Location: Food Quality Laboratory
Project Number: 8042-43440-006-014-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jan 16, 2024
End Date: Jan 15, 2025
Objective:
The proposed project seeks to develop novel seed films and hydrogels to support microgreen seed germination and plant growth on Earth and in space. Specifically, FQL will 1) develop biodegradable polymers with targeted water holding capacity and aeration; 2) characterize the physical and chemical properties of these polymers; and 3) assess seed germination, growth, and metabolomic profiles of the plants.
Approach:
A variety of commercially available polymers will be screened for their suitability as plant growth media in both normal (earth) gravity and in microgravity (simulated via a clinostat). These include sodium polyacrylate, polyurethane, open-cell phenolic plastic foam, and water storing crystals. Focus will be given to the group of polymers that exhibit superior biocompatibility compared to synthetic polymers and are available with different chain lengths and degrees of substitution. The combination of the above two parameters, together with fine-tuned crosslinker content (e.g., Ca2+, Fe2+, or polymeric counterions such as chitosan), may lead to desirable water-retention capacity and mechanical strength. Moreover, the functional groups on the biopolymers may allow for acquisition of new functionalities, such as controlled nutrient release.
The water holding capacity, the porosity, and stability of the matrix will be evaluated. The textural properties such as hardness and adhesion (important for root growth) of the matrix will be examined. The ability of the matrix to fix seeds and support germination will be tested. Seeds of interest to NASA will be embedded into the growth media using Nanofiber. The as-prepared package will be situated and hydrated in a clinostat. For the dehydrated growing matrix, an additional study will be carried out to establish the effect of rehydration level on the plant growth. Light, water, and fertilizers will be delivered at pre-determined dose/intensity and intervals. Attributes to be evaluated during the growth period will include seed holding capacity (percentage of seeds retained on the matrix after being applied on the clinostat), seed germination rate, and plant growth rates (quantified by time-dependent change in plant weight, dry mass, nitrogen content, and height). Metabolomics of microgreens will be investigated. Microgreens grown in commercial potting soil will be used as a control.
