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What conditions are the most favourable for microbial food production? -…
What conditions are the most favourable for microbial food production?
What are microbes?
Microbes are also reffered to as microorgansisms, which cause disease or fermentation; A microorganisms which causes
fermentation
occurs through metabolic reactions which produce enzymes to break down carbohydrates into sugars, which are further broken down into alcholos or carbon dioxide.
Yeasts are eukaryotic organsims which reproduce asexually, and are form up to 1500 species and more of single celled fungi. Yeast can be found in nature within soils and the surface of plants such leafs as plant nectars. Yeast has two primary uses today within the societal economy; Breadmaking and Alcohol making.
Types of Microbes
[M. Pelzcar, 2022]
Fungi
Yeast is an microorgansism from the fungi family.
Justification:
Yeast is easily accessible in the school laborotory environment, in the form of dry yeast.
Archaea
Bacteria
Protozoa
Viruses
Microorganism Reactions:
Yeast Fermentation
The formula for anaerobic respiration yeast fermentation is: C6H12O6(aq) —> 2C2H5OH(l) + 2CO2(g)
Glucose —> Ethynol + Carbon Dioxide
During yeast fermentation, the yeast cells convert glucose molecules into carbon dioxide and ethynol emmisions through yeast respiration. In breadmaking, the release of carbon dioxide causes the bread to rise, and the ethynol evaporates when baking.
Consumption of various microbes can be beneficial to th body through improving digestive and heart health.
Foods containing microbes:
Yogurt
Kimchi
Tempeh
Miso
Kombucha
Pickles
Factors which can impact the reaction of yeast fermentation
Tempurature
Temperature impacts the effectiveness of yeast fermentation, as heat induces and increases the rate of reaction between the yeast molecules and the solvent (water).
Higher temperatures provide more energy in the form of kinetic energy of the yeast activity.
Bakers use warmer temperatures to set the yeast, as this forms a larger expansion as the activated yeast within the dough.
Justification:
As mentioned, activated yeast requires to be in heat to begin fermentation. As the tempurature increases, the areobic chemical reactions also occurs more rapidly, which results with an increased amont of C02 and Ethanol production [M. Yilmaztekin et al]
Light exposure
Since it's so sensitive to light, it's often placed in a dark place so that the light does not break apart the cell membranes and destroy them.
Different colours of light destroy the cells at different rates, so this experiment will help you find out the best conditions to store and package yeast.
Justification:
Yeast cells are extremely sensitive to light, as cell membranes can be destroyed by light [Education.com]. Direct light can inhibit yeast growth and respiration/fermentation [T. Mamouneas].
pH Levels
Optimal ph levels for yeast fermentation is approximately 5.0. While yeast fermentation does not grow below approximately 2.8.Optimal growth finishes completely at around 6.0.
Justification:
Yeast cells require a slightly acidic environemnt for optimum fermentation. The ideal pH level for yeast fermentation is 4.5 to 5.0, where a pH level too low or too high can cause "chemical stress" upon the yeast cells, which impacts the rate of reaction of the yeast fermentation.
Amount of sugar/ Type of sugar
Sugar solution has to be at atleast 37 degrees to activate fermentation
Option 1: manipulate the amount of sucrose solution with a consistent amount of yeast.
Making a “dough slurry” and mixing different amounts of sugar into the slurry, them placing each into consistent temperatures of water (37)
Option 2: manipulate the type of sugar used to make the sucrose solution with a consistent amount of yeast
Making a “dough slurry” and mixing different types of sugar (brown sugar, coconut sugar, white sugar, and sweetener) into the dough. Then placing into consistent temperatures of water (37)
Justification:
One of the many requirements for yeast fermentation is a food source, sugar. Yeast cells break down glucose, which results in the release of carbon dioxide and ethanol, where 3% of sugar provides the optimum yeast fermentation demonstrated through the rise in dough (mL) [E. Buehler, 2014].
Amount of Water in dough
In lower water contents, yeast fermentations take longer to activate the yeast fermentation.
Moisture is a requirement for yeast fermentation activation
Yeast activation and the initiation of fermentation are triggered by hydration, from either water or some other liquid, and the presence of a food source [S. Phillips, 2000]
Justification:
Yeast fermentation requires many factors for activation: Heat, food and
moisture
. Yeast is activated through hydration, from water or any liquid source, as well as a food source, such as sugar [S. Phillips, 2000]