This thesis focused on evaluation of the lactic acid bacteria (LAB) collection for their potential antihypertensive abilities and production of fermented whey bases for development of fermented whey beverages. For this aim, over 400 LAB were screened for their proteolytic activities in different skim milk media. Among the LAB, 39 (13%) were determined as highly proteolytic. Strains were selected to produce fermented milks, 11 LAB out of 34 with highest ACE inhibitor activities were utilized to generate fermented whey bases with co–cultures of Lactobacillus brevis D9 and Lactococcus lactis ssp. lactis C24. Proteolytic activities and ACE inhibitor activities in fermented milks were detected in the range of 4.11-1.8 mg/L Leucine and 49–86% activity, respectively. In co–culture fermented whey bases, ACE inhibitor activities found in the range of 80–97%. Proteolytic activities of 13 selected LAB were also determined during fermentation by HPLC and SDS–PAGE with evaluating the degradation profiles of whey proteins. GABA production capability of 33 strains among 300 LAB were observed in modified broth media after 48 h incubation at 37 or 42 °C using thin layer chromatography (TLC). In order to develop the fermented whey beverage base, total of 10 species of Lactobacillus e.g. Lactiplantibacillus plantarum, Latilactobacillus curvatus and Levilactobacillus brevis were selected according to their GABA concentrations yielded e.g. 50–367 mg/L into the modified broth media. Accordingly, GABA concentrations in fermented whey bases were quantified in the range of 11–21mg/L after 24h at 37 C.