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Folia Microbiologica Oct 2021Rhodococcus spp. strains are widespread in diverse natural and anthropized environments thanks to their high metabolic versatility, biodegradation activities, and unique... (Review)
Review
Rhodococcus spp. strains are widespread in diverse natural and anthropized environments thanks to their high metabolic versatility, biodegradation activities, and unique adaptation capacities to several stress conditions such as the presence of toxic compounds and environmental fluctuations. Additionally, the capability of Rhodococcus spp. strains to produce high value-added products has received considerable attention, mostly in relation to lipid accumulation. In relation with this, several works carried out omic studies and genome comparative analyses to investigate the genetic and genomic basis of these anabolic capacities, frequently in association with the bioconversion of renewable resources and low-cost substrates into triacylglycerols. This review is focused on these omic analyses and the genetic and metabolic approaches used to improve the biosynthetic and bioconversion performance of Rhodococcus. In particular, this review summarizes the works that applied heterologous expression of specific genes and adaptive laboratory evolution approaches to manipulate anabolic performance. Furthermore, recent molecular toolkits for targeted genome editing as well as genome-based metabolic models are described here as novel and promising strategies for genome-scaled rational design of Rhodococcus cells for efficient biosynthetic processes application.
Topics: Biodegradation, Environmental; Genome, Bacterial; Genomics; Metabolic Engineering; Rhodococcus; Systems Biology
PubMed: 34215934
DOI: 10.1007/s12223-021-00892-y -
Applied Microbiology and Biotechnology Oct 2020Bacteria belonging to Rhodococcus genus represent ideal candidates for microbial biotechnology applications because of their metabolic versatility, ability to degrade a... (Review)
Review
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. Graphical abstract.
Topics: Biotechnology; Industrial Waste; Refuse Disposal; Rhodococcus; Triglycerides
PubMed: 32918579
DOI: 10.1007/s00253-020-10861-z -
Plants (Basel, Switzerland) Sep 2020Steroids are a group of organic compounds that include sex hormones, adrenal cortical hormones, sterols, and phytosterols. In mammals, steroid biosynthesis starts from... (Review)
Review
Steroids are a group of organic compounds that include sex hormones, adrenal cortical hormones, sterols, and phytosterols. In mammals, steroid biosynthesis starts from cholesterol via multiple steps to the final steroid and occurs in the gonads, adrenal glands, and placenta. This highly regulated pathway involves several cytochrome P450, as well as different dehydrogenases and reductases. Steroids in mammals have also been associated with drug production. Steroid pharmaceuticals such as testosterone and progesterone represent the second largest category of marketed medical products. There heterologous production through microbial transformation of phytosterols has gained interest in the last couple of decades. Phytosterols being the plants sterols serve as inexpensive substrates for the production of steroid derivatives. Various genes and biochemical pathways involved in phytosterol degradation have been identified in many Rhodococcus and Mycobacterium species. Apart from an early investigation in mammals, presence of steroids such as androsteroids and progesterone has also been demonstrated in plants. Their main role is linked with growth, development, and reproduction. Even though plants share some chemical features with mammals, the biosynthesis is different, with the first C22 hydroxylation as an example. This is performed by CYP11A1 in mammals and CYP90B1 in plants. Moreover, the entire plant steroid biosynthesis is not fully elucidated. Knowing this pathway could provide new processes for the industrial biotechnological production of steroid hormones in plants.
PubMed: 32899410
DOI: 10.3390/plants9091144 -
Pathogens (Basel, Switzerland) Aug 2021Under conditions of increasing environmental pollution, true saprophytes are capable of changing their survival strategies and demonstrating certain pathogenicity... (Review)
Review
Under conditions of increasing environmental pollution, true saprophytes are capable of changing their survival strategies and demonstrating certain pathogenicity factors. Actinobacteria of the genus , typical soil and aquatic biotope inhabitants, are characterized by high ecological plasticity and a wide range of oxidized organic substrates, including hydrocarbons and their derivatives. Their cell adaptations, such as the ability of adhering and colonizing surfaces, a complex life cycle, formation of resting cells and capsule-like structures, diauxotrophy, and a rigid cell wall, developed against the negative effects of anthropogenic pollutants are discussed and the risks of possible pathogenization of free-living saprotrophic species are proposed. Due to universal adaptation features, species are among the candidates, if further anthropogenic pressure increases, to move into the group of potentially pathogenic organisms with "unprofessional" parasitism, and to join an expanding list of infectious agents as facultative or occasional parasites.
PubMed: 34451438
DOI: 10.3390/pathogens10080974 -
Molecular Microbiology Jul 2019Rhodococcus equi is the only recognized animal pathogenic species within an extended genus of metabolically versatile Actinobacteria of considerable biotechnological... (Review)
Review
Rhodococcus equi is the only recognized animal pathogenic species within an extended genus of metabolically versatile Actinobacteria of considerable biotechnological interest. Best known as a horse pathogen, R. equi is commonly isolated from other animal species, particularly pigs and ruminants, and causes severe opportunistic infections in people. As typical in the rhodococci, R. equi niche specialization is extrachromosomally determined, via a conjugative virulence plasmid that promotes intramacrophage survival. Progress in the molecular understanding of R. equi and its recent rise as a novel paradigm of multihost adaptation has been accompanied by an unusual nomenclatural instability, with a confusing succession of names: "Prescottia equi", "Prescotella equi", Corynebacterium hoagii and Rhodococcus hoagii. This article reviews current advances in the genomics, biology and virulence of this pathogenic actinobacterium with a unique mechanism of plasmid-transferable animal host tropism. It also discusses the taxonomic and nomenclatural issues around R. equi in the light of recent phylogenomic evidence that confirms its membership as a bona fide Rhodococcus.
Topics: Actinomycetales Infections; Animals; Genomics; Horses; Phylogeny; Plasmids; Rhodococcus; Rhodococcus equi; Swine; Virulence
PubMed: 31099908
DOI: 10.1111/mmi.14267 -
Emerging Infectious Diseases Sep 2022A multidrug-resistant clone of the animal and human pathogen Rhodococcus equi, MDR-RE 2287, has been circulating among equine farms in the United States since the 2000s....
A multidrug-resistant clone of the animal and human pathogen Rhodococcus equi, MDR-RE 2287, has been circulating among equine farms in the United States since the 2000s. We report the detection of MDR-RE 2287 outside the United States. Our finding highlights the risk for MDR-RE spreading internationally with horse movements.
Topics: Actinomycetales Infections; Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Horse Diseases; Horses; Humans; Macrolides; Rhodococcus equi; Rifampin; United States
PubMed: 35997496
DOI: 10.3201/eid2809.220222 -
Applied Bionics and Biomechanics 2021The pollution of toxic heavy metals is considered one of the most important environmental issues which has accelerated dramatically due to changing industrial... (Review)
Review
The pollution of toxic heavy metals is considered one of the most important environmental issues which has accelerated dramatically due to changing industrial activities. This review focuses on the most common methods, strategies, and biological approaches of heavy metal bioremediation. Also, it provides a general overview of the role of microorganisms in the bioremediation of heavy metals in polluted environments. Advanced methods of heavy metal remediation include physicochemical and biological methods; the latter can be further classified into in situ and ex situ bioremediation. The in situ process includes bioventing, biosparging, biostimulation, bioaugmentation, and phytoremediation. Ex situ bioremediation includes land farming, composting, biopiles, and bioreactors. Bioremediation uses naturally occurring microorganisms such as , , , , and . Generally, bioremediation is of very less effort, less labor intensive, cheap, ecofriendly, sustainable, and relatively easy to implement. Most of the disadvantages of bioremediation relate to the slowness and time-consumption; furthermore, the products of biodegradation sometimes become more toxic than the original compound. The performance evaluation of bioremediation might be difficult as it has no acceptable endpoint. There is a need for further studies to develop bioremediation technologies in order to find more biological solutions for bioremediation of heavy metal contamination from different environmental systems.
PubMed: 34804199
DOI: 10.1155/2021/1609149 -
Pharmaceuticals (Basel, Switzerland) Aug 2022The ability of actinobacteria of the genus to biotransform the monoterpenoid (-)-isopulegol has been established for the first time. . strain IEGM 1362 was selected as...
The ability of actinobacteria of the genus to biotransform the monoterpenoid (-)-isopulegol has been established for the first time. . strain IEGM 1362 was selected as a bacterium capable of metabolizing (-)-isopulegol to form new, previously unknown, 10-hydroxy () and 10-carboxy () derivatives, which may presumably have antitumor activity and act as respiratory stimulants and cancer prevention agents. In the experiments, optimal conditions were selected to provide the maximum target catalytic activity of rhodococci. Using up-to-date (TEM, AFM-CLSM, and EDX) and traditional (cell size, roughness, and zeta potential measurements) biophysical and microbiological methods, it was shown that (-)-isopulegol and halloysite nanotubes did not negatively affect the bacterial cells. The data obtained expand our knowledge of the biocatalytic potential of rhodococci and their possible involvement in the synthesis of pharmacologically active compounds from plant derivatives.
PubMed: 36015112
DOI: 10.3390/ph15080964 -
Animals : An Open Access Journal From... Oct 2020The aim of this review was to summarize studies on equine rhodococcosis over the last decade. For many years has remained one of the major health challenges in the... (Review)
Review
The aim of this review was to summarize studies on equine rhodococcosis over the last decade. For many years has remained one of the major health challenges in the equine breeding industry worldwide. Recently, many novel approaches and ideas have been described and some of them were initially implemented into the clinical practice. This study reviews a variety of new information about neonatal susceptibility, clinical appearance, considered and applied diagnostic procedures and treatment alternatives, factors limiting accurate prognosis, ideas regarding environmental management and prophylaxis considerations. Although multiple research were conducted, the main problems such as high morbidity and mortality, a lack of reliable prevention strategies and treatment limitations are still unresolved and require further scientific effort.
PubMed: 33081047
DOI: 10.3390/ani10101910