.5 µm by 4 to 18 µm, and have fewer

coils than Leptospira . The periplasmic flagella originate from

either end of the spirochete (where they are anchored to the

cytoplasmic membrane) and wind around the protoplasmic

cylinder, imparting both motility and shape to the organism—in

contrast to other bacteria, in which the peptidoglycan layer

determines the shape

http://www.nature.com/nri/journal/v4/n2/fig_tab/nri1267_F1.html

The transmission of

Borrelia burgdorferi

to the mammalian

host and the

dissemination of the

spirochete to the

joint. Elucidation of

Lyme arthritis

Allen C. Steere

and Lisa

Glickstein

Nature Reviews

Immunology 4,

143-152 (February

2004)

http://www.aldf.com/images/2004LymeDiseaseCaseMap.jpg

Lyme Disease 2004 Reported Cases

http://www.aldf.com/images/LymeDiseaseRisk.gif

Lyme Disease Risk Map

Lyme Disease Risk Map

http://www.hpl.umces.edu/faculty/bcrump/FISH.pdf

http://www.hpl.umces.edu/faculty/bcrump/Micro-FISH.pdf

http://kentsimmons.uwinnipeg.ca/16cm05/1116/16biomes.htm

In Situ Analysis of Phototrophic Sulfur

Bacteria in the Chemocline of Meromictic

Lake Cadagno (Switzerland)

Appl Environ Microbiol. 1999 March; 65(3): 1325–1330.

Mauro Tonolla,* Antonella Demarta,1 Raffaele Peduzzi,1 and

Dittmar Hahn2,3

Cantonal Institute of Bacteriology, Microbial Ecology

(University of Geneva), CH-6904 Lugano,1 and Swiss Federal

Institute of Technology (ETH), Institute of Terrestrial Ecology,

Soil Biology, CH-8952 Schlieren,2 Switzerland, and

Department of Biology, Rutgers University, Newark, New

Jersey 07102-18113

Received August 5, 1998; Accepted December 8, 1998.

In situ detection of

phototrophic sulfur

bacteria with Cy3-labeled

probes Cmok453,

targeting Chromatium

okenii DSM16 (a);

Apur453, targeting

Amoebobacter purpureus

DSM4197 (b); S453D,

targeting clone 261 (c);

and S453F, targeting

clones 335 and 371 (d).

Bar, 10 um.

Vertical distribution of physicochemical parameters and bacteria in the chemocline of Lake

Cadagno at a depth of between 11 and 14 m. (a) Sulfide (○) and turbidity (●). (b) Cells detectable

after in situ hybridization with probes Cmok453 ([open triangle]) and Laro453 ([filled lozenge]).

(c) Cells detectable after in situ hybridization with probes S453D (?) and Apur453 (?). (d) Cells

detectable after in situ hybridization with probe S453F (?); the sum of cells detectable after in situ

hybridization with probes Apur453, Laro453, S453D, and S453F ([left filled triangle]); and the

number of small-celled phototrophic sulfur bacteria determined by using autofluorescence and

cell size as distinctive criteria ([open triangle]). The data, determined from 40 microscopic fields

of three samples, are expressed as means ± standard errors.

Preventative Health National Research

Flagship Protective Foods Stream, CRC-3

Project

Gut Bacterial Population Profiles and

Relationships To Diet and Health

Dr. Michael Conlon

CSIRO Human Nutrition

Adelaide, Australia

www.dar.csiro.au/.../Michael%20Conlon%20CSS%20Presentation%20August%202006.ppt

The task is to detect and count particular species of bacteria

found in human faeces

A fluorescent RNA probe is hybridized to bacteria of interest in

the sample

Various artefacts including autofluorescence of the background

and other bacteria, clumping and inhomogeneity of spatial

distribution, non-specificity of probe, can make this an

extremely challenging image analysis problem

A state-of-the-art segmentation scheme has been developed

A candidate image object must satisfy strict size, shape, and

intensity criteria before being counted

www.dar.csiro.au/.../Michael%20Conlon%20CSS%20Presentation%20August%202006.ppt

Dilute faeces stained with a Cy3 (red) labelled rRNA

probe specific for the F. prausnitzii bacterium.

www.dar.csiro.au/.../Michael%20Conlon%20CSS%20Presentation%20August%202006.ppt

Segmentation result. Note the segmenter is

designed to delineate all bright image objects

www.dar.csiro.au/.../Michael%20Conlon%20CSS%20Presentation%20August%202006.ppt

Detected F. prausnitzii bacteria after applying

strict size-shape-morphology-brightness criteria.

www.dar.csiro.au/.../Michael%20Conlon%20CSS%20Presentation%20August%202006.ppt

The End