Скачать или смотреть TFA Presents: The New Taxonomy of Lactobacillus (Michael Gänzle, PhD & Ben Wolfe, PhD)

Companion presentation: http://bit.ly/34mPNpK. For Ben Wolfe's highly informative chat sidebar, click "Show More" below.
Hear from Michael Gänzle, PhD, one of the authors of the new Lactobacillus taxonomy, in conversation with Ben Wolfe, PhD, Associate Professor at Tufts University discuss how and why the genus was split into functionally relevant groups that share physiological traits, metabolic properties, and lifestyles— all of which may facilitate our understanding of common mechanisms that explain their relevance in food fermentations and the health benefits of lactobacilli for humans.

00:22:52 Ben Wolfe: I will present some background info in the chat on terms Michael uses in case you are not familiar with them
00:23:10 Sarah Adams: That would be great, thank you!
00:23:14 Ben Wolfe: 16S is a genetic region of bacterial DNA that scientists sequence to identify them at the species level.
00:25:30 Ben Wolfe: AAI (pairwise amino acid identity) is a metric scientists use to compare how similar sequences are between different types of bacteria. A high (90-100) AAI means that sequences are very similar.
00:26:27 Ishita Bhatia: Tuning in from India! And thank you, Ben :)
00:26:53 Alex Lewin: I have a question: There is an idea in the fermentation community that colonies of microbes "evolve" in meaningfully short timeframes, whether it's due to selective pressures or due to assimilation of exogenous genetic material. I'd like to hear Ben and Michael's thoughts about that.
00:27:16 Ben Wolfe: A ‘core genome’ refers to the set of genes that can be found in all species in a group of bacterial species. Accessory genes would be those genes that are only found in some species. All cars have engines to make them drive (core). Not all cars have a sunroof (accessory).
00:28:47 Amelia Nielson-Stowell: This is helpful Ben, thanks.
00:30:25 Ben Wolfe: A phylogeny (or phylogenetic tree) is a visual representation of how organisms are related to each other. The phylogenetic trees that Michael is discussing are based on DNA sequences. https://en.wikipedia.org/wiki/Phyloge...
00:33:29 Ben Wolfe: In the tree Michael is currently showing, there are branches just like on an actual tree. The tips of the branches represent individual lactic acid bacteria species. The closer that the tips are to one another, the more closely related the bacteria are to one another.
00:33:43 Alex Lewin: So there are 4 genera (genuses)?
00:34:58 Ben Wolfe: Each color (on the branches) represents a genus (according to the newly proposed system).
00:35:18 Alex Lewin: Thanks Ben
00:36:19 Ben Wolfe: In case you need a refresher on homofermentative vs. heterofermenative: https://www.uoguelph.ca/foodscience/b...
00:40:03 Ben Wolfe: Here is the paper Michael is referring to (behind a paywall, but you can email Michael to request a PDF): https://www.microbiologyresearch.org/...
00:40:40 Ben Wolfe: Here is the tool to convert old names to new names: http://lactotax.embl.de/wuyts/lactotax/
00:52:24 Nicholas Zemp: General Lactobacillus question: Is there a key (that doesn't involve PCR/DNA analysis) to differentiate the different new taxa or genera?
00:52:26 Ben Wolfe: https://www.ualberta.ca/-/media/F0CE8...
00:52:49 Alex Lewin: I found the periodic table of fermented foods that Michael mentioned:
00:54:47 Alex Lewin: https://www.ualberta.ca/-/media/F0CE8...
01:05:04 Alex Lewin: Great--thank you Michael and Ben!
01:06:35 Ben Wolfe: Here is a link to the new phylogenetic tree of Lactobacillus from Michael’s website: https://drive.google.com/drive/folder...
01:07:20 Dahnby Jun: Thank you Ben! You’re right, it would make a great holiday gift for us fermentation nerds~