Location: Sustainable Biofuels and Co-products Research
Project Number: 8072-41000-099-000-D
Project Type: In-House Appropriated
Start Date: May 19, 2015
End Date: May 19, 2020
Objective:
Objective 1: Enable commercial processes for converting microbial lipids and the
byproducts of their fermentation into marketable products.
Sub-objective 1: Production of microbial glycolipids and variants to enhance
commercial viability.
1A: Genetic engineering of P. chlororaphis for production of RL from low-cost
bioglycerol and soy-sugar byproduct.
1B: Fermentative production of short-chain (C=12) and very-long-chain (C22)
sophorolipids.
Sub-objective 2: Synthesis and testing of value-added products from glycolipids
and components.
Enabling chemical and/or enzymatic production of glycolipid components and testing products as novel antimicrobial agents and novel sugar substitutes.
Approach:
To enhance the commercial viability of microbial glycolipids (i.e., sophorolipids, SLs; and rhamnolipids, RLs), their high-value antimicrobial property will be extensively researched in this project for full exploitation in end-user industrial applications. Accordingly, the structure-function relationship of the antimicrobial activity of these glycolipids will be established by first biosynthesizing various structurally varied glycolipids through the use of new producing strains and uniquely synthesized oleochemicals from fats and oils as fermentative feedstocks. The resultant microbial SLs containing very-long-chain (C22) and short-chain (C</=12) fatty acid, and previously produced medium-chain (C16-18) SLs and the RLs from non-pathogenic bacterium, will then be assayed for antimicrobial activity to establish structure-function correlation. The mechanism(s) of action of these glycolipids will be studied by screening their bacteriostatic/bacteriocidal potency against various industrially relevant and detrimental Gram-positive and Gram-negative bacteria. Cellular structural changes of sensitive target bacteria will be studied by microscopic analysis to further elucidate the glycolipids’ mode of action. Equally important for the commercial viability of microbial glycolipids is a low production cost. Metabolic engineering and fermentation optimization of the bioprocesses for utilizing low-cost bioglycerol and soybean-based waste streams to produce C22- and C</=12-SLs and RLs will be studied. Techno-economic analysis of the process will be performed.
