Is agarose biodegradable? (7 properties of agarose) 

In this article, the biodegradability of agarose will be discussed. Other related topics covered will be: 

• What is agarose?
• What are the properties of agarose?
• What are the applications of agarose?
• What is biodegradability?
• What is the waste hierarchy based on biodegradability?
• What are the examples of biodegradable and non-biodegradable waste?
• FAQs

Is agarose biodegradable?

Yes, agarose is biodegradable. Agarose is obtained mostly from sea algae (red seaweed) and contains β-D-galactose and 3,6-anhydro-L-galactose units in its structures.

The physical, chemical and thermal stability given by agarose make it a good fit to be used in molecular assays and separation techniques such as gel electrophoresis, motility assays, culture media, and chromatography. 

Agarose is used to isolate, separate and study large molecules like proteins and nucleic acid. Since it is obtained from a natural source, it is biodegradable. 

What is agarose?

Agarose is a polysaccharide that may be purified from agar or agar-bearing marine algae. Agarose is regarded as non-toxic and does not contain any harmful polymerisation by-products as is the case generally. 

A polysaccharide is a large molecule which may be made from many monosaccharides. As per other definitions, a polysaccharide is a molecule that can be broken down into many smaller molecules (at least 2) by hydrolysis.

Typical examples of polysaccharides may be cellulose, starch and glycogen. All these are made from repeating monosaccharides and can be broken down by the action of breaking factors in presence of water. 

Agarose is a polysaccharide. It is also made of monosaccharides linked together. These monosaccharides are alternating β-D-galactose and 3,6-anhydro-L-galactose units. Agarose can also be broken down into these units by the action of hydrolysis. 

We have seen that agarose is made from agar or marine algae sources of agar. Agar is a jelly-like or gelatin-like substance that is usually obtained from algae and can be processed into flakes, powders, and sheets. 

Since the source of agarose is nature, it can be asserted that agarose is harmless and non-toxic. This is because it coincides with the basic code of nature, unlike synthetic polymers like polyester or polyvinyl chloride. 

What are the properties of agarose? (7 properties of agarose) 

Agarose is a polysaccharide made from units of β-D-galactose and 3,6-anhydro-L-galactose. There are certain properties of agarose due to which it is extensively used in molecular assays and separation techniques.

The properties of agarose like physical and thermal stability are what make it a decent substitute for a number of materials like agar. The gels made from agarose have larger pore sizes due to which these gels are used to isolate, separate and study macromolecules like proteins and nucleic acids. 

The properties of agarose may be: 

• Non-toxic
• Co-polymer 
• Obtained from organic sources
• High gel strength 
• Chemical and thermal stability 
• Anti-convective properties
• Sieving properties 

What are the applications of agarose?

The most prominent use of agarose is in molecular biology where agarose is employed for the separation of biomolecules. Examples of these large molecules can be nucleic acids such as DNA or RNA. 

The reason why agarose is employed in the separation and characterisation of large molecules is because of its unique properties that are given off by agarose. 

It is stable in terms of chemicals and temperature. This means that agarose can be used in mediums where there is a need for high temperatures and potent chemicals. Another reason why agarose is selected for the separation of large molecules is that it is not chemically complex which facilitates the separation process. 

The gels that are made from agarose are fit for the separation of large molecules because the pore size of agarose gel is quite large. This is another edge which is regarded as unmatched generally. 

The major applications that agarose are: 

• Used in agarose gel electrophoresis 
• Used in protein purification
• Used in immunodiffusion
• Used in immunoelectrophoresis 
• Used in motility assays 
• Used in solid culture media

Due to the large pore size, agarose gels are used to separate and resolve large molecules such as nucleic acids (DNA or RNA). It is the most common application of agarose gel. 

In every lab of molecular biology, there will be agarose gel electrophoresis because this process is very important in molecular biology research. All molecular biology research is incomplete without agarose gel electrophoresis. 

The agarose gels may also be employed to separate proteins. This may be done through a number of approaches such as: 

• Gel filtration chromatography 
• Affinity chromatography
• Ion-exchange chromatography

The properties of agarose like chemical and thermal stability and good gel strength make agarose a good fit to be used in these processes that are involved in the separation, isolation and characterisation of large molecules. 

Agarose may also be used in culture media as a substitute or alternative to agar. This is because agarose may be purer which results in better analysis. The physical, thermal and chemical stability of agarose is another reason why it can be replaced with agar for culture media. 

Another place where agarose can be used as an alternative or substitute to agar is in motility assays. Motility assays are designed to assess the motility and mobility of motile species wherein this motility can be assessed and tracked by employing the porous nature of agarose gel. 

What is biodegradability?

An understanding of biodegradability is important in knowing whether agarose is biodegradable or not. 

Biodegradability can be explained as a natural process through which microbes break down complex waste into simpler substances. This conversion is also facilitated by external conditions such as temperature or sunlight. 

The main driver of biodegradation is microbes. These microbes include bacteria, algae, fungi, protozoa, yeast, and decomposers. They break down the structures of complex waste so that the simple waste may become part of nature again. 

Biodegradability is nature’s way to ensure that there is no waste and that the waste produced is taken back into the system. It is because mother nature is aware that if there is waste, there will be complications and obstructions. 

To understand this, the article invited you to an analogy. Imagine that for some reason you are unable to dispose of waste in your home or office. The situation may be manageable for some days but not very long.

Now, imagine that you can not dispose of the waste for several hundred years. The first thought that you will get is that your home or office will become unlivable. The same is the case for biodegradability and the earth. 

Biodegradability is the earth’s dustbin and earth is our home. If there is no biodegradability, there is no waste disposal. This will, eventually, steal our home’ capacity to sustain life. Results? Mass extinction and environmental degradations. 

What is the waste hierarchy based on biodegradability?

Biodegradability is the earth’s natural way to eliminate waste by making sure that it gets back to the system. However, there has been corruption in this naturality as well. 

Regarding biodegradability, there is a general understanding that natural materials and natural waste are biodegradable. This is because it coincides with the code of nature. The microbes have no difficulty in breaking down the structures of this type of waste. 

On the other hand, we have the type of waste which can not be degraded by the action of microbes. This type of waste is mostly considered man-made. That is because microbes are unable to degrade the inner structures of synthetic materials and as a result, this type of waste may persist for hundreds of years. 

Do you remember the analogy of the last section? If you do, you will also remember that if there is an incapacity to biodegrade, then this means that nature’s capacity to sustain and promote life is being taken away. 

The same is the case with non-biodegradable waste. Non-biodegradable waste is known to cause a lot of harm to nature and man, other than being non-biodegradable. These may be: 

• Greenhouse effect
• Global warming
• Deforestation
• Soil leaching
• Pollution
• Soil erosion 
• Destruction of habitats
• Disruption of food chains
• Species endangerment 
• Loss of life 
• Medical complications
• Harm to the economy
• Unforeseen and unprecedented climatic anomalies 
• Pest & insect attacks 

These are some of the effects to illustrate why biodegradable waste is important and needed. 

What are the examples of biodegradable and non-biodegradable waste?

In this section, various examples of biodegradable and non-biodegradable waste will be covered to further our understanding of the concept and science of biodegradability. 

Biodegradable waste is that waste can be degraded by the action of microbes. This type of waste may degrade readily or may also take some months. As per some studies, biodegradable waste (like bio-plastics) may even take some years to degrade. Examples of biodegradable waste include: 

• Food waste
• Plant waste
• Waste from slaughterhouse 
• Natural fibres
• Natural fabrics 
• Semi-synthetic material obtained from plant or animal sources (like rayon fabric) 
• Animal waste
• Manure
• Sewage 
• Crop waste

Non-biodegradable waste, on the other hand, can not be degraded by the action of microbes. It is mainly because microbes are unable to break the structures of this type of waste. 

It is generally perceived that materials that are synthesised in the lab from petroleum or fossil fuels are not biodegradable. The tragedy is that with increased commercialisation and consumerism, more such waste is generated which leaves us with unprecedented and grave issues. 

Synthetic polymers are regarded as the most common non-biodegradable waste. Other examples may include: 

• Electronic waste
• Plastics 
• Hospital waste 
• Synthetic resins
• Synthetic fibres
• Dyneema 
• Polyvinyl Chloride
• Nuclear waste
• Hazardous waste
• Chemical waste

Is agarose biodegradable?

For a material to be biodegradable, it has to be sourced from nature. Natural materials can be degraded by the action of microbes whereas, non-natural materials can not be degraded by the action of microbes.

Agarose is a polysaccharide made from units of β-D-galactose and 3,6-anhydro-L-galactose. It is mostly extracted from red algae also referred to as red seaweed. 

Since agarose is obtained from nature, it is plausible to conclude that agarose is biodegradable and will degrade readily by the action of microbes. 

Conclusion 

It is concluded that agarose is obtained mostly from sea algae (red seaweed) and contains β-D-galactose and 3,6-anhydro-L-galactose units in its structures.

The physical, chemical and thermal stability given by agarose make it a good fit to be used in molecular assays and separation techniques such as gel electrophoresis, motility assays, culture media, and chromatography. 

Agarose is used to isolate, separate and study large molecules like proteins and nucleic acid. Since it is obtained from a natural source, it is biodegradable. 

Frequently Asked Questions: Is agarose biodegradable?

What is the most common use of agarose?

The most common use of agarose is to be used in agarose gel electrophoresis. 

How is agarose better than agar?

The physical, chemical and thermal stability of agarose makes it better than agar. That is why it is replaced with agar in motility assays and culture media. 

References

• Normand, V., Lootens, D. L., Amici, E., Plucknett, K. P., & Aymard, P. (2000). New insight into agarose gel mechanical properties. Biomacromolecules, 1(4), 730-738.

• Upcroft, P., & Upcroft, J. A. (1993). Comparison of properties of agarose for electrophoresis of DNA. Journal of Chromatography B: Biomedical Sciences and Applications, 618(1-2), 79-93.
  
• Salati, M. A., Khazai, J., Tahmuri, A. M., Samadi, A., Taghizadeh, A., Taghizadeh, M., … & Mozafari, M. (2020). Agarose-based biomaterials: opportunities and challenges in cartilage tissue engineering. Polymers, 12(5), 1150.

• Tanwar, A., Ladage, P., Kodam, K. M., & Ottoor, D. (2020). Biodegradable and biocompatible agarose–poly (vinyl alcohol) hydrogel for the in vitro investigation of ibuprofen release. Chemical Papers, 74(6), 1965-1978.

• Armisén, R. (1991). Agar and agarose biotechnological applications. In International Workshop on Gelidium (pp. 157-166). Springer, Dordrecht.