The Pinkish-Salt Lake of 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 collected Part 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 bacteriaMicro 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. 1 st 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