Desulfurococcus fermentans sp. nov., a novel hyperthermophilic archaeon from a Kamchatka hot spring, and emended description of the genus Desulfurococcus

Abstract

An obligately anaerobic, hyperthermophilic, organoheterotrophic archaeon, strain Z-1312T, was isolated from a freshwater hot spring of the Uzon caldera (Kamchatka Peninsula, Russia). The cells were regular cocci, 1–4 μm in diameter, with one long flagellum. The cell envelope was composed of a globular layer attached to the cytoplasmic membrane. The temperature range for growth was 63–89 °C, with an optimum between 80 and 82 °C. The pH range for growth at 80 °C was 4·8–6·8, with an optimum at pH 6·0. Strain Z-1312T grew by hydrolysis and/or fermentation of a wide range of polymeric and monomeric substrates, including agarose, amygdalin, arabinose, arbutin, casein hydrolysate, cellulose (filter paper, microcrystalline cellulose, carboxymethyl cellulose), dextran, dulcitol, fructose, lactose, laminarin, lichenan, maltose, pectin, peptone, ribose, starch and sucrose. No growth was detected on glucose, xylose, mannitol or sorbitol. Growth products when sucrose or starch were used as the substrate were acetate, H2 and CO2. Elemental sulfur, thiosulfate and nitrate added as potential electron acceptors for anaerobic respiration did not stimulate growth when tested with starch as the substrate. H2 at 100 % in the gas phase did not inhibit growth on starch or peptone. The G+C content of the DNA was 42·5 mol%. 16S rRNA gene sequence analysis placed the isolated strain Z-1312T as a member of the genus Desulfurococcus, where it represented a novel species, for which the name Desulfurococcus fermentans sp. nov. (type strain Z-1312T=DSM 16532 T=VKM V-2316T) is proposed.

Polyamine analysis of methanogens, thermophiles and extreme halophiles belonging to the domain Archaea

“…It is speculated that the production of spermine (343) and thermopentamine (3343) from spermidine (34) is more dominant than the production of norspermine (333) and caldopentamine (3333) from norspermidine (33), in A. pernix at a higher temperature. Norspermidine, spermidine, homospermidine, norspermine, spermine ( and thermospermine ) were detected in Desulfurococcus fermentans 32) of the order Desulfurococcales as well as three other Desulfurococcus species previously analyzed. 'Caldococcus noboribetus' 3) and Ignisphaera aggregans 31) belonging to this order contained norspermine as a major polyamine.…”

Identification and characterization of a multidomain hyperthermophilic cellulase from an archaeal enrichment

“…The list includes the archaeon D. fermentans (up to 89 °C), and the bacterium C. bescii 6,19 . C. bescii was recently reported to grow at up to 90 °C on Avicel, filter paper and switchgrass 19 .…”

“…To date, only one hyperthermophilic archaeon, Desulfurococcus fermentans, demonstrated growth on crystalline cellulose (filter paper) at an optimum temperature of 81 °C (ref. 6). The genome sequences of many species of hyperthermophilic archaea do encode endoglucanases, notably Pyrococcus and Sulfolobus spp.…”

Complete Genome Sequence of Desulfurococcus fermentans, a Hyperthermophilic Cellulolytic Crenarchaeon Isolated from a Freshwater Hot Spring in Kamchatka, Russia

“…esulfurococcus fermentans, a hyperthermophilic crenarchaeon belonging to the Desulfurococcaceae family, is the first reported cellulytic archaeon (6). It was isolated from a freshwater hot spring of the Uzon caldera on the Kamchatka peninsula, Russia.…”

“…It ferments cellulose and various other carbohydrates (fructose, lactose, maltose, ribose, and starch) and peptides in peptone and casein hydrolysate for growth and produces hydrogen in the process (6); hydrogen production is not impeded by hydrogen accumulation (6). In contrast, other Desulfurococcus species do not utilize cellulose, are inhibited by hydrogen, and require elemental sulfur for growth (1,4,6,7,9); reduction of sulfur to H 2 S removes inhibition by hydrogen. D. fermentans neither requires nor is stimulated by elemental sulfur (6).…”