[Halomonas chromatireducens sp. nov., a new denitrifying facultatively haloalkaliphilic bacterium from soda salt marshes capable of aerobic chromate reduction].

A heterotrophic bacterial strain AGD 8-3 capable of denitrification under extreme haloalkaline conditions was isolated from soda solonchak soils of the Kulunda steppe (Russia). The strain was classified within the genus Halomonas. According to the results of 16S rRNA gene sequencing, Halomonas axialensis, H. meridiana, and H. aquamarina are most closely related to strain AGD 8-3 (96.6% similarity). Similar to other members of the genus, the strain can grow within a wide range of salinity and pH. The strain was found to be capable of aerobic reduction of chromate and selenite on mineral media at 160 g/l salinity and pH 9.5-10. The relatively low level of phylogenetic similarity and the phenotypic characteristics supported classification of strain AGD 8-3 as a new species Halomonas chromatireducens.

[Microbial communities on the monuments of Moscow and St. Petersburg: biodiversity and trophic relations]. / Mikrobnye soobshchestva na mramornykh pamiatnikakh Sankt-Peterburga i Moskvy: vidovoi sostav (raznoobrazie) i troficheskie vzaimootnosheniia.

Stone monuments situated in the Alexander Nevsky Abbey, the Summer Garden, and the Smolenskoe Cemetery, St. Petersburg, and marble and limestone sculptures and tombstones situated in the Novodevichy Convent and the Donskoy Monastery, Moscow, were investigated for their microbial contamination. The architectural objects studied date to the 12th century. The monuments in the Alexander Nevsky Abbey were found to be severely contaminated with micromycetes belonging to 24 genera (primarily of the class Deuteromycetes). The analysis of the samples taken from the monuments of the Donskoy Monastery by the serial dilution technique showed that they were contaminated with bacteria at a density of (1-1.7) x 10(5) cells/g. This value, however, turned out to be 1 to 2 orders greater when the bacterial population was evaluated by the luciferin-luciferase method. We succeeded in identifying 12 bacterial genera; however, this number may be increased in the course of further studies. Some preventive measures to control the biodeterioration of stone heritage are discussed.