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In my understanding bacteria is a simple thing to grow as it requires: a Nutrition concentration at the right Temperature with the right Gaseous concentration at the right pH with additional Ions and salt suspended in water.

So one can have a vat with some disturbing/mixing mechanism and just have your bacteria grow in a specially formulated growth medium. This is simpler than managing something like algae that requires sunlight to photosynthesize.

Bacteria can duplicate at a rate as fast as every 10 minutes at a exponential rate this can generate a lot of biomass.

Bacteria has a cell wall consisting of a sugar protein called Peptidoglycan and coupled with the small volumes of bio-materials and gas volumes that bacteriums develop could potentially be sufficient to sustain a human as far as I understand it.

Now my question is: Is it possible to sustain a human as they exist today by growing bacteria in a vat, draining the growth medium, "sterilizing" the bacteria by sonic pressure or something like microwaving the contents of the vat, then eating/drinking the goop/sludge that is left which should exist of biomass that is human digestible.

I know that there are algae "pills" made from compressed algae that allows a human to generate ATP without the consumption of carbohydrates, so I'm trying to figure out if the same is possible with bacteria biomass.

Apologies if there are any problems with my post, first post. Didn't have enough rep to post in the meta sandbox.

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    $\begingroup$ Why do you need such a high-tech solution to kill the bacteria? Boiling the soup will do just fine. Pasteurization works too. And growing bacteria (or, for that matter, yeasts) on an industrial scale is not at all simple. If it was simple we would have done it already on a large scale. We have begun growing genetically modified strains of Saccharomyces to make bioethanol from agricultural and silvicultural waste. $\endgroup$ – AlexP Sep 7 at 12:06
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    $\begingroup$ You still need to farm something to feed the bacteria, or use a photosynthetic bacteria, in which case it already exists. Spirulina is a single celled blue green algae farmed for food. $\endgroup$ – John Sep 7 at 13:46
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    $\begingroup$ Those algae pills are full of carbohydrates, There is no healthy way for humans to generate atp without carbohydrates. $\endgroup$ – John Sep 7 at 14:11
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This is simpler than managing something like algae that requires sunlight to photosynthesize.

Bacteria can duplicate at a rate as fast as every 10 minutes at a exponential rate this can generate a lot of biomass.

There Ain't No Such Thing As A Free Lunch, even if you make it with a load of bacteria. The nice thing about photosynthetic algae is that the feedstock you use to grow them with is basically air, water with a sprinkling of nutrients, and then some light (sunlight or grow lamps, according to availability and convenience).

Conversely, non-photosynthetic organisms (such as the yeasts L.Dutch mentioned) require generous amounts of food to get them going. Renan's beer requires a decent amount of barley to be saccharified to provide the sugars the yeast needs to eat in order to replicate and provide useful metabolic byproducts. To get that feedstock, you need to grow crops, and you need additional energy and infrastructure to turn those crops into stuff that your microorganisms like eating. And, y'know, you could just grow human food on the barley farms instead, and cut out the middlemanorganism.

So what you really need is not just a bacterium that produces food gloop (by being edible and nutritious by itself, or by synthesising an excess of things good for people) but a feedstock for it that does not require a farm to grow it. I have no idea what you'd use for that. With sufficient effort and handwaving, maybe you could make something that eats crude oil and secretes food, but that sounds like a pretty serious bioengineering challenge.

I know that there are algae "pills" made from compressed algae... I'm trying to figure out if the same is possible with bacteria biomass.

You are presumably referring to spirulina. Despite photosynthetic bacteria being commonly referred to as "blue-green algae", "algae" is now generally used to mean only eukaryotic photosynthesisers and cyanobacteria are definitely not eukaryotes. Thus, spirulina already fulfills your requirement. Probably not a good idea to use it as your only source of protein unless you've found a way to ensure that the end products is definitely free of all of the toxins that various cyanobacteria species produce which can cause serious long term health effects. I believe (though I'm definitely not certain) that this is the only example of a purely bacterial-derived foodstuff in existence (as opposed to bacterially modified foodstuffs, which are very common).

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What you propose here has already been proposed with a slightly different micro organism: not bacteria, but yeasts.

Just to cite an example, in Asimov's work The caves of steel mankind, having abandoned the surface of the planet Earth to live in enormous underground cities, relies on cultures of yeasts to obtain nutrition.

Some integration of nutrients is probably necessary, together with some manipulation to make the whole thing mole palatable to humans (a squishy goo is hardly comparable to steak with potatoes or a vegetarian curry when it come to watering one's mouth), but in principle it is possible.

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    $\begingroup$ Beer is made with yeasts too. It's liquid bread and most people (me not included) find it palatable, with many being addicted to it. $\endgroup$ – Renan Sep 7 at 10:23
  • $\begingroup$ The millennial project proposed doing the same thing with blue green algae. en.wikipedia.org/wiki/The_Millennial_Project $\endgroup$ – John Sep 7 at 13:48
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    $\begingroup$ A very cool recent real-world example would be Perfect Day. It's a biotech food company that is currently developing ice cream (and eventually other foods: cheese, milk, etc.) where yeast produce the casein and whey that traditionally would come from cow's milk. Upsides include being vegan (no animals involved, just yeast fungi), lactose free (so more people can enjoy full-flavor ice cream), and less carbon footprint (cow-fart methane is replaced by yeast-farts which can be collected right off the growth vat). $\endgroup$ – LetEpsilonBeLessThanZero Sep 8 at 0:06
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Using bacteria could extend the range of carbon fixing organisms that make our food.

1: We want carboyhydrate to eat. Green plants and algae fix CO2 into carbohydrate using the energy of the sun. But they are not the only photosynthesizers: purple sulfur bacteria also fix CO2 into carbohydrate using the energy of the sun. There are yet other bacteria who fix CO2 into carbohydrate using other energy sources as well, like methane or hydrogen. It might be more efficient in some circumstances to use your energy to produce energetic chemicals for these bacteria (1 step), rather than use your energy to produce light which green things can use for energy (2 steps).

  1. We need amino acids to eat. Lots of things (e.g. plants, yeast) can synthesize amino acids if provided organic nitrogen - fertilizer. Only a few microbes can start with N2 and fix it into organic nitrogen.

One of these is the green algae Nostoc.

https://dgrin.com/discussion/259217/the-blob-nostoc-commune

nostoc

It caught my eye because I have been reading Charles Fort, and growths of nostoc are invoked to explain "star jelly" or unexplained blobs of goo that seem to have fallen from the sky. Star jelly is photosynthetic and nutritious - it is also called "fat choy" and is dried and eaten. I propose for your fiction that your people maintain tanks of sweet gooey star jelly.

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I think a bacterial stew would be deficient in protein because, as you described, bacteria are chemical factories encased in an edible bag, and are not meaty. They contain amino acids but may not contain all the essential amino acids we need in our diet.

I imagine you could work around this, though. If your bacteria weren’t simple single celled organisms but were instead multicellular like paramecium that formed, in effect, a complete protein for us. Or your larder also contained a bacteria bioengineered to produce a complete set of amino acids for our diet the same way some bacteria produce antibiotics or toxins, then that fluid could be harvested and used a broth for your stew.

I think the primary challenge would be constraining other organisms from spawning in your bacterial mediums. You would be growing them on such a scale that small scale contamination by other organisms could result in large crop failures — toxic or noxious byproducts generated by free-rider organisms that snuck into the mix.

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    $\begingroup$ EDL - we do not require long proteins. We only require amino acids, the building blocks of protein. Once we eat them, we can make our proteins out of those. healthline.com/nutrition/essential-amino-acids $\endgroup$ – Willk Sep 7 at 21:31
  • $\begingroup$ @Willk, thanks for the correction. $\endgroup$ – EDL Sep 8 at 1:41
  • $\begingroup$ Bacteria, almost invariable, contain every amino acid. In fact, almost every organisms contains every amino acid; the problem comes from long, repetitive molecules used to form structure in, e.g., plants resulting in a highly biased composition of amino acids provided. Bacteria do not have these molecules and so a bacterial stew would probably provide essential amino acids at a reasonable level. A lack of essential fatty acids, and other micronutrients, on the other hand might be a problem; I don't know. $\endgroup$ – Jack Aidley Sep 9 at 12:19

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