Technical Overview of Agar Agar Powder (Bacteriological Grade)
Agar Agar Powder (Bacteriological Grade) – TM Media is an unbranched polysaccharide extracted from red algae species such as Gelidium. This bacteriological grade, Agar Agar Powder, is widely used practically for all pathogenic and non-pathogenic bacteria as well as fungi. Agar Agar is prepared from species of red seaweeds specially selected for their agar gel production, using stainless steel equipment and observing good manufacturing practice.
Physical and Chemical Properties
Regarding its physical form, it is an off-white to creamish-coloured free-flowing powder having a particle size that can pass through a 40 ASTM screen. It has good firmness, elasticity, clarity and stability. Furthermore, it lacks nutritional value and melts at approximately 100°C and easily solidifies at room temperature. Its interaction with water is specific: it swells but does not dissolve when suspended in cold water. However, it is soluble in hot water, and solubility is facilitated by soaking the powder in cold water.
Role in Microbiological Culture Media
Agar Agar Powder is used as a solidifying constituent in Microbiological Culture Media. It gives a stable surface for organisms to grow in the Culture Vessel which aids in the observation of colony morphology. It does not inhibit the growth of microorganisms. Hence, it does not affect bacteria growth and is perfect to work with at room temperature. It remains intact and doesn’t break down by microorganisms. Because of these properties, it can be used in plates, bottles, and slants. It is suitable for clinical, bacterial and yeast transformation studies. Additionally, Agar Agar Powder has a high mineral/metal content and thus is advantageous to use in certain Culture Media.
Standard Usage and Concentrations
The application of this material depends on the specific requirements of the study. Bacteriological Agar is generally used in a concentration of 1 – 2% for Microbiological Culture Media preparations, 0.5% for motility testing and 0.1% maximum for anaerobes and microaerophiles growth.
Summary of Usage Parameters:
- General Culture Media: 1 – 2% concentration
- Motility Testing: 0.5% concentration
- Anaerobes/Microaerophiles: 0.1% maximum concentration
