How do bacteria in sauerkraut stay alive?

  • Thread starter Zeynel
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In summary, the bacteria that ferment cabbage will barely feel the mechanical forces. What is more disruptive is the pH, but even so, bacteria are fairly hardy.
  • #1
Zeynel
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When I make sauerkraut after adding salt I pound the cabbage with a wooden mallet to release its juice. Then I press it hard into the jar. I was wondering how the lactobacillus that ferment the cabbage survive the pounding and pressing. Thanks.
 
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  • #2
Bacteria will barely 'feel' the mechanical forces- maybe a tickle :) What is more disruptive is the pH, but even so, bacteria are fairly hardy. Remember, all your gut bacteria had to first survive a trip through your pH 0 stomach and then time in your duodenum- an environment that completely destroys fats, proteins, and carbohydrates.
 
  • #3
Andy Resnick said:
Bacteria will barely 'feel' the mechanical forces- maybe a tickle :)
As a layman I wonder why. If I slam my fist down hard on a counter, the bacteria between my fist and the counter most likely is still there right? Why does it not get smashed? :)
 
  • #4
Greg Bernhardt said:
As a layman I wonder why. If I slam my fist down hard on a counter, the bacteria between my fist and the counter most likely is still there right? Why does it not get smashed? :)

Bacteria (and plant cells) have a rigid cell wall- granted, there are many different flavors of bacterial cell walls, but let's keep it simple for now. The bacterial cell wall can support a pressure difference of about 20 atm (http://www.textbookofbacteriology.net/structure_5.html), which translates to about 300 pounds /in^2. So, if you want to mechanically crush a bacterium, you will need to apply about 40 atm positive pressure (since the inside of the bacterium is osmotically pressurized with respect to the outside), or 600 lb/in^2: think John Goodman stomping down with stiletto heels... or maybe don't think about that :(

The cognitive dissonance here stems from the small size of bacteria- we aren't used to thinking in terms of the microscale.
 
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  • #5
Andy Resnick said:
Bacteria will barely 'feel' the mechanical forces- maybe a tickle :) What is more disruptive is the pH, but even so, bacteria are fairly hardy. Remember, all your gut bacteria had to first survive a trip through your pH 0 stomach and then time in your duodenum- an environment that completely destroys fats, proteins, and carbohydrates.

Ok, thanks. This answers my question.

Let me ask a different question:

Are these bacteria --lacto-bacillus species-- sensitive to light? Does it matter if I leave the jar out in the light or in the dark?
 
  • #6
Hmm. Light will not penetrate far into fermenting cabbage. Photoinhibition does occur in Lactobacillus spp. for some enzymatic processes. Answer: probably not very much. Use plastic or ceramic vessels if you are worried about it. You do not have to hide it away somewhere.

Example showing photoinhibition of the manganese catalase enzyme:
jxb.oxfordjournals.org/content/57/8/1809.full.pdf
 
  • #7
I have some 3 or 4 years old saurkraut in a gallon jar in the fridge. It has accumulated a lot of white stuff at the top and about 1/3 downwards. It still smells OK and I have heated and cooked it and it tastes good. Is the white just lots of the lactobacillus probably now dead.?? How long does it actually live? Its not mold. I like to experiment with fermented foods. If it smells OK, then its usually is. The nose seems to really analyze edibility very quickly. Tho certain things like limburger cheese are strange, my nose still said OK , you can eat it!
 

1. How do bacteria survive in sauerkraut?

The bacteria in sauerkraut, specifically Lactobacillus species, survive by converting sugars in the cabbage into lactic acid through the process of fermentation. This acidic environment is inhospitable to harmful bacteria, allowing the Lactobacillus to thrive and keep the sauerkraut preserved.

2. What type of bacteria is found in sauerkraut?

The predominant bacteria found in sauerkraut is Lactobacillus, specifically Lactobacillus plantarum. Other bacteria that may be present include Leuconostoc mesenteroides and Pediococcus pentosaceus.

3. How do bacteria in sauerkraut benefit our health?

The bacteria in sauerkraut, specifically Lactobacillus, are probiotics that can help improve our gut health. They aid in digestion, strengthen our immune system, and may even have anti-inflammatory properties.

4. Can the bacteria in sauerkraut make us sick?

The bacteria in sauerkraut are generally considered safe and beneficial for consumption. However, if the sauerkraut is not properly fermented or contaminated during the production process, harmful bacteria can grow and cause food poisoning. It is important to consume sauerkraut from reputable sources and to follow proper storage and handling guidelines.

5. What conditions are ideal for the growth of bacteria in sauerkraut?

The growth of bacteria in sauerkraut is dependent on the environment created during the fermentation process. The ideal conditions for growth include a salt concentration of 2-3%, a temperature range of 15-25°C, and an anaerobic (oxygen-free) environment. These conditions promote the growth of beneficial bacteria and inhibit the growth of harmful bacteria.

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