Novel Methylotrophy Genes of Methylobacterium extorquens AM1 Identified by using Transposon Mutagenesis Including a Putative Dihydromethanopterin Reductase

Ten novel methylotrophy genes of the facultative methylotroph Methylobacterium extorquens AM1 were identified from a transposon mutagenesis screen. One of these genes encodes a product having identity with dihydrofolate reductase (DHFR). This mutant has a C(1)-defective and methanol-sensitive phenotype that has previously only been observed for strains defective in tetrahydromethanopterin (H(4)MPT)-dependent formaldehyde oxidation. These results suggest that this gene, dmrA, may encode dihydromethanopterin reductase, an activity analogous to that of DHFR that is required for the final step of H(4)MPT biosynthesis

Genomics of psychrophilic bacteria and archaea

Genomes are available for a wide range of psychrophilic bacteria and archaea. As of early 2017, approximately 130 cold-adapted species have genome sequences. Several studies complement this data with functional studies. In this review the cold adaptation traits of psychrophilic microorganisms are explored from a genome-centric point of view including surveys of traits across genomes. A broader view of psychrophiles in terms of growth rates amongst life on Earth explaining what a psychrophile represents is presented. Trait surveys, limited to the perspective of gene gain, reveal prevalence of genes demonstratively providing better growth at low temperature including compatible solute uptake and synthesis, antifreeze proteins and polyunsaturated fatty acids and investigate their functional relevance to psychrophily. This includes revealing prevalent antifreeze DUF3494-type proteins that occur in all domains of life but is limited to cold-adapted taxa and is absent in higher-temperature adapted life