The Fine Structure of Yeast Regenerating Protoplasts

Abstract

The process of regeneration of Candida utilis and Pichia polymorpha protoplasts obtained by means of an enzyme preparation from Streptomyces violaceus M R and an enzyme preparation from the snail (Helix pomatia) was followed with the electron microscope. A reticular network of fibrils making up a tube or surrounding the regenerating protoplasts was observed. The fibrils are glucan fibrils, and in C . utilis they are packed in groups of 5 or 6. P. polymorpha fibrils occurred singly. The fibrils are the framework for building the new cell wall. The relation between fibrils and plasmalemma particles is discussed.

Dynamics of Cell Wall Formation in Fission Yeast,Schizosaccharomyces pombe

“…When protoplasts of S. cerevisiae and several other species of yeasts were incubated in an osmotically stabilized liquid medium, a dense microfibrillar network composed of glucans, particularly ␤-glucan, was formed on the protoplast surface (Eddy and Williamson, 1959;Kopecká et al, 1967;Kopecká, 1975, 1978;Nečas, 1965;Popob et al, 1980;Uruburu et al, 1968). Gobal et al (1984) also reported that a similar type of fibrillar glucan network was formed on reverting protoplasts of C. albicans.…”

Cell wall synthesis in yeast protoplasts.

“…Uruburu et al (112) described osmotic-resistant tubular forms in growing C utilis and Pichia polymorpha protoplasts. Their aberrant cell walls consisted of a fibrillar framework.…”

Metabolism of [14C]Glucose by Regenerating Spheroplasts of Candida albicans

“…2). In addition, electron and light microscopy have indicated that spheroplasts synthesize the major part of the wall during the first 6 h incubation (Popov et al, 1980;Uruburu et al, 1968;Necas, 1971). Regenerating spheroplasts showed a faster rate of glucose removal from the medium (Fig.…”

“…Glucose (5 mM) gave a suitable compromise between maximum incorporation and glucan with a high specific activity. In previous studies on the reversion of fungal protoplasts, the composition of the medium used varied from simple, like that used in the present study (Uruburu et al, 1968) to complex (FarkBs & Svoboda, 1980). Wessels et al (1976) concluded that, after removal of the lytic enzymes used in protoplast formation, little else besides a carbon source is required to obtain regeneration.…”