Singulispaera mucilagenosa sp. nov., a novel acid-tolerant representative of the order Planctomycetales

• Published in: Microbiology (New York) Vol. 80; no. 1; pp. 101 - 107
• Main Authors: Zaicnikova, M. V, Berestovskaya, Yu. Yu, Akimov, V. N, Kostrikina, N. A, Vasilieva, L. V
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : SP MAIK Nauka/Interperiodica 01.02.2011; SP MAIK Nauka/Interperiodica
• Subjects: Biomedical and Life Sciences; Experimental Articles; Life Sciences; Medical Microbiology; Microbiology; Planctomycetales; xylotrophic community; planctomycetes; low-mineral waters; wood decomposition; acid-tolerant bacteria
• ISSN: 0026-2617; 1608-3237
• DOI: 10.1134/S002626171101019X

Two novel strains of budding bacteria, Z-0071T and Z-0072, were isolated from dystrophic humified waters formed by xylotrophic fungi in the course of spruce wood degradation. The cells of both strains are coccoid (0.95-1.80 μm), nonmotile, single or arranged in pairs. The cells have a complex system of intracellular membranes and are covered with fimbriae and surrounded by a mucous capsule up to 0.3 μm thick. Both strains are aerobic organoheterotrophic, mesophilic, and acid-tolerant microorganisms that are able to grow under microaerobic conditions. They utilize N-acetyl-glucosamine, carbohydrates, and lactate as growth substrates. The strains grow in a pH range of 4.0-7.5 with an optimum at 6.0-6.5. The temperature range for growth is 4-30°C, with an optimum at 25-28°C. Strains Z-0071T and Z-0072, inhabitants of dystrophic low-mineral waters, are NaCl-sensitive: the NaCl content in the media above 0.5 g/l inhibited growth. The main fatty acids of strains Z-0071T and Z-0072 are C₁₆:₀, C₁₈:₁ω₉c, and C₁₈:₂ω₉c, ₁₂c. The DNA G + C base content is 51.2-51.7 mol %. The sequences of the 16S rRNA gene fragments (1310 bp) of strains Z-0071T and Z-0072 were found to be identical. The obtained sequences showed a 94.3% similarity with the sequences of the type strain of the most closely related species Singulisphaera acidiphila MOB10≅T. The phenotypic and phylogenetic properties of strains Z-0071T and Z-0072 support classification of these strains within the genus Singulisphaera as a new species Singulisphaera mucilagenosa sp. nov., with the type strain Z-0071T (VKM B-2626).