Brought to you courtesy of the red, white, and blue–pigments of nontuberculous mycobacteria

Tran, Tru; Dawrs, Stephanie N.; Norton, Grant J.; Virdi, Ravleen; Honda, Jennifer R.

doi:10.3934/microbiol.2020026

Cited by 6 publications

(3 citation statements)

References 93 publications

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“…Based on the pseudogenization of metabolic pathways across the MU strains, a niche model was generated. This proposed niche shields the bacteria from UV radiation due to the loss of the undecylprodigiosin production pathway [ 25 ] in addition to the loss of the crtB gene [ 5 ] This niche fosters oxidative metabolism due to the loss of the dissimilatory nitrate reduction metabolic pathway that serves as an electron acceptor under anaerobic conditions [ 26 ]. The niche has a lower temperature as compared to its previous environment due to the loss of the Crassulacean acid metabolism (CAM) cycle light stage which is important for adapting to warm temperatures [ 27 ].…”

Section: Discussionmentioning

confidence: 99%

Pseudogenomic insights into the evolution of Mycobacterium ulcerans

Kyei-Baffour,

Owusu-Boateng,

Isawumi

et al. 2024

BMC Genomics

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Background Buruli ulcer (BU) disease, caused by Mycobacterium ulcerans (MU), and characterized by necrotic ulcers is still a health problem in Africa and Australia. The genome of the bacterium has several pseudogenes due to recent evolutionary events and environmental pressures. Pseudogenes are genetic elements regarded as nonessential in bacteria, however, they are less studied due to limited available tools to provide understanding of their evolution and roles in MU pathogenicity. Results This study developed a bioinformatic pipeline to profile the pseudogenomes of sequenced MU clinical isolates from different countries. One hundred and seventy-two MU genomes analyzed revealed that pseudogenomes of African strains corresponded to the two African lineages 1 and 2. Pseudogenomes were lineage and location specific and African lineage 1 was further divided into A and B. Lineage 2 had less relaxation in positive selection than lineage 1 which may signify different evolutionary points. Based on the Gil-Latorre model, African MU strains may be in the latter stages of evolutionary adaption and are adapting to an environment rich in metabolic resources with a lower temperature and decreased UV radiation. The environment fosters oxidative metabolism and MU may be less reliant on some secondary metabolites. In-house pseudogenomes from Ghana and Cote d’Ivoire were different from other African strains, however, they were identified as African strains. Conclusion Our bioinformatic pipeline provides pseudogenomic insights to complement other whole genome analyses, providing a better view of the evolution of the genome of MU and suggest an adaptation model which is important in understanding transmission. MU pseudogene profiles vary based on lineage and country, and an apparent reduction in insertion sequences used for the detection of MU which may adversely affect the sensitivity of diagnosis.

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Section: Discussionmentioning

confidence: 99%

Pseudogenomic insights into the evolution of Mycobacterium ulcerans

Kyei-Baffour,

Owusu-Boateng,

Isawumi

et al. 2024

BMC Genomics

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“…The collection of crtR mutants generated herein will facilitate experiments to investigate these unknowns. Lastly, microbial carotenoids are known to play a wide range of roles, including in host-pathogen interaction and virulence [ 45 , 95 , 96 , 97 ]. The mutants generated in this work will also enable research to probe the relevance of carotenes/carotenogenesis in the virulence of Mk in infection models and the ex vivo fitness of the bacterium under different environmental stresses.…”

Section: Discussionmentioning

confidence: 99%

Genetic Underpinnings of Carotenogenesis and Light-Induced Transcriptome Remodeling in the Opportunistic Pathogen Mycobacterium kansasii

2023

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Mycobacterium kansasii (Mk) causes opportunistic pulmonary infections with tuberculosis-like features. The bacterium is well known for its photochromogenicity, i.e., the production of carotenoid pigments in response to light. The genetics defining the photochromogenic phenotype of Mk has not been investigated and defined pigmentation mutants to facilitate studies on the role of carotenes in the bacterium’s biology are not available thus far. In this study, we set out to identify genetic determinants involved in Mk photochromogenicity. We screened a library of ~150,000 transposon mutants for colonies with pigmentation abnormalities. The screen rendered a collection of ~200 mutants. Each of these mutants could be assigned to one of four distinct phenotypic groups. The insertion sites in the mutant collection clustered in three chromosomal regions. A combination of phenotypic analysis, sequence bioinformatics, and gene expression studies linked these regions to carotene biosynthesis, carotene degradation, and monounsaturated fatty acid biosynthesis. Furthermore, introduction of the identified carotenoid biosynthetic gene cluster into non-pigmented Mycobacterium smegmatis endowed the bacterium with photochromogenicity. The studies also led to identification of MarR-type and TetR/AcrR-type regulators controlling photochromogenicity and carotenoid breakdown, respectively. Lastly, the work presented also provides a first insight into the Mk transcriptome changes in response to light.

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“…Soil bacteria demonstrate better productivity; for example, Gordonia alkanivorans cultivated on a sulfate-containing medium under light was able to synthesize lutein, canthaxanthin, and astaxanthin at a level of >2 mg/g of dry weight in total [17]. Rapid-growing nonpathogenic Mycolicibacterium strains able to synthesize β-carotene and some other pigments also can be considered as promising carotenoid producers [18]. However, the productivity of bacterial strains is inferior to that of fungal and yeast cultures.…”

Section: Introductionmentioning

confidence: 99%

Enhanced β-Carotene Production in Mycolicibacterium neoaurum Ac-501/22 by Combining Mutagenesis, Strain Selection, and Subsequent Fermentation Optimization

Yaderets,

Karpova,

Glagoleva

et al. 2023

Fermentation

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A continuing interest of scientists regarding the development of new β-carotene production technologies is due to the high biological activity of this compound and its wide application range. Bacteria are considered among the possible β-carotene producers convenient for industrial use. The purpose of this study was to develop a Mycolicibacterium neoaurum strain with an enhanced ability for β-carotene production and to optimize the fermentation conditions to improve the final yield of the target compound. Using chemical mutagenesis with N-nitroso-N-methylurea along with further strain selection, a M. neoaurum strain Ac-501/22, whose productivity was 2.7-fold higher than that of the parental strain Ac-501, was developed. The effect of nitrogen and carbon sources as well as cultivation conditions on the growth of M. neoaurum Ac-501/22 and β-carotene production were studied to select the optimal fermentation regime. Due to an increase in the temperature of cultivation from 30 to 35 °C, replacement of glucose with glycerin (20.0 g/L) and degreased soybean flour with powdered milk (10.0 g/L), and increase in the urea content from 0.5 to 1.0 g/L, the level of β-carotene production was improved to 183.0 mg/kg that was 35% higher than in the control. Further strain fermentation in a 3 L bioreactor using an optimized medium with the pH level maintained at 7.0–7.2 and 50% pO2 provided the maximum output of the target compound (262.4 mg/kg of dry biomass) that confirmed the prospects of the developed strain as an industrial β-carotene producer.

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Brought to you courtesy of the red, white, and blue–pigments of nontuberculous mycobacteria

Cited by 6 publications

References 93 publications

Pseudogenomic insights into the evolution of Mycobacterium ulcerans

Pseudogenomic insights into the evolution of Mycobacterium ulcerans

Genetic Underpinnings of Carotenogenesis and Light-Induced Transcriptome Remodeling in the Opportunistic Pathogen Mycobacterium kansasii

Enhanced β-Carotene Production in Mycolicibacterium neoaurum Ac-501/22 by Combining Mutagenesis, Strain Selection, and Subsequent Fermentation Optimization

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