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The first culture media was liquid media, designed by Louis Pasteur in 1860. [2] This was used in the laboratory until Robert Koch's development of solid media in 1881. [3] Koch's method of using a flat plate for his solid media was replaced by Julius Richard Petri's round box in 1887. [2]
Microbial food cultures are live bacteria, yeasts or moulds used in food production. Microbial food cultures carry out the fermentation process in foodstuffs. Used by humans since the Neolithic period (around 10 000 years BC) [1] fermentation helps to preserve perishable foods and to improve their nutritional and organoleptic qualities (in this case, taste, sight, smell, touch).
The liquid culture pasteur developed allowed for the visulization of promoting or inhibiting growth of specific bacteria. This same technique is utilized today through various mediums like Mannitol salt agar, a solid medium. Solid cultures were developed in 1881 when Robert Koch solidified the liquid media through the addition of agar [2]
A 2' x 4' petri plate filled with 14L (liters) of seaweed derived agar medium created by Harvard scientists that was used to see how E. coli evolved to be resistant to antibiotics. The mega plate also helped study more unique concepts of microbiology such as parallel evolution, mutation selection, colonial interference etc. [ 13 ]
[3] [4] Microbiologists traditionally relied on culture, staining, and microscopy for the isolation and identification of microorganisms. However, less than 1% of the microorganisms present in common environments can be cultured in isolation using current means. [5]
An agar plate – an example of a bacterial growth medium*: Specifically, it is a streak plate; the orange lines and dots are formed by bacterial colonies.. A growth medium or culture medium is a solid, liquid, or semi-solid designed to support the growth of a population of microorganisms or cells via the process of cell proliferation [1] or small plants like the moss Physcomitrella patens. [2]
The catalase test tests whether a microbe produces the enzyme catalase, which catalyzes the breakdown of hydrogen peroxide. Smearing a colony sample onto a glass slide and adding a solution of hydrogen peroxide (3% H 2 O 2) will indicate whether the enzyme is present or not. Bubbling is a positive test while nothing happening is a negative result.
An inoculation loop (also called a smear loop, inoculation wand or microstreaker) is a simple tool used mainly by microbiologists to pick up and transfer a small sample of microorganisms called inoculum from a microbial culture, e.g. for streaking on a culture plate. [1] [2] This process is called inoculation. The tool consists of a thin handle ...