Abstract
Vibrio marinus, an obligately psychrophilic marine bacterium, deaminated nineof 17 amino acids tested with both L-glutamine and L-serine displaying the greatest deaminationrates.
The L-serine deamination temperature response of washed cells depended upon the growthtemperature of V. marinus MP-1. Cells grown at 15°C displayed optimum activity at 40°C, and a shoulder at 15°C, whereas 4°C grown cells revealed two temperature optima, one at 38and the other at 11°C, this suggests that the 4°C grown cells are physiologicallydifferent thanthe 15°C grown cells.
It is suggested that these peaks in deamination of L-serine at different temperatures mightbe due to the loss of permeability control above the maximum growth temperature (20°C) of the organism.
Hydrostatic pressure stimulated or suppressed L-serine deamination by washed cellsdepending upon the temperature at which the cells were grown and the incubation temperatureof the reaction mixture. Cells grown at 15 or 4°C had deamination stimulated under pressurein the following cases:(i) cells grown at 15°C and tested for deamination at 15°C, (ii) cellsgrown at 4°C and tested at 4°C and (iii) cells grown at 4°C and tested at 15°C. When cellswere grown at 15°C and tested at 4°C no stimulation of deamination activity due topressurewas observed.
