Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 

Researchers reveal how ocean bacteria use light to grow

Tuesday 19 August 2014

Researchers reveal how ocean bacteria use light to grow

Sunlight stimulates common ocean bacteria to use carbon dioxide for growth when high-quality organic carbon food sources are scarce, according to surprising research by an international team that includes a University of Otago researcher.

The team’s new study suggests that these versatile bacteria may play a more significant role in the biogeochemistry of the oceans, and thus global climate processes, than previously thought. Their findings are published this week in the prestigious international journal PNAS.

The researchers, who include Otago marine scientist Dr Federico Baltar, investigated a marine bacterium called Dokdonia which contains a light-absorbing pigment named proteorhodopsin (PR).
Marine bacteria are the most abundant organisms in the ocean, accounting for up to 90% of its global biomass, and up to half are thought to be PR-containing.

Dr Baltar says this pigment’s existence in ocean bacteria was first discovered by other researchers in 2000, revealing a whole new class of micro-organisms capable of harnessing sunlight in the ocean through means other than photosynthesis.

To tease out the mechanisms underlying how such bacteria were using light to grow, he and his co-authors analysed gene expression in Dokdonia in light and dark and nutrient rich and nutrient poor conditions.

“We discovered that light profoundly affects Dokdonia’s patterns of gene expression and metabolic activities, and that these responses are influenced by the availability of organic matter and its quality,” Dr Baltar says.

The changes included that when they were exposed to light the bacteria switched to obtaining one-third of their cellular carbon from CO2.

“These bacteria’s ability to use both inorganic and organic carbon to grow makes them remarkably flexible micro-organisms that can quickly adapt to the highly variable conditions in their ocean environment,” he says.

Dr Baltar says the findings are the microbial equivalent of discovering that kittens lie in the sun not because they enjoy the warmth, but because they are using light energy for sustenance until their next meal.

ENDS

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

By May 2018: Wider, Earlier Microbead Ban

The sale and manufacture of wash-off products containing plastic microbeads will be banned in New Zealand earlier than previously expected, Associate Environment Minister Scott Simpson announced today. More>>

ALSO:

Snail-ier Mail: NZ Post To Ditch FastPost

New Zealand Post customers will see a change to how they can send priority mail from 1 January 2018. The FastPost service will no longer be available from this date. More>>

ALSO:

Property Institute: English Backs Of Debt To Income Plan

Property Institute of New Zealand Chief Executive Ashley Church is applauding today’s decision, by Prime Minister Bill English, to take Debt-to-income ratios off the table as a tool available to the Reserve Bank. More>>

ALSO:

Divesting: NZ Super Fund Shifts Passive Equities To Low-Carbon

The NZ$35 billion NZ Super Fund’s NZ$14 billion global passive equity portfolio, 40% of the overall Fund, is now low-carbon, the Guardians of New Zealand Superannuation announced today. More>>

ALSO:

Split Decision - Appeal Planned: EPA Allows Taranaki Bight Seabed Mine

The Decision-making Committee, appointed by the Board of the Environmental Protection Authority to decide a marine consent application by Trans-Tasman Resources Ltd, has granted consent, subject to conditions, for the company to mine iron sands off the South Taranaki Bight. More>>

ALSO: