en Biochemistry Biochemistry پژوهشي Orginal research papers <span lang="EN-GB" style="font-size:11.0pt"><span calibri="" style="font-family:"><span style="color:black">This study investigated the effects of whey powder (WP), used as a nutrient medium, on the biomass production, biochemical composition, and pigment content of <i>Haematococcus pluvialis</i> and <i>Scenedesmus</i> sp. The experimental design was set up with four groups and all groups had three replicates.&nbsp; The control group (C) contained only Bold Basal Medium with 3-fold nitrogen and vitamins (3N-BBM+V) without WP.&nbsp; The second experimental group was formulated as 3N-BBM+V with 5 g L⁻&sup1; WP (W5), the third group as 3N-BBM+V with 10 g L⁻&sup1; WP (W10), and the fourth group as 3N-BBM+V with 15 g L⁻&sup1; WP (W15). In this study, the highest mean biomass was obtained as 0.88 g L⁻&sup1; for <i>H. pluvialis</i> (WP10) and 0.45 g L⁻&sup1; for <i>Scenedesmus </i>sp. (WP15). The maximum total lipid productivities of <i><span style="background:white">H. pluvialis</span></i><span style="background:white"> and <i>Scenedesmus</i> sp.&nbsp; </span>were recorded as 43% (w/w, dry weight) in the WP5 group and 66% (w/w, dry weight) in the WP10 group, respectively. Under mixotrophic conditions, the highest protein contents were obtained in WP10 for <i>H. pluvialis</i> (<span style="background:white">20.94 mg mL^-1</span>) and in WP15 for <i>Scenedesmus</i> sp. (<span style="background:white">44.94 mg mL^-1</span>). Astaxanthin, carotenoid and phycocyanin productivity of <i>H. pluvialis</i> and <i>Scenedesmus</i> sp. was highly determined under mixotrophic conditions. <span style="background:white">In conclusion, the present study demonstrates that the supplementation of the culture medium with whey powder significantly enhances both biomass production and biochemical composition. Therefore, whey powder can be recommended as an effective supplementary nutrient source for the cultivation of these microalgae.</span></span></span></span> Algal protein, Amino acid, Algal lipid, Fatty acid, Astaxanthin 349 366 http://jifro.ir/browse.php?a_code=A-10-1633-3&slc_lang=en&sid=1 O. Fakioglu ozden.fakioglu@atauni.edu.tr 100319475328460058805 100319475328460058805 Yes Department of Basic Science, Ataturk University, Faculty of Fisheries, Türkiye G. Kaban gkaban@atauni.edu.tr 100319475328460058806 100319475328460058806 No Department of Food Engineering, Ataturk University, Faculty of Agriculture, Türkiye B. Aydogdu busra--aydogdu@hotmail.com 100319475328460058807 100319475328460058807 No Department of Basic Science, Ataturk University, Faculty of Fisheries, Türkiye Z.E. Nuhoglu zeynepesran@gmail.com 100319475328460058808 100319475328460058808 No Department of Food Engineering, Ataturk University, Faculty of Agriculture, Türkiye H. Arslan harunarslan@atauni.edu.tr 100319475328460058809 100319475328460058809 No Department of Basic Science, Ataturk University, Faculty of Fisheries, Türkiye