STUDY OF BACTERIAL DIVERSITY OF A SALTERN CRYSTALLISATION POND ('SALINE DI TARQUINIA', ITALY) AND ITS CORRELATION WITH SALINITY VARIATIONS

摘要

Marine salterns comprise a number of shallow pools connected in sequence showing increasing salinity from cca. 35% (the first pool served by sea water) up to above 300% in the last pools (crystallisers). The 'Saline di Tarquinia' salterns are located between two rivers (Mignone and Marta) on the Tyrrhenian coast (Central Italy). Covering an area of ca. 90 ha (more than 100 interconnected ponds) along a low sandy coast, they are parted from the sea by a dunes array. They were used for industrial salt production until 1997 being converted into a natural reserve since 1980. In this work, diversity of the total bacterial community, obtained from water collected in a crystallisation pool of 'Saline di Tarquinia' salterns, was evaluated by PCR-DGGE, during a two years sampling campaign, in relation to the pool salinity variations. The studied pool was characterised by general high salt concentrations with significant monthly fluctuations (104-400%). Information regarding chemical and physical parameters of the pool (salinity, temperature, BOD5, dissolved oxygen and concentration of chloropheopigments) was obtained. The results showed that despite the high salinity reached, the communities varied considerably along the whole sampling period, indicating a noteworthy complexity, not correlated to seasonal or salinity variations.