Artificial seawater can help marine microbes grow

Scientists have concocted an artificial seawater medium that can be used to successfully cultivate abundant marine micro-organisms, a study says.

"We developed an artificial media which means you can make it in the lab; and anyone can order these chemicals and make this media anywhere in the world," said one of the researchers Cameron Thrash, assistant professor at Louisiana State University in the US.

The artificial seawater media consists of about 60 ingredients that include chemical elements such as calcium, sodium, magnesium plus organic and inorganic nitrogen, carbon, trace metals and B vitamins.

Prior to this discovery, many of the most abundant micro-organisms in the ocean that have been successfully cultured were done so with the aid of natural seawater media.

Seawater is naturally low in nutrients, and many marine microbes are adapted to those conditions.

The painstaking culturing process that includes filtering and sterilising the seawater can pose many challenges.

First, it requires access to large volumes of seawater, which can be logistically challenging for research labs that are not located near the coast.

Secondly, the composition of natural seawater is not clearly defined or understood. Therefore, it is difficult to characterise it physiologically. Thirdly, the composition of seawater at various times and places chemically changes.

To solve some of these challenges, the researchers created a complex yet defined artificial seawater media that is portable and reproducible.

The findings were published in the open access journal mSphere.

Although there are other artificial seawater media available, this is the first time an artificial medium has led to the isolation of highly abundant marine microbes such as SAR11, a group of organisms that has been difficult to cultivate.

This new tool may benefit genomics researchers, marine chemists and the microbial research community.

--IANS

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