Single-Cell Encapsulation of Non-Spore Forming Probiotic Bacteria for Increased Survivability Under Environmental Extremes

Spore-forming bacterial cells possess extensive capabilities to survive extreme environmental conditions. The goal of this thesis is to explore the use of lipid-protein nanoparticles, extracted from the spore coats of a few distinct bacterial species, as a barrier and coating to protect probiotics from a range of distinct environmental pressures. Orally delivered probiotics must maintain a high viable cell count and be able to be stored for long periods without nutritional influx in order to be effective in humans and other animals. I aim to understand how to characterize and manipulate the spore-based coating’s highly resistant, protective mechanisms for application across multiple families of beneficial bacteria to increase their survivability, both throughout the stress involved in manufacturing and conditions during digestion. This research contributes to the foundational work for the improvement of oral probiotic viability, namely by producing multiple cross-order spore coated probiotics that have no sporulation mechanism themselves, and by showing the spore coat efficiently imparts its resiliencies on non-spore forming bacteria. In this work, I establish the ability for mechanically extruded spore coat nanoparticles (SCN) to be used for single-cell bacterial encapsulation of distantly related species. This protective layer increases their survivability under a wide range of physical extremes, including near boiling temperatures and acidic pH. I also show the ability for this coating and the cells’ biofilm to act as a filter for viral particles less than 150 nm in size. These characteristics are likely due to the spore coat’s function as a passive filter-like material, but I hypothesize this quality is reinforced with active spore coat proteins in the SCN.

Date

2024-11-15

Resource Type

Text

Resource Subtype

Thesis (Masters Degree)

Full item page