Mass production of Baker’s Yeast

Aim:

To cultivate and mass production of Baker’s Yeast.

Introduction:

            Bakers yeast is a commercial preparation consisting of dried cells of one or more strains of the fungus Saccharomyces cerevisiae, used as a leavening in baking. Saccharomyces cerevisiae is known as top-fermenting yeast. It is one of the major types of yeast used in the brewing of beer so called because during the fermentation process it rises to top of the fermentation vessel. Beers that use top-fermenting yeast are called ales, and for that reason these yeasts are also sometimes called "ale yeasts". Top-fermenting yeasts are unable to ferment some types of sugars, and the resulting beer is sweeter and "fruitier".

Materials Required:

YPD (Yeast Extract-Peptone-Dextrose) Medium / Potato Dextrose Broth

Yeast Strain (Saccharomyces cerevisiae)

Sugarcane Molasses

Procedure:

Strain Preparation/ Seed Culture Preparation:

            The seed culture was developed by inoculating a single colony of S. cerevisiae into a growth medium. The culture was incubated at 37°C for 24 h- 48 h at 150 rpm after adjusting the pH to 7.0.

Batch culture method

Shake-flask cultures Batch cultures in 250 mL Erlenmeyer flasks were applied with 100 mL malt or molasses-based medium, inoculated with 2 mL pre-seed culture. The initial pH was adjusted to 4.5 and the flasks were incubated at 30 C with shaking at 150 rpm. Growth was monitored by measuring the absorbance at 600 nm through using a spectrophotometer by various time intervals.

Result:

The mass production of yeast in batch culture method was observed and measures the cell mass by UV spectrophotometer.

Ref:

Ehab Ragheb El-Helow, Yasser Elbahloul, Ebaa Ebrahim El-Sharouny, Sara Ramadan Ali & Atef Abdel-Mageed Ali (2015) Economic production of baker's yeast using a new Saccharomycescerevisiae isolate, Biotechnology & Biotechnological Equipment, 29:4, 705-713, DOI: 10.1080/13102818.2015.1038302