Our Waste, Our “Hidden Treasure”

As in a war, free radicals contained in cigarette smokes and motorized vehicle exhaust pose a constant threat, ready to attack the human body at all times. Therefore, we need an effective strategy to defend our body. Carotenoid may be the answer.

Carotenoid is a pigment often used for food coloring. This compound has a high antioxidant activity, in which they fight free radicals often found as air pollutants, food contaminants, or a product of radiation.

“A healthy environment will lead to a better world”. Renna Eliana Warjoto, S.Si., M.Sc. embraces this idea by looking into the promising use of the yeast Rhodosporidium paludigenum in producing carotenoid from common waste, such as orange peel and molasses; the latter is the byproduct of sugarcane processing. Common waste is often overlooked, yet it bears a potential to be transformed into high value products, one of which is carotenoid.


orange peelOrange peel waste may potentially be used for carotenoid production. Source: bbc.com


The production of carotenoid may be boosted by including economically viable substrate such as tapioca flour. However, Rhodosporidium paludigenum is lacking the mechanism to metabolize the starch content of tapioca flour and therefore requires extra help to digest starch. In this case, the bacterium Bacillus subtilis or the mold Aspergillus oryzae may play a role in degrading starch into the simpler sugar glucose. Following that, Rhodosporidium paludigenum will use glucose to produce carotenoid.

The above system, in which more than one microorganisms are grown together in a specific medium to result in a specific product, is known as co-culture. Imagine how a weaver and a tailor may work together to create a shirt from a yarn. The weaver will assemble each thread of yarn into a sheet of cloth. This cloth will then be transformed by the tailor into a wearable shirt as the final product.

Taking into the above analogy, in her research, Warjoto aims to optimize the appropriate conditions to induce the cooperation among Rhodosporidium paludigenum, Bacillus subtilis, and Aspergillus oryzae, to obtain carotenoid as their end product.  This idea was developed in collaboration with Dr. Tresnawati Purwadaria, an expert in fermentation technology. Prof. Dr. Bibiana Widiyati Lay, a microbiology mogul, also contributed her expertise in this project.

This research encourages us to stop undermining common waste. With proper technology, our waste may be used to create products with high economic value. Let’s explore the inherent potential of waste to promote a healthy environment and a better world!


This article is written by Meinanda Ashar, Adrina Weisa, Ananda Mutiara Cinta, and Olivia Tisna Tampake as a class project for the Science Communication course. They are third and fourth year students in the Biology Program, Faculty of Biotechnology, Atma Jaya Catholic University of Indonesia.

Editor: Renna Eliana Warjoto


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