Traditional yeast screening, biochemical profiling and identification testing in Ziziphus mauritiana

Author

Mbayimbayi, Lovedale.

Title

Traditional yeast screening, biochemical profiling and identification testing in Ziziphus mauritiana

Abstract

The study of yeasts associated with fruits has gained significant attention in recent years due to their potential for biotechnological applications. Ziziphus mauritiana fruits fall into this category and have been studied extensively due to their potential applications in food and beverage production. This study aimed to investigate the yeast diversity present in Ziziphus mauritiana through traditional screening methods, by conducting biochemical profiling. It was hypothesized that Ziziphus mauritiana contain a diverse range of yeast species with the potential of novel strains with unique advantageous properties. Masau fruit samples were collected in the Dande area and they were collected as dried Masau fruits from the trees and markets.
In order to characterize yeasts associated with Ziziphus mauritiana., morphological tests were employed, which involved isolating and identifying the yeasts through techniques such as culturing on selective media while inhibiting the growth of other bacteria and microscopic analysis. Altogether 13 yeast isolates were obtained from the fruit samples using the pour plate and streak plate method. Characterization of the yeasts using several biochemical tests (urease, catalase, glucose assimilation and sugar fermentation tests) revealed that this pool of yeast strains belong to genera of Saccharomyces, Candida, Pichia, and Issatchenkia. The samples were serially diluted (10-1to 10-10) with 0.1% peptone water solution. Yeasts in the above dilutions were isolated and enumerated using pour plate technique. The total colony counts calculated were 1.14 × 1013 cfu/ml, 1.67 × 1013 cfu/ml, and 1.98 × 1013 cfu/ml from the dilutions of 1 x 10-10 from Sabouraud Dextrose Agar (SDA), Potato Dextrose Agar (PDA) and Yeast Extract Agar (YEA) respectively.
One-way ANOVA analysis showed statistically significant differences between the means of colony plate counts of the three selective growth media used to culture the yeasts (p=0.00642<0.05). However, further research should be done on identifying and isolating specific strains of masau yeast that are most suitable for alcoholic beverage production using advanced techniques such as molecular identification using DNA sequencing.

Date

May 2024

Publisher

BUSE

Keywords

Yeast screening,

Biochemical profiling,

Testing in Ziziphus mauritiana.

Supervisor

Prof. Zvidzai,