Srivastava, Kailash Chandra;
(1975)
Effect on Temperature on Growth and Ultrastructure of Yeasts.
Doctoral thesis (Ph.D), University of London.
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Abstract
Using three different media - dextrose yeast extract peptone (DYEP)t glycerol yeast extract peptone (GLYEP), and nutrient broth (KL>) > effects cf temperature were. studied on the growth and ultrastructure of four psychrophilic yeasts: Candida gelida YS66, Cryptococcus albidus YS5, Rhodotorula rubra YSSO and Trichosporon pullulans YS17. Mesophilic counterparts of the latter 3 of these psychrophiles and 3 strains of Saccharoryces cerevisiae were also included. The experimental results showed highest growth rates and cell crop in DYEP and least in GLYEP or NB depending on the orga: ism. Both, the cell crop and growth rates, were decreased upon incubation at the non-optimum temperatures in all media. In S. cerevisiae petite mutants were induced as a result of incubation at lower restrictive temperatures. Ultrastructurally, there was a difference in the capsule an wall amongst the organisms exarained. The thickness of wall and cEtpsule changed in different media and at different temperatures There was no change in the fine structure of the capsule but there was a change in the structure of wall at some temperatures. Paramural bodies, plasmalemmasomes and lomasomes were noted in gelida YS66. Paramural bodies were also noticed in Cry. albidus YS5, cerevisiae 262 aad2 and in mesophilic T. pullula The degree of convolution of the plasmalemma was greater or smaller with variations in temperature and media. As a result; of variations in tenyperature and medium, change in number of mitochondria, nuclear pores, storage organelles and vacuoles ware noticed. Variations were also noticed in the structure and dimensions of mitochondria, nucleus and vacuoles. The endoplasmic reticulum was more extensive at lower temperatures. The volume of cells increased at temperatxires lower than the optimum temperature. Variations in other dimensions were also noted. The monosaccharide composition of capsular polysaccharide was also changed with the alteration in medium.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Effect on Temperature on Growth and Ultrastructure of Yeasts |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10207155 |
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