Alex Loy Profile picture
Aug 31, 2020 25 tweets 23 min read
Hey geomicrobiology and microbiome tweeps!

Do you know that the sulfosugar #sulfoquinovose (SQ) is a ubiquitous microbial nutrient in the environment and in a vegetarian diet?


Here comes some SQ propaganda…a thread

#sulfurcycle #carboncycle #H2S #microbiome #diet Image
First, for #sulfoquinovose newbies, I very much recommend the wonderful review by Ethan Goddard-Borger @ethangbaus & Spencer Williams @sjwill99

Sulfoquinovose in the biosphere: occurrence, metabolism and functions…
#sulfoquinovose is a sulfonated glucose and most often found as polar head group of sulfoquinovosyl diacylglycerol (SQDG), a ubiquitous sulfolipid in the photosynthetic membranes of all green land plants, algae, dinoflagellates, and cyanobacteria Image
SQDG is one of the most abundant organic sulfur compounds in the biosphere (production rate of 100,000,000,000 tons per year!) and can represent up to a third of the total lipids in leafy green vegetables #spinach #lettuce #greenonion Image
SQDG #sulfoquinovose are abundant sources of carbon and sulfur in the global nutrient cycles and substrates for the gut microbiota of animals/humans that like their greens

Think of popeye's diet #spinach 🥬as the ultimate #sulfoquinovose boost for your gut microbiota 😉 Image
So how is all the #sulfoquinovose in the environment and our guts degraded?

Thanks to the work of team @DSchleheck

Three bacterial pathways for #sulfoquinovose degradation (sulfoglycolytic pathways) are currently known Image
1. pathway: E.coli and some other Enterobacteriaceae have the sulfo-EMP (Embden-Meyerhof-Parnas) pathway for #sulfoquinovose breakdown and growth

Note that the sulfo-EMP pathway is an additional, analogous pathway to the classical EMP pathway…
2. pathway: Pseudomonas putida and some other Proteobacteria have the sulfo-ED pathway for #sulfoquinovose breakdown and growth…
3. pathway: The newly discovered SFT pathway is present in some aerobic and anaerobic Firmicutes and named after its characteristic sulfofructose transaldolase (SFT)…
All three #sulfoquinovose pathways encode a #sulfoquinovosidase (an alpha-glucosidase in the glycoside hydrolase family 31 - GH31) that cleaves SQ from SQ-glycosides such as SQDG… Image
Aerobic and anaerobic glycolytic #sulfoquinovose (C6) degradation produces a classical C3-compound for growth – either pyruvate or dihydroxyacetone phosphate (DHAP) – and a C3-sulfonate that is excreted – either sulfolactate or dihydroxypropanesulfonate (DHPS) Image
The #sulfoquinovose degradation products #sulfolactate and #DHPS can be utilized by other microorganisms as carbon and/or sulfur sources and energy sources via intracellular production of #sulfite (S oxidation state +4) = electron donor or acceptor…
Sulfonates #DHPS are nutrients and energy sources for sulfur oxidizers in the pelagic ocean

Check out work by the teams of Mary Ann Moran & @BryndanDurham for more info!…… Image
Green-diet-derived #sulfoquinovose is an exclusive growth substrate and thus a potential prebiotic of some abundant bacterial commensals in the human gut

Yet, complete degradation of SQ by cross-feeding of #DHPS produces #H2S

Our new preprint…
Eubacterium rectale and Bilophila wadsworthia cooperatively catabolize #sulfoquinovose to acetate and #H2S as main products in human fecal microcosms and in co-culture

Interspecies transfer of #DHPS links a green diet with #H2S production in the gut

#spinach #Popeye Image
Eubacterium rectale ferments #sulfoquinovose to DHPS via the SFT pathway

which is exclusive to E. rectale and few other intestinal Firmicutes species such as Feacalibacterium prausnitzii Image
Across the fecal metatranscriptomes of many individuals
#sulfoquinovose degradation was expressed prevalently and abundantly (top 33% of all microbial pathways) Image
and mostly by Eubacterium rectale and Feacalibacterium prausnitzii Image
Bilophila utilizes #DHPS as electron acceptor via a new oxygen-sensitive glycyl-radical enzyme that releases sulfite from DHPS for anaerobic respiration to #H2S via the DsrABC pathway

The DHPS sulfite-lyase cleaves #DHPS into hydroxyacetone and #sulfite… Image
In parallel, the DHPS sulfite-lyase was also discovered by the team of Yan Zhang, with additional biochemical and structural data

Excitingly, they also describe a DHPS-dehydratase in bacteria that ferment DHPS without #H2S production…
In Bilophila and other bacteria, the DHPS sulfite-lyase is paralogous to isethionate sulfite-lyase, a key enzyme in anaerobic taurine degradation that was also discovered by the teams of @DSchleheck…
and Yan Zhang… Image
#metatranscriptome analysis of DsrABC-sulfite reduction and DHPS/isethionate sulfite-lyase activities suggested Bilophila and other Desulfovibrionaceae use mostly #taurine but also #DHPS for #H2S production in the human gut Image
Thanks for reading!

Keep in mind that #sulfoquinovose metabolism is a core physiological attribute of the human gut that is likely modifiable by diet - think of #Popeye #spinach 😉- and contributes to host health…

#H2S #acetate #microbiome #prebiotic Image

#H2S is a Janus-faced molecule

with detrimental



and beneficial effects…

on the intestinal environment Image
The complex host-endogenous…

and microbial processes…

that regulate intestinal #H2S homeostasis and how they are influenced by #diet or health state are yet insufficiently defined

• • •

Missing some Tweet in this thread? You can try to force a refresh

Keep Current with Alex Loy

Alex Loy Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!


Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!


0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy


3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us on Twitter!