Projects / Programmes
Self-assembled and advanced biopolymer coatings for
microencapsulation of probiotics and starter cultures
Code |
Science |
Field |
Subfield |
4.03.00 |
Biotechnical sciences |
Plant production |
|
Code |
Science |
Field |
4.01 |
Agricultural and Veterinary Sciences |
Agriculture, Forestry and Fisheries |
microbial microencapsulation; carrier design; biopolymers; self assembly; augmented fermentation; targeted delivery; product inhibition resistance
Researchers (27)
Organisations (4)
Abstract
Microencapsulation involves coating or entrapping of a core material with a polymeric material to generate microspheres, microcapsules or micro aggregates in the size range of 1–1000 µm. This versatile technology has been used to encapsulate a wide array of products such as pharmaceuticals, flavours, volatile oils, plant extracts, enzymes and other functional compounds. In recent decades, this technology has also been applied to the area of microbial cell immobilization owing to its numerous advantages over other cell immobilization techniques. Due to the abundance of natural biopolymers of diverse surface and colloidal properties, as well as the ability to study their interactions at the molecular level, numerous opportunities are offered for dedicated development of advanced delivery systems for encapsulation of microorganisms, especially for biotechnological food processes and in development of probiotics intended for ingestion. The purpose of encapsulation of cells is strongly dependent on its intended end-use. For encapsulation of starter cultures used in various fermentation processes, the goal is to shorten the period of adaptation in the slurry, achieve high cell density within the carrier, improve the kinetics of the process, reduce the possibility of microbial contamination and allow for easier separation and reuse of biomass for the next batch. For the case of probiotics which are intended for ingestion, the objectives of encapsulation are different as the carrier provides protection during storage and digestion, as well as in more advanced applications acting as a delivery system to reach target parts of the digestive tract or other tissues. In the field of material science, a number of properties have been shown to provide the basis for linking of biopolymers and related molecules as natural building blocks to provide either hollow, or porous and non-porous structures with varying degrees of internal and external organization thus indicating a part of their encapsulating potential. In particular, polymers, such as structural components of the cell wall of plants (pectin) or algae (alginate) or starch and its derivatives offer numerous possibilities for the preparation of materials with controlled size, morphology, surface and structural properties. Our project will be based on thorough characterization of the respective natural substances (mostly plant derived polysaccharides and other plant-based components), and their use as building blocks for self-assembly or targeted organization. The acquired supramolecular structures will serve as stand-alone encapsulants, as well as dedicated structural templates for a wide variety of microbial encapsulation approaches in order to suit to products, which are intended for ingestion and / or for contact with foodstuffs. The selected carriers will be used for two markedly different end-use applications, i.e. (i) for encapsulation of yeasts for optimized ethanol production, (ii) and to improve gut retention and act as a prebiotic for our own isolates of lactobacillus probiotics. In both cases, we will determine the encapsulation efficiency parameters, the level of supported and sustained microbial activity, as well as at the cellular level, the capability of the encapsulation system for fermentation or targeted delivery of microorganisms. The research project will set out to reach beyond the established alginate hydrogel systems using plant derived materials with more precisely defined surface characteristics in order to study the overlying physical, chemical and biological mechanisms that govern the efficiency of the microencapsulation process. We will employ and extend recent advances in the field of material science in order to generate in depth knowledge to allow for the design of food safe encapsulation carriers, perform through characterisation and material screening, as well as assess the suitability of such microencapsulated biomass for tacking current specific field i