Cyclodextrin glycosyltransferase: a key enzyme in the assimilation of starch by the halophilic archaeon Haloferax mediterranei.

A cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.

Gene cloning, heterologous overexpression and optimized refolding of the NAD-glutamate dehydrogenase from Haloferax mediterranei.

The NAD-dependent glutamate dehydrogenase (GDH) gene from the halophilic archaeon Haloferax mediterranei has been cloned. The analysis of the nucleotide sequence revealed an open reading frame of 1323 bp that encodes a NAD-GDH. The amino acid sequence displayed high homology with those from other sources, especially the highly conserved residues involved in 2-oxoglutarate binding.

Occurrence of two different glutamate dehydrogenase activities in the halophilic bacterium Salinibacter ruber.

Salinibacter ruber, an extremely halophilic member of the domain Bacteria, has two different cytoplasmic glutamate dehydrogenase activities, marked as GDHI and GDHII. GDHI showed a strong dependence on high salt concentrations for stability, but not for activity, displaying maximal activity in the absence of salts. GDHII depended on high salt concentrations for both activity and stability.

Large-scale cultivation of acidophilic hyperthermophiles for recovery of secreted proteins.

An electric water heater was modified for large-scale cultivation of aerobic acidophilic hyperthermophiles to enable recovery of secreted proteins. Critical changes included thermostat replacement, redesign of the temperature control circuit, and removal of the cathodic anticorrosion system. These alterations provided accurate temperature and pH control.

Targeted disruption of the alpha-amylase gene in the hyperthermophilic archaeon Sulfolobus solfataricus.

Sulfolobus solfataricus secretes an acid-resistant alpha-amylase (amyA) during growth on starch as the sole carbon and energy source. Synthesis of this activity is subject to catabolite repression. To better understand alpha-amylase function and regulation, the structural gene was identified and disrupted and the resulting mutant was characterized.