It is a waste to discard the pure cultures which you have worked to isolate. It is fairly simple to keep the cultures for a few month, even a few years. Be the only kid on your block that has his own culture collection. You would especially want to save any named cultures which you received from professional bacteriologists. When I began my own culture collection I found I learned more in a year than I had in the previous 15 years. You will learn a lot about the Genera of bacteria by reading and maintaining your cultures. You really begin learning when you run some simple tests to make sure the cultures are labelled correctly. Grow them on Ulrich milk or plain milk. gram stain, TSI, it is not so difficult. Make up lots of tubes of TSI or something close and test each of your cultres.
See page b026a and print out a copy. You can make charts like this for your own collection. Giving info for the media and species that you have. Page b026b gives the literature results for 20 bacteria from human, meat, and dairy products and most will grow on TGY and meat/milk media. Page b26c is 20 bacteria from the environment: soil, water, decaying plants, and ______.
Protect your cultures from dust.
Never put a non-sterile inoculating loop or needle into your culture.
When you need a sample, just touch your loop to the bacteria. Don't dig.
Keep a subculture as your working culture so you do not have to enter your master culture often.
Some species produce spores and survive for extended periods. Bacillus spores survive for decades. Clostridium spores do not seem to survive as well. Spores of other genera do not seem to live more than a year or so.
Some non-sporulating species have survived for long periods. More on this later.
Often a species will survive much longer on a certain medium.
Some survive longer at room temperature. Others live longer at refrigerator temperatures.
Some live longer in refrigerator, some at room temperature.
under mineral oil
dried on silica gel
Some genera you may collect because they are distinctive and you should learn them. Look over the Genera page for ideas.
Bacillus - form spores in prsence of air. Only a few are pathogens.
Micrococcus - small round, somewhat inert. Most are safe.
Pseudomonas - Able to eat anythng - because of this some are pathogens, but many are "safe".
a good way to begin learning the genera. Sugested genera.
Do not collect strains which may be pathogenic (cause disease or infections) in humans and animals. Read all you can find about such pathogens and that knowledge will help you avoid accidently acquiring a dangerous culture. Only a few bacteria can cause disease in both plants and animals. Therefore, isolating bacteria from rotten fruit and plants is often, but not always, safe. Many Clostridium species which can grow in stagnant, rotting, often smelly, meat and plant materials, or feces, may be pathogenic in humans.
Planned: add some paragraphs for suggested "usually safe" bacteria. Learning the Gerne by having a collection of the safe bacteria. mites CAN BE A PROBLEM
To be continued.
It is nice to have some named reference cultures. Perhaps a teacher or lab worker will give you his old tubes after he transfers his cultures. Your biology teacher may let you take samples from the cultures you are using in his class.
Set out plates to catch bacteria from the air. other sources. Dairy products bacteris. Collect only from evironments where all the bacteria should be harmless .
Collect and isolate bacteria only from enviroments where all the bcteria have a good chance of being harmless such as: dairy foods. surfaces of plants. rotten fruit or vegetables, open air,
keep away from kids and adults who know nothing. no pathogens.
This page will encourage and provide info on starting your own collection. You need some tubes but the cost is worth the effort. Some cultures from nature do not llive as well as those from collections.
Revision #2 1999 Feb 1