One of these models is constituted by Head systems and other systems deriving from that one. They belong to formal languages and are computing systems written in grammar style. They can be also viewed as rewriting systems. Basic objects are words over finite alphabets and the main concern is to device rules allowing to capture the interesting biological phenomena.
A question raised by those researches was the computing power of the grammar proposed for modelling DNA-features. It turns out that the question of universal computations in the sense of Turing machines was investigated and the answer turned out to be positive.
The talk will also indicate the most recent results obtained in that direction, giving also the techniques used for proving universality results for systems as small as possible with respect to parameters as the number of test tubes which has some analogy with what test tubes are.