Authors: S F Baldia A D Evangelista E V Aralar A E Santiago
Publish Date: 2007/10/06
Volume: 19, Issue: 6, Pages: 607-613
Abstract
Phytoplankton supports fisheries and aquaculture production Its vital role as food for aquatic animals like mollusks shrimp and fish cannot be overemphasized Because of its contribution as a food source for fish the growth kinetics of Microcystis aeruginosa a dominant cyanobacterium in the lake was studied The regular occurrence of M aeruginosa is experienced during the months of May to July or from September to November in Laguna de Bay the largest freshwater lake in the Philippines M aeruginosa was collected from Laguna de Bay isolated and established in axenic conditions Data on the growth kinetic parameters for nitratenitrogen and phosphatephosphorus utilization by M aeruginosa gave the following values halfsaturation constant K s 0530 mg N L−1 and 0024 mg P L−1 respectively maximum growth rate μ max 0671 d−1 and 0668 d−1 respectively maximum cell yield 65 and 654 log cells ml−1 respectively nutrient level for saturated growth yield 871 mg N L−1 and 022 mg P L−1 respectively and minimum cell quota Q 0 282 pg N cell−1 and 0064 pg P cell−1 respectively The low K s value and high maximum growth rate μ max for phosphorus by M aeruginosa would suggest a high efficiency of phosphorus utilization On the other hand the high K s value for nitrogen indicated a low rate of uptake for this nutrient
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