Studied this in lab. Media must contain nitrate in addition to nutrients, otherwise won't work. Also, in scavenger hunt at end of course, one target microbe will be Pseudomonas , enrichment culture depends on its ability to grown anaerobically using nitrate reduction. Process called sulfate reduction . Have unique cytochrome c3.
Sulfate is common in seawater.
Common in estuaries. One of most common inorganic ions. Obligate anaerobes, archaebacteria. Produce methane as waste product. Methanogens typically live alongside bacteria that produce hydrogen by fermentation, remove hydrogen as it is made.