TY  - JOUR
A1  - Villalobos, Alvaro S.
A1  - Wiese, Jutta
A1  - Imhoff, Johannes F.
A1  - Dorador, Cristina
A1  - Keller, Alexander
A1  - Hentschel, Ute
T1  - Systematic affiliation and genome analysis of Subtercola vilae DB165T with particular emphasis on cold adaptation of an isolate from a high-altitude cold volcano lake
JF  - Microorganisms
N2  - Among the Microbacteriaceae the species of Subtercola and Agreia form closely associated clusters. Phylogenetic analysis demonstrated three major phylogenetic branches of these species. One of these branches contains the two psychrophilic species Subtercola frigoramans and Subtercola vilae, together with a larger number of isolates from various cold environments. Genomic evidence supports the separation of Agreia and Subtercola species. In order to gain insight into the ability of S. vilae to adapt to life in this extreme environment, we analyzed the genome with a particular focus on properties related to possible adaptation to a cold environment. General properties of the genome are presented, including carbon and energy metabolism, as well as secondary metabolite production. The repertoire of genes in the genome of S. vilae DB165\(^T\) linked to adaptations to the harsh conditions found in Llullaillaco Volcano Lake includes several mechanisms to transcribe proteins under low temperatures, such as a high number of tRNAs and cold shock proteins. In addition, S. vilae DB165\(^T\) is capable of producing a number of proteins to cope with oxidative stress, which is of particular relevance at low temperature environments, in which reactive oxygen species are more abundant. Most important, it obtains capacities to produce cryo-protectants, and to combat against ice crystal formation, it produces ice-binding proteins. Two new ice-binding proteins were identified which are unique to S. vilae DB165\(^T\). These results indicate that S. vilae has the capacity to employ different mechanisms to live under the extreme and cold conditions prevalent in Llullaillaco Volcano Lake.
KW  - cold adaptation
KW  - Subtercola vilae
KW  - genome analysis
KW  - systematic affiliation
KW  - Llullaillaco Volcano
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-197394
SN  - 2076-2607
VL  - 7
IS  - 4
ER  - 
TY  - JOUR
A1  - Imhoff, Johannes F.
A1  - Rahn, Tanja
A1  - Künzel, Sven
A1  - Keller, Alexander
A1  - Neulinger, Sven C.
T1  - Osmotic adaptation and compatible solute biosynthesis of phototrophic bacteria as revealed from genome analyses
JF  - Microorganisms
N2  - Osmotic adaptation and accumulation of compatible solutes is a key process for life at high osmotic pressure and elevated salt concentrations. Most important solutes that can protect cell structures and metabolic processes at high salt concentrations are glycine betaine and ectoine. The genome analysis of more than 130 phototrophic bacteria shows that biosynthesis of glycine betaine is common among marine and halophilic phototrophic Proteobacteria and their chemotrophic relatives, as well as in representatives of Pirellulaceae and Actinobacteria, but are also found in halophilic Cyanobacteria and Chloroherpeton thalassium. This ability correlates well with the successful toleration of extreme salt concentrations. Freshwater bacteria in general lack the possibilities to synthesize and often also to take up these compounds. The biosynthesis of ectoine is found in the phylogenetic lines of phototrophic Alpha- and Gammaproteobacteria, most prominent in the Halorhodospira species and a number of Rhodobacteraceae. It is also common among Streptomycetes and Bacilli. The phylogeny of glycine-sarcosine methyltransferase (GMT) and diaminobutyrate-pyruvate aminotransferase (EctB) sequences correlate well with otherwise established phylogenetic groups. Most significantly, GMT sequences of cyanobacteria form two major phylogenetic branches and the branch of Halorhodospira species is distinct from all other Ectothiorhodospiraceae. A variety of transport systems for osmolytes are present in the studied bacteria.
KW  - genomes of photosynthetic bacteria
KW  - glycine betaine biosynthesis
KW  - ectoine biosynthesis
KW  - osmotic adaptation
KW  - phylogeny of osmolyte biosynthesis
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-220161
SN  - 2076-2607
VL  - 9
IS  - 1
ER  -