- Volume 62, Issue Pt_7, 2012

A Gram-stain-negative, rod-shaped bacterium (strain K-39T) was isolated from the thermophilic phase of the composting process for oyster mushroom substrate preparation. The strain grew at 40–80 °C (optimum, 65–75 °C), at pH 5–9 (optimum, pH 7), in media containing up to 1.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain K-39T formed a distinct lineage within the genus Thermus . Its closest cultivated relative was Thermus islandicus PRI 3838T (96.8 % similarity). The DNA G+C content of strain K-39T was 71.3 mol%. The new strain could be differentiated from the related taxa by not being able to hydrolyse starch. The predominant fatty acids of strain K-39T were iso-C17 : 0 and anteiso-C17 : 0. Strain K-39T contained a lower amount of the fatty acid iso-C15 : 0 as compared to related species of the genus Thermus . The predominant respiratory quinone of the new isolate was menaquinone MK-8. On the basis of a taxonomic study using a polyphasic approach, strain K-39T is considered to represent a novel species of the genus Thermus , for which the name Thermus composti sp. nov. is proposed. The type strain is K-39T ( = DSM 21686T = NCAIM B 02340T).

Two strains of subdivision 1 Acidobacteria , a pink-pigmented bacterium KA1T and a colourless isolate WH120T, were obtained from acidic Sphagnum peat and wood under decay by the white-rot fungus Hyploma fasciculare, respectively. Cells of these isolates were Gram-negative-staining, non-motile, short rods, which were covered by large polysaccharide capsules and occurred singly, in pairs, or in short chains. Strains KA1T and WH120T were strictly aerobic mesophiles that grew between 10 and 33 °C, with an optimum at 22–28 °C. Both isolates developed under acidic conditions, but strain WH120T was more acidophilic (pH growth range 3.5–6.4; optimum, 4.0–4.5) than strain KA1T (pH growth range 3.5–7.3; optimum , 5.0–5.5). The preferred growth substrates were sugars. In addition, the wood-derived isolate WH120T grew on oxalate, lactate and xylan, while the peat-inhabiting acidobacterium strain KA1T utilized galacturonate, glucuronate and pectin. The major fatty acids were iso-C15 : 0 and iso-C17 : 1ω8c; the cells also contained significant amounts of 13,16-dimethyl octacosanedioic acid. The quinone was MK-8. The DNA G+C contents of strains KA1T and WH120T were 54.1 and 51.7 mol%, respectively. Strains KA1T and WH120T displayed 97.8 % 16S rRNA gene sequence similarity to each other. The closest recognized relatives were Acidobacterium capsulatum and Telmatobacter bradus (93.4–94.3 % 16S rRNA gene sequence similarity). These species differed from strains KA1T and WH120T by their ability to grow under anoxic conditions, the absence of capsules, presence of cell motility and differing fatty acid composition. Based on these differences, the two new isolates are proposed as representing a novel genus, Acidicapsa gen. nov., and two novel species. Acidicapsa borealis gen. nov., sp. nov. is the type species for the new genus with strain KA1T ( = DSM 23886T = LMG 25897T = VKM B-2678T) as the type strain. The name Acidicapsa ligni sp. nov. is proposed for strain WH120T ( = LMG 26244T = VKM B-2677T = NCCB 100371T).

A strain of a novel mucoralean fungus was isolated from a nest of the invasive paper wasp, Polistes dominulus. Phylogenetic analysis based on the internal transcribed spacer (ITS) regions and 5.8S rRNA gene sequences, along with physiological tests, revealed that this strain represents a novel species within the genus Mucor. The novel species also includes a representative that had previously been characterized as part of the Mucor hiemalis complex. Unlike the type strain of M. hiemalis, these two strains can grow at 37 °C and sporulate at 35 °C. Here, we present a partial resolution of the M. hiemalis species complex and propose the novel species Mucor nidicola sp. nov. to accommodate the isolate; the type strain of M. nidicola is F53T ( = NRRL 54520T = UAMH 11442T = CBS 130359T).

A novel anamorphic yeast, strain LTH 6662T, was isolated from cassava sourdough. The isolate supposedly originated from cassava flour or was a contaminant thereof. Sequencing of the D1/D2 domain of the 26S rRNA gene indicated that strain LTH 6662T represents a novel species. Its closest relatives were members of the Cryptococcus humicola complex. The novel strain had several physiological characteristics that differed from those of related species: the ability to assimilate raffinose and cadaverine; the inability to assimilate soluble starch, xylitol, galactitol, butane-2,3-diol, sodium nitrite and lysine; the ability to grow without vitamins and at 42 °C; and the inability to produce starch-like substances. Its major ubiquinone was Q-10. In addition, buds were formed on small neck-like structures. In liquid medium, green or blue fluorescent substances were produced. The name Cryptococcus thermophilus sp. nov. is proposed, with LTH 6662T ( = DSM 19443T = CBS 10687T) as the type strain.