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Comment by stevenjgarner | Hacker News Reader

How is it "grossly incorrect"? Using both taxonomic and size classification, is it not accurate to refer to a blue-green alga as a "microbe" or "microorganism." [1]

A microbe (or microorganism) is generally defined as an organism that is microscopic—too small to be seen clearly by the naked eye. Blue-green algae fit this definition as they are single-celled or form microscopic colonies.

The scientific name for blue-green algae is cyanobacteria, which are technically a type of bacteria, universally classified as microbes. [2] They are prokaryotes (lacking a nucleus and other membrane-bound organelles), and the two prokaryotic domains of life (Bacteria and Archaea) are composed entirely of microbes.

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC9025173/

[2] https://doh.wa.gov/community-and-environment/contaminants/bl...

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It is grossly incorrect because it does not "produce oxygen from Martian soil".

This is extremely misleading, because on Mars Martian soil is abundant, while water is very scarce, so the title makes the reader believe that this cyanobacterium solves easily the production of oxygen.

It does not help at all for oxygen production. If you have water, then it is easy to produce hydrogen by electrolysis, using solar energy. Getting water on Mars is the hard problem.

There are chances that such cyanobacteria will be used on Mars, but for producing protein and other useful organic substances, with oxygen only as a byproduct.

However I believe that at least for the more distant future there is a better alternative to the use of cyanobacteria: the capture of solar energy by artificial means, coupled with the synthesis of some simple organic substance, e.g. glycerol or glycine, which can then be used to feed a culture of fungi located underground, which can then produce proteins and all the other complex substances needed for human food. There already are genetically modified fungi that can produce whey protein or chicken egg white protein suitable for human consumption.

This variant is better because photovoltaic cells have better efficiency for capturing solar energy and without environmental constraints, while genetically modified fungi can produce proteins of better quality than cyanobacteria and also any other complex organic substances that will be needed.

I think the problem with your post is that it started a list of "incorrect statements" with a statement that wasn't incorrect.

Maybe I have not been clear enough, but there was no list of incorrect statements, as I was criticizing only a title.

I did not say that was anything incorrect in calling a blue-green alga as "microbe". I have only mentioned what kind of "microbe" they had in mind in order to explain why the title is incorrect in claiming that the "microbe" makes oxygen from Martian soil, because blue-green algae, like plants and like any other living beings from Earth that can produce oxygen, produce the oxygen by splitting it from water and by using energy captured from solar light.

There are no known living beings that can produce oxygen from anything else than water, so if such a "microbe" had been discovered, that would have been a much more important discovery than the possible use of cyanobacteria on Mars.

Unlike the capabilities of catalyzing other chemical reactions, which frequently have appeared multiple times in the history of life, the ability to produce free oxygen has appeared only once and then it has been inherited from that source by all living beings that can do this, even if this heritage has been often transferred between very unrelated living beings. Therefore there exists a unique mechanism for this reaction, based on the oxidation of manganese with the help of solar light, which then oxidizes the oxygen from water into free dioxygen.

The Martian soil is full of oxygen, but most of that oxygen is tightly bound on metallic cations, so it would require a very high amount of energy to be dissociated from them.

Nevertheless, it should be possible to develop an electrolytic process for producing oxygen from the perchlorates that are abundant in Martian soil, saving the precious water for other purposes, i.e. for those that need the hydrogen from water, e.g. for making fuel and food.

> How is it "grossly incorrect"?

Perhaps it's not glossly incorrect, but I classyfy it as "super ultra mega misleading".

I'd like a title like "*Cyanobacteria survives in water contamined with martian soil"

HN title at the moment is: Researchers Find Microbe Capable of Producing Oxygen from Martian Soil

Article title at the moment is: Microbe That Could Turn Martian Dust into Oxygen

Neither of those are particularly misleading, but requires you to read it carefully I suppose, otherwise it can misleading I suppose. I guess "Martian Dust" is the most misleading part of the quote, as the soil isn't actually Martian of origin, but actually "materials that are similar to Martian soil".

Both titles are very misleading, because neither "oxygen is produced from Martian soil" nor "Martian dust is turned into oxygen".

As I have said, the oxygen comes only from water, which is missing on Mars, unlike the abundant Martian soil or Martian dust.

So the "microbe" does not solve the problem of oxygen production, which is obtaining water. With water, making oxygen by electrolysis is trivial and a problem solved long ago.

The cyanobacterium can make various useful organic substances, like proteins and vitamins. The fact that it also makes some oxygen is a minor additional advantage.

Even if such cyanobacteria will be grown on Mars, most of the oxygen will be made by electrolysis anyway, because the efficiency from solar light to free oxygen is much better and the photovoltaic cells continue to function in a much wider range of temperatures.

> As I have said, the oxygen comes only from water, which is missing on Mars

The title nor the article itself doesn't claim otherwise, unless I'm missing something?

It's also not claiming that the microbe somehow solve the problem of obtaining water, or anything else.

The only thing they claim is that this specific microbe, under the right circumstances, can produce oxygen while it grows in Martian-like soil. That's what the article claims, and the titles.

You have reproduced yourself the 2 titles, which contain:

"Microbe Capable of Producing Oxygen from Martian Soil"

"Microbe That Could Turn Martian Dust into Oxygen"

The words "producing X from Y" and "turn Y into X" are extremely clear and they do not admit alternative interpretations. They both claim that X=oxygen comes from Y=soil|dust, contrary to what you say, that the titles do not contain such claims.

I normally avoid to follow the fashion of accusing posters of being AI bots, but such a failure of comprehension could be explained only for an AI bot, or perhaps for someone who understands very little English, but the latter explanation does not match the correct English of the message.

Perhaps you have used an English translation service that has confused you?

Nah. It doesn't look like a bot. Just someone that does not know about cyanobacteria. Relevant xkcd https://xkcd.com/1053/ https://xkcd.com/2501/

How cyanobacteria work is not intuitive, even how plant work is not intuitive https://en.wikipedia.org/wiki/Jan_Baptist_van_Helmont#Willow... Even after reading it, it is not intuitive.

You probably know that cyanobacteria produce most(?)[1] of the oxygen on Earth, moreover the plants (and algae) use a "trapped cyanobacteria" to produce the oxygen. So all the oxygen on Earth is produced by free or trapped cyanobacteria. Moreover, when cyanobacteria started to produce oxygen they killed most of the previous bacterias. So we agree it's not surprising that a cyanobacteria can produce oxygen.

You probably know that in photosynthesis the light is used to extract the oxygen from the water, but most people think the oxygen is extracted from the CO2. It super non intuitive. Well, after the oxygen is extracted, there is hydrogen as leftover (as NADH, not as H2). This is used after a few super weird steps to transform the CO2 into water and sugar.

The article does not discuss about the CO2. I guess it's a problem if the cyanobacteria has no CO2 to dump the hydrogen, but I'm not sure[2]. The press article links to another press article that links to a review in a journal that links to a few research articles by the same author. I only read up to the review, and they don't mention the CO2. Life is too shot to search and read all the research articles, so I'll never know. My guess is that they just tested this in Earth atmosphere, but Mars has also CO2 (not sure about the partial pressure), so I guess CO2 is not a problem. So CO2 is important and it's not mentioned anywhere.

More importantly is nitrogen in a useful form (not as N2). I guess Martian soil has no nitrates or ammonia to be absorbed by the cyanobacteria. According to Wikipedia only a few cyanobacteria can fixate nitrogen, and apparently not this cyanobacteria. So with only the nutrients from Martian soil the cyanobacteria will not be able to make proteins and die after a while. It's a very important fertilizer for farms. So biologically available nitrogen is important and it's not mentioned anywhere.

In conclusion, unless someone has a strong background in chemistry or biology or something, it's very difficult to see how misleading an inaccurate is the title in spite they are not a bot.

[1] IIRC "most", but I can't find a source now.

[2] Can plants grow in pure nitrogen+soil+water? It look´s like an experiment for Cody's Lab.

"Producing Oxygen from Martian Soil" to me implies that martian soil is the thing being turned into oxygen.

Agree with that interpretation. Perhaps "Microbe extracts oxygen from the water in Martian soils" would be short and intriguing enough to be correct and interesting enough to click on!

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