Now showing items 1-2 of 2

    • Article

      Nitrogen and phosphorus utilization in the cyanobacterium Microcystis aeruginosa isolated from Laguna de Bay, Philippines 

      SF Baldia, AD Evangelista, EV Aralar & AE Santiago - Journal of Applied Phycology, 2007 - Springer Verlag
      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 nitrate-nitrogen and phosphate-phosphorus utilization by M. aeruginosa gave the following values: half-saturation constant (Ks), 0.530 mg N. L−1 and 0.024 mg P. L−1 respectively; maximum growth rate (μmax), 0.671. d−1 and 0.668. d−1 respectively; maximum cell yield, 6.5 and 6.54 log, cells. ml−1 respectively; nutrient level for saturated growth yield, 8.71 mg N. L−1 and 0.22 mg P. L−1 respectively; and minimum cell quota (Q0), 2.82 pg N. cell−1 and 0.064 pg P. cell−1 respectively. The low Ks value and high maximum growth rate (μmax) for phosphorus by M. aeruginosa would suggest a high efficiency of phosphorus utilization. On the other hand, the high Ks value for nitrogen indicated a low rate of uptake for this nutrient.
    • Conference paper

      Studies on the chemical composition of a cyanophyte, Spirulina platensis. 

      SF Baldia, T Nishijima, K Fukami & Y Hata - In LM Chou, AD Munro, TJ Lam, TW Chen, LKK Cheong, JK Ding, KK Hooi, HW Khoo, VPE Phang & KF Shim (Eds.), The Third Asian Fisheries Forum. Proceedings of the Third Asian Fisheries Forum, 26-30 October 1992, Singapore, 1994 - Asian Fisheries Society
      The chemical composition of Spirulina platensis NIES-46 and K-2 strains grown under varios condition of hight intensity and temperature were determined. The dry weight, chla, carotenoid, carbohydrate, protein, and lipid content in INES-46 strain were affected by various light intensities.

      Changes in carbohydrate, protein, and pigment content in INES-46 and K-2 strains occurred with different temperature condition, with the growth yield of NIES-46 strain increasing significantly with increased protein content.

      S. platensis NIES-46 and K2 strains contained sufficient quantities of essential amino acid except for methionine and histidine. The increase in the content of 18:2 and 18:2n6 fatty acids with respect to changes in light intensity and temperature would be important in maximizing their in S. platensis.