TRASH

WITH FOOD SCRAPS AND OTHER ORGANIC INGREDIENTS, A BU BIOREACTOR PROJECT MODELS SUSTAINABLE MANUFACTURING

BY PATRICK L. KENNEDY

It’s a kind of vessel where different ingredients are combined. The resulting broth percolates and, in time, produces a solution to a societal problem, whether the product is a line of cells that kill cancer, bacteria that decontaminate water, or plant-derived alternatives to petroleum-based plastics and fuels.

That description fits an actual container system called a bioreactor—and it’s a fair picture of the convergent approach in synthetic biology. In a bioreactor, the ingredients are cells and nutrients—for example, the byproducts of food scraps. In a convergent—that is, collaborative and cross-disciplinary—project, the ingredients are ideas and expertise.

So perhaps it is no surprise that, as part of a federal push for more and better bioreactors, the Boston University College of Engineering has been tapped for help. Because at ENG, convergence is the way things are done. Arguably, the college’s synthetic biology research is exhibit A.

Moving Beyond Fossil Fuels

A bioreactor is a key component of biomanufacturing. Instead of smokestacks pumping toxins into the atmosphere, biomanufacturing makes use of naturally occurring microorganisms and processes to make things—not just medicines and gene therapies, but also cleaner and greener materials, machine oils, detergents, fuels, fabrics, fragrances and even foods. It has the potential to revolutionize industry while dramatically cutting carbon emissions.

But, to realize that vision, biomanufacturing needs to be scaled up. In the United States in particular, the sector needs to grow significantly if we’re to avoid supply chain disruptions and security breaches.

That’s why Schmidt Futures and the US Department of Defense have awarded a $3 million grant to a team of researchers from ENG, Capra Biosciences, Inc. and other collaborators to make a smarter, more efficient bioreactor. From ENG, the project is led by Assistant Professor Rabia Yazicigil (ECE), Professor Douglas Densmore (ECE, BME) and Associate Professor Ahmad “Mo” Khalil (BME).

A prototype of Capra Biosciences’ biofilm reactor. Sustainable feedstocks are continuously circulated through the reactor and converted into useful chemical products, such as retinol, by the cells in the biofilm. Capra is working with BU to develop and integrate advanced sensor technologies into the reactor and to use BU’s eVOLVER platform as a tool to optimize reactor performance.

eVOLVER’s electronic modules and series of pumps and valves precisely control fluid flow and culture conditions.

The public, private and academic entities involved are part of a consortium called BioIndustrial Manufacturing and Design Ecosystem (BioMADE), which is aimed at making domestic biomanufacturing safe, sustainable and economically viable. Khalil, Yazicigil and Densmore are working with Capra Biosciences to refine and replicate the startup’s reactor technology on a grand scale.

Capra has developed a new kind of continuous flow bioreactor using biofilm, essentially a layer of slime hospitable to bacteria. The goal is to produce cosmetics, as well as lubricants for motors and other machinery, from biological rather than petrochemical sources. “We want to engineer organisms to help us make products sustainably and cost-competitively,” says Capra cofounder Andrew Magyar, “so consumers won’t have to decide, ‘Do I want the sustainable option or the cheap option?’”

Making the business feasible will require automation and novel quality-control and security measures. The trio from BU— combining their backgrounds in genetic engineering, electronics and automation—has proposed an innovative bioreactor design that checks all those boxes.

“This kind of convergence of disciplines is amazing,” says Magyar. “It is the future in terms of where advances in biotechnology are coming from, and BU is definitely at the forefront.”

A Technology Evolves

Khalil began his career as a mechanical engineer, but today he is better known as a pioneer of synthetic biology. In particular, Khalil’s team builds molecular “circuits,” and they have translated these insights into gene circuit engineering platforms that enable the programming of human cells, such as immune cells, for a new generation of cellular therapies that might one day be used to combat diseases such as cancer. (See sidebar.)

“We like to ask the simple yet bold questions, ‘What if we built it?’ and ‘What can we learn from this process?’” says Khalil. “That inverse approach to the study of biology forces one to question prevailing assumptions, and it can lead to surprising results.”