Table of Contents
ISRN Biotechnology
Volume 2013, Article ID 734612, 12 pages
Research Article

Effect of Potassium Ions on Protoplast Generation during Yeast Induction from Mucor circinelloides Tieghem

Department of Crop Science, Ambrose Alli University, Ekpoma, Nigeria

Received 29 June 2012; Accepted 25 July 2012

Academic Editors: B. Castiglioni and M. de L. Polizeli

Copyright © 2013 C. O. Omoifo. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Mucor circinelloides aerobically exhibits coenocytic thallic growth habit with straight and circinate sporangiophores which culminate in globose or pyriform columellae enclosed within sporangial walls. It undergoes dimorphic switch with its conversion to multipolar budding yeast-like cells or thallic conidia. This paper confirms the induction of plurality of reproductive structures of the pleomorphic microorganism in minimal medium. Furthermore, construction of pH differentials at inflection points in the biphasic profiles during sporangiospore-yeast transformation indicated the intensity of H+ release from intracellular medium of the growing microorganism in a study conducted with K+ levels (0.0, 0.5, 0.7, 0.9, 1.0,1.10 g/L)-mediated broths. Optimum proton release was at 0.00 and 1.0 g/L K+-supplemented broths, but specific growth rate was least in the latter. It also coincided with a preponderance of neoplastic units, protoplasts, and terminal budding yeast cells. On either side of this K+ level, variation in morphologies, including neoplasts, protoplasts, septate hyphae, thallic, holothallic, and holoblastic conidia, was greater, although olive-green septate hyphae with vesicular conidiogenous apparatus occurred at all K+ levels tested. This study suggested that following the establishment of transmembrane pH gradient across protoplast membrane, operation of Mitchellian proton pump was further promoted, thus leading to active transport mechanism, a prelude to yeast morphology induction.