Amino acids profile of six freshwater Algae in the northern region of Bangladesh: A solution for the protein supplement of poultry feed

Algae is an important natural source of protein, specifically amino acid source, which are the building blocks of enzymes, hormones, nucleic acids, etc. Herein, the amino acid composition was investigated in six commonly growing fresh-water algae. The number of amino acids in Oscillatoria brevis, Spirulina platensis, Pithophora kewensis, Euglena viridis, Hydrodictyon reticulatum, and Aphanocapsa holsatica were detected 15, 12, 17, 15, 14, and 15, respectively. Among studied algal species, the amino acids: proline (29239.3 +/- 276.4 mu g/g), histidine (10056.8 +/- 85.4 mu g/g), aspartic (3030.6 +/- 48.6 mu g/g), threonine (1492.3 +/- 31.8 mu g/g) were detected in the highest amount in O. brevis, S. platensis, P. kewensis, A. holsatica, respectively. It is reported that the range of the ratio between 50/50 to 60/40 of essential amino acid/(nonessential amino acid + conditional essential amino acid) promotes maximum growth performance and best energy utilization. The obtained results of this study suggested that a combination of A. holsatica, H. reticulatum, and O. brevis can provide a good ratio (48/52) of amino acids and the noble source of essential amino acids for feed or food supplements, especially for poultry's stamina and, consequently, welfare.