Pulsed electric field as a non-thermal intensification strategy for biomass production of Lacticaseibacillus paracasei in alternative growth media

Abstract This research presents a non-thermal intensification strategy for biomass production of Lacticaseibacillus paracasei by integrating pulsed electric field (PEF) pretreatment with a cost-effective waste-derived medium. The medium, formulated from corn steep liquor, grape pomace, and apple peel, was optimised using Response Surface Methodology (RSM). Optimised conditions supported biomass yields of 4.44 g L −1 (standard strain, L1) and 4.45 g L −1 (indigenous strain, L2). To further enhance productivity, inoculum suspensions and sterile medium were exposed to PEF (0.5–1.5 kV cm −1 , 20–50 pulses, 2–10 μs). Sub lethal treatments improved growth, with the most effective setting (1.0 kV cm −1 , 30 pulses, 5 μs) increasing biomass by 12% (L1) and 18% (L2) relative to controls. Pretreated inocula were more effective than pretreated media, suggesting that reversible membrane permeabilisation facilitated nutrient uptake and metabolic activation. Growth kinetics were modelled using exponential and Gompertz equations, with the Gompertz model offering superior fit ( R 2 > 0.98). These findings demonstrate that combining waste valorisation with PEF pretreatment provides a scalable and sustainable approach to microbial biomass production, highlighting its potential for food and bioprocess industries.