Carbon is Key for Getting Algae to Pump Out More Oil

Overturning two long-held misconceptions about oil production in algae, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory show that ramping up the microbes’ overall metabolism by feeding them more carbon increases oil production as the organisms continue to grow. The findings — published online in the journal Plant and Cell Physiology on May 28, 2012 — may point to new ways to turn photosynthetic green algae into tiny “green factories” for producing raw materials for alternative fuels.

“We are interested in algae because they grow very quickly and can efficiently convert carbon dioxide into carbon-chain molecules like starch and oils,” said Brookhaven biologist Changcheng Xu, the paper’s lead author. With eight times the energy density of starch, algal oil in particular could be an ideal raw material for making biodiesel and other renewable fuels.

But there have been some problems turning microscopic algae into oil producing factories.
For one thing, when the tiny microbes take in carbon dioxide for photosynthesis, they preferentially convert the carbon into starch rather than oils. “Normally, algae produce very little oil,” Xu said.

Before the current research, the only way scientists knew to tip the balance in favor of oil production was to starve the algae of certain key nutrients, like nitrogen. Oil output would increase, but the algae would stop growing — not ideal conditions for continuous production.

Another issue was that scientists didn’t know much about the details of oil biochemistry in algae. “Much of what we thought we knew was inferred from studies performed on higher plants,” said Brookhaven biochemist John Shanklin, a co-author who’s conducted extensive research on plant oil production. Recent studies have hinted at big differences between the microbial algae and their more complex photosynthetic relatives.

“Our goal was to learn all we could about the factors that contribute to oil production in algae, including those that control metabolic switching between starch and oil, to see if we could shift the balance to oil production without stopping algae growth,” Xu said.

The scientists grew cultures of Chlamydomonas reinhardtii — the “fruit fly” of algae — under a variety of nutrient conditions, with and without inhibitors that would limit specific biochemical pathways. They also studied a mutant Chlamydomonas that lacks the capacity to make starch. By comparing how much oil accumulated over time in the two strains across the various conditions, they were able to learn why carbon preferentially partitions into starch rather than oil, and how to affect the process.

The main finding was that feeding the algae more carbon (in the form of acetate) quickly maxed out the production of starch to the point that any additional carbon was channeled into high-gear oil production. And, most significantly, under the excess carbon condition and without nutrient deprivation, the microbes kept growing while producing oil.

“This overturns the previously held dogma that algae growth and increased oil production are mutually exclusive,” Xu said.

The detailed studies, conducted mainly by Brookhaven research associates Jilian Fan and Chengshi Yan, showed that the amount of carbon was the key factor determining how much oil was produced: more carbon resulted in more oil; less carbon limited production. This was another surprise because a lot of approaches for increasing oil production have focused on the role of enzymes involved in producing fatty acids and oils. In this study, inhibiting enzyme production had little effect on oil output.

“This is an example of a substantial difference between algae and higher plants,” said Shanklin.
In plants, the enzymes directly involved in the oil biosynthetic pathway are the limiting factors in oil production. In algae, the limiting step is not in the oil biosynthesis itself, but further back in central metabolism.

This is not all that different from what we see in human metabolism, Xu points out: Eating more carbon-rich carbohydrates pushes our metabolism to increase oil (fat) production and storage.

“It’s kind of surprising that, in some ways, we’re more like algae than higher plants are,” Xu said, noting that scientists in other fields may be interested in the details of metabolic switching uncovered by this research.

But the next step for the Brookhaven team will be to look more closely at the differences in carbon partitioning in algae and plants. This part of the work will be led by co-author Jorg Schwender, an expert in metabolic flux studies. The team will also work to translate what they’ve learned in a model algal species into information that can help increase the yield of commercial algal strains for the production of raw materials for biofuels.

Climate Change Envoy Warns Against Cutting Investment in Green Energy

The government's climate change envoy has warned that failure to take more action to invest in a low carbon economy is a threat to the future "prosperity and security" of the British people.

John Ashton, who has just stepped down from his post at the Foreign Office, told MPs that the UK was still considered an influential global player on climate change, but signalled that position was at risk as the country was falling behind on investment in energy efficiency and clean energy.

This in turn would make it harder to meet global targets to limit global warming to 2C - the level at which experts consider most countries will cope with the ensuing disruption to weather patterns.

"Failure to deal with climate change would amplify already dangerous stresses arising from food, water and energy insecurity," Ashton told the energy and climate change select committee. "This potentially unmanageable combination of stresses poses a systemic risk to the security and prosperity of our country."
In 2004 the government's then chief scientist, Professor Sir David King, made headlines around the world when he declared that climate change was "the most severe problem we are facing today, more serious even than the threat of terrorism".

However, the growing political consensus for tackling climate change, which culminated in the 2008 Climate Change Act committing the UK to binding emissions reductions, has appeared to be breaking down in the last two years as lack of economic growth and savage public spending cuts have eroded support for sometimes costly policies.

These issues came to a head in February when more than 100 Conservative MPs signed a letter to the prime minister, David Cameron, calling for an end to onshore windfarms.

Ashton, who left his six-year post two weeks ago, said he sympathised with concerns that UK efforts to combat climate change would be an expensive failure if other countries did not follow suit. However in a thinly-veiled warning about the damage done by draining political support for 'green' policies, he said the UK's diplomatic efforts to persuade other countries to reduce the world's reliance on oil and other fossil fuels "depends on what we are doing at home" and the "consensus across the political spectrum".

Ashton also told MPs that far from leading the world, the UK was falling behind important economic competitors such as Germany, Korea, China and Japan in some of the big future industries such as offshore wind energy and carbon capture and storage systems for gas and coal power stations.

"Internationally we must resolve the false choice, exacerbated by the current crisis, between economic security and climate security," said Ashton. "A rapid shift to low carbon growth is essential for security, competitiveness and prosperity, not an intolerable risk to competitiveness, jobs and growth."

"Politically we must address this not as a distraction from our current problems, but as part of the solution to them," he added.

Tory committee member Dr Phillip Lee challenged Ashton, however, suggesting that there were still hundreds of millions of people who wanted a better standard of living in developing countries like China, and in the UK during the recession, who would not support policies which pushed up the price of energy and so goods and services they wanted to buy.

"It's seen that going green is going to slow down the growth that we need," added Lee.

Carbon Tax 'alarmism' Doesn't fit Facts, Scientists Warn

SCIENTISTS from around the world, including the former head of Australia's National Climate Centre, are calling for calm on global warming, saying alarmist rhetoric is not backed by evidence and is being used to increase taxes.

Writing in The Wall Street Journal, the 16 scientists say a "large and growing number" of scientists and engineers do not agree that drastic action on global warming is needed. "The number of scientific 'heretics' is growing with each passing year. The reason is a collection of stubborn scientific facts," they say. "Perhaps the most inconvenient fact is the lack of global warming for well over 10 years now."

Low-income Australian families 'battle energy bills'

LOW-income families are buckling under the strain of rising energy bills, a leading social welfare charity says.

Anglicare Sydney has recorded a sharp increase in the number of people seeking emergency aid to help meet household energy costs, which have risen 17.3 per cent since July.

Low-income families are under the highest pressure, Anglicare's director of advocacy Sue King said in a statement.

"Anglicare Sydney has given out $10,000 more in assistance for energy bills in the first quarter of this financial year compared with the same time last year,'' she continued.

"The increase in the amount of energy assistance distributed directly relates to the increase in electricity prices.''

It comes as the NSW Energy and Water Ombudsman confirmed many customers are now facing financial hardship because of rising energy bills, with a steady stream of complaints about large arrears and disconnections.

Ombudsman Clare Petre revealed there had been an eight per cent increase in complaints from customers facing disconnection during the last financial year.

There was an 18 per cent increase from customers who had been disconnected due to financial hardship.

Read more: http://www.news.com.au/money/cost-of-living/low-income-australian-families-battle-energy-bills/story-fnagkbpv-1226196732635#ixzz1d1vhMVWH