Star Turn: Paul Bridge

Pat Leon saw the man from Kew sharing his passion for fungi with Birkbeck students.

Paul Bridge has a lifelong love affair with fungi. It took him away to Papua New Guinea and other tropical climes and it has now taken him to Kew Gardens, where he passed much of his early career working for Cabi Bioscience. He spends half his working week there, and the other half at Birkbeck College, London, where he is professor in the School of Biological and Chemical Sciences.

On a blustery October day, he emerges, bearded, bespectacled and pipe-smoking, from Kew's imposing Edwardian mycology building, to greet his students. There are three, all mature: a Spaniard, a Sri Lankan and a Brit. He divides the students up between offices or labs, planning to move between them as the morning progresses.

His first student is Ana Perez-Sierra, a plant pathologist in the advisory service at Wisley Gardens, part of the Royal Horticultural Society. She is trying to identify isolates of Armillaria (aka honey fungus) from Africa for a self-financed PhD.

"Honey fungus is a really common problem for gardeners," she says. "We get lots of calls from RHS members asking about fungi on their plants. I've even had someone with it on their rhubarb."

Ana has brought a disc with the DNA sequences of her specimens and is looking for matches using the internet.

"Today we are doing a 'look-and-see' at a free site," says Bridge. "Modern technology means we are getting new DNA sequences, but the tie-up is still difficult because the taxonomy of fungi is very flexible. You will see names people say don't exist. There are disagreements over the number of fungal groups and names.

"Fungi have got two names. Simply put: one for its sexual state and one for its asexual state. Over evolutionary time, it seems some fungi have lost their sexual state and are asexual."

Bridges guides Ana through logging on to the European Bioinformatics Institute website where they look at the Armillaria sequencing submitted to find a small set of similar sequences. Ana then cuts and pastes them onto her own document. The site allows her to run an interactive program and gives results in a number of visual formats - bands, a family tree and a 3-D space shot.

Bridge gets excited when he sees them. "I'd say you may be looking at a species there," he says.

It is too early to be sure, but Ana will continue her work using the facilities at Wisley, which will reap the benefits of her results.

Bridge's next port of call is the laboratory upstairs where Swarna Sivakumaran is analysing disappointing results from samples of eucalyptus fungi she has diluted. Swarna is from Sri Lanka, and Bridge has helped her find PhD funding from a small charity, the Fungal Royal Trust.

He looks at her black-and-white photos of DNA and immediately identifies that the DNA is too concentrated. "This is a good lesson. Dissolve it more," he says.

In the next room, undergraduate Lynton McLain also has a mixing problem. The conical flask in his hand looks as if something has burnt at the bottom. Lynton is collecting wood fungi for an undergraduate project on how it rots lignin. There is a link with Bridge's own research on finding a way to stop a fungal pathogen, Ganoderma , from attacking and destroying oil palms, tea and rubber crops.

Over coffee in Kew Library, with its stunning view of the River Thames, Bridge talks about why he likes Birkbeck teaching. "The people who choose Birkbeck do so because there is lots of flexibility. They can work and study, and it recognises qualifications from other countries," he says.

"The beauty about the link with Kew is the reference collections. There are 800,000 dried specimens in the herbarium and, tucked away in a box, Ana and I found a sample of honey fungi collected in Malawi in 1977." A small find but fuel enough for a fungi passion.