Thaslim Arif 2
First Name: Thaslim
Surname: Arif
Position: Research Student

Research title: Cyanobacterial Allelopathy

Start date: October 2011

Cyanobacteria play a complex role in the environment. When conditions are favourable, cyanobacteria rapidly multiply and form blooms. During such growth, they produce an array of secondary metabolites, some of which have been classified by WHO as ‘possible carcinogens’, e.g. Microcystins. Though cyanobacteria are known to produce about 800 different secondary metabolites, their function to the producing organism and their ecological role are debated. One of the possible functions could be interspecies communication i.e. allelopathy. Though it is widely accepted that allelopathy is a common phenomenon among cyanobacterial, conclusive evidence is rare and it is still unclear how allelopathy affects the growth and metabolism of the host and other cyanobacteria within its ecology.

The aim of my study is to investigate allelopathy within cyanobacterial species. The organism Microcystis aeruginosa PCC 7806, which produces numerous secondary metabolites was studied to understand its growth and secondary metabolite production dynamics. With this information, cohabiting organisms such as Anabaena flos-aquae UTEX 1444 and Planktothrix agardhii CYA29 would be assessed for their allelopathic characteristics towards M. aeruginosa PCC 7806. Preliminary data from my study confirms that allelochemicals do exist within cyanobacterial community and that they demonstrate potent activities. A very polar compound excreted by A.flos-aquae has shown strong inhibitory action against the secondary metabolite production of M.aeruginosa PCC 7806. To date, this is the first report of a naturally produced compound with such significant inhibitory effect on a toxin producing organism. In future, protocols to purify this compound will be developed followed by its chemical characterization. In later stages, the presence of this compound in the environment will be studied.

This research is expected to confirm the phenomenon of Allelopathy between cyanobacterial species. Further, the novel compound isolated will be investigated for commercially exploitable properties such as cyanobacterial blooms mitigation, antibiotic, antimalarial or anticancer properties.