The Role of Agarase in Agar-Degrading Bacteria
The Role of Agarase in Agar-Degrading Bacteria
Abstract
Agar-Degrading (agarolytic) Bacteria is physiological class of bacteria capable of utilising agar as a sole carbon source. This ability is made available by the use of agarases - enzymes which break down agarose into oligosaccharides. This physiological class branches through genii, regardless of Gram Stain status or morphology. Through a review of scientific literature we can find identification methods, optimum conditions and the general function and location of agarolytic bacteria, as well as methods to culture them in vitro for study and experimentation.
Agar is a gelatinous substance derived from algae and seaweed that has found considerable use in laboratories as a medium for bacterial growth. Seaweed is fairly common in oceans, with Gelidium amansii (a species of red algae heavily used for agar) usually found in East and Southeast Asian coasts. Coupled with differing nutrients, inhibitors and indicators, Agar plates can be utilised as both a selective and differentiating medium by allowing only bacteria with the required properties to flourish(2).
By preparing a nutrient agar plate that has agar as its only carbon source, it is possible to screen for agar-degrading bacteria, as they are the only ones that may survive. The key of their ability to obtain carbon from agar alone is their capability of synthesizing agarase, the first enzyme in the agar catabolic pathway(8).
Agarase
Agarases are classified as either α-agarases or β-agarases based upon whether they degrade α or β linkages in agarose, breaking them into oligosaccharides. α-agarases yield oligosaccharides with 3.6 anhydro-L-galactose at the reducing end whereas β-agarases result in D-galactose residues. (3) While the optimal pH of agarase is 5.5, it is stable at a tolerant range, from 4.0 to 9.0.(1)
(10)
The above diagram serves as a model of enzyme activity which agarase (as an enzyme) should behave similarly
Abstract
Agar-Degrading (agarolytic) Bacteria is physiological class of bacteria capable of utilising agar as a sole carbon source. This ability is made available by the use of agarases - enzymes which break down agarose into oligosaccharides. This physiological class branches through genii, regardless of Gram Stain status or morphology. Through a review of scientific literature we can find identification methods, optimum conditions and the general function and location of agarolytic bacteria, as well as methods to culture them in vitro for study and experimentation.
Agar is a gelatinous substance derived from algae and seaweed that has found considerable use in laboratories as a medium for bacterial growth. Seaweed is fairly common in oceans, with Gelidium amansii (a species of red algae heavily used for agar) usually found in East and Southeast Asian coasts. Coupled with differing nutrients, inhibitors and indicators, Agar plates can be utilised as both a selective and differentiating medium by allowing only bacteria with the required properties to flourish(2).
By preparing a nutrient agar plate that has agar as its only carbon source, it is possible to screen for agar-degrading bacteria, as they are the only ones that may survive. The key of their ability to obtain carbon from agar alone is their capability of synthesizing agarase, the first enzyme in the agar catabolic pathway(8).
Agarase
Agarases are classified as either α-agarases or β-agarases based upon whether they degrade α or β linkages in agarose, breaking them into oligosaccharides. α-agarases yield oligosaccharides with 3.6 anhydro-L-galactose at the reducing end whereas β-agarases result in D-galactose residues. (3) While the optimal pH of agarase is 5.5, it is stable at a tolerant range, from 4.0 to 9.0.(1)
(10)
The above diagram serves as a model of enzyme activity which agarase (as an enzyme) should behave similarly
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