Cosmopolitan microbes -- hitchhikers on Darwin's dust

Dec 04, 2007

Scientists have analysed aerial dust samples collected by Charles Darwin and confirmed that microbes can travel across continents without the need for planes or trains - rather bacteria and fungi hitch-hike by attaching to dust particles.

In a paper published in Environmental Microbiology, Dr. Anna Gorbushina (Carl-von-Ossietzky University, Oldenburg, Germany), Professor William Broughton (University of Geneva, Switzerland) and their colleagues analysed dust samples collected by Charles Darwin and others almost 200 years ago.

Geo-chemical analyses showed that these samples contained wind-fractionated dust from West Africa and some travelled as far as the Caribbean. Their results clearly show that diverse microbes, including ascomycetes, and eubacteria can live for centuries and survive intercontinental travel.

Desert storms stir up and deposit 50million tonnes of dust particles from the Sahara to the Amazon every year. The largest, single source of dust on the planet is the Bodélé Depression in Northern Chad. As surface sand is whipped up into the air, larger particles are continually lost, and only the finest (< 10microns) reach the troposphere where they are blown on Trade Winds across the Atlantic. Similar fractionation of microbes also occurs, and only some survive travel across oceans.

“These findings push forward our understanding of planetary microbial ecology.” said Professor Broughton.

But could inter-continental spread of microbial hitch-hikers lead to the spread of contaminants or disease? “Obviously, intercontinental spread of micro-organisms has been with us for a very long time, so unless land-use patterns in the Western Sahara have changed recently, disasters like the demise of coral in the Caribbean, cannot be ascribed to the intercontinental travel of desert bugs” said Professor Broughton.

Source: Wiley-Blackwell

Explore further: How to tell what a donkey is thinking

add to favorites email to friend print save as pdf

Related Stories

Dust-plumes power intercontinental microbial migrations

Dec 17, 2012

Along with pollutants from Asia, transpacific dust plumes deliver vast quantities of microbes to North America, according to a manuscript published online ahead of print in the journal Applied and Environmental Microbiology.

Recommended for you

The ABC's of animal speech: Not so random after all

1 hour ago

The calls of many animals, from whales to wolves, might contain more language-like structure than previously thought, according to study that raises new questions about the evolutionary origins of human language.

Manatees could lose their endangered species status

11 hours ago

About 2,500 manatees have perished in Florida over the last four years, heightening tension between conservationists and property owners as federal officials prepare to decide whether to down-list the creature to threatened ...

User comments : 0