Occurrence and role of di-myo-inositol-1,1[prime]-phosphate in methanococcus igneus

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Applied and Environmental Microbiology; (United States)

OSTI ID:6872772

Ciulla, R A; Roberts, M F ^[1]; Burggraf, S; Stetter, K O ^[2]

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1. Boston College, Chestnut Hill, MA (United States)
2. Univ. of Regensburg (Germany)

Methanococcus igneus, a hyperthermophilic marine methanogen (optimum growth temperature of 88[degrees]C) with a 25-min doubling time, synthesizes an unusual inositol phosphodiester which is present at high intracellular concentrations along with L-[alpha]-glutamate and [beta]-glutamate. Identification of this compound as a dimeric inositol phosphodiester (di-myo-inositol-1,1[prime]-phosphate) was provided by two-dimensional nuclear magnetic resonance methods. The intracellular levels of all three negatively charged solutes (L-[alpha]-glutamate, [beta]-glutamate, and the inositol phosphodiester) increase with increasing levels of external NaCl, although the inositol compound shows much smaller increases with increasing NaCl levels than the glutamate isomers. The turnover of these solutes was examined by [sup 13]CO[sub 2]-pulse-CO[sub 2]-chase experiments. The results indicated that both the [beta]-glutamate and the inositol phospodiester behaved as compatible solutes and were not efficiently metabolized by cells as was L-[alpha]-glutamate. At a fixed external NaCl concentration, lower ammonium levels increased the fraction of the inositol dimer present in extracts. The most pronounced changes in di-myo-inositol-1,1[prime]-phosphate occurred as a function of cell growth temperature. While the organism grows over a relatively wide temperature range, the phosphodiester accumulated only when M. igneus was grown at temperatures of [>=]80[degrees]C. Thus, this unusual compound is a non-nitrogen-containing osmolyte preferentially synthesized at high growth temperatures. 20 refs., 4 figs., 1 tab.

• DOE Contract Number: FG02-91ER20025
• OSTI ID: 6872772
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 60:10; ISSN AEMIDF; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

550700* -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOCHEMISTRY
CHEMISTRY
ECOLOGICAL CONCENTRATION
ENZYMES
ESTERASES
HYDROLASES
METHANOGENIC BACTERIA
MICROORGANISMS
ORGANIC COMPOUNDS
PHOSPHODIESTERASES
PROTEINS
THERMOPHILIC CONDITIONS