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

Abstract

The Rhodococcus genus exhibits diverse enzymatic activity that can be exploited in the conversion of natural and anthropogenic nitrogenous compounds. This catalytic response provides a selective advantage in terms of available nutrients while also serving to remove otherwise harmful xenobiotics. This review provides a critical assessment of the literature on bioconversion of organonitrogen compounds with a consideration of applications in bioremediation and commercial biotechnology. By examining the major nitro-organic compounds (amino acids, amines, nitriles, amides and nitroaromatics) in turn, the considerable repertoire of Rhodococcus spp. is established. The available published enzyme reaction data is coupled with genomic characterisation to provide a molecular basis for Rhodococcus enzyme activity with an assessment of the cellular properties that aid substrate accessibility and ensure stability. The metabolic gene clusters associated with the observed reaction pathways are identified and future directions in enzyme optimisation and metabolic engineering are assessed.Alanine dehydrogenase (RHA1_ro01495, ald1, ald2) and aspartate ammonia lyase (aspA1, aspA2, aspA3), with corresponding transaminases, provide alternative ping-pong (bi-bi) systems. Specificity and cellular catalytic efficiency is extended by a number of genes encoding asparagine dehydrogenase, arginine, cysteine, histidine and serine ammonia lyase ( Table 2). The production of

The pathogenic actinobacterium Rhodococcus equi: what's in a name?

“…The metabolic complexity of the environmental Rhodococcus spp. is a likely reflection of the isolation criteria, seeking for specific abilities such as degradation of multiple aromatic pollutants, biotransformation or production of secondary metabolites (van der Geize and Dijkhuizen, ; Larkin et al , ; Yamashita et al , ; Kitagawa and Tamura, ; Holder et al , ; Foster et al , ). For example, compared to R. equi , the polychlorinated biphenyl degrader R. jostii RHA1 contains a much larger complement of unique metabolic genes, aromatic gene clusters (29 vs only three), non‐ribosomal peptide synthases (24 vs 11) and polyketide synthases (7 vs 1 in R. equi ) (McLeod et al , ; Letek et al , ).…”

A Potential of a Malaysia Strain, Rhodococcus Ukmp-5m as a Biocatalyst in Bioremediation of Nitrile

“…The genus Rhodococcus was recognised as one of the most potential microorganism besides Pseudomonads for remediation of pollutants as the strains have an extensive catabolic versatility, unique enzymatic capabilities and robust cellular physiology [28,29] and which in turn, possesses the ability to degrade large number of organic compounds, ranging from natural, xenobiotic to anthropogenic compounds with high toxicity and concentrations [30,31]. The original habitat of Rhodococcus spp also contributes to the high potential microorganism applied in bioremediation.…”

“…A range of enzymes of Rhodococcus has been reported for this matter, i.e. phenol hydroxylase, cyanide hydratase, nitrilase and nitrile hydratase [5,30].…”

O microbioma de áreas de recuo de geleiras na Ilha Rei George, Antártica

“…Estavam presentes as vias incompletas de degradação de benzoato, aminobenzoato, tolueno, xileno, estireno, esteroides, fenilacetato, catechol e ácido cinâmico. Considerando que algumas linhagens não possuem todas as enzimas para degradação total de certos xenobióticos (FOSTER et al, 2014), não é possível ter certeza se as vias incompletas são decorrentes de sua cepa ou da (in)completude do MAG. A presença de genes codificadores de urease (ureABC) também é um indicativo de biorremediação, uma vez que é sensível a óleo (ZHANG; HUO; ZHU, 2012) e atua na mineralização de metais pesados (LI; CHENG; GUO, 2013).…”