The Lactobacillus helveticus OSU-PECh-4A strain, from the Ohio State University Parker Chair collection, produces exceptional β-galactosidase activity using acid whey as a culture medium, compared with a commercial broth. The strain has a genome sequence of 1,834,843 bp, and its GC content is 36.69%. Using InterProScan v5.50-84.0 software, four genes with putative β-galactosidase function were found.