A new isolation method for labyrinthulids using a bacterium, Psychrobacterphenylpyruvicus

A new isolation method for labyrinthulids, marine microbes with spindle-sha ped vegetative cells and gliding movement, is presented. The method for iso lating labyrinthulids has been found to be more difficult and less reproduc ible than that for thraustochytrids, classified in the same order. So far s erum seawater agar fortified with antibiotics has been proposed to be the b est for isolation of labyrinthulids. The method presented here involves pla cing plant samples on an agar medium on which a marine bacterium, Psychroba cter phenyl-pyruvicus, has been grown. The new method, which utilizes falle n mangrove leaves as source material, was more than twice as effective as i solation agar medium without the bacterium. The increased effectiveness app ears to derive partly from the bacterial colonies' delaying extension of fu ngal mycelium. The bacterium was more effective for the isolation of labyri nthulids than either the bacterium Shewanella sp. or the yeast Rhodotorula rubra.