Biotechnology of Rhodococcus for the production of valuable compounds

Abstract

Bacteria belonging to Rhodococcus genus represent ideal candidates for microbial biotechnology applications because of their metabolic versatility, ability to degrade a wide range of organic compounds, and resistance to various stress conditions, such as metal toxicity, desiccation, and high concentration of organic solvents. Rhodococcus spp. strains have also peculiar biosynthetic activities that contribute to their strong persistence in harsh and contaminated environments and provide them a competitive advantage over other microorganisms. This review is focused on the metabolic features of Rhodococcus genus and their potential use in biotechnology strategies for the production of compounds with environmental, industrial, and medical relevance such as biosurfactants, bioflocculants, carotenoids, triacylglycerols, polyhydroxyalkanoate, siderophores, antimicrobials, and metal-based nanostructures. These biosynthetic capacities can also be exploited to obtain high value-added products from low-cost substrates (industrial wastes and contaminants), offering the possibility to efficiently recover valuable resources and providing possible waste disposal solutions. Rhodococcus spp. strains have also recently been pointed out as a source of novel bioactive molecules highlighting the need to extend the knowledge on biosynthetic capacities of members of this genus and their potential utilization in the framework of bioeconomy. Key points • Rhodococcus possesses promising biosynthetic and bioconversion capacities. • Rhodococcus bioconversion capacities can provide waste disposal solutions. • Rhodococcus bioproducts have environmental, industrial, and medical relevance.

Processing of Metals and Metalloids by Actinobacteria: Cell Resistance Mechanisms and Synthesis of Metal(loid)-Based Nanostructures

“…[ 66 , 77 ], and in the binding and chelating of As 3+ cations in A. oxydans ATW2 and ATW3, Kokuria rosea ATW4, R. erythropolis ATW1 and S43 under Fe-deficiency [ 72 ]. Particularly, Fe- or As-siderophore complexes extracted from A. oxydans ATW3 and R. erythropolis ATW1 showed distinct physical-chemical characteristics, indicating the occurrence, in Actinobacteria, of multiple co-existing chelators with different metal(loid) selectivity [ 16 , 72 ].…”

“…In particular, the survival and development of bacteria in extreme and harsh environments (e.g., in the presence of toxic metals) is allowed by the evolution of inducible mechanisms associated with specific genetic traits (i.e., referred to as resistance) and/or adaptation ones related to intrinsic biochemical features (i.e., referred to as tolerance) [ 15 ]. These metabolic activities can be exploited to lower metal(loid) concentration to acceptable and safe levels in order to restore contaminated ecological niches and metal transformation for their recovery (e.g., metal-based nanostructure bioproduction) [ 16 ].…”

Systems biology and metabolic engineering of Rhodococcus for bioconversion and biosynthesis processes

“…Other valuable compounds that can be produced by Rhodococcus spp. strains are glycolipid biosurfactants, carotenoids, polyhydroxyalkanoates (PHAs), metal-based nanomaterials, and novel antimicrobials (Cappelletti et al 2020). While experimental works have mostly investigated culture conditions and suitable substrates for efficient biotechnological applications, the identification of specific genes/proteins involved in these biosynthetic pathways has been for a long time hindered by the lack of efficient molecular methods/tools generally applicable to Rhodococcus spp.…”

“…Previous reviews summarize the regulation and the metabolic pathways involved in lipid accumulation in Rhodococcus (Alvarez et al 2019), the different valuable compounds biosynthesized by members of this genus (Cappelletti et al 2020) and those specifically derived from lignocellulose/lignin bioconversion (Anthony et al 2019). Conversely, the present review is focused on the main genetic manipulation and metabolic engineering strategies applied to modify this genus strains to extend and optimize their biosynthetic capabilities and biotechnological applications (summarized in Table 1; Figs.…”

Detection of Rhodococcus fascians, the Causative Agent of Lily Fasciation in South Korea

“…The genus Rhodococcus contains Gram-positive aerobic bacterial species belonging to the phylum Actinobacteria. These bacteria can be isolated from water, soil, and marine habitats, including harsh ecological regions such as the Arctic, deserts, and heavily polluted areas [ 1 , 2 ]. Interest in Rhodococcus species has been increasing because of their biotechnological applications and potential in bioremediation [ 3 , 4 ].…”