Effect of Temperature, pH and Media on the Recovery of Aerobic Heterotrophic Bacteria from the Rabbitfish Siganus rivulatus

1997 Journal of King Abdulaziz University-Marine Sciences  
A BSTRACf . As part o f on goin g stu d ies o n the micro biology of the ra bbitfish Siganus rivulatus, farmed in sea cage sites at Jeddah , method s have been devised fo r the e nume ra tion a nd recovery o f dominant ae ro bic hete rotrophic bac teria . T hus, from a co mpariso n o f II med ia a t pH 6.5-9 .5 , inc uba tio n tempe ratures of 5-40°C a nd statistical a nalysis of the data by me an s of the stude nt's t-tcst , th e high est num ber o f' ae rob ic het e rot roph ic bacte ria was
more » ... h ic bacte ria was co nsiste ntly reco ver ed o n med ium A3 , which com prise d 2.4 % (W IV ) sod ium chl oride , 0.7% (WIV ) magne sium sulphate , 0.075% (W IV ) pot assium ch lori de, 0 . 1% (WIV) bac te rio logica l pe pto ne (O xoi d ) a nd 1.5% (WI V) agar (Oxoid No . I) at pH 7. 2-7.8 with incu bation a t 20-25°C for 14 da ys. Usin g thi s regim e . the aerobic het e rot roph ic ba cterial popu la tio ns o n th e gills of S. rivulat us a nd fro m th e surrou ndings wat er (fish cages a nd o pen sea) were est ima ted a t 6 x 10S l g. 3.3 x 104/m l a nd 6.6 x 10 2/ ml, respectivel y. The pre se nce of high er q ua ntities o f a d iver se ran ge of organic nu trients ( inclu d ing bacteriolo gical peptone. yeas t e xtract, be er e xtrac t a nd case in) led to the reco ver y of reduced number s of bacteri a fro m bot h gill a nd wat er sa m ples .
doi:10.4197/mar.8-1.11 fatcat:qalfw4rrmfbdxjzkyqjozrfa3a