Pathogenic fungi use plants’ proteins against them.

Fungal diseases in plants cause huge economic problems for farmers worldwide, either by reducing crop yield or by killing plants outright. These disease-causing fungi produce an array of compounds, known as ‘virulence factors’ that they use to breach plant defences. The two are locked in a constant arms race, with the plant trying to produce defences that let it stay one step ahead of the pathogen. This is often described as the Red Queen Hypothesis.

A new paper by Djamei et al. has revealed the nature of one of the virulence factors of Ustilago maydis, the fungal agent that causes maize smut. U. maydis requires live plants to survive, secreting many protein effectors that suppress the plant’s defence response and alter its metabolic pathways to suit the fungus. Most of these proteins are of unknown function.

Guest Post: Sequencing for the microbiological masses

Despite being in its relative infancy, genome sequencing (and the technologies that drive it) have become central to much of the molecular biology that we take for granted. In this guest post, Nick Tucker takes a closer look at the past, present and potential future of DNA sequencing as it becomes cheaper and more readily available.

Mining databases of microbial genomes has rapidly become a routine part of experimental work for microbiologists the world over. It must be impossible for this year’s new intake of PhD students to imagine a world without them. But let’s reminisce for a moment, just to see how far we’ve come.

Bacterial spam mail

History dictates that Alexander Fleming will be best remembered for his discovery of penicillin, what with him winning the Nobel Prize and all. Perhaps what he should be remembered for, however, are the paintings he made on agar using different coloured bacteria. Quite why this culturally important art form never caught on is anybody’s guess.

It may have been Fleming’s strange hobby that inspired a group of scientists to go one stage further and develop an encrypted messaging system (obviously), which uses printed patterns, known as arrays, of different coloured bacteria. These bugs are coloured by the expression of genetically engineered fluorescent proteins, and the scientists in question have called the system ‘steganography by printed arrays of microbes’, or (ahem) SPAM for short…

Bugs in bugs in bugs

Symbiotic relationships, where organisms of different species work together for mutual gain, have been studied extensively in numerous biological systems, but modern genomic techniques are revolutionising our understanding of how these interactions work at the molecular level. A recent paper by John McCutcheon and Carol von Dohlen has reported an interesting case of a ‘three-way symbiosis’ between the mealybug (Planococcus citri) – a significant pest of plants – and two species of bacteria.

This interaction shows a high level of metabolic complementarity: the genes for several amino acid biosynthetic pathways that are essential to the mealybug are spread across the genomes of the three different species. This makes the mealybug completely dependent on its bacterial symbionts.

Event review: The Xenotext

Christian Bök

Sometimes I get invitations that are just too intriguing to pass up. Last month I was lucky enough to visit the Whitechapel Gallery in London to hear a talk by Dr Christian Bök (left), an experimental Canadian poet who’s been working with bacteria to get them to do something pretty special.

Last year I was sitting on the science floor of the British Library (procrastinating) when I read that Craig Venter had encoded a line from James Joyce’s novel A Portrait of the Artist as a Young Man into the genome of his ‘synthetic lifeform’: “To live, to err, to fall, to triumph, to recreate life out of life.” I thought this was pretty neat.

Dr Bök has taken this idea and run with it. He explained how he has been engineering a bacterium to be the storage vessel for a poem but, at the same time, be a poet itself. The project is called the ‘Xenotext’. Confused? Stick with me, and I’ll do my best to explain it.

Mixing your drugs kills superbugs!

Pseudomonas aeruginosa

We hear a lot in the news about multidrug-resistant (MDR) bacteria but not very much about the efforts made to tackle these so-called ‘superbugs’.

At the recent ‘Antibiotics 2011’ meeting hosted by the Royal Society of Chemistry, I heard some interesting talks from senior scientists working for the pharmaceutical giants GlaxoSmithKline and Bayer.

Copper takes on the superbugs

This video shows a live experiment carried out at the University of Southampton demonstrating that copper very effectively kills MRSA. This raises the possiblity that copper surfaces could be introduced into hospitals and used to cover areas that are frequently touched by patients, visitors and healthcare professionals. We think this is pretty cool!

The video was originally posted here: http://www.southampton.ac.uk/promotion/copper_02.shtml

Guest Post: Measuring Impact in the field of Microbiology

How do we judge whether a research paper is any good? One straightforward way is to measure how often the article is downloaded online – but that doesn’t tell us if the readers actually thought the article was significant once they’d read it. Instead we can monitor how often an article is cited in the writings of other scientists. We can even do this for all the articles published by a particular journal (for example, in the last two or five years) and divide the total cites by the number of articles published to get an impact factor: Bingo, journal impact instantly measured!

Impact factors are a flawed and derided metric but – whisper it – by and large they also reflect many microbiologists’ perceptions and prejudices about the status of the journals in which we publish. When drafting a manuscript, it’s likely that each of us approaches choosing which journal we want to submit our work to in much the same way: we assess the scope and significance of the piece of work to be written up and then have a gut instinct as to which journal will accept it.

Biofuels from the termite gut?

Eusocial insects are remarkable creatures, they divide their labour, care for their young and some of these insects developed agriculture long before modern humans evolved. Now it seems they could offer us a way out of the current energy crisis and our crippling reliance on fossil fuels.

Releasing the sugars trapped in lignocellulose is the rate limiting step in bioethanol production and currently relies on chemical and mechanical treatment. Termites feed on plant detritus and their guts can efficiently convert lignocellulose (also known as wood) into sugars. So how do they do it?

Event Review: Crafty little bacteria

A species unknown to science

Last week I had the pleasure of attending an event mixing craftwork with bacteriology. It sounds like an odd combination, but was in fact the latest in a series of outreach events organised by Science London.

Joining 50 other people in London’s Drink, Shop & Do cafe, I arrived with my pals from the British Science Association to find tables festooned with felt, thread, and glitter. Our task was to create a bacterium from what was available to us. You can see some of our efforts in the photos below; mine is the expertly crafted blue circle with glued-on eyes and multi-coloured flagella. Prizes were available for the best creation. I did not win a prize. The winner did use some purple thread to Gram-stain his effort, which I thought was rather clever.

In addition to the craft, there was a quiz all about microbiology. I did not win the quiz. I got over my embarrassment with the aid of G&T pecan pie, so all was well…