Everything is Connected!

Prologue

On November 2015, Indonesia massively highlighted as the second worst plastic polluters to the sea. It inspires us to develop a project benefiting the environment and Indonesia image. We came up with a project named Dewaruci. It should be inspiring and sustainable. For that, we involve various stakeholder into our project design, execution, and future outlook. Here is how everything is connected.

Bioreactor Concept Design

Dr.Sri Harjati Suhardi gave us an insight into the future application of our project. She suggests us to build a safety containment in order to prove the GMO is safe first. Therefore, we made a bioreactor concept as the first stage of future application. We hope this concept could be enhanced and realized in the near future.

The bioreactor operates on batch mode with a hundred liters of capacity. To satisfy the air requirement, we supply 2 vvm continuously to the vessel. The medium used is 1.5 kg of molasses as a minimum carbon source. The nitrogen sources used is fish waste which amount 0.5 kg on minimum. A hundred milliliter Kanamicyn used to prevent another bacteria growth in the vessel. Sea water input for a batch operation is 100L. The diagram is given below:

There are two operation stage:

1. Inoculation Stage

On this stage, the bacteria growth until reaches quorum sensing, 1 × 107 times of the initial bacterial number. According to our growth kinetics model, the time needed to reach the quorum sensing is 10 hours. The assumption used is the bacterial growth rate is half its maximum value.

2. Degradation Stage

Sea water is pumped into vessel and the bacteria will degrade the plastic debris as well as micro-plastic. The mixing rate should be reduced in order to minimize the drag force when bacteria starts forming a biofilm on PET surface.

According to ethylene terephthalate production model, we can calculate degraded PET by stoichiometric reaction approach:

Hence, we got 0.84 mg of PET that degraded. Reaction yields can calculate by equations :

So we get yield of this reaction 49.93%(w/w), that affordable to scale up into higher production.

Productivity can also calculate based on data that we have. Productivity calculated by equation :

Productivity of the reaction is 0.00209 g(L-1 h-1). From this data, we could calculate the production capacity which is the multiplication of productivity to bioreactor capacity on a yearly basis. The production capacity would be 1.83 kg/year for a 100L bioreactor. Beside analyzing a technical side, we also calculate the economical side. The bioreactor is not purposed to be a profitable tool rather a remediation tool. Hence, we only calculate the investment and operational cost. One unit of bioreactor would need a capital cost:

To operate a single bioreactor would need a medium that cost:

We assume the bioreactor would operate on a weekly basis. Hence, the operational cost would be fitted for 52 weeks or 52 batch. The total medium cost would be 818 USD/year. Electricity cost was calculated by using national tariff which is Rp 1467/kWh or 0.11 USD/kWh. Overall, the total cost to operate a 100L bioreactor is 2467 USD/year.

Indonesia iGEM Booklet Vol. 1

Lastly, we put all the affordable knowledge into one documented media, Indonesia iGEM Booklet Vol. 1. Public engagement program gave us an overview about people awareness on synthetic biology. We are trying to increase the awareness by writing a booklet. The booklet was written in Bahasa to prevent a language barrier in the learning process. It is consist of the synthetic biology basic knowledge and our projects. The basic knowledge includes the definition of synthetic biology, part, device, and system. We also elaborate the previous, recent and future outlook of our iGEM projects. We put the past four years of ITB team human practice, dry lab, and wet lab in detail. It was our contribution to inspire another Indonesian team. The booklet then distributed to academician through an email. We hope this effort could generate more innovative solution through synbio field in Indonesia.

Conclusion