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Inside the Lab Microbiology and immunology, Clinical care, Laboratory management

Under the Sea

Newly enforced trade restrictions on Gelidium seaweed, harvested predominantly in Morocco, are causing a shortage of an essential microbiology ingredient: agar. According to a recent report in Nature (1), with prices at an all-time high of US$35–45 per kilo, almost triple the normal price, this has obvious implications for researchers who rely on agar for microbial culture. Companies including Thermo Fisher are scaling back on the range of agar products they offer, says the report, and both suppliers and microbiologists could soon start to feel the pinch.

The trade restrictions were established in 2010 but only recently enforced, among concerns around overharvesting of the algae. Gelidium and similar types of red algae grow in naturally-occurring seaweed beds, and are harvested by divers or along the shore, making it impossible to simply increase production in line with demand. Pedro Sanchez, deputy managing director of the Spanish company Industrias Roko that produces around 40 percent of the global supply of agar, says, “It’s not cultivated, and it’s not possible to cultivate – although we’ve wasted a lot of money trying to do it in the past. We are forced to reduce our production according to raw material availability, and we estimate the reduction affecting bacteriological grade agar is around 25 percent.”

Both trade restrictions and industry cutbacks have obvious repercussions for the microbiologists at the end of the supply chain. “We haven’t been affected as yet, but if our agar supply does run low, we will not be able to carry out certain experiments,” says Adam Roberts, senior lecturer in Molecular Microbiology, University College London, UK. “For example, when analyzing environmental isolates for antibiotic production as part of our Swab and Send project, we need to supplement the rich brain heart infusion agar with extra raw agar to achieve 4 percent agar. We couldn’t carry out this project without the extra raw agar,” he adds.

And if the shortage does worsen? “It would be a bit of a disaster really. In research laboratories it would hinder the progress of projects in multiple fields of research, and it wouldn’t just affect microbiology – the more worrying outcome would be if clinical diagnostics labs ran short. This could impact patient treatments and potentially lead to treatment failure, for example, if an antibiogram cannot be performed”, he explains.

As there is currently no suitable alternative to agar for culturing microbes, continuation of the shortage could have serious repercussions for microbiology. “If somebody came up with a suitable alternative they would be very rich very quickly” Roberts adds.

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  1. E Callaway, “Lab stable agar hit by seaweed shortage”, Nature, 10, 7581 (2015). Available at: Accessed January 13, 2016. PMID: 26659158
About the Author
Roisin McGuigan

I have an extensive academic background in the life sciences, having studied forensic biology and human medical genetics in my time at Strathclyde and Glasgow Universities. My research, data presentation and bioinformatics skills plus my ‘wet lab’ experience have been a superb grounding for my role as an Associate Editor at Texere Publishing. The job allows me to utilize my hard-learned academic skills and experience in my current position within an exciting and contemporary publishing company.

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