Namibia Conference and Workshop
Ministry of Fisheries and Resources, Swakopmund 29 - 30 April 2013

Presenter Biographies

AMI BEN-AMOTZ - Emeritus Professor of Marine Phycology
Nature Beta Technologies, Eilat, Israel

Ami Ben-Amotz received his B.Sc. & M.Sc. degrees at the Hebrew University of Jerusalem and the PhD at Weitzman Institute of Science (WIS), Israel, the last on studies related to the halotolerant alga Dunaliella. After post doctorate studies at Brandeis University, USA, on hydrogen production by marine algae Prof. Ben-Amotz returned to Israel and initiated academic and research activities at the National Institute of Oceanography (NIO) and at the WIS with the late Prof. M. Avron to study the biology, physiology, biochemistry and biotechnology of marine microalgae with emphasis on Dunaliella. The fruitful cooperation opened the way to establishment of the commercial Dunaliella production plant in Eilat, known today as Nature Beta Technologies Ltd., (NBT) Israel, a subsidiary of Nikken Sohonsha Co., Japan. Along his extensive career with marine microalgae, Prof. Ben-Amotz served as Head of the Department of Marine Biology at the NIO and Head of the Dunaliella Section at the WIS, Chief Scientist of NBT and recently as Chief Scientist of Nikken Sohonsha Co., Japan. Prof. Ben-Amotz served as President of the 8th International Marine Biotechnology Conference which was held in Eilat, Israel in March 2007. Upon his retirement of NIO Prof. Ben-Amotz founded Seambiotic Ltd., a company devoted to the cultivation of marine microalgae on industrial wastes including electric power plants for the production of feasible algae for bio-fuels, feed, food and high value products. Prof. Ben-Amotz has about 150 publications including two books published the first in 1992 and the second in 2009. He supervised dozens of students mostly on aspects related to marine algae, Dunaliella and natural products.

PRESENTATION ABSTRACT BY AMI BEN AMOTZ

Topic: Glycerol and beta-Carotene Production by Dunaliella: Glycerol

• Dunaliella adapts to high extracellular osmotic stress by synthesis of very high content of intracellular cytosolic glycerol, different than halobacteria which accumulate ions.
• Glycerol is produced either photosynthetically by carbon dioxide or by degradation of intracellular starch reserves.
• The induction of glycerol synthesis or reassimilation is triggered by cell volume changes. 
• Activation of glycerol synthesis does not involve de novo protein biosynthesis. Glycerol phosphate dehydrogenase, dihydroxyacetone phosphate reductase and phosphofructokinase are probably the checkpoint enzymes which control glycerol synthesis.
• The molecular mechanism which triggers glycerol production in Dunaliella is not yet known. Changes in the plasma membrane, inorganic phosphate, and pH following osmotic shocks suggest that plasma membrane sensors as well as soluble metabolites are involved in the activation of glycerol synthesis.  

Beta-Carotene

• Dunaliella adapts to high solar radiation by the accumulation of high content of chloroplastic peripheral extra-plastidic beta-carotene acting as light screen to prevent photooxidation.
• The beta-carotene of Dunaliella is composed of two stereoisomers, all-trans and 9-cis reaching a ratio of 1/1 under certain growth conditions.
• The beta-carotene of Dunaliella is stored within distinguished oil globules of special lipid profile.
• The content of beta-carotene and the isomeric ratio in the algal oily globules is manipulated and regulated by external environmental stimuli such as salt, light, nutrients and temperature.

Biotechnology

Currently Dunaliella is one of the very few microalgae that are commercially exploited. Although it is now cultivated intensively mainly for beta-carotene production, Dunaliella can grow autotrophically also extensively on carbon dioxide for the production of both glycerol and beta-carotene. The ability to use natural resources of sea and salt water, arid land, flue gas and solar radiation on wide global distribution makes this halo tolerant alga most attractive for open cultivation and commercialization for bioenergy and natural products.