Showing posts with label bioreactors. Show all posts
Showing posts with label bioreactors. Show all posts

Monday, October 26, 2020

436 - Copper Concentrates Culture Current

Geobacter sulferreducens
By Mantapia11147,
CC BY-SA 4.0
This episode: Copper electrodes, rather than killing bacteria in microbial fuel cells, allow them to generate higher densities of electric current!

Download Episode (5.0 MB, 7.2 minutes)

Show notes:
Microbe of the episode: Xipapillomavirus 2


Takeaways
Copper is widely used as a way to make surfaces and materials antimicrobial, to cut down on the spread of pathogens in hospitals and other environments. Among other mechanisms, it reacts with oxygen to form reactive oxygen species that are very harsh on microbial proteins. But copper is also a good electrical conductor, which would be useful to use in microbial fuel cells, which exploit bacterial metabolism to generate electricity. Microbes form biofilms on an electrode and transfer electrons to it as a way for them to generate energy. Most such fuel cells have used graphite electrodes to avoid toxicity.

In this study, fuel cell bacteria grew well on a copper electrode in an oxygen-free environment. The copper actually allowed them to increase the amount of current they produced per unit of area, as ionic copper diffused through the biofilm and allowed electrons to flow through the biofilm to the electrode from layers farther from the electrode that otherwise would not have access. Even graphite electrodes could be improved by adding these copper ions to the biofilm directly.

Journal Paper:
Beuth L, Pfeiffer CP, Schröder U. 2020. Copper-bottomed: electrochemically active bacteria exploit conductive sulphide networks for enhanced electrogeneity. Energy Environ Sci 13:3102–3109.

Other interesting stories:

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.

Monday, June 1, 2020

422 - Frigid Phototrophs Fuel Fords

Algae growing in 20-liter bioreactor

Kim et. al, 2020. CC BY 4.0

This episode: Producing both biodiesel and bioethanol fuels from cold-loving Arctic algae!


Download Episode (8.7 MB, 12.6 minutes)

Show notes:
Microbe of the episode: Royal Farm virus

Takeaways
Renewable fuels such as biofuels can allow existing infrastructure and vehicles to continue to operate in a more sustainable manner, which could reduce the cost and impact of switching to new/different systems of transportation like electricity. Economically competitive methods of producing biofuels are still being explored and developed.

In this study, Arctic algae are grown in cold temperatures using only light, carbon dioxide, and a few minerals, and then broken down to produce biodiesel and bioethanol, which can be used as fuel in many different internal combustion engines. The amounts produced are comparable to other algae-based systems being researched, and use of the cold-loving organisms could reduce the cost of production in colder latitudes and seasons.

Journal Paper:
Kim EJ, Kim S, Choi H-G, Han SJ. 2020. Co-production of biodiesel and bioethanol using psychrophilic microalga Chlamydomonas sp. KNM0029C isolated from Arctic sea ice. Biotechnol Biofuel 13:20.

Other interesting stories:

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.

Monday, May 18, 2020

BacterioFiles 420 - Cell Societies Stay Stable

Bacteroides species
This episode: Simplified gut communities growing in bioreactors grow and metabolize reproducibly, with only moderate variations, even when individual members of the community are absent!


Download Episode (8.2 MB, 11.9 minutes)

Show notes:
Microbe of the episode: Citrobacter virus Merlin

Takeaways
The community of microbes in our guts is highly complex, with thousands of species all interacting with each other, with our own cells, and with the contents of our diet. Each region of the gut has a different collection of microbes as well. Many questions remain to be answered about the functions and fluctuations of these communities. How can we study such a complex system? Which species, if any, are most important for its continued function?

In this study, a simplified community of only 14 species is grown repeatedly in bioreactors, and one species at a time is left out of the community to see what will change in its absence. This reveals effects different species have on the overall growth, carbon source consumption, and production of various metabolites relevant to gut health. Some microbes have large effects, but none of them appears to be crucial for the overall function and stability of the community.

Journal Paper:
Gutiérrez N, Garrido D. 2019. Species Deletions from Microbiome Consortia Reveal Key Metabolic Interactions between Gut Microbes. mSystems 4:e00185-19.

Other interesting stories:

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.

Monday, March 4, 2019

BacterioFiles 376 - Pressurized Pollutant Pulls Products

Bacillus megaterium
By Osmoregulator, CCBY-SA 3.0
This episode: Supercritical carbon dioxide and bacteria that can grow in it make a great combination for biofuel production!

Download Episode (9.4 MB, 10.2 minutes)

Show notes:
Microbe of the episode: Flexibacter aggregans

Takeaways
Biofuels are an important part of humanity's move away from non-renewable resources. They have a higher energy density than batteries are yet able to achieve, giving them significant advantages for transportation purposes in which tapping into an electric grid isn't possible. Depending on the biofuel, they also have the advantage of existing infrastructure: we don't need to build a whole new system of charging or refueling stations, but can use the systems already in place.

However, biofuels as a collection of technologies still need some refinements. Yields for the more potentially sustainable approaches are low, and the lower the concentration of a soluble fuel, the more difficult it is to separate it from the non-fuel components of a fermentation. Microbial products also face the risk of contamination of a fermentation by unwanted organisms that use up the substrate without producing desirable products.

In this study, supercritical carbon dioxide is considered as a fix for both of these problems. The gas is pressurized to a point at which it is indistinguishable from liquid. A strain of Bacillus megaterium is specially selected as capable of growing and fermenting in this environment, while contaminants are inhibited. The solvent potential of supercritical carbon dioxide also serves as a way to extract the biofuel product—in this case, isobutanol—from the aqueous part of the culture medium. While it needs some development, this approach yields promising results.

Journal Paper:
Boock JT, Freedman AJE, Tompsett GA, Muse SK, Allen AJ, Jackson LA, Castro-Dominguez B, Timko MT, Prather KLJ, Thompson JR. 2019. Engineered microbial biofuel production and recovery under supercritical carbon dioxide. Nat Commun 10:587.

Other interesting stories:

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, RSS, Google Play. Support the show at Patreon, or check out the show at Twitter or Facebook.

Monday, January 14, 2019

BacterioFiles 369 - Powering Purple Prokaryote Protonation

This episode: Purple phototrophic bacteria could use certain kinds of wastewater, along with electric current, to produce valuable products like hydrogen without much waste!

Thanks to Dr. Ioanna Vasiliadou for her contribution!

Download Episode (12.7 MB, 13.9 minutes)

Show notes:
Microbe of the episode: Streptomyces tendae

News item

Takeaways
Purple phototrophic bacteria can take light energy and use it to help power their metabolism. They're not dependent on it like plants, but can use light or other energy sources for their versatile metabolism.

This versatility makes them very interesting candidates for industrial biotechnology applications. These bacteria can take in various combinations of nutrients and produce a number of different valuable products, including protein-rich feed, bioplastics, and biofuels such as hydrogen gas.

Today's study shows they can also take up electrons directly to help make their biofuel production process even more environmentally sustainable.

Journal Paper:
Vasiliadou IA, Berná A, Manchon C, Melero JA, Martinez F, Esteve-Nuñez A, Puyol D. 2018. Biological and Bioelectrochemical Systems for Hydrogen Production and Carbon Fixation Using Purple Phototrophic Bacteria. Front Energy Res 6:107.

Other interesting stories:

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, RSS, Google Play. Support the show at Patreon, or check out the show at Twitter or Facebook.

Monday, September 10, 2018

BacterioFiles 355 - Photon Factors Favor Fancy Fuels

Saccharomyces cerevisiae yeast
This episode: Engineering yeast to control their metabolism using light and dark for the production of advanced biofuels and chemicals!

Download Episode (16.1 MB, 17.7 minutes)

Show notes:
Microbe of the episode: Equine arteritis virus

News item

Journal Paper:
Zhao EM, Zhang Y, Mehl J, Park H, Lalwani MA, Toettcher JE, Avalos JL. 2018. Optogenetic regulation of engineered cellular metabolism for microbial chemical production. Nature 555:683–687.

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, RSS, Google Play. Support the show at Patreon, or check out the show at Twitter or Facebook.

Episode outline:

Monday, July 30, 2018

BacterioFiles 349 - Magnet Microbes Make Millivolts

Magnetotactic bacteria with
magnetosome chains visible
From: Edouard Alphandéry
Front. Bioeng. Biotechnol.
DOI: 10.3389/fbioe.2014.00005
This episode: Bacteria that contain tiny magnets can generate an electric current!

Download Episode (6.8 MB, 7.4 minutes)

Show notes:
Microbe of the episode: Mamastrovirus 2

Journal Paper:
Smit B.A., Van Zyl E., Joubert J.J., Meyer W., Prévéral S., Lefèvre C.T., Venter S.N. 2018. Magnetotactic bacteria used to generate electricity based on Faraday’s law of electromagnetic induction. Lett Appl Microbiol 66:362–367.

Other interesting stories:

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, RSS, Google Play. Support the show at Patreon, or check out the show at Twitter or Facebook.

Episode outline:

Monday, January 8, 2018

BacterioFiles 323 - Clostridium Capturing Carbon with Walter Sandoval

Walter Sandoval in lab
This episode: I talk with Dr. Walter Sandoval-Espinola, a researcher from Paraguay, now a postdoc at Harvard, about his discovery that biofuel-producing bacteria Clostridium beijerinckii can also transform CO2 and carbon monoxide into biofuels!

Download Episode (37 MB, 40.4 minutes)

Show notes:
News item en español

Find Walter on Twitter or LinkedIn

Journal Paper:
Sandoval-Espinola WJ, Chinn MS, Thon MR, Bruno-Bárcena JM. 2017. Evidence of mixotrophic carbon-capture by n-butanol-producer Clostridium beijerinckii. Sci Rep 7:12759.

Other interesting stories:
  • Even microbes can help mix up lake water
  • Using drones to sample whale microbiome
  • Prebiotics could affect gut even without microbe involvement (paper)
  • Bacteria do better in changing environments when they cooperate
  • Newly discovered bacterial defense against phages (paper)

  • Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

    Subscribe: iTunes, RSS, Google Play. Support the show at Patreon, or check out the show at Twitter or Facebook.

    Monday, January 9, 2017

    BacterioFiles 281 - Prokaryote Partners Produce Plastic

    Azotobacter vinelandii
    This episode: Microbes with complementary abilities help each other grow and produce useful stuff from the air!
    Download Episode (12 MB, 13.2 minutes)

    Show notes:
    Journal Paper:
    Smith MJ, Francis MB. 2016. A designed A. vinelandii-S. elongatus coculture for chemical photoproduction from air, water, phosphate and trace metals. ACS Synth Biol 5:955–961.

    Other interesting stories:
  • Bypass surgery might fix diabetes by modifying gut community
  • Using bacteria to make wrinkly graphene with different properties
  • Figuring out what controls where microbes live in plants
  • Gut bacteria maybe related to rheumatoid arthritis
  • Gut bacteria maybe related to multiple sclerosis

  • Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

    Subscribe at iTunes or Google Play, support the show at Patreon, or check out the show at Twitter, or Facebook

    Monday, November 7, 2016

    BacterioFiles 275 - Building Bacterial Batteries

    This episode: Scientists build a battery out of microbes and electrodes that can store and release electricity repeatedly!
    Download Episode (7.5 MB, 8.1 minutes)

    Show notes:
    News item

    Interesting articles about anaerobic digesters
    Journal Paper:
    Molenaar SD, Mol AR, Sleutels THJA, ter Heijne A, Buisman CJN. 2016. Microbial Rechargeable Battery: Energy Storage and Recovery through Acetate. Environ Sci Technol Lett 3:144–149.

    Other interesting stories:
  • Viruses are transferred with fecal transplant, but only ones that attack bacteria (paper)
  • Communities of microbes on skin don't change much
  • Antibodies from mother in milk help babies tolerate good microbes
  • Bacteria could help control insects by killing males
  • More associations between childhood bacteria and asthma

  • Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

    Subscribe at iTunes or Google Play, support the show at Patreon, or check out the show at Twitter, or Facebook

    Monday, September 5, 2016

    BacterioFiles 266 - Solar Cyborg Cells Capture Carbon

    From: Jiang, B., Henstra, A.M., Paulo, P.L., Balk, M., Van Doesburg, W., and Stams, A.J.M. (2009) Atypical one-carbon metabolism of an acetogenic and hydrogenogenic Moorella thermoacetica strain. Archives of Microbiology 191: 123-131.
    Cells of Moorella thermoacetica
    forming spores in culture
    This episode: Adding exotic elements to convert spore-forming bacteria into light-capturing cyborgs that convert carbon dioxide into useful chemicals!
    Download Episode (9.7 MB, 10.5 minutes)

    Show notes:
    News item 1/News item 2

    Journal Paper:
    Sakimoto KK, Wong AB, Yang P. 2016. Self-photosensitization of nonphotosynthetic bacteria for solar-to-chemical production. Science 351:74–77.

    Other interesting stories:
  • Unusual archaeal virus sorta looks like Ebola (paper)
  • Understanding how probiotics could prevent cancer in mice (paper)
  • Giant viruses have immune system against virophages
  • Using evolution to help yeast produce more ethanol from biomass (paper)
  • Remnants of viruses in our DNA helps us fight off infections

  • Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

    Subscribe at iTunes or Google Play, check out the show at Twitter, or Facebook

    Monday, July 27, 2015

    BacterioFiles 222 - Cells Store Solar Sparks

    The setup. Torella et al. 2015
    This episode: Bacteria engineered to produce liquid fuel can eat carbon dioxide and hydrogen from solar-powered water-splitting!

    Download Episode (11.2 MB, 12.25 minutes)

    Show notes:
    Journal Paper

    Other interesting stories:
  • Some bugs need their vitamin-producing microbes, but kill them to harvest the vitamins
  • How specific gut microbes influence immune system (paper)
  • Bacteria used to produce various food ingredients
  • Bacteria could produce polyester beads that bind specific proteins (paper)
  • Rainforest bacteria could help plants grow better in poorer soil (paper)

  • Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

    Subscribe at iTunes, check out the show at Twitter, MicrobeWorld, or Facebook

    This show features music from Mevio's podsafe Music Alley.

    Monday, May 11, 2015

    BacterioFiles 214 - Cable-Chlorophyte Coop Conducts Current

    Cable bacteria
    Malkin and Meysman, 2015
    This episode: Cable bacteria and algae set up electric grid in sediments!

    Download Episode (6 MB, 6.5 minutes)

    Show notes:
    Journal Paper

    Other interesting stories:
  • Daily rhythms are important for gut microbes and their hosts
  • Wild yeasts are very diverse in the smells they produce (paper)
  • Gut microbiome may be involved in alcoholism (paper)
  • Tiny tiny viruses can have very big effect on ocean carbon
  • Mouse lupus correlates with certain gut bacteria

  • Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

    Subscribe at iTunes, check out the show at Twitter, MicrobeWorld, or Facebook

    This show features music from Mevio's podsafe Music Alley.

    Monday, February 9, 2015

    BacterioFiles 201 - Plastic-Producing Prokaryote Process

    PHB granules in cells
    This episode: Bacteria from wastewater treatment sludge can produce lots of biodegradable plastic!

    Download Episode (7.1 MB, 7.75 minutes)

    Show notes:
    Journal Paper

    Other interesting stories:
  • Soil bacterium spores could treat tumors when injected
  • In mice, antibiotics early in life disrupt metabolism
  • Figuring out what our microbiome does in the body after we die (paper)
  • Microbes affect geological formations in caves
  • Insect gut microbes may be good source of new antibiotics

  • Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

    Subscribe at iTunes, check out the show at Twitter, MicrobeWorld, or Facebook

    This show features music from Mevio's podsafe Music Alley.

    Monday, February 2, 2015

    Monday, July 28, 2014