What is a culture in microbiology?
Growing Bacteria in Culture A population of bacteria grown in the laboratory is referred to as a culture. A pure culture contains only one single type; a mixed culture contains two or more different bacteria.
Why do microbiology labs need stock cultures?
There are a number of reasons why a microbiology laboratory needs stock cultures in good condition. The typical stock culture collection may contain isolates that fall into one or more of the following categories: Isolates used in the preparation of inoculated samples and specimens for quality control and training purposes
Why learn how to culture a single bacterial species?
Learning how to culture bacteria is the first step to many a project, so let’s start laying the foundation for your future Nobel Prize! Why Do We Want to Culture a Single Bacterial Species? Bacteria culturing is carried out for a plethora of reasons, including: to aid in the clinical diagnosis of pathogens (or their absence) in patient samples
What are the different methods of bacterial culture?
Another method of bacterial culture is liquid culture, in which the desired bacteria are suspended in liquid broth, a nutrient medium. These are ideal for preparation of an antimicrobial assay.
What is bacterial stock culture?
Stock cultures are microorganisms maintained for the purpose of keeping the microorganisms viable. Maintaining cultures internally may seem like the most cost-effective solution.
What is broth culture in microbiology?
Broth culture is any type of liquid used to grow bacteria. Its name comes from the frequent use of beef extract, but many other types of ingredients are used. The broth culture can be either defined or undefined.
What are the 4 types of culture in microbiology?
These are classified into six types: (1) Basal media, (2) Enriched media, (3) Selective (4) Indicator media, (5) Transport media, and (6) Storage media. 1. BASAL MEDIA. Basal media are those that may be used for growth (culture) of bacteria that do not need enrichment of the media.
What is a bacteria culture called?
A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions.
What is a stock culture?
[ stŏk ] n. A culture of a microorganism maintained solely to keep it viable for subculture into fresh medium.
Is a broth a culture?
Bacteria and other microbes, like yeast, can be cultured in broth. It's not the same broth you'd find in your soup, but it has similarities. Broth cultures are liquid cultures used to grow bacteria in laboratories. To create a broth culture, a scientist begins with a sterile liquid growth medium.
What is culture methods in microbiology?
Culture methods involve taking samples from the field and detecting the presence of microbe by culturing them. From the amount of microbial species their influence on corrosion is estimated. Culture media to grow different microbes have been established.
How do you subculture bacteria?
These cell types can be subcultured by simply taking a small volume of the parent culture and diluting it in fresh growth medium. Cell density in these cultures is normally measured in cells per milliliter for large eukaryotic cells, or as optical density for 600nm light for smaller cells like bacteria.
What are types of culture?
The two basic types of culture are material culture, physical things produced by a society, and nonmaterial culture, intangible things produced by a society.
What is inoculation in microbiology?
In simple terms, inoculation in microbiology is the process of introducing microbes into a culture media so that it reproduces there. Commonly, it is used in the introduction of vaccines, serum or any antigenic substance in the body so as to boost immunity against a particular disease.
What is batch culture in microbiology?
Batch culture is a closed culture system that contains limited amounts of nutrients. In batch culture cells grow in a finite volume of liquid medium and are usually maintained in conical flasks on orbital shakers at a speed of 80–120 rpm.
What is microorganism cultivation?
Cultivation is the process of propagating organisms by providing the proper environmental conditions. Parasites, bacteria, and viruses all generally require cultivation for detailed study.
What is bacterial culture?
Bacterial culture is a method that allows the multiplication of bacterial cells in or on a culture medium under controlled laboratory conditions. The exact conditions required for optimal replication will depend on the target bacterial species.
Aerobic culture vs anaerobic culture
Most bacteria can grow to some extent in the presence of oxygen, known as aerobic culture. But for optimal growth, the conditions should be adjusted to suit the target bacterium. Species found in atmospheric conditions, such as on the skin surface or in the upper respiratory tract, will typically grow well in the presence of oxygen.
Bacterial culture methods
To be cultured successfully, bacteria require the provision of nutrients in the culture medium. There are many different formulations available to suit the differing nutritional needs of bacterial species. The type of medium you choose will depend on the purpose of the culture.
Bacterial growth curve
While rates of division will vary between bacterial species, they will normally follow the same general growth pattern in broth culture. The number of bacterial cells in a culture can be estimated by various means including plating and colony counting or by measuring the turbidity of the culture with UV-visible spectroscopy.
Obtaining a pure culture
A pure culture is one that only contains the bacterial species you wish to grow. The ease with which this can be achieved is likely to depend very much on the source of your sample, the abundance of the target species compared to other species and the target species itself.
Applications of bacterial culture
There are many reasons why it may be necessary or desirable to culture bacterial cells. Here, we consider some of the common purposes.
Why Do We Want to Culture a Single Bacterial Species?
Bacteria culturing is carried out for a plethora of reasons, including:
Sterilize Your Bacterial Culture Tools Before Use!
You can easily sterilize utensils, liquids and agar media via a number of methods in the lab. While you work, you can dip glass or metal culturing tools (such as inoculating loops or cell spreaders) in alcohol and hold them in the flame of a Bunsen burner for about 30 seconds to ensure complete sterility before use.
Keeping Your Bench Clean and Aseptic Technique
Another important thing to keep in mind while trying to achieve sterility is your work space. Areas where you culture bacteria should be treated in a manner similar to how you treat a PCR work space:
Use Antibiotics to Prevent Unwanted Bacterial Growth
As well as practicing aseptic technique, another common way to avoid unwanted bacteria is to take advantage of an antibiotic selection marker provided to your clone via plasmid transformation.
Plates? Liquid media? Tubes? Oh my!
You can use a number of different types of media to grow bacteria, and all of them can be supplemented with these antibiotics as required by the plasmids or experimental goals.
Bacterial Growth Conditions – Optimum Temperature
Conditions in which bacterial cultures are grown can really impact your overall success. Typically, bacteria are grown at 37°C, because this closely simulates the temperature of the human body. Not all bacterial species, however, grow optimally at 37°C, so identifying an optimal growth temperature is important.
Position Your Bacteria for Success!
Having these tools at your disposal can go a long way towards putting yourself in the best position for long term success as you go back to frozen cultures time and time again. Early failures can lead to headaches that last years, so be careful from the start!
Background Information
Bacterial glycerol stocks are important for long-term storage of plasmids. Although you can store your plasmid DNA at -20°C, many labs also create bacterial glycerol stocks of their plasmids.
Protocol Video
Watch the protocol video below to learn how to create bacterial glycerol stocks.
Tips and FAQ
The optimal concentration of long-term glycerol storage is unknown. Most labs store bacteria in 15-25% glycerol.
What Is Bacterial Culture?
What's The Difference Between Aerobic Culture vs Anaerobic Culture?
- Most bacteria can grow to some extent in the presence of oxygen, known as aerobic culture. But for optimal growth, the conditions should be adjusted to suit the target bacterium. Species found in atmospheric conditions, such as on the skin surface or in the upper respiratory tract, will typically grow well in the presence of oxygen. Species that ar...
Bacterial Culture Methods
- To be cultured successfully, bacteria require the provision of nutrients in the culture medium. There are many different formulations available to suit the differing nutritional needs of bacterial species. The type of medium you choose will depend on the purpose of the culture. Rich, nutrient or complete media can be helpful when trying to bulk up a pure culture and get the bacterial cell…
What's A Bacterial Growth curve?
- While rates of division will vary between bacterial species, they will normally follow the same general growth pattern in broth culture. The number of bacterial cells in a culture can be estimated by various means including plating and colony counting or by measuring the turbidity of the culture with UV-visible spectroscopy. When this is plotted (typically on a logarithmic scale) a…
Obtaining A Pure Culture
- A pure culture is one that only contains the bacterial species you wish to grow. The ease with which this can be achieved is likely to depend very much on the source of your sample, the abundance of the target species compared to other species and the target species itself. If your source is another pure culture or a strain that has been isolated and stored in the freezer, then th…
Common Problems with Bacterial Culture
- Contamination– Contamination of bacterial cultures can be very problematic, particularly if it goes undetected. At best, it can mean the need to reisolate a pure culture, but at worst could lead to...
- Overgrowth of some species– Some bacterial species grow easily and vigorously. When attempting to isolate a species from a mixed sample, these vigorous species may overgrow …
- Contamination– Contamination of bacterial cultures can be very problematic, particularly if it goes undetected. At best, it can mean the need to reisolate a pure culture, but at worst could lead to...
- Overgrowth of some species– Some bacterial species grow easily and vigorously. When attempting to isolate a species from a mixed sample, these vigorous species may overgrow and mask the presence of...
- Antibiotic treatment prior to sampling– In a diagnostic setting, it is important to know if antibiotic treatment has been administered prior to sampling. If this is the case, failure to culture a p...
- Incorrect growth conditions– The use of inappropriate or suboptimal growth conditionsmay i…
Applications of Bacterial Culture
- There are many reasons why it may be necessary or desirable to culture bacterial cells. Here, we consider some of the common purposes.