Biochemical and functional benchmarking of plant protein hydrolysates in serum-reduced adherent CHO-K1 cell culture

Chinese Hamster Ovary (CHO) cells are used for therapeutic protein production. Although industrial platforms rely on serum-free media, fetal bovine serum (FBS) remains common in research and development. Reducing serum while maintaining cell growth is of interest. In this study, CHO-K1 cells were adapted from 10% to 1% FBS in Ham's F-12 medium. Six plant protein hydrolysates (wheat, soy, pea, broad bean, rice, and a rice-pea blend) were biochemically characterized and evaluated for their effects on cell proliferation under serum-reduced conditions. CHO-K1 cells tolerated adaptation to 1% FBS, although proliferation decreased compared to 10% FBS. Supplementation with hydrolysates improved cell growth in a concentration-dependent but nonlinear manner, with low concentrations more favorable than higher concentrations. Wheat (W106) and broad bean (F120) peptones showed the strongest effects, partially restoring proliferation toward high-serum conditions. This study provides an evaluation of plant hydrolysates and supports their use as supplements in serum-reduced CHO-K1 culture.