Glaciozyma Anarctica PI12: Lab Analysis

The optimal growth temperature for Glaciozyma antarctica PI12 is 12oC (Boo et al., 2013). The upper temperature limit for growth is 20oC. However, some psychrophilic yeast such as Candida psychrophila (optimal growth temperature of 15oC) can tolerate temperature up to 25oC for three hours (Deegenaars & Watson, 2006). Low temperature for the growth of Glaciozyma antarctica PI12 is difficult to determine accurately. One of the factors is the technical difficulties to determine the amount of antifreeze substrate required to be added to the media to prevent freezing, and often the amount added will cause inhibition to growth. With this limitation, a low temperature limit between -12oC, -7oC and -5oC has been used.

G. antarctica PI12 grow optimally
(2013) reported several doubling times of G. antarctica PI12 exhibited at different temperatures, 4oC (doubling time 35 h and 45 min), -7oC (doubling time 55 h and 20 min), 10oC (doubling time 38 h 25 min) and 15oC (doubling time 45 h 15 min), using Tryptic Soy Agar and broth.

The doubling time of G. antarctica PI12 in our study showed a higher doubling time as compared to Hashim et al. (2013). One of the factors that contribute to the differences is the medium used. Yeast Potato Dextrose (YPD) medium. YPD contained the yeast extract which supply all types of amino acids necessary for growth, whereas TSA contained enzymatic digested casein and soybean meat, which the component consider much complicated than YPD. This indicated that G. antarctica PI12 brew better in YPD than in TSA.

Aerobic and anaerobic analysis of Glaciozyma antarctica PI12
From the aerobic and anaerobic analysis (Figure 1C), the result showed that the growth of G. antarctica PI12 was ameliorated with oxygen. The blue line indicated the growth of G. antarctica PI12 with oxygen and the red line indicated the growth of G. antarctica PI12 without oxygen. The result can be improved by reducing the aeration for anaerobic testing in order to obtain much significant difference against aerobic
The cell division began when 1) The bud is formed from the mother cell; 2) The budding side of the mother cell is pointed due to a pulling effect; 3) The bud cell will elongate while attaching to its mother cell; 4) The bud cell elongated until the length is about the mother cell’s length; 5) The bud cell detached from the mother cell, and start another budding cycle; 6) the bud cell may not detach from the mother cell while starting another budding cycle. The same illustration was merged with the data from the DAPI signal observed from the microscopic analysis Figure 4 (B). Three major events were observed for DAPI stained cells. 1) The sphere bud is formed from the mother cell (no fluorescence found in the bud cell); 2) When the bud is large enough, some of the fluorescence signal (nucleic acids) was found in between of the budding; 3) When the fluorescence signal (nucleic acids) was found in the between the sphere bud cell and the mother cell. Nucleic division occurred at this point.

The length is defined as the longest distance from a point to another point of the cells. The cell length is different because of the budding system. In which, we defined the length below 10 µm as bud cells, whereas, any length greater than 10 µm as mature cells. The diameter, defined as the shortest distance from a point to another point of the cell is relatively constant as compared to the length, with an