The Pinkish-Salt Lakeof Jeddah

A Remarkable Biological Phenomenon

of the Year 2009

Dr. A. N. Abo-khatwa

It should be called the “Dream Lake” from Disney Theme Park

A saline-loving (Halophytic) and very ancient (Archeo-) heat-loving (Thermophilic) pinkish

bacteria is flourishing in the bottom and the surface of the very salty lake

Located South of the Amana building; forming a beautiful colorful scenery of a

remarkable biological phenomenon

This phenomenon has been reported in California, Nevada and in Western Australia

A sharp contrast between the lake color and the sea

 . Water samples were collectedPart went to Marine Science Lab and the other to the

Microbiology Lab at KAU

• Marine Science investigation revealed No red tide algae, such as the dinoflagellate Goyaulax spp. Only a limited number of at least 4 species of green algae, among them Spirulena Sp, and few cyanobacteria were present. An interesting algae with 4 flagella was als recorded but few in number.

• water samples produced a reddish sediment upon centrifugation at 5,000 rpm (round per minutes),

• A bacteriologist from KAU is currently investigating the composition of the red pellet after isolation and purification of bacteria.

King Abdul-Aziz (KAU) Investigation

• A pinkish salt lake in California (2006)

• Is considered one of the remarkable biological phenomenon

• Solar evaporation, high salt content, and limited circulation stimulate the massive growth of purple halobacteria (salt-loving bacteria)

Similar phenomena in the World

A Pinkish Lake in Western Australia (2007)

Salt Crystal

Rods of halophytic bacteria Micro Alga

Salt Crystal

A diagram of water contents at high magnification (2,000x)

Salt crystals from a California pinkish Lake covered with tiny pinkish bacteria

• A water sample from the pinkish salty lake on the left and after being centrifuged at 5,000 rpm on the right.

• The red sediment in the bottom of the tube found to be of red halophytic bacteria.

1st step in the investigation

• The pinkish or reddish pigment is embedded in the bacterial cell wall.

• The reason for bacteria producing this pigment is to use as a filter (as we use sun-glasses) to protect itself from severe sun light.

• The chemical nature of the colorful pigment is related to retinal and beta carotene, which are found in the retina of our eyes and in carrots.

• The pigment has been isolated and some industries found it useful as food supplement (in the making of vitamin pills), in dying textiles & making tinted glass.

About the Pinkish Pigment

Recommendations• The pinkish lake is not a bad sign of pollution and should be kept as is. If the high salinity of the lake drops down, bacteria will soon die and the color will disappear.

• It is one of the rare biological phenomenon, which is not very common around the world.

• Schools should be encouraged to bring their children to the lake and science teachers should tell them the fascinating story behind it.

Thank You