Week 1 HW: Final Project Ideas

1. What would you like to biomanufacture and why? I would like to make a microbial inoculant for a traditional milpa, or Three Sisters system, of corn, beans, and squash. The inoculant would contain beneficial bacteria and fungi that could help the plants get nutrients from the soil while also potentially helping them survive periods of drought or flooding. I became interested in this idea because of my background and interest in agriculture, especially Indigenous agricultural systems. A lot of modern agriculture is based around growing one crop at a time, while a milpa grows multiple crops together. Corn, beans, and squash can benefit each other in different ways, so I thought it would be interesting to see if beneficial microorganisms could also be selected specifically for the three crops growing together instead of for only one crop. I am especially interested in making the inoculant help with water stress. Drought is an obvious problem for agriculture, but too much water can also be damaging. Flooding can leave soil saturated with water and reduce the amount of oxygen available to plant roots. I have seen examples of both problems affecting Indigenous farming communities. A few years ago, severe flooding in Oaxaca damaged agricultural fields, while more recently a Mam woman I follow who grows traditional crops with her family in Georgia described their crops struggling with drought. My idea would be to find bacteria and fungi that already have useful relationships with plants and combine several of them into one product. Some might help plants obtain nutrients, while others might help plants deal with drought or very wet soil. The goal would not necessarily be to make the plants completely drought- or flood-proof. Instead, I would want to see whether the inoculant could make the Three Sisters more resilient so that they have a better chance of surviving stressful growing conditions and still producing a crop.

2. What living system would you use? I would use beneficial bacteria and fungi associated with plants and soil. My first approach would be to look for microorganisms that already have useful traits instead of immediately trying to genetically modify them. For example, microorganisms could potentially be collected from the roots or surrounding soil of plants that are doing well under drought or very wet conditions. I would then want to test which microorganisms benefit corn, beans, and squash. Some bacteria or fungi could help the plants access nutrients such as nitrogen or phosphorus. Others could potentially affect root growth or help plants respond to water stress. I do not think one microorganism would necessarily need to do everything. The final inoculant could contain several different microorganisms that each provide a different benefit. For example, it might contain: bacteria that help make nutrients available to plants; fungi that help roots access water and nutrients; microorganisms associated with better drought tolerance; microorganisms associated with better tolerance of waterlogged soil. These organisms could be grown separately and eventually combined into one inoculant. If naturally occurring microorganisms were not enough, it might eventually be possible to modify bacteria or fungi to improve certain traits. However, I would first want to see what could be accomplished using microorganisms that already exist.

3. How would you use automation? I think automation would be most useful for testing lots of different microorganisms and combinations of microorganisms. There could potentially be dozens of bacteria and fungi worth testing. Doing every combination by hand would take a very long time. A liquid-handling robot could help prepare different microbial combinations in small experiments so that the same amounts are used each time. The plants could then be grown under different conditions. Some could receive normal watering, some could experience drought, and others could experience very wet or waterlogged soil. I could compare things such as plant survival, growth, root growth, and final biomass. More detailed experiments could also measure how much water the plants are using or how stressed they are. Automation could help narrow a large number of possible microbial combinations down to a smaller number that would then be worth testing in a greenhouse or field. If the inoculant eventually became a real product, the microorganisms would probably need to be grown using much larger equipment than what was used during these early experiments.

4. How much would you need to make, and how long would it take? A. How much? For this project, I would define a meaningful first scale as producing enough inoculant for one hectare of a Three Sisters field. I do not yet know what the correct amount of microorganisms per hectare would be. This would depend on how concentrated the inoculant was and whether it was applied to the seeds, roots, or soil. For a rough estimate, I will assume that I need 10 liters of concentrated microbial inoculant per hectare. That would mean: 1 hectare × 10 L/hectare = 10 L of inoculant If it were eventually used on 100 hectares: 100 hectares × 10 L/hectare = 1,000 L of inoculant This is only an initial estimate. I would need to research existing microbial agricultural products to determine a more realistic application rate. B. How long? The amount of time needed would depend on which microorganisms are eventually selected. For a rough estimate, I will assume that the bacteria could be grown over approximately 1–2 days. Additional time would then be needed to prepare the original cultures, combine the microorganisms, and make sure the finished inoculant contains the organisms that it is supposed to. I would therefore roughly estimate several days to produce one batch. Producing enough for one hectare might be possible using relatively small equipment. Producing enough for hundreds or thousands of hectares would require much larger tanks or multiple tanks operating at the same time. The fungi might also be more difficult to produce than the bacteria. Some beneficial fungi depend on plants to grow, so I would need to research how those organisms are commercially produced before I could make a good estimate for them.

5. What don’t you know yet? There are several major things I would need to learn before knowing whether this idea could actually work.

6. Can the same microorganisms benefit corn, beans, and squash? Because these are three different plants, a microorganism that works well with one might not work with the others. I would need to test whether one community of microorganisms could work with all three crops growing together.

7. Can one inoculant help with both drought and flooding? Drought and flooding are almost opposite problems. During drought there is too little water, while during flooding the soil can contain so much water that the roots do not receive enough oxygen. I do not know whether microorganisms that help during drought would also survive and remain useful during flooding. It may require different microorganisms working together.

8. Would it actually work in a field? Something that works in a controlled laboratory or greenhouse experiment may not work the same way in agricultural soil. There are already many microorganisms living in soil, and temperature, rainfall, soil type, and other factors could affect the introduced microorganisms. I would eventually want to compare Three Sisters plots with and without the inoculant under normal watering, drought, and waterlogged conditions. This would show whether the inoculant actually improves plant survival, growth, or yield under realistic conditions.