Growth and nutritional value of a tropical green alga, Ankistrodesmus convolutus Corda, in agro-industrial effluents

Use of agro-industrial effluents for microalgal culture was investigated using a tropical freshwater green alga,Ankistrodesmus convolutus cultured in various dilutions of latex concentrate effluent (LCRE), standardMalaysian rubber effluent (SMRE) and digested palm oil mill effluent (POMED). Ankistrodesmus convolutusgrown in 40% and 60% LCRE, 60% SMRE and 10% POMED showed significantly higher (P < 0.05) specific growth rate in terms of cell number and chlorophyll a than that grown in other effluent media and inorganicfertiliser (N:P:K = 1:1:0.5) as control Total biomass of this microalgae grown in 60% LCRE, 60% SMRE and10% POMED was significantly higher (P < 0.05) than that cultured in other effluent media and the control.Ankistrodesmus convolutus cultured in 40% and 60% LCRE, 60% SMRE and 10% POMED showedsignificantly (P < 0.05) higher amount of crude protein and lipid than that grown in other effluent media andthe control. Significantly higher (P < 0.05) amount of most of the essential amino adds (EAAs) except a few werefound in A. convolutus cultured in 60% LCRE and 60% SMRE than that grown in other effluent mediaand control. Ankistrodesmus convolutus cultured in 10% POMED resulted in significantly higher (P < 0.05)amount of all the EAAs except threonine and tyrosine that were grown in other POMED media and control.Ankistrodesmus convolutus grown in 40% and 60% LCRE, contained significantly higher (P < 0.05)amounts of all the C18 and C20 polyunsaturated fatty adds (PUFAs) than that cultured in other SMRE mediaand control, except eicosadienoic add (20: 2n~ll). A similar trend of PUFAs was recorded in A. convolutuscultured in 60% SMRE except dcosatrienoic add (20:3n-6) and arachidonic add (20:4n-6). It was found thatA. convolutus contained significantly (P < 0.05) higher amount of PUFAs such as linoleic add (18:2n-6),linoknic add (18:3n-3) and arachidonic add (20:4n-6) when grown in 10% POMED than that cultured inother POMED media and control. This study showed that A. convolutus grown in 40-60% rubber and 10%POMED has higher nutritional value that that cultured in other effluent media and inogranic fertilizer.