Microbial ecology

Figure 21.3

DAPI fluorescent staining for DNA

Live dead stain

Fluorescent antibody

Arabidopsis root and shoot and DEC8D pgfp

FISH

Microbial mat and microelectrodes top cyanobacteria next anaerobic photosynthetics and heterotrophs

Figure 21.9

Figure 21.17

Figure 21.19A and B

Figure 21.22Figure 21.23

Microbes Associated with Roots The environment surrounding a plant root can be further subdivided into two categories: - Rhizoplane: The plant root surface - Rhizosphere: The region of soil outside the rhizoplane that receives substances from the root Particular microbial species are adapted to these environments. Figure 21.27

Microbial Communities within Plants Endophytes are bacteria or fungi that colonize the transport vessels of plants. - Produce alkaloids and enzymes that deter plant pathogens and root-feeding nematodes Endophytic pathogens pose a problem for the food industry because the bacteria cannot be “washed off” from raw produce. Figure 21.31

Wetland Soils A wetland is a region of land that undergoes seasonal fluctuations in water level. - Dry and oxygenated vs. water-saturated and anaerobic Many kinds of anaerobic bacteria inhabit wetlands. - Denitrifiers - Fermenters The anoxic conditions of wetlands also favor methanogenesis. Figure 21.30

Figure A and B

Figure 21.41

Vertebrate Gut Fermentation Figure 21.42