Food-dependent set-up of the DiDGI® dynamic in vitro system: Correlation with the porcine model for protein digestion of soya-based food.

The present study compared in vivo protein digestion in a miniature pig model with the dynamic in vitro system DiDGI®, using three digestive compartments (stomach, duodenum, and jejunum + ileum). Two soya-based meals-commercial soya milk and tofu-were studied, each with the same macronutrient content but different macrostructures. Our aim was to first deduce from the in vivo experiments in pigs key digestive parameters such as gastric pH, stomach emptying kinetics, and intestinal transit time, in order to design a relevant set-up for the dynamic in vitro system. Then, we compared digestive samples collected at fixed sampling times from both in vivo and in vitro models regarding different values related to proteolysis. We observed similar evolutions of gastric peptide distribution and duodenal proteolysis between models. Overall, apparent ileal digestibility of nitrogen was similar in vitro and in vivo and the differences between the two meals were conserved between models.

High-throughput screening of filamentous fungi using nanoliter-range droplet-based microfluidics.

Filamentous fungi are an extremely important source of industrial enzymes because of their capacity to secrete large quantities of proteins. Currently, functional screening of fungi is associated with low throughput and high costs, which severely limits the discovery of novel enzymatic activities and better production strains. Here, we describe a nanoliter-range droplet-based microfluidic system specially adapted for the high-throughput sceening (HTS) of large filamentous fungi libraries for secreted enzyme activities. The platform allowed (i) compartmentalization of single spores in ~10 nl droplets, (ii) germination and mycelium growth and (iii) high-throughput sorting of fungi based on enzymatic activity. A 10(4) clone UV-mutated library of Aspergillus niger was screened based on α-amylase activity in just 90 minutes. Active clones were enriched 196-fold after a single round of microfluidic HTS. The platform is a powerful tool for the development of new production strains with low cost, space and time footprint and should bring enormous benefit for improving the viability of biotechnological processes.