Growth characteristics of Thiobacterium sp from the plume of hydrothermal vents of the North Fiji Basin

A chemosynthetic bacterium of the genus Thiobacterium was isolated from the plume of hydrothermal vents of the North Fiji Basin.The bacterium occurred singly as rods mostly sized 0.2 by l.Opm, and having a population growth rate varying between 0.025 and 0.1 h-' during the lag phase of its growth cycle.During exponential growth, cells occurred singly and in short chains as larger rods of 0.5 by 1.5 pm with a population growth rate from 0.1 to 0.5 h-'.When bacterial growth reached stationary phase, the malority of cells occurred in chains which were extensively branched and embedded in a gelatinous material.In the late stationary phase, branching cells constructed a network structure to grow finally into a bladder-like colony.Population growth rates during the early stationary growth phase were again 0.025 to 0.1 h-'.During the death phase, when population growth rates were from -0.6 to 0.025h-', the chains and colonies of bacterial cells broke up into single cells.