Algae transformed into a 'biofactory' for green fuel and plastics

What this confirms is that in extreme CO2 rich conditions, that life will consume CO2 and produce hydro carbons giving us a biological pathway to eliminate dense CO2 atmospheres.  Venus, here we come.

We do not do enough extreme conditions work, biological or otherwise either.  This  shows just how promising it can be.  hot wet rocks and CO2 happens naturally, even today.  We may well also need to loom harder.

At least we now have a working biology to work with.

Algae transformed into a 'biofactory' for green fuel and plastics

A strain of green algae has been artificially evolved to turn carbon dioxide into sustainable fuel and plastic

By James Woodford

1 August 2024

Chlamydomonas pacifica algae growing in an outdoor pond

João Vitor Dutra Molino

https://www.newscientist.com/article/2442136-algae-transformed-into-a-biofactory-for-green-fuel-and-plastics/?

A newly discovered species of algae has been transformed through selective breeding and genetic engineering to survive and produce fuel in environments that would kill most organisms. The research is a step towards using algae-based “biofactories” to make sustainable alternatives to fossil fuels.

The new species, Chlamydomonas pacifica, was found in 2020 in a pond at the University of California in San Diego. The engineered strain can produce oil even when grown in wastewater at temperatures above 40°C (104°F), at a pH higher than 11, in full sunlight and in pretty saline conditions – half as salty as the ocean.

Stephen Mayfield at the San Diego campus and his colleagues initially set out to find a species that thrives in highly alkaline conditions and develop it for biodiesel production. In alkaline conditions, predators of the algae can’t grow and the water can hold more carbon dioxide. “The more CO2 you put in the water, that’s food for algae and the faster they grow,” says Mayfield.

With C. pacifica, the researchers not only discovered a highly alkaline-tolerant species, but one that can reproduce sexually. This meant they could use selective breeding to produce a strain with exceptional tolerance of high salinity, high light levels and high temperatures.

“There is no other extremophile algae that we know of that you can do breeding [with],” says Mayfield.

Like other green algae, C. pacifica produces fat to store energy as part of its normal life cycle. However, organisms that live in very harsh environments don’t usually make good yields of commercially useful products, says Mayfield. “Most of the time, if an algae is growing under extreme conditions, their main job is just to stay alive.”

To make C. pacifica more useful, the researchers inserted genes from soya beans that are known to increase fat production in other algae species.

The result was an increase in fat content from 28 per cent in the parent strain up to 36 per cent in the engineered version.

In a separate process, the fats can be converted into biodiesel or polyurethane, a kind of plastic used in waterproof fabrics and many other applications. Mayfield says shoes made from algae-based materials are already approaching a similar cost to those made from petroleum-derived substances and have the benefit of being fully biodegradable when disposed of.

Turning to algae to create oil makes sense. Many of the natural resources we use today came from extremophile bacteria and algae in the deep past, says Mayfield. “That is where 100 per cent of our petroleum comes from,” he says.

“That’s why we have these enormous fossil fuel reserves, because for hundreds of millions of years extremophile algae turned an atmosphere that was 20 per cent CO2 and very low oxygen into an atmosphere that is 20 per cent oxygen today, with CO2 only a fraction of a percent. And where did all that CO2 go? It went into what we know as fossil fuels, ancient algae oil.”

Wider interest in the tweaked C. pacifica is taking off. A company in Australia has already asked for the strain to be sent for commercial evaluation.

Labs around the world are now making elite strains of algae with similar potential to the new Californian one, says Peter Ralph from the University of Technology in Sydney.

For Mayfield’s strain, the big test is whether it can be successfully scaled up and survive in a large pond instead of in a container, says Ralph.

He also says there is little risk of the engineered algae becoming a weed, since it only thrives under specific extreme conditions. “As soon as it lands in a pond that has a pH of 7 and is 20°C [68°F], it won’t be competitive,” he says.

Mayfield suggests that algae similar to C. pacifica could one day survive on Mars and transform its environment. “There can be an extremophile algae that can terraform Mars just like there was an extremophile algae that terraformed Earth,” he says.