Wakame waste

May 01, 2008

Bacteria that feed on seaweed could help in the disposal of pollutants in the world's oceans, according to a new study by researchers in China and Japan. The discovery is reported in the International Journal of Biotechnology.

Shinichi Nagata of the Environmental Biochemistry Group, at Kobe University, Japan, working with colleagues at Shimane University and at Nankai University, China, explain that as marine pollution is on the increase novel approaches to removing toxic contaminants is becoming an increasingly pressing issue. They point out that various species of seaweed are able to extract toxic compounds from seawater and point to the brown seaweed, Undaria pinnatifida, known as wakame in Japan as having been the focus of research in this area for almost a decade.

Wakame can thrive evening the presence of carbon, ammonium, nitrate and phosphate in sea water that would otherwise be lifeless. However, there remains the problem of how to dispose of planted wakame, once it has feasted on organic and inorganic pollutants in seawater.

Organic pollutants are absorbed by cultured wakame and so cultivated wakame must be treated as a kind of toxic waste rather than a useful byproduct of marine bioremediation. The researchers point out that there may be a simple solution to the disposal problem. Natural wakame has been used as a fertilizer since ancient times, they explain, so the composting process could be an effective means of degrading wakame into a useful form and so recycling organic substances containing C, N and P from coastal waters.

The team has now found a highly efficient way to accelerate the composting process in the form of a novel marine bacterium, identified as a Halomonas species and given the label AW4.

Partial DNA analysis helped identify the active species isolated from the seaweeds in Awaji Island, Japan. The researchers explain that strain AW4 grows well even at high salt (sodium chloride) concentrations and can reduce the total organic components, including pollutant content, of the seaweed significantly within a week.

Source: Inderscience Publishers

Explore further: Norway tests out 'animal rights cops'

Related Stories

Nuclear fears contaminate sales for Japan farmers

Jan 14, 2013

Mayumi Kurasawa's seaweed company saw seven of its factories swept away by Japan's 2011 tsunami. Nearly two years later, sales continue to be eroded by consumer fears over nuclear contamination.

Fast-growing kelp invades San Francisco Bay

Jul 10, 2009

(AP) -- A fast-growing kelp from the Far East has spread along the California coast from Los Angeles to San Francisco Bay, worrying marine scientists and outpacing eradication efforts.

Recommended for you

Species' evolutionary choice—disperse or adapt?

8 minutes ago

Dispersal and adaptation are two fundamental evolutionary strategies available to species given an environment. Generalists, like dandelions, send their offspring far and wide. Specialists, like alpine flowers, ...

Genetic variation is a necessity

41 minutes ago

The Earth is constantly changing. For new species to be able to adapt and cope with the changes, there must be sufficient genetic diversity, or genetic variation, in the population. But what type of diversity is required ...

Barking mad? Doggie DNA to track foulers in London

52 minutes ago

A London borough—aptly named Barking and Dagenham—unveiled plans on Tuesday to crack down on irresponsible dog owners by checking their pet's poo against a DNA database it will build up.

Norway tests out 'animal rights cops'

14 hours ago

Norwegian police is creating a unit to investigate cruelty to animals, the government said Monday, arguing that those who hurt animals often harm people too.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.