A scum that is far from useless

Do not judge a book by its cover as the ugly pond scum or microalgae might just offer many benefits

By AZALEA AZUAR

USELESS or contemptible people are called “pond scum” — a term which also refers to the gooey and unattractive mass microalgae that grow on the surface of the water.

For those very much into landscaping, the unsightly pond scum would be among the first things that would be removed from ponds or fountains.

Well, do not judge a book by its cover, as the ugly pond scum or microalgae might just offer many benefits.

If it’s in the right hands, the microalgae can be utilised in a wide range of chemical products with applications in the feed, food, nutritional, cosmetic and pharmaceutical industries.

These microscopic species are one of the earliest life forms to exist on Earth. Microalgae have been in our oceans since the Earth’s environment was formed over three billion years ago.

The diversity of microalgae is vast and it has not been fully exposed. In fact, there are more than 50,000 known microalgae species that currently live in oceans and freshwater, but only 30,000 species have been studied.

These microorganisms only contain a simple cell structure and they are able to grow in diverse environmental conditions.

Microalgae have a large surface to volume body ratio which enables them to absorb a large amount of nutrients.

They are able to capture solar energy with an efficiency of 10 to 50 times higher compared to terrestrial plants.

Ancient and Wholesome

Microalgae are rich with nutrients and have an abundant source of vitamins and minerals. Since they have all the essential amino acids, microalgal proteins have a great

potential to be an alternative protein source. The proteins from the simple life form also have high techno-functional potential, which means it can be used as an emulsifier.

Due to their high content in essential nutrients and protein, among the microalgal genera that’s widely used for human consumption are arthrospira, chlorella and aphanizomenon.

However, using microalgae as a source of bulk proteins is still a new idea.

Chlorella and arthrospira produce high-quality proteins as they both have well-balanced amino acid profiles.

They follow the World Health Organisation recommendations regarding human’s requirements of essential amino acids, which are similar to conventional protein sources, such as soybeans and eggs.

This makes them not just suitable for vegan-friendly dishes, but more sustainable as they have lower land requirements compared to animal-based proteins.

Microalgae also have smaller carbon footprint compared to rice. Some of the advantages of microalgae over other plant-based proteins are the minimal freshwater consumption, the possibility of growing in seawater, the usage of non-arable land for cultivation and the potential replacement of non-sustainable soy imports.

However, the consumption of microalgae dates back to more than 2,000 years when the

Chinese first used microalgae as food. The ancient Aztecs used the cyanobacterium Spirulina from Lake Texcoco (Mexico) circa AD 1300.

Spanish chroniclers had shared stories about local fishermen collecting blue-green masses from the lakes.The mass was then prepared as a dry cake which is known as tecuitlatl.

In another parts of the world, the populations on Chad have been harvesting Spirulina from Lake Kossorom for centuries and using it as food for daily basis.

The Nostoc genera have been used since ancient times for the preparation of traditional dishes in Northern Europe, North America and North Asia.

Since fruits and vegetables are scarcely available in cold climatic zones, the Nostoc genus of microalgae is used as a dietary fibre source to replace them.

N. commune, which is consumed by the Chinese and Japanese, is used as an ingredient for soups and salads or to be fried with meat, and it is sold between US$70 (RM299.60) to US$120 per kg of dry weight.

Microalgae products are available in the forms of health food, tablets, capsules and liquids.

These substances are also mixed with pastes, snacks, candy, gums, noodles, wine, beverages and breakfast cereals.

Not Much Knowledge about Microalgae

Microalgae are a prolific source of bioactive compounds which could be an important element in people’s daily life, says Dr Foo

While other countries have been utilising microalgae as food, Malaysia has yet to incorporate rich-protein microalgae into our food.

“To my knowledge, I have not seen microalgae incorporated in local cuisines to date and would be delighted to hear from any food industry representatives who are working on microalgae applications,” said Dr Foo Su Chern, a lecturer at the School of Science, Monash University Malaysia.

She said it is understandable as the accessibility to local microalgae biomass is still limited.

“This could be due to the microscopic size ranging from 1μm to 100μm, rendering them inconspicuous to the naked eye. Also, the current lack of knowledge and expertise for growing, harvesting and usage of microalgae impedes its wider usage,” Dr Foo said.

This includes know-how and accessibility to seed cultures which delay the progress of microalgae production.

Microalgae would be the primary source for plant-based proteins in the future, if the production is at a cost low enough to compete with existing protein sources.

“There is still room for improvement for Malaysia in the microalgae consumption market. For example, Spirulina is currently the most popularly used species in the food and beverage (F&B) sector,” she said.

According to Dr Foo, there are 200,000 to several million species of microalgae in existence compared to higher plants which account for about 250,000 species.

She believes that the known natural microalgae are just a small part of the true potential of microalgae.

“The opportunities for expansion could be in terms of species, depending on the type of applications, for example, food, energy and value-added products like nutraceuticals or cosmeceuticals,” she explained.

Malaysia has a great potential to cultivate microalgae, thanks to the tropical climate with consistent sunshine all-year-round.

Microalgae can be grown as an alternative biomass source to complement the existing palm oil in the country since it has a high photosynthetic capacity.

At the same time, it can provide feedstock for value-added products, feed and food.

However, Dr Foo does not think that Malaysia has the technology yet.

“However, with existing green policies such as the national green technology policy and sustainability awareness, consumers and industries would be more compelled to adopt green technology.

“This generates demand, which could then significantly lower the capital cost of photobioreactors,” she said.

Fuelling the Future

The consumption of microalgae dates back to more than 2,000 years when the Chinese first used microalgae as food (Source: GXN Ganoderma Facebook)

Other than food, microalgae can be used in many applications such as wastewater bioremediation. This is seen as a sustainable alternative to wastewater treatment.

“Wastewater high in nitrate and phosphate becomes nutrients for certain microalgae species to grow and thrive in. The harvested biomass can then be converted to energy,” Dr Foo added.

She said more local companies could adopt this new technology with the help of financial support or incentives from the government.

In 2013, the world’s first algae-powered building was built in Germany for the International Building Exhibition in Hamburg.

Now, how does a building covered with large green panels work?

Apparently, the heat and biomass generated by the façade are sent to the building’s energy management centre via a closed-loop system, whereby the biomass is harvested through floatation and heated by a heat exchange.

The excess heat from the bioreactors can be used to supply hot water or even heat up the building, or stored for later use since the system is fully integrated with the building services — much like how solar panels work.

To Dr Foo, the short-term cost is high from installation and maintenance for these bioreactors.

But rest assured, the high cost is worth it as in return, we would receive better air quality, lower carbon footprint and a continuous supply of biomass useful to humans.

“ Photobioreactors are now designed to be easy to clean where cultures could be automatically monitored with real-time sensors and controls. Making cultivation easier and cheaper is one of the main objectives for our research group,” Dr Foo explained.

She also tried to incorporate new and interesting findings from her research group during her lectures to introduce newcomers into microalgae.

Studying Microalgae

Spirulina is currently the most popularly used species in the F&B sector (source: FB)

Dr Foo became interested in microalgae when she was doing her undergraduate final year project.

She looked through the microscope only to discover a whole new world of beautiful, intricate and gem-like microorganisms.

“I started recognising the potential from further reading, which leads me to embarking on a PhD journey in the biotechnology discipline. I wanted to unveil the substance’s potential for food, nutraceuticals
and cosmeceuticals,” Dr Foo said.

With the microscopic size, microalgae are inconspicuous and challenging to recover from the culture media. Dr Foo said the current recovery method, such as centrifugation, is an energy-intensive process.

Dr Foo has been bioprospecting for tropical microalgae species found in Sunway’s South Quay lake.

The objective of the experiment is to further study carbon capture and produce valuable compounds.

“We have selected a locally isolated species called Chlorella sorokiniana as the target species due to its high growth rate, biomass productivity and antioxidant properties,” she added.

The project is funded by Sunway Group’s Sustainable Community Grant Scheme. The second phase of the project would involve building a cost-effective photobioreactor that would grow the microalgae biomass via photosynthesis at a larger scale.

The photobioreactor will be built by a Monash Malaysia’s school of engineering lecturer and a master’s student.

Finally, the biomass will be harvested during the third phase and bioactive, such as antioxidants from the microalgae cells, will be extracted by the ionic liquids. Ab out RM60,000 to RM70,000 have been given to fabricate and design the bioreactor.

“Our research team would like to share our latest findings at the forum and consequently further existing collaborative opportunities or spark new interests. Also, a multi-term funding will provide valuable opportunities to review and refine the project for continuous improvement and scalability with each successive iteration,” Dr Foo said.

She is of the opinion that microalgae are a prolific source of bioactive compounds which could be an important element in people’s daily life.

“As we go along this path, I believe that a strong and supportive team — which I am deeply thankful for — is crucial in solving the inevitable challenges that are and will be encountered. Finally, there is still so much to uncover in the field of microalgae biotechnology for the people, the profit and the planet,”