Tuesday, November 1, 2011

Red Sea Corals

At the tail end of our trip to Petra, Jordan in October we spent one night along the Jordanian section of the Red Sea shore.  Mom and I took a boat tour with a see through seating level below the water line.  It was a fun way to see the coral reefs, including a sunken ship and an old American tank that was placed there specifically to try to encourage new coral development.

On our drive back to town, we talked to the staff of the company and it turns out they are involved in the preservation of the corals, as well as running their tourism business. 

Below is a summary I wrote following the speaker at the first class meeting on November 3rd. 

During our first seminar, Eugene Rosenberg, Dept. of Molecular Microbiology and Biotechnology at TAU provided us an overview of his lab’s research into coral bleaching.  He shared with us the three anthropogenic factors contributing to coral reef deterioration – 1) water pollution, 2) over fishing, and 3) seawater temperature increases.  He elaborated on the impact of temperature increases which correlated with a loss of endosymbiotic algae every summer from 1995-2002.  

However, since then, his team has not been able to isolate V. shiloi, the bacteria studied and understood to act as an infectious disease for the O. patagonica coral found in the eastern Mediterranean.  This discovery led to development of his coral probiotic hypothesis.  The importance of this finding is that it shows that coral, like all other plants and animals, live in a symbiotic relationship with a set of bacteria.  This combination of host and microorganisms is called a holobiont.  The bacteria are more rapidly adaptable to changes in the holobiont’s environment than the host is.  Over time, the type and quantity of bacteria that joins the host impacts the overall function of the holobiont.  In this case, the coral acquired beneficial bacteria that killed V. Shiloi. 

It is only in recent decades that the ability to study bacteria that are “viable but not culturable,” (VBNC) has become possible.  New techniques like this have increased our knowledge, and yet we are only at the beginning.  For example, Professor Rosenberg shared the history of knowledge on bacteria in the human gut, believed to have about 100 types in the 1970s, and now known to have at least 40,000.  In addition, he stated that these bacteria hold 200 times greater genetic material than we, as the human host, do.  It is also important to note that the holobiont is not just the sum of the genetic material of the host plus the microorganisms.  The symbiotic relationship enhances the adaptability and survival of the collective group.

His findings are significant because he has extrapolated the coral probiotic hypothesis to the hologenome theory of evolution.  This theory has far-reaching, cross-disciplinary implications, from human health, to social structures, and just about every topic under the umbrella of environmental studies.  It has the potential to change the way we view relationships between species, from the Darwinian focus on competition, to that of cooperation.

No comments:

Post a Comment