Construction of complex bacteriogenic protocells from living material assembly.

Abstract

Protocell research offers diverse opportunities to understand cellular processes and the foundations of life and holds attractive potential applications across various fields. However, it is still a formidable task to construct a true-to-life synthetic cell with high organizational and functional complexity. Here we present a protocol for constructing bacteriogenic protocells by employing prokaryotes as on-site repositories of compositional, functional and structural building blocks to address this challenge. This approach is based on the capture and processing of two spatially segregated bacterial colonies within individual coacervate microdroplets to produce membrane-bounded, molecularly crowded, compositionally, structurally and functionally complex synthetic cells. The bacteriogenic protocells inherit sufficient biological components from their bacterial building units to exhibit highly integrated life-like properties, including biocatalysis, glycolysis and gene expression. The protocells can be endogenously remodeled to acquire diverse proto-organelles including a spatially partitioned nucleus-like DNA/histone-based condensate to store genetic material, membrane-bounded water vacuoles to adjust cellular osmotic pressure, a three-dimensional network of F-actin proto-cytoskeleton to support structural stability and proto-mitochondria to generate endogenous ATP as source of energy. The protocells ultimately develop a nonspherical morphology due to the continuous biogeneration of metabolic products by implanted living bacteria cells. This protocol provides a novel living material assembly strategy for the construction of functional protoliving microdevices and offers opportunities for potential applications in engineered synthetic biology and biomedicine. The protocol takes ~27 d to complete and requires expertise in microbiology, phase separation, biochemistry and molecular biology related techniques.