Overview of our experiment

Objective

After performing this experiment we should be able:

• To describe well about every part of bioreactor component
•  To understand basic steps in bioreactor preparation
•  To handle basic operation procedure of a bioreactor
• To carrying out of yeast ( Saccharomyces cerevisiae ) fermentation using batch mode
• To conduct an analysis on determination of the cell concentration and measuring glucose uptake by yeast
• To monitor fermentation profile and behavior

What is actually happened during our practical class?

         (Day 1) 

·         Unpack the bioreactor that just arrived from Swiss. Very far isn’t it??

·         Familiarization with the Bioreactor and its Operation conducted by our coordinator, Mr. Shaman from Infors.

·         Seed Culture Preparation

       (Day 2) 

·         Equipment and media sterilization. 

   (Day 3) 

·         Inoculation, fermentation and monitoring.

·         Sampling. Came to our lab at midnight & early in the morning.

·         Lunch together at KFC. The most exciting & enjoyable moment.

   (Day 4)

·         Fermentation stop

·         Cleaning and washing

·         Fermentation profile analysis using IRIS software

Introduction

Our experiment is on carry on as below:

Figure 1: Overview flow chart of fermentation step

We are using Minifors fermenter that is made by Swiss Company name Infors. The fermenter system consist the basic usual process parameters for fermentation.

• Stirrer speed (rpm)
• Temperature
• pH
• pO₂
• Antifoam/level
• Feed
• PC Software: Iris

Figure 2: Minifors fermenter

Saccharomyces cerevisiae is used in this practical class and commonly known as "baker’s yeast" or "brewer’s yeast". The yeast ferments sugars present in medium, giving off carbon dioxide (CO₂) and alcohol (ethanol).

Figure 3: Glucose utilization pathway of Saccharomyces cerevisiae

Explain the purpose of each ingredient found in the YPEG media.

The ingredients found in the YPEG media are:

·         Yeast extract                                       1 %

·         Peptone                                               2 %

·         Glucose                                               2 %

·         Added with dH₂O.

Peptone contains amino acids that promote to the growing of the cells.

Yeast extract is used to provide organic compounds, vitamins and certain trace elements that helpful for yeast growth.

Glucose is a simple form of sugar, serve as a carbon sources for the yeast.

Distilled water is used to suspend the solids to dissolve it.

Why is it to calibrate the pH probe?

Calibration of the pH probe is used in 2 different buffer solutions (pH 7 and pH 4) to ensure the success of the pH measurement and proper subsequent maintenance of the probe.