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A newly recognized third fundamental mechanism of energy conservation in biology, electron bifurcation, uses free energy from exergonic redox reactions to drive endergonic redox reactions. Flavin-based electron bifurcation furnishes low-potential electrons to demanding chemical reactions, such as reduction of dinitrogen to ammonia. We employed the heterodimeric flavoenzyme FixAB from the. The lipolytic bacteria in milk, cream and butter are of interest from the standpoint of the development of defects in these products. Presumably, rancidity is the most important of such defects, although since many of the lipolytic bacteria also attack constituents of milk other than fat, additional defects may be involved. Comparatively little attention has been given to the numbers of. Only bacteria displaying fluorescence from both DFHBI-1T and YO3-biotin were selected for. EC 50 was calculated in GraphPad Prism 7.0b for Mac OS X. Reetobrata Basu & John J.
Honors Thesis
Title
Author
Date of Award
Spring 5-9-2020
Document Type
Honors Thesis
Department/Major
Biology
First Advisor
Dr. Jake Kerby
Second Advisor
Dr. Andrea Liebl
Third Advisor
Beate Wone
Keywords
Batrachochytrium dendrobatidis, Chytridiomycosis, Serratia marcescens, Genetic engineering
Subject Categories
Animal Diseases | Behavior and Ethology | Biodiversity | Integrative Biology | Microbiology | Other Animal Sciences
Abstract
The fungal pathogen Batrochochytrium dendrobatidis (Bd) has been threatening amphibian populations across the globe. Recent work has discovered that bacteria isolated from certain populations of amphibians protect hosts from this pathogen. This project focuses on the anti-fungal mechanisms of Serratia marcescens, a species of bacteria isolated from a Costa Rican frog that dramatically inhibited Bd in culture. Wild-type and recombinant S. marcescens was introduced to the microbiomes of a live amphibian host, Acris blanchardi (Blanchard's Cricket Frog) and then challenged with Bd to examine the protective effects of this bacteria. The experiment includes recombinant S. marcescens with the genetic pathway responsible for the production of prodigiosin interrupted. This work observed significantly greater movement among frogs treated with wild-type Sm when compared to the other bacteria treatments. There were also significant differences in mean mass and snout-vent length (SVL) between the washed and unwashed treatments. In particular, mean SVL was greater in washed frogs compared to unwashed frogs of the wild-type Sm and no bacteria treatments. These efforts will aid in the future conservation of amphibian species worldwide.
Recommended Citation
Schmidt, Emme L., 'Influences of Anti-Bd Bacteria on Amphibians and their Microbiomes' (2020). Honors Thesis. 99.
https://red.library.usd.edu/honors-thesis/99
Included in
Animal Diseases Commons, Behavior and Ethology Commons, Biodiversity Commons, Integrative Biology Commons, Microbiology Commons, Other Animal Sciences Commons
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Cheap plastics abound, and they're a mixed bag – pun intended.
The IV container that saves a life ends up on a landfill. Or that milk jug from the store ends up floating gently down a stream, with dozens others.
For all their convenience, plastics are massive environmental headaches.
'The main problem is that most synthetic plastic is not completely biodegradable. It cannot be broken down by living organisms, which is why it lasts for hundreds of years after being discarded,' says Taylor Weiss, a former post-doc in the Ducat lab.
Scientists are trying to synthesize environmentally-friendly plastic alternatives, using bacteria.
And it exists: 100% biologically-derived. 100% biodegradable.
But it is too expensive to mass market.
Now, in a study, published in the journal Metabolic Engineering, Taylor and the Ducat lab propose a new production method, powered by sunlight and an ancient microorganism, that could significantly cut costs.
Cyanos: micro powerhouses
'Present bioplastic production relies on feeding plastic-producing bacteria with large quantities of sugars from crops, like corn or sugarcane,' Taylor says. 'But these crops also feed people and animals, so we risk competing for limited agricultural resources and driving food prices up in the long term.'
Mac Os Mojave
A promising alternative is working with cyanobacteria, microorganisms that harness sunlight to produce chemical compounds, through photosynthesis.
Cyanos (for short) thrive in environments hostile to crops, like iceberg walls or the edges of hot springs, minimizing competition for agricultural land.
That's why they're hot in the biotech industry, with scientists wanting to genetically tweak them to create products for human consumption, like electricity, biofuels, even food and oxygen for future manned outposts on Mars!
A bioplastic consortium engineered
There's a catch. Cyanos are great at photosynthesis, but not so much at making bioplastics.
Current methods where cyanos do it all - collect the sun's energy, the carbon, and the create the bioplastic - end up inefficient.
So, Taylor and his colleagues thought, why not split the workload with other organisms?
They started out with a cyano strain that naturally produces sugar. They tweaked them to constantly leak the sugar into a surrounding salt water medium.
Then, they paired the cyanos with natural bacteria that make bioplastic. The bacteria fed on the leaked sugar, which is to bacteria what honey is to bears. (For more, see the video above.)
Over five months of testing, the pairing turned out prolific and robust:
Basu Bacteria Mac Os Catalina
- Processed biomass contained a near constant 30% bioplastic content, four times more than the best cyano working alone.
- Production rates were over twenty times faster.
The system is also relatively inexpensive to maintain.
'Harvesting bioproducts is a common costly bottleneck,' Taylor adds, 'It involves collecting and regrowing microorganisms from scratch, each production cycle. But, we trap our cyanos in a hydrogel bead for reuse after each harvest.'
Basu Bacteria Mac Os Download
Also cutting costs was the fact the plastic-producing bacteria thoroughly outcompeted other unwelcome contaminating bacteria trying to get to the sugar, without the need for human support.
From plastic to perfumes and medicines
Taylor's cooperative seems to continuously improve with time, without human meddling.
Working with one organism can be hard, because it typically prioritizes its health and growth over producing for us.
'But this pair has complementary strengths: the cyanos are constantly producing sugar, and the bacteria are constantly beefing up on it, which encourages the cyanos to keep producing.'
Looking ahead, Taylor wants to improve productivity and diversify the bioproduct line.
'We've laid the foundation for a 'plug-and-play' system where a cyano can be gradually upgraded to produce more sugar. We eventually want to pair it with diverse specialist bacteria to create many cheaper, green bioproducts like fuels, fragrances, dyes, and medicines.'
'Ultimately, we aren't just creating alternatives to synthetic products. We're figuring out how to ask Nature to do what it does best: figure out the problem for us.'
Mac Os Download
This work was primarily funded by the National Science Foundation. The MSU-DOE Plant Research Laboratory also relies on major funding from the US Department of Energy, Office of Science, Basic Energy Sciences.
