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.

Andrew Wilkie Sets out Conditions to Support Carbon Tax

JULIA Gillard can secure the final vote she needs to pass the carbon tax if she promises to protect a zinc mine in Hobart.

Tasmanian MP Andrew Wilkie last night met the Prime Minister to discuss his terms after she won support from the Greens and independents Rob Oakeshott and Tony Windsor for the package.

Mr Wilkie also wants to make Tasmania a renewable energy hub and guarantee compensation for low-income earners.

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Ms Gillard last night called premiers to postpone a planned meeting next week on health reform. It will allow her to go on a national tour to sell the carbon tax.

Government MPs and staff yesterday were briefed to be on a "war footing" for a major campaign after the package was unveiled on Sunday. The PM will make a televised address to the nation on Sunday night.

Ms Gillard said she would spend next week directly answering questions from the public.

"I will be wearing out my shoe leather, literally," she told Parliament.

Victorian Liberal Kelly O'Dwyer, from Higgins, challenged the PM to attend a town hall meeting in her electorate.http://www.blogger.com/img/blank.gif

Opposition Leader Tony Abbott said the PM was "running away from scrutiny" by refusing to announce it before Parliament began a five-week recess tomorrow.

He wrote to Ms Gillard and urged her to recall Parliament next week.

Liberal climate spokesman Greg Hunt said: "When it comes to cost of living, this will be Sunday bloody Sunday."

Source

Carbon tax relief to end at $150,000

JULIA Gillard has indicated that most families on incomes above $150,000 will miss out on compensation under the proposed carbon tax plan to be unveiled next month.

This comes as Tony Abbott today will promise tax cuts from a Coalition government when it scraps the carbon tax and accompanying compensation measures.

Ms Gillard has strongly defended the $150,000 figure, saying people earning that amount are not rich but ''they're a lot better off than the vast majority of Australian families''. She pointed out that the average household income was $68,000 and only one in 10 households earned more than $150,000.

Prime Minister Julia Gillard has indicated carbon tax compensation will be cut-off at $150,000. Photo: Alex Ellinghausen

The Prime Minister, in comments to The Saturday Age, confirmed the compensation package would include income tax cuts and family payment increases, as well as increases in pensions and allowances.

''By providing tax cuts and increases in payments this way, we can take account of people's different family circumstances - whether they're on high or low incomes, whether they're bringing up kids or not,'' Ms Gillard said.

Mr Abbott's pledge of tax cuts is to counter the government's potentially damaging refrain that he will ''rip away'' people's compensation when he scraps the carbon tax.

By getting the promise out before the package is released, he aims to limit the government's ability to run a fear campaign on what people would lose under the Coalition. The opposition has said people won't need compensation if the carbon tax is gone.

In a speech to the Liberal federal council today, the Opposition Leader will say: ''At the next election, the Coalition will deliver tax cuts that are not just compensation. It will be a tax cut without a carbon tax. Our tax cuts will recognise the cost of living pressures that are hitting families and small business hard.

''Our tax cuts will be designed to restore people's hope, to reward harder work with higher pay.''

Mr Abbott will say voters will understand that a tax reduction to compensate for a tax increase, as planned by the government, ''is not a cut but a con''. He will say his tax cuts will be funded from ''prudent economies in government spending'' and ''policy-driven improvements in the productivity of our economy''.

Under the government's compensation package, the income threshold of $150,000 is not a precise cut-off point, but families earning more than that should not expect help for higher power bills and other costs flowing from a carbon tax.

The opposition criticised the budget for freezing the $150,000 income threshold on primary earners for eligibility for family tax benefit B, but this week allowed the legislation through Parliament.

Ms Gillard said that ''there are people in our community doing it much tougher'' than those on $150,000 and ''most of my attention is on looking after people who really need that extra bit of help''.

Pre-empting criticism about not providing compensation for those further up the income scale, Ms Gillard said: ''I want to make sure that ordinary working families can make a difference and help tackle climate change without having to make financial sacrifices along the way.

''It's people on lower incomes who spend the highest proportion of their income on energy. They are the people who most need financial help … That's why our assistance will be focused on pensioners, low-income earners and middle-income earners.''

Mr Abbott will say that his Coalition government would ''build on the Howard legacy of reducing personal income taxes for everyone and especially delivering a fair go for middle-income earners with children''.

Source http://www.smh.com.au

Australia Releases Rules for CO2 Credits from Culling Camels

Killing camels to earn carbon credits might seem an extreme way to fight climate change, but the Australian government on Thursday issued detailed rules that will help investors do just that.

Adelaide-based Northwest Carbon, a carbon project developer, has developed the rules, or methodology, governing a strict camel culling programme that would also cut greenhouse gas emissions.

Like cows and sheep, camel digestive tracts produce large amounts of methane, a much more powerful greenhouse gas than carbon dioxide, with adults producing about a tonne of methane a year.

With no natural predators, camels now number more than one million in Australia's desert centre and the population is growing quickly.

The methodology is one of many being developed under the government's Carbon Farming Initiative (CFI), the country's first nationally regulated carbon offset programme that aims to reward farmers and investors for steps that cut greenhouse gas emissions on the land.

The government, which supports Northwest Carbon's 63-page methodology, released the rules for public consultation on Thursday.

Legislation for the Carbon Farming Initiative is being debated before parliament, and it is likely to be approved. The scheme is far less controversial than a separate carbon pricing programme the government is struggling to win support for.

Camels, introduced in the 19th century, have become a major pest in Australia. They trample large areas of vegetation, damage water holes and compete with native species for food.

Camel culling under the methodology could generate up to 18 million carbon credits, with more than 650,000 created per year during the initial three to five years, Northwest Carbon said in a statement on Thursday.

Cutting methane from landfills, better management of grassland burning and tree plantations are also approved methods under the CFI, in addition to feral animal management.

Once the CFI is running, polluters will be able to buy offsets from approved projects or they can be sold overseas. But the scheme is expected to start off slowly until parliament also passes the separate laws that put a national price on carbon emissions.
Agriculture can comprise a large portion of a country's greenhouse gas emissions. In Australia, it is about 15 percent, while in New Zealand dairy farming, sheep grazing and other activities generate about half the country's total, mostly methane from livestock. One cow can emit 1.5 tonnes of methane a year.