New Scientist - USA (2022-05-07)

7 May 2022 | New Scientist | 19

News

MORE than 300 ways to convert
widely available chemical waste
into a range of drugs and fertilisers
have been identified by a software
program. The researchers behind
the tool believe it will optimise
the chemical industry and allow
the recycling of by-products that
would otherwise need to be stored.
Bartosz Grzybowski at US
software and chemistry company
Allchemy and his colleagues used
their software, also known as
Allchemy, to look for useful
products from 189 small
molecules that are regularly
created as by-products of
large-scale industrial processes
around the world. An additional
56 molecules that are commonly
created from chemical waste
during recycling processes
were also included.
The software created a vast
database of all the possible
combinations of chemicals
and the processes that could be
used to combine them. Running
on a single high-end server, the
program took about a month to

calculate the hundreds of billions

of combinations. These were then

narrowed down to only those

processes that led to the creation

of drugs, fertilisers or other useful

molecules (Nature, doi.org/hrxd).

Grzybowski says that all of

the discovered processes could

eventually have been found by

humans, but the vast scale of

possible processes made them

incredibly hard to spot. Among

the discovered molecules were

drugs to treat leprosy and heart

disease, but Grzybowski says

that his favourite result was an

antibiotic that can be produced

from lactate, which comes from

waste plastic bottles, and phenol,

a by-product of coal mining.

“I was hoping to find aspirin

or something, but it’s actually

much more interesting than

that,” he says. “It actually

solves the problem of circular

chemistry, pretty much in

an exhaustive way.”

Grzybowski had previously

worked on projects to create new

methods to synthesise specific

molecules, but he says that this

software works in the other

direction: it takes a list of

available resources and finds

all the possible uses for them.

“This chemistry is pretty

straightforward. The difficulty is

in spotting the opportunity,” he

says. “The building blocks are very

simple, but when you start talking

about 200 waste molecules,

within one step of combinations

you have 40,000 options.”

Grzybowski says he hopes

that Allchemy will eventually

lead to a “Tinder for molecules”.

Chemical companies could put

in details of all of their available

waste products, other companies

could list molecules they would

like to have synthesised for

a specific purpose, and third

parties could bid to perform the

waste-to-drug synthesis. This

would reduce waste from the

global chemical supply chain

and perhaps also lower the cost

of drugs and other products.

Judy Lee at the University of

Surrey, UK, says identifying uses

for chemical waste in the lab is

useful, but scaling up that process

may be more difficult. “Something

that’s developed in the lab needs

to be translated in a profitable way

into a large pilot scale,” she says.

“The purity of that compound

is important as well. If you can’t

purify it enough to be useful,

then there will be a problem.”  ❚

Chemistry

Matthew Sparkes

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Chemical waste can be recycled

into a range of drugs and fertilisers

Workers at a chemical

waste disposal facility

in Ankara, Turkey

Wildlife

THE summit of Llullaillaco, a
massive Andean volcano straddling
the border of Argentina and Chile,
is hostile to animal life: it is
perpetually frigid, exceptionally
dry and oxygen poor. But scientists
found mice there in 2020, and their
latest research adds to evidence
that the tiny rodents may actually
make the highest reaches of the
volcanic peak their home.
A few years ago, Jay Storz at the
University of Nebraska in Lincoln
and Marcial Quiroga-Carmona at

the Austral University of Chile in

Valdivia, with other researchers,

reported a new high-elevation

record holder among mammals: a

leaf-eared mouse now identified as

belonging to the species Phyllotis

vaccarum. It was captured on

Llullaillaco’s summit, which is

6739 metres above sea level.

However, there were still

questions about whether the mice

really spent their lives near the

summit. Most documentation of

altitude records for animals are

based on single observations,

says Scott Steppan at Florida State

University, one of the researchers.

“It doesn’t really tell you if

[the animals are] adapted to

that extreme elevation,” he says.

Individuals may visit high elevations

briefly, while the population mostly

lives at a much lower altitude.

Now, the team has pulled

together more data to make

the case that the mice sustain

populations at, or at least very near

to, the volcano’s summit (Journal

of Mammalogy, doi.org/hrsz).

For instance, the researchers

analysed the microbial community

collected from soil in a mouse

runway – a route that the mice

repeatedly scurry across – at

an altitude of 6154 metres.

They discovered that it was

dominated by animal-associated

bacteria that imply a sustained

presence of mice in the area.

Elsewhere near the top of

Llullaillaco, the soil mostly

contains stress-tolerant fungi. ❚

Volcano-dwelling

mice are highest-

living mammals

Jake Buehler

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A leaf-eared mouse

(Phyllotis vaccarum) found

near the peak of Llullaillaco