Extracellular Phosphomannan as a Phosphate Reserve in the Yeast Kuraishia capsulata

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L. P. Lichko, T. V. Kulakovskaya^*, and I. S. Kulaev

Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, pr. Nauki 5, 142290 Pushchino, Moscow Region, Russia; fax: (495) 956-3370; E-mail: alla@ibpm.pushchino.ru

^* To whom correspondence should be addressed.

Received February 21, 2013; Revision received February 26, 2013

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We have found that extracellular phosphomannan is the main phosphate reserve in the yeast Kuraishia capsulata, in contrast to other yeast species effectively absorbing P_i. Under nitrogen starvation, K. capsulata absorbed essentially all P_i from the medium containing 240 mM glucose, 2.5 mM MgSO₄, and 11 mM KH₂PO₄. Inorganic polyphosphate level in the cells was about 14% of the P_i absorbed. Most of the P_i (~60%) was found in the fraction of extracellular phosphomannan that can be used as a carbon and phosphorus source by this yeast in deficient media.

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KEY WORDS: inorganic polyphosphate, phosphomannan, phosphate accumulation, nitrogen deficit, yeast, Kuraishia capsulata

DOI: 10.1134/S0006297913060138

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