Bioethanol

The most important thing to start this experiment is to understand mainly, what a bioreactor is. A bioreactor is a container or system that maintains a biologically active environment. In some cases, a bioreactor is a vessel in which a chemical process involving organisms or biochemically active substances derived from such organisms is carried out. This process can be aerobic or anaerobic. These bioreactors are commonly cylindrical, ranging in size from a few milliliters to cubic meters, and are usually made of stainless steel. Thanks to the use of bioreactors, science has been able to present advances in recent years, managing to create vaccines, antibiotics, produce alcoholic beverages such as wine and beers; so it was decided to try one with simple elements to see if it would produce ethane through the fermentation of a banana peel.

1 sachet of yeast

Link of reference: Levadura Tradi-Pan 55 g | Walmart

1 bacteriological loop

Link of reference: Asa Bacteriológica De Nicromo Calibre 1/1000 Roja 3mm 10 Pzs | Meses sin intereses (mercadolibre.com.mx)

blender

Link of reference:LICUADORA SUPER CHEF KOBLENZ DE 3 VELOCIDADES | The Home Depot México

1 T-shirt with distilled water

Link of reference:Piseta de seguridad para agua destilada 500ml. Modelo CRM-46046-115E Científica Vela Quin S de R.L de C.V

1 glass of alcohol

link of reference:Piseta de seguridad para etanol 500ml. Modelo CRM-46046-120E Científica Vela Quin S de R.L de C.V

1 spoon

Link of reference: Espátula - Cuchara De Laboratorio De Acero Inoxidable | MercadoLibre

2 fisher lighters

Link of reference:CHEMIT (chemitargentina.com.ar)

1 small digital autoclave

Link of reference:AUTOCLAVE DIGITAL DE 24 LITROS - GREETMED - ASIA EUROPA IMPORT SAC

lighter

Link of reference:Yeepi BBQ Long Lighter 5002B Assorted Colors (20 Units) | Gas Lighter Malaysia

1 1000 ml autoclave bottle

Link of reference:Frasco Para Laboratorio 1000ml Graduado C/ Tapa Autoclavable | Envío gratis (mercadolibre.com.mx) 1 500 ml autoclave bottle

Link of reference:Frasco Para Laboratorio 1000ml Graduado C/ Tapa Autoclavable | Envío gratis (mercadolibre.com.mx) 1 250 ml measuring cylinder

Link of reference: Probeta de vidrio - 250ml - Tu Cerveza Casera 

Refractometer

Link of reference.Refractómetro Irfora Refractómetro digital de azúcar Brix Medidor de dulzura de mano electrónico Ran Irfora Refractómetro | Walmart en línea

1 pair of asbestos gloves

Link of reference:Guante De Asbesto Guantes De Asbesto Para Objetos Calientes | Envío gratis (mercadolibre.com.mx) 3L capacity container

Link of reference:Botellas De Agua Plásticas De La Bebida De Tres 19 Litros O De 5 Galones Stock de ilustración - Ilustración de azul, reciclable: 78507062 (dreamstime.com) Indelible marker pen

Link of reference: Plumón indeleble - Sodimac.com.pe

pH strips

Link of reference:Tiras De Papel Ph Rango 0-14 Caja Con 100 | MercadoLibre

Aluminum foil

Link of reference:Papel para Regalo en Caja Despachadora - 24" x 100', Aluminio Plateado S-12353 - Uline 

Wash and blend the banana peels until you get a paste. Place 250 mL of the macerated shells in the 500 mL autoclavable laboratory bottle. label the bottle: INOCULUM, place the rest of the paste in the other 1000 mL autoclavable laboratory bottle, label it as NO INOCULUM. Sterilize both vials at 115 to 120°C for ten minutes, cool to room temperature.

After the sterilization process is finished, the jars are carefully removed and one of them is meticulously placed in a bucket with cold water to avoid any accident; the reason why it is decided to use the bucket with cold water is to cool the jar with 250ml of mixture because it will be used as an inoculum object.

After cooling, a sterile area is extended in a 30cm x 30cm perimeter and two Fisher burners are connected to the gas area and turned on, it is important that the Fisher burners are turned on because this will mark the sterile area. Under sterile conditions, inoculate the jar labeled INOCULUM with the yeast. Incubate the inoculum for eight days at room temperature.

Store the NO INOCULUM bottle in the refrigerator at 4°C until use. Sterilize the 5L glass bottle by washing it with the sanitizing solution, let it dry and store it until use. It is left for 7 days. 

Once the 8 days have passed, the inoculum liquid will be poured into the non-inoculum and stirred to transfer to the 5L jug.

The growth of the flasks will be reviewed, but especially that of the inoculated one, since what we want to know is if CO2 was generated, we know that CO2 was generated due to the pressure that was generated in the flask, the steps that were carried out were to create the perimeter sterilized, with two Fisher burners on the sides and everything previously disinfected with the help of ethanol and cotton. In a 5-liter jug, both mixtures will be put, both the inoculated and the non-inoculated ones, and they will be mixed correctly. Later, the jug will be left ajar to prevent the pressure generated by the CO2 from causing an accident. We clean everything and leave it until the next day. 

See the changes that are generated in color, in size, in pH and calculate its temperature in Brix degrees, this is done after a week and since everything is inside the 5-liter jug, monitoring any movement and waiting for it to produce ethanol, it is important to note that this is a homemade bioreactor and ethanol production is expected in a 15-day environment. 

15 days have passed and all that time the measurement was continued and step 3 continued during those days.

The crucial and most important moment for this bioreactor has arrived and that is to check if ethanol was generated. This is done as follows: 2 Fisher burners and the bioreactor in the middle are placed in a sterilized space, it is opened taking care of the presence of factors that may intervene and a small amount of the liquid produced is removed, poured with a strainer into a beaker and we put a lighter in the beaker, if combustion occurs that means that ethanol was produced, in our case there was ethanol production which leaves us with the conclusion that the bioreactor was successful.