Role of amine oxidase expression to maintain putrescine homeostasis in Rhodococcus opacus

The repertoire of nitrogen assimilation in Rhodococcus: catalysis, pathways and relevance in biotechnology and bioremediation

“…Such evolutionary pressures have lead to a diverse array of enzymes frequently with plasticity to act on chemically related substrates and periodically prevalent energy sources and essential nutrients . Full exploitation of Rhodococcus in bioremediation and biotechnology therefore requires a fundamental understanding of these processes from both a genomic and enzymatic perspective, and an appreciation of their role within the organism as part of the nitrogen cycle and associated regulatory aspects (repression and induction). We evaluate here the physiological and genomic basis for catalytic activity/selectivity and identify candidate genes in nitrogen assimilation.…”

“…This is distinct from the action of taurine dioxygenase, which generates ammonia and is utilised by Rhodococcus principally for sulphur assimilation . Genomic and proteomic analyses have also identified a new class of acetonitrile hydratase and a putrescine degradation pathway that utilises amine oxidases . In addition to enzymes that have been characterised, metabolic clusters of genes found throughout the genome provide insight into probable reaction mechanisms in the bacterium.…”

“…They are established carcinogens with recorded incidences of human cancer linked to the industrial production and handling of amines . It is recognised that bio‐conversion of amines has a critical role to play in environmental remediation, treatment of livestock waste, wine, fish and meat spoilage, enantioselective synthesis of fine chemicals and pathogenesis and diagnosis . While bacteria can utilise amines through the action of amine dehydrogenases or catabolic routes found in Pseudomonas and Paracoccus denitrificans , deamination in Rhodococcus is normally promoted by amine oxidases.…”

“…can be linked to substrate specificity, facilitating effective amine utilisation at low available nitrogen concentration . Recent work has established three copper dependant oxidases in Rhodococcus opacus DSM 43250, induced by pre‐treatment with aliphatic monoamines, diamines and primary aromatic amines as sole nitrogen source . van Hellemond and co‐workers identified a homologue (92% identities) of a FAD dependant putrescine oxidase isolated from Rhodococcus erythropolis .…”

“…Microbial diamine specific oxidases have been explicitly characterised in Rhodococcus spp. and Micrococcus rubens but a wider distribution has been proposed . These oxidases act to modulate intracellular putrescine, an amine that alters transcription and growth, ensuring viability in response to a range of stressors that impact on pollution treatment strategies, such as pH, oxygen radicals, ultraviolet light, γ‐radiation and antibiotics .…”