N:P RATIO OF SYNTETIC WASTEWATER IMPACT UPON CHANGING ON SPECIES, GROWTH RATE, CHEMICALCOMPOSITION OF MICROALGAE: BATCH CULTURE TECHNIQUE
ABSTRACT: The aim of this
study to examine the effect of N:P ratio of synthetic wastewater on changing
species composition, growth rate, carbohydrate content of microalgae. Microalgae
was cultured for 14 days at 1 L round flask bottles using batch culture with WC
media and 24 hours light illumination. Nitrogen were consists of 5 concentrations,
such as 10, 20, 30, 40 and 50 mg/L-N and for Phosphorus were used 5
concentration which were 2, 4, 6, 8 and 10 mg/L-P. Variables measured were
growth rate based on optical density, species composition, total fatty acid and
carbohydrate content. There were 11 genus of algae found, which were Chlorella
sp, Oscillatoriasp, Scenedesmussp, Actinastrumsp, Chlorococcumsp, Coelastrumsp,
Gleokininasp, Keratococcussp, Merismopediasp, Monoraphidiumsp and Spirulina sp.
Three species dominated at all NP treatments, such as Oscillatoriasp, Chlorella
sp and Scenedesmus sp. Samples with low P concentration were dominated by Oscillatoriasp,
while treatments with high P concentration were dominated by Chlorella sp and
Scenedesmus sp. The highest total cell abundance was found at treatment of 40
mg/L-N and 6 mg/L-P, account for 2,272,500 cell/mL. However, there was no
particular pattern of total cell abundance among NP treatments. In general, specific
growth rate was slightly low at high P concentration for all N treatments.
There was no clear pattern of % carbohydrate per dry weight among NP
treatments. The highest % carbohydrate per DW was 1.16% at lowest N
concentration (10 mg/L-N) and at the highest P concentration (50 mg/L-P).
Treatment with 30 mg/L-N and 6 mg/L-P showed having the lowest % carbohydrate
per DW.
Author: Nita Rukminasari
Journal Code: jpperikanangg150007
