The intensification of processes is essential for the sustainability of the biorefinery concept. Enzyme catalysis assisted by ultrasound (US) may offer interesting opportunities in the agri-food sector because the cavitation effect provided by this technology has been shown to improve the efficiency of the biocatalysts. This review presents the recent advances in this field, focused on three main applications: ultrasound-assisted enzymatic extractions (UAEE), US hydrolysis reactions, and synthesis reactions assisted by US for the manufacturing of agri-food produce and ingredients, enabling the upgrading of agro-industrial waste. Some theoretical and experimental aspects of US that must be considered are also reviewed. Ultrasonic intensity (UI) is the main parameter affecting the catalytic activity of enzymes, but a lack of standardization for its quantification makes it unsuitable to properly compare results. Applications of enzyme catalysis assisted by US in agri-foods have been mostly concentrated in UAEE of bioactive compounds. In second place, US hydrolysis reactions have been applied for juice and beverage manufacturing, with some interesting applications for producing bioactive peptides. In last place, a few efforts have been performed regarding synthesis reactions, mainly through trans and esterification to produce structured lipids and sugar esters, while incipient applications for the synthesis of oligosaccharides show promising results. In most cases, US has improved the reaction yield, but much information is lacking on how different sonication conditions affect kinetic parameters. Future research should be performed under a multidisciplinary approach for better comprehension of a very complex phenomenon that occurs in very short time periods.

Nanoparticles with antimicrobial properties are used in thousands of nano-enabled consumer products. Therefore, it is important to understand the response mechanisms of bacteria that are exposed to these nanoparticles at different conditions. Moreover, it is necessary to evaluate possible microbial adaptation mechanisms. In our study, Escherichia coli K-12 MG1655 (E. coli) were grown continuously in bioreactors at two specific growth rates (0.1 h⁻¹ and 0.2 h⁻¹) and then exposed to chronic concentrations of casein-coated silver nanoparticles (AgNPs) [1 mg L⁻¹] for about 180 generations. After initiating the injection of AgNPs, the results showed a change in growth kinetic parameters between non-exposed and exposed systems. Maximum yield (Y_max) decreased by 33%, while the maintenance coefficient (m_s) increased by 52%. This evidence was indicating the versatility of the culture to growth in the exposed conditions and even the ability to achieve a new stationary state. However, the adaptation was achieved at a metabolic cost. Comparing the concentration and composition of extra-cellular substances that were produced showed differences between the control and exposed conditions, and also between the exposed systems in the two growth conditions. In the AgNPs-exposed bioreactor (EB) growing at 0.1 h⁻¹, AgNPs–ES complexes showed that the ratio of the area representing β-sheets to the area representing α-helix proteins was 2.4, which implies the formation of a protein corona, while at an exposed growth rate of 0.2 h⁻¹ this ratio was <1, indicating no protein corona. Transcriptomic results showed gene regulation in response to AgNPs exposure as a function of the specific growth rate. Batch exposure tests using the resultant cultures for each condition showed a lower inhibitory effect for the AgNPs on EB at 0.1 h⁻¹ than on control bacteria (CB) at 0.1 h⁻¹ in terms of membrane permeation and reactive oxygen species generation. Overall, our study showed that culture growth conditions significantly affects bacterial response to nanoparticle exposure. Therefore, these growth parameters should be determined and reported when performing toxicological tests.