Culture media

[Quimico]

Hi, do somebody know any culture media for cultivating interesting microorganisms? I´ve tried with different substances like sodium silicate, lettuce (for paremecium), magnesium hidroxide etc. But do somebody know a culture media you have tried that you would want to share and what kind of microorganisms are able to grow in? Or what conditions do you use for cultivating?

[zzffnn]

I think most microscopists use original pond water with original mud and vegetation. That way you would see oroginal resident protists. Some sunshine, air and fish flakes help but don't overdo them (I would rather put less than enough than too much).

[Oliver]

Hello,
Hay infusions are sometimes used to culture paramecia and other microorganisms, but the problem is that they also promote rapid bacterial growth. The bacteria (while needed as a food source) may soon overgrow the Paramecia and reduce the oxygen content of the water (causing everything to die off). There are also serious safety concerns with Hay Infusions (hiĝ bacterial concentration), so I generally do not recommend them, even though some websites say that this is an experiment which can be done with children. You also do not know which microorganisms generally "win" the battle.

Due to the unstable conditions of enriching microorganisms, I generally recommend the making of microcosms (aquariums, terraria etc) and then use this as a natural source for microscopy.

I have also tried to culture algae. Take a jar with pond water and some algae and add a small amount of plant fertilizer. And wait. The water will turn green as algae start to grow. Do not overfertilize, aerate well but do not agitate too much.

Oliver.

[einman]

I have found some good ideas in this book:

Culture Methods for Invertebrate Animals
galtsoff, paul
Published by Dover Publications, 1959

You can pick up a copy on Abebooks for about $3.00 plus shipping

[75RR]

einman's recommended book is available at: https://archive.org/details/culturemethodsfo00galt

Skimming through it I found what reads like a witches brew!

"A CULTURE MEDIUM FOR HYDATINA SENTA*
Josephine C. Ferris, University of Nebraska

BRING to the boiling point in 1oo cc. of water 1 gram of urea crystals, 1 gram of dried blood, and 1 gram of dried ox gall. Filter and add 3cc.of this triple solution to 1oocc. of tap or rainwater. This solution is very satisfactory for pedigree cultures of this rotifer in watch glasses if fed on Polytoma cultures. [See p. 61.] If the Polytoma is cultured in a bone meal and hay solution it should be washed at least twice by centrifuging and decanting.

References
For the culture of Hydatina asplanchna see p. 210. For the culture of Philodina see p. 143."

Note: I recommend that Oliver's caution "on bacteria" be taken seriously.

[einman]

While Oliver's caution would seem to make sense, and I believe we should always err on the side of caution, I have used Hay infusions since I was 13 years old. I did a search on Google and found nothing related to harmful bacteria in Hay infusions. I did find Oliver's article in a 2011 issue of Microbe Hunter regarding Hay infusions.

Does anyone have any citations indicating the potential harm from hay infusions. I was planning on making one with the Hay left over from Halloween.

[75RR]

I believe Oliver's caution was based on the risk entailed by a process that by its very nature produces high concentrations of random bacteria. Much higher concentrations than one would normally find in an average everyday drop of sampled water.