Arm and the South Arm, due to the stop of free circulation the North Arm routinely has higher
salinity. Bacteria are very important to the health of both arms of the lake. Bacteria are the
simplest and most primitive of all life. They are prokaryotic unicellular organisms. That means
that they consist of one cell that has no defined nucleus and are in the Biological Kingdom
WHY ARE BACTERIA IMPORTANT?
Bacteria digest organic matter, such as dead brine shrimp,brine flies, and algae. In doing so
they recycle nutrients such as nitrogen and phosphorus and return it to the food web. They also
digest the uric acid, an organic form of nitrogen excreted by the Brine Shrimp and Brine Flies,
thereby releasing Ammonia (NH3) , Biocarbonate (HCO3), and Carbonite ion (CO3). These
compounds, especially ammonia, are used by the algae. Bacteria are also a major food source
for developing young Brine Shrimp and Brine Flies.
WHAT IS THE BIOLOGY OF THE SOUTH ARM?
The South Arm has a lower salinity and therefore has more types of Bacteria. As many as 15
distinct types of bacteria have been found, but further studies are necessary. The types
commonly found are:
non motile sphere
Bacillus cohaerens motile rod, single or in pairs
Bacillus freudenreichii motile rod, single or in chains
Bacillus mycoides rods in chains with spores
Achromobacter solitarium slender motile rods
Achromobacter album non motile rods
Achromobacter hartlebii motile single rods
Flavobacterium arborescens non motile rods, pairs or chains
Bacterioides rigidus motile slender rods, single or in pairs
Serratia salinaria single motile rods, non motile in GSL
Cellulomus subcreta single motile rods, non motile in GSL
( Fredrick, 1924 in Gwynn, 1980)
WHAT IS THE BIOLOGY OF THE NORTH ARM?
Due to the high salinity the North Arm has far fewer types of bacteria. In fact only two types
have been found, the Halobacterium and Halococcus.
Some of these halobacteria have been found have a rhodopsinprotein in the cell
membrane that is capable of producing ATP in the absence of oxygen and in the presence of
light. (Post, 1977a) Basically this means that the bacteria is capable of producing energy in the
form of ATP. There are many theory's about the use of this energy and the rhodopsinprotein;
one is that the bacteria needs the energy for extreme salt regulation, another is that it helps in
The rhodopsinprotein is what gives the bacteria its reddish color. At the end of the growing
season when there is a
large concentration of bacteria
it gives the water a reddish tint.
Another interesting phenomenon; generally only found in the North Arm of the lake, is that
Brine Shrimp contain a bacterial symbiont. The current theory is that because the diet of the
Brine Shrimp is so severely limited in the North Arm due to the salinity, the symbiont allows the
shrimp to survive by helping them to obtain the vitamins that they need. That would explain why
the symbionts are not found in the brine shrimp of the South Arm, because the lower salinity
allows a greater variety of organisms in the food web. (Post, and Youssef 1977)
Post, F.J., 1977a, Microbiology of the Great Salt Lake north arm, Hydrobiologia 81, 59-69.
Post, F.J., 1977b, The Microbial Ecology of the Great Salt Lake, Microbial Ecology 3, 143-165.
Post, F.J. & N.N. Youssef, 1977, A procaryotic intracellular symbiont
of the Great Salt Lake brine shrimp Artemia salina (L.), Can J. Microbiol.