REHOVOT, Israel - A bacterium that produces the powerful natural antioxidant pigment astaxanthin has been discovered by a research team from Hebrew University, of Jerusalem.

The bacterium, called Paracoccus marcusi, was named for Menashe Marcus, a professor and former head of the department of genetics at Hebrew University.

“In humans, astaxanthin has been found to play an important role in cancer and tumor prevention as well as in eliciting a positive response in the immune system and in preventing visual deterioration,“ said Joseph Hirschberg, head of the research team and professor at Hebrew University's Alexander Silberman Institute of Life Sciences.

Astaxanthin, one of the carotenoid family of natural pigments, embues the skin of many organisms - including salmon, shrimp and various exotic fishes - with intense yellow, orange and red hues. It is produced by microalgae, which consume the bacteria and which in turn are consumed by these organisms. The pigment is retained unchanged as it is passed up through the food chain.

Until now, astaxanthin has been extracted from crustacea and algae, a limited and expensive process. Chemically synthetic astaxanthin does not have the same molecular structure as the natural product, nor its powerful antioxidant activity.

The astaxanthin from P. marcusi is secreted outside the bacteria. The pigment is produced in bubble-like structures which are easy to collect and from which the pigment can be extracted in its natural form .

“The pigment can be literally washed off the newly discovered bacterium, considerably easier than extracting it from the consumers of it, which should add significantly to the natural pigment's biotechnological availability and immediately lower the cost of astaxanthin,“ said Aharon Oren, of the department of microbial and molecular ecology at the Silberman Institute. Oren participated in identifying and characterizing the bacterium.

“This unique phenomenon has not been observed in bacteria before and it has far-reaching consequences for the use of the bacterium to produce astaxanthin,“ said Oren.

The Yissum Research Development Co., which is part of the Hebrew University, has patented the process for obtaining astaxanthin from the new bacterium.

Synthetic dyes, especially the red dyes, have been linked with various health problems, so it is anticipated that the availability of an antioxidant dye will have a broad impact. Further research and development is in progress to make this possible. The bacterium has been sent to the official European bacteria depository, which, according to the Budapest Covenant, ensures the commercial rights for the discoverer are protected. *