Vassle, från miljöproblem till mervärdesprodukt via Candida intermedia?
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Typ
Examensarbete på kandidatnivå
Program
Publicerad
2020
Författare
Gold Rodal, Iris
Johansson, Julia
Johansson, Anton
Nielsen-Munk, Cornelia
Schiller, Alice
Svensson, Johanna
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
In the endeavor of making the dairy industry more environmentally sustainable, a
resource with potential is cheese whey, a high nutrient and low monetary valued byproduct
of cheese manufacturing. This study explores the potential for the utilization
of cheese whey as a nutrient source for microbial cultivation of the yeast Candida
intermedia. The aim is to optimize batch growth conditions for C. intermedia with
regard to maximization of the yeast biomass titer, by means of experimental design.
Employing synthetic cheese whey of varying composition as culture media, factors
related to growth conditions were screened against the response in yeast concentration.
This was done using a De nitive Screening Design as experimental setup. The
most in
uential factors, lactose and vitamin concentrations as well as temperature,
were then optimized by response surface methodology applying a Central Composite
Orthogonal Design. After 72 h of growth under the predicted optimal conditions, a
12% higher biomass titer was attained in comparison to the initially proposed growth
conditions. The recorded speci c growth rates were similar. However, the yeast biomass
yield for the optimized growth conditions were lower than for the original. In
conclusion, these results show the great potential of combining experimental design
and wet lab yeast cultivations for optimizing yeast biomass production. The project
has resulted in an increased understanding of factors in
uencing C. intermedia's capacity
to convert nutrients in whey to yeast biomass and is thereby one step towards
a future industrial implementation.