Talk:Yeast

Yeast doesn't grow as a strict anaerobe.

Though yeast doesn't require oxygen as a terminal electron acceptor, it is required as a growth cofactor/nutrient for the production of sterols and unsaturated fatty acids (see PMID: 13192151 and PMID: 13034889). Thus, yeast will not grow in strictly anaerobic (no oxygen) conditions without supplementation of these compounds. So, I think the following is wrong: "Yeast species either require oxygen for aerobic cellular respiration (obligate aerobes) or are anaerobic, but also have aerobic methods of energy production (facultative anaerobes)" — Preceding unsigned comment added by 209.124.189.39 (talk) 22:53, 12 February 2013 (UTC)

Note from same user - the above is true for laboratory strains of Saccharomyces cerevisiae. I don't know about other yeasts. — Preceding unsigned comment added by 209.124.189.39 (talk) 17:45, 15 February 2013 (UTC)

What is Yeast Respiration?

What is Yeast Respiration? — Preceding unsigned comment added by 74.78.16.137 (talk) 22:48, 11 March 2013 (UTC)

Semi-protection

This article has been semi-protected. Semi-protection prevents edits from unregistered users (IP addresses), as well as edits from any account that is not autoconfirmed (is at least four days old and has at least ten edits to Wikipedia) or confirmed. Such users can request edits to this article by proposing them on this talk page, using the {{Edit semi-protected}} template if necessary to gain attention. New users may also request the confirmed user right by visiting Requests for permissions. SilkTork ^{✔Tea time} 21:30, 8 April 2013 (UTC)

GA Reassessment

This discussion is transcluded from Talk:Yeast/GA2. The edit link for this section can be used to add comments to the reassessment.

Landed on this page as a redirect from brewing yeast, and thought the information was unclear, and in some places insecure. I noted the section on Yeast extract is unsourced. I then noted other areas in the article are unsourced. This was made a Good Article in 2007, and the last assessment was in Feb 2010, over three years ago. I think it's worth another assessment. SilkTork ^{✔Tea time} 21:23, 8 April 2013 (UTC)

GA review – see WP:WIAGA for criteria

1. Is it reasonably well written?

   A. Prose quality:

   B. MoS compliance for lead, layout, words to watch, fiction, and lists:

2. Is it factually accurate and verifiable?

   A. Has an appropriate reference section:

   B. Citation to reliable sources where necessary:

   C. No original research:

3. Is it broad in its coverage?

   A. Major aspects:

   B. Focused:

4. Is it neutral?

   Fair representation without bias:

5. Is it stable?

   No edit wars, etc:

6. Does it contain images to illustrate the topic?

   A. Images are tagged with their copyright status, and valid fair use rationales are provided for non-free content:

   B. Images are provided if possible and are relevant to the topic, and have suitable captions:

7. Overall:

   Pass or Fail:

• The article is stable, but on looking through the article history I noticed a high level of IP and new account vandalism without any balancing positive IP edits, so I will semi-protect the article. SilkTork ^{✔Tea time} 21:27, 8 April 2013 (UTC)

• Prose is not clear and easy to follow for the general reader. There is too much unexplained WP:JARGON. SilkTork ^{✔Tea time} 21:37, 8 April 2013 (UTC)

• Lead. To meet GA criteria 1(b), which relates to specific manual of style guidelines, the article needs to comply with the advice in WP:LEAD. That is, in addition to being an introduction, the lead needs to be an adequate overview of the whole of the article. As a rough guide, each major section in the article should be represented with an appropriate summary in the lead. Also, the article should provide further details on all the things mentioned in the lead. And, the first few sentences should mention the most notable features of the article's subject - the essential facts that every reader should know. I note there are statements in the lead that are not in the main body - such as "Yeasts have recently been used to generate electricity in microbial fuel cells,[7] and produce ethanol for the biofuel industry", and there is information in the main body which is not summarised in the lead, such as the sections on beer and wine and yeast extract. SilkTork ^{✔Tea time} 21:47, 8 April 2013 (UTC)

• I haven't researched the subject to know if the coverage is broad enough. I don't think on the whole that any aspect gets undue attention, though some trimming on the beer and the baking might be helpful, as there are Wikipedia articles readers can go to if they wish for more detailed information. SilkTork ^{✔Tea time} 21:54, 8 April 2013 (UTC)

On hold

There is useful information in this article, and it would be good to tidy it up. The main area needing attention is the clarity of meaning. The language is more suited to a specialist publication. Wikipedia is a general encyclopedia with the aim of providing a summary of topics for the general reader. If readers cannot understand the article, then it is not helping them understand the topic. The next area is sourcing. Without appropriate sourcing a reader cannot trust the information in the article. The next area to pay attention to is the lead. The lead is not just an introduction, it is a standalone mini article which summarises the main points of the body. Many (most?) readers only read the lead.

I'll notify main contributors and put on hold for an initial seven days. SilkTork ^{✔Tea time} 22:00, 8 April 2013 (UTC)

• I think the article also falls short on criteria 3a (major aspects) and 3b (focused). There should be separate sections on classification/nomenclature, cell biology, genetics, and perhaps chemotaxonomy. The beer/wine/baking sections should probably be pared down and moved to baker's yeast and other appropriate daughter articles. I intend to work on this article, but for logistical reasons would be happier to have the article demoted from GA in the interim (and will need a while to bring it back up to standard). Of course, anyone else is free to help :) Sasata (talk) 22:56, 8 April 2013 (UTC)

I understand the reasoning behind having the article delisted. It can be more motivating to work to bring an article to an audited condition, than to try to salvage one. In the first you are working for a positive result, in the second you are working to prevent a negative result. I also think there is a lot of work for a GAR, so a period of work done without a time limit and a reviewer looking over people's shoulder can be helpful. I will wait for the seven days though, and listen to what others have to say - unless we get a quick consensus to delist. SilkTork ^{✔Tea time} 23:03, 8 April 2013 (UTC)

• Thanks for the notification, SilkTork, though I'm actually not a major contributor to this article. I'm flat-out at work right now but I'll try to take a look over the weekend. Adrian J. Hunter^{(talk•contribs)} 23:23, 8 April 2013 (UTC)

(I'll only have time for small changes, so no objection to delisting if that's what others want. Adrian J. Hunter^{(talk•contribs)} 10:36, 9 April 2013 (UTC))

If there's another support for delisting I will do it promptly rather than wait for the seven days. SilkTork ^{✔Tea time} 12:17, 9 April 2013 (UTC)

Delist

There's no activity, and three people agreeing to a delist with no objections, so I'll cut this short and delist. SilkTork ^{✔Tea time} 16:34, 12 April 2013 (UTC)

Fleischmann's Yeast

Does anyone have any citations/sources that support the claim that Fleischmann yeast raises twice as fast? None are given in the article and given the specific nature of the claim, it would seem there is high potential that it is in fact hyperbole and/or marketing.

I do not edit under an account and tend to refrain from editing outside of grammatical/mechanical errors, so could someone watching this article look in to the section I am referring to? 211.31.42.104 (talk) 16:10, 1 September 2013 (UTC)

Pasteur effect

In this article, the Pasteur effect is described as the increase in yeast cell growth but decrease in alcoholic fermentation as oxygen is bubbled through a yeast broth.

However, an article cited as Reference 11 (Phillips T. "Planets in a bottle: more about yeast". Science@NASA. Retrieved 15 January 2012.) in the previous sentence says:

"The great medical microbiologist, Louis Pasteur, played a central role in proving this conversion to ethanol required living organisms, rather than a chemical catalyst. Pasteur showed that by bubbling oxygen into the yeast broth, the cells could be made to stop growing, but ferment vigorously--an observation later called the Pasteur Effect. "

I think Phillips has it completely backwards and this conspicuous error now erodes any faith I might otherwise have had in the rest of the Phillips article. I suggest deleting it from the reference list altogether.

Shroomdocny130.102.158.18 (talk) 04:03, 30 October 2013 (UTC)

fermentation preferred130.102.158.21 (talk) 01:21, 20 January 2014 (UTC)

"In breadmaking, the yeast initially respires aerobically, producing carbon dioxide and water. When the oxygen is depleted, fermentation begins"

My understanding is that this is incorrect as S. cerevisiae prefers to ferment and will switch to aerobic respiration of the fermentation products once the glucose becomes depleted. 130.102.158.21 (talk) 01:21, 20 January 2014 (UTC)

Sentence not too clear

In the section on pathogenic yeasts, the following is included:

"They are the species primarily responsible for cryptococcosis, a fungal disease that occurs in about one million HIV/AIDS patients, causing over 600,000 deaths annually."

The cited reference makes it clear that the deaths are among those with HIV infections, but the sentence does not. From initial reading, I was unsure whether the 600,000 were only the HIV patients or were total in society. After all, it does not state that the condition is exclusive to HIV patients. A simple modification to clarify might be good (I can't edit). Perhaps:

"They are the species primarily responsible for cryptococcosis. This fungal disease occurs in about one million HIV/AIDS patients and is fatal in over 600,000 cases annually."

Perhaps someone can suggest something better. 99.245.230.104 (talk) 20:26, 27 March 2014 (UTC)

a chapter could be added on the use of yeast in the production of fermented milk products

Could a knowledgeable contributor please add a section on the use of yeast in the production of fermented milk products? NikosZ (talk) 10:11, 10 November 2014 (UTC)

Numbers don't add up

"... with 1,500 species currently described (estimated to be 1% of all fungal species)"

This seems to imply that there are 150,000 species of fungi in total, whereas the Fungus article says estimated 1.5 million to 5 million species. It may be that the total number of yeast species greatly exceeds the number of described ones, and that the 1% figure is supposed to be applied to the former, but this is not made clear. 81.157.10.242 (talk) 14:50, 18 November 2014 (UTC)

Fixed, thanks for the note. Sasata (talk) 15:34, 18 November 2014 (UTC)

Removal of biosynthesis?

Hi User:Sasata, why are you so keen on removing the bit about biosynthesis? This is just one example, you can add many more if you want. I don't think it's right to not mention at least once that yeast are used to produce quite a few things aside. Sakimonk ^talk 22:13, 16 August 2015 (UTC)

Much of what was already discussed on the morphine talk page applies here. If you could provide examples of well-established uses of yeast being used as biosynthetic factories, that would be much better than an example that has only been performed in a single research lab. Sasata (talk) 22:40, 16 August 2015 (UTC)

You moved insulin production down under "scientific reseach". That is just completely wrong - biosynthesis is a real industrial production tool, not "research". Thue (talk) 16:48, 20 August 2015 (UTC)

There's a good source here e.g.: "20% [of biopharmaceuticals] are being produced by S. cerevisiae". To be fair though, the opiate information is probably not worthy of inclusion in this article at the moment. SmartSE (talk) 17:32, 20 August 2015 (UTC)

Added, thanks Smartse. Sasata (talk) 17:43, 20 August 2015 (UTC)

External links modified

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Ale vs Lager

The section on beer yeasts seems confused. Paragraph 1 differentiates S. cerevisiae from S. pastorianus (formerly known as S. carlsbergensis). The second paragraph reverses this: "Decades ago, taxonomists reclassified S. carlsbergensis (uvarum) as a member of S. cerevisiae, noting that the only distinct difference between the two is metabolic". The pages Saccharomyces pastorianus and Saccharomyces cerevisiae appear to treat them as different species. Martin of Sheffield (talk) 16:28, 27 April 2016 (UTC)

Reference Formatting

Hello! There have been some recent changes to the references that I must say I don't understand. I came to this article yesterday due to its inclusion in CS1 maint: Multiple names in authors list. The purpose of the category is to flag articles which have citations with parameter |author= followed by multiple author names. This interferes with collection of COinS metadata on the article (which allows the references section to be easily understood by other programs). To remedy this, I changed all instances of |author=xxx,xxx,xx.... to |author1=xxx |author2=xxx... This was reverted by User:Sasata and changed to |authors=xxx, xxx, xxx... This version also doesn't allow for metadata collection. I assumed (based on other discussions on User:Sasata's talk page) that their problem was with inconsistent reference formatting (which I had introduced). So I changed the references to a consistent style which would also allow for metadata collection. That way everyone is a winner. Apparently, I assumed incorrectly (that's what happens when you assume of course) because User:Sasata again reverted my changes to return to format |authors=xx,xxx,xx... So, my point: the benefit of |author1=xxx |author2=xxx... is that we can collect metadata and the references section can be easily understood by other programs. Is there any benefit to |authors=xxx,xxx,xxx...? If there is, please communicate clearly what that is. Currently, I don't understand the insistence on the old way. Also, I'd welcome other opinions on why some ways would be better than others. Thanks! Ajpolino (talk) 01:43, 30 May 2016 (UTC)

A second question: a recent edit removed several accessdates from sources. Is there a reasoning behind this? My understanding was that the accessdate was useful to have in case the URL goes dead. Then we know what archive date we should look for. Is there a reason for the accessdates to be removed? Thanks for the help! Ajpolino (talk) 01:45, 30 May 2016 (UTC)

Grammatical error in lead

The lead currently says

The yeast lineage originated hundreds of million years ago. The correct phrase is:

The yeast lineage originated hundreds of millions of years ago.

Could an editor please fix this? 86.154.102.132 (talk) 08:12, 1 September 2016 (UTC)

Semi-protected edit request on 13 October 2016

please enter after the paragraph

96.248.74.216 (talk) 00:09, 13 October 2016 (UTC)

Enter what, exactly? Stickee (talk) 01:20, 13 October 2016 (UTC)

Speculation vs fact

Can we please separate out the evolutionary speculation from the scientific facts? Thanks 144.121.22.134 (talk) 19:58, 14 November 2017 (UTC)

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Sensible properties?

physical, chemical, and sensible properties of a food

Perhaps use more common English. Jidanni (talk) 13:02, 4 November 2018 (UTC)

Redundant phrasing

The phrasing of "as pseudohyphae or false hyphae" is redundant. Geezus42 (talk) 13:15, 12 March 2019 (UTC)

Attribution

Text and references copied from Yeast to Candida blankii. See former article's history for a list of contributors. 7&6=thirteen (☎) 11:44, 25 March 2019 (UTC)

Text and references copied from Candida blankii to Yeast. See former article's history for a list of contributors. 7&6=thirteen (☎) 15:55, 27 March 2019 (UTC)

Semi-protected edit request on 15 June 2019

In the first paragraph about yeast as a nutritional supplement it says.

"... (contrary to some claims, it contains little or no vitamin B12[60] )"

Citation 60 does not work, therefore it should be removed. LLifeform (talk) 00:40, 15 June 2019 (UTC)

I replaced the link with an archived version. Saucy^{[talk – contribs]} 04:26, 15 June 2019 (UTC)

Semi-protected edit request on 9 October 2019

Add to last section entitled "symbiosis": The scarabeid beetle associated yeast,Spathaspora passalidarum represents another example of symbiosis. This is one of the few species of yeast that is able to efficiently ferment xylose, aiding in the digestion of plant cells walls in the beetle's digestive tract. Dzmokry (talk) 16:36, 9 October 2019 (UTC)

 Not done: please provide reliable sources that support the change you want to be made. —KuyaBriBri^Talk 18:28, 9 October 2019 (UTC)

This source added by Dzmokry in the wrong place. Moved here by Martin of Sheffield (talk) 07:48, 15 October 2019 (UTC)

References

 Done comrade waddie96 ★ (talk) 17:57, 28 October 2019 (UTC)

Sentence structure issue.

In the initial discussion of "kahm yeast" there is need for the word "is" before "usually". Just temporarily lop out the material between the 1st & 3rd commas of the sentence and what I mean should quickly be very clear.

Sorry. Unable to make this tiny tweak myself because of semi-protection.

Also, I've already learned a bunch about yeast. Thanks folks. — Preceding unsigned comment added by 71.193.160.62 (talk) 05:29, 8 June 2020 (UTC)

 Done – I've broken the sentence since it already had both parentheses and parenthetical commas. Martin of Sheffield (talk) 13:13, 8 June 2020 (UTC)

S. carlsbergensis

• "Decades ago,[vague] taxonomists reclassified S. carlsbergensis (uvarum) as a member of S. cerevisiae,..."*. Really? Saccharomyces pastorianus says *"This situation was rectified using DNA-DNA reallocation techniques in 1985 when Vaughan-Martini and Kurtzman returned the species name to S. pastorianus under the type strain CBS 1538 and relegated the two former species assigned by Hansen in 1908, S. carlsbergensis CBS 1513 and S. monacensis CBS 1503,[16] to the status of synonyms."* 2A00:23C7:7B18:9600:FD73:17C:3DBC:35EE (talk) 10:42, 14 June 2021 (UTC)

Semi-protected edit request on 2 January 2022

Second sentence in the lede: "Yeast evolved from multicellular ancestors" - Reference 5 given (Yong E - 16 January 2012) is a long article about selecting yeast lines whose cells stick together after division. Beside that faultive separation after division is still a long way from multicellularity, the statement "Yeast evolved from multicellular ancestors" is mentioned in passing as a fact without references or justification. I could find a few places giving this claim as a vague hypotese of a minority but I could not find any funded reference explaining how yeast could evolve from which multicellular organisms, so this claim is higly disputable and I would take it off until some more solid reference is presented.
I suggest to change the whole sentence from "Yeasts are unicellular organisms that evolved from multicellular ancestors,[5] with some species having the ability to ... "
to "Some species have the ability to ... "
Greetings 2003:F5:6F02:7E00:C161:70BC:9A0B:D7E0 (talk) 19:09, 2 January 2022 (UTC) Marco PB 2003:F5:6F02:7E00:C161:70BC:9A0B:D7E0 (talk) 19:09, 2 January 2022 (UTC)

It's an article by Ed Yong and the quote is from the author of the paper, so I'd be careful questioning it. There's also

• budding and fission yeasts, as members of distinct monophyletic clades, are likely to be independently derived from a multicellular ancestor from this paper

• This has a specific quote S. cerevisiae and S. pombe underwent independent evolutionary transitions to unicellularity from a multicellular common ancestor.

• Yeast evolution likely accompanied genome reduction in a much more complex multicellular ancestor from this paper.

I'm closing this as  Not done: but since I'm not particularly qualified in this field, feel free to reopen if you have concerns. --Hemantha (talk) 08:35, 3 January 2022 (UTC)

Science

Yeast with two features 103.148.23.227 (talk) 01:51, 7 July 2022 (UTC)

Error in YEAST article

The sentence citing source (5)("Yeasts are unicellular organisms that evolved from multicellular ancestors"), has incorrectly stated the premise of the article which stated the exact opposite, that single cell yeast can turn into multiple cell organisms, NOT the other way around as the sentence in the article states. The movement is from single cell to multiple cell, not visa versa. GenoGoodBoy (talk) 13:19, 3 September 2022 (UTC)

Semi-protected edit request on 7 March 2023

yeast is in bread. 103.176.216.15 (talk) 04:02, 7 March 2023 (UTC)

 Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. -Lemonaka‎ 13:37, 8 March 2023 (UTC)

Kahm Yeast - suggest removal of reference, or at least clarification of it.

Kahm yeast is a commonly used term in food fermentation groups, so outright removal may not be warranted, however what is commonly referred to as "kahm yeast", the weird thready, wavy, alien looking covering on the surface of a fermentation, is actually a pellicle (something sadly Wikipedia doesn't have a page for specifically, instead referring to a SCOBY which is again entirely different). A pellicle is a type of biofilm created by both yeast and bacteria, possibly both at the same time, and can include the microbes themselves, but the bulk of the matter is not made of microbes directly. It would be good to help clear up the confusion on this page. Gremlyn1 (talk) 19:07, 29 March 2023 (UTC)

Multicellular origin of yeast

"Yeasts are unicellular organisms that evolved from multicellular ancestors,[5]" The claim that single celled yeast evolved from multicellular ancestors is based on a misunderstanding of the source. The article shows single celled yeast can evolve into a simple multicellular form. It says nothing about the evolutionary history of yeast. James xx45933 (talk) 14:17, 20 July 2023 (UTC)