Unknown bacteria is found to eat metal

SCIENTISTS have discovered previously unknown bacteria – which eats metal.

The microbes, which a biochemist stumbled upon by accident, consumes manganese and is the first organism known to eat the metallic substance.

Microbiologist Dr Jared Leadbetter found the bacteria by accident after unrelated experiments using a light, chalk-like form of manganese.

He had left a glass jar coated with the substance to soak in tap water in his office sink before going away for several months.

When he returned, the jar was coated with a dark material which turned out to be the oxidised – or ‘used-up’ – manganese.

When it reacts with oxygen – a process called oxidisation – it takes the form of a dark, clumpy substance which has been found in distribution systems.

Researchers knew about bacteria and fungi that could oxidise manganese but they had only speculated that yet-to-be-identified microbes might be able to harness the process to grow.

Dr Leadbetter said: “I thought ‘What is that?’; I started to wonder if longsought-after microbes might be responsible, so we systematically performed tests to figure that out.

“These are the first bacteria found to use manganese as their source of fuel.

“A wonderful aspect of microbes in nature is that they can metabolise seemingly unlikely materials, like metals, yielding energy useful to the cell.”

With the help of colleague Dr Hang Yu, the pair – who both work at the California Institute of Technology (Caltech) – discovered the bacteria can also use manganese to convert carbon dioxide into biomass through a process called chemosynthesis – similar to photosynthesis in plants but using manganese instead of light.