Enhanced cell growth, production, and mAb quality produced in Chinese hamster ovary-K1 cells by supplementing polyamine in the media.

Polyamines such as putrescine (PUT), spermidine (SPD), and spermine (SPM) are amine group-containing biomolecules that regulate multiple intracellular functions such as proliferation, differentiation, and stress response in mammalian cells. Although these biomolecules can be generated intracellularly, lack of polyamine-synthesizing activity has occasionally been reported in a few mammalian cell lines such as Chinese hamster ovary (CHO)-K1; thus, polyamine supplementation in serum-free media is required to support cell growth and production. In the present study, the effects of biogenic polyamines PUT, SPD, and SPM in media on cell growth, production, metabolism, and antibody quality were explored in cultures of antibody-producing CHO-K1 cells. Polyamine withdrawal from media significantly suppressed cell growth and production. On the other hand, enhanced culture performance was achieved in polyamine-containing media conditions in a dose-dependent manner regardless of polyamine type. In addition, in polyamine-deprived medium, distinguishing metabolic features, such as enriched glycolysis and suppressed amino acid consumption, were observed and accompanied by higher heterogeneity of antibody quality compared with the optimal concentration of polyamines. Furthermore, an excessive concentration of polyamines negatively affected culture performance as well as antibody quality. Hence, the results suggest that polyamine-related metabolism needs to be further investigated and polyamines in cell growth media should be optimized as a controllable parameter in CHO cell culture bioprocessing. KEY POINTS: • Polyamine supplementation enhanced cell growth and production in a dose-dependent manner • Polyamine type and concentration in the media affected mAb quality • Optimizing polyamines in the media is suggested in CHO cell bioprocessing.

Comparison of acrylamide and furan concentrations, antioxidant activities, and volatile profiles in cold or hot brew coffees.

The aim of this study was to investigate the formation of furan and acrylamide and to compare antioxidant capacities and volatile compounds in cold or hot brewed coffees. Cold brews were prepared at 5 °C and 20 °C for 12 h. using steeping and dripping, and hot brews were prepared at 80 °C and 95 °C for 5 min. using the pour-over method. Furan contents of cold steeping at 5 °C and hot brewed at 80 °C showed the higher levels significantly (p < 0.05), which were 17.0 ± 0.5 and 10.6 ± 0.1 ng/mL, respectively. However, acrylamide contents in cold steeping at 5 °C and hot brew at 80 °C showed lower levels, which were 4.1 ± 0.4 and 3.5 ± 0.1 ng/mL respectively. Cold brews at 20 °C showed the highest levels of antioxidant activities while hot brews showed similar levels with cold brews at 5 °C. This study confirms that levels of different beneficial and hazardous chemical compounds could be manipulated by adjusting the coffee extraction conditions.

Reduction of total, organic, and inorganic arsenic content in Hizikia fusiforme (Hijiki).

This study aimed to evaluate the reduction of total, organic, and inorganic arsenic content in Hizikia fusiforme (hijiki). Initially, the six most common arsenic compounds in hijiki and its organs were evaluated, among which only arsenate and arsenobetaine were detected. Thereafter, the entire plant, including the stalk and leaves, was treated with heat and NaCl solution, individually and in combination. Heating at 90 °C for 5 min significantly reduced arsenic content in hijiki by approximately 33-80%. Treatment with NaCl solution significantly reduced arsenic content in hijiki, except for arsenobetaine content in the stalk. Combinatorial treatment further decreased arsenic content by more than 5-20%. In conclusion, consumption of hijiki after boiling at 90 °C and soaking in 2% NaCl solution reduces the intake of inorganic arsenic by consumers.