Glutathione: A powerful but rare cofactor among Actinobacteria

Lienkamp, Anna C; Heine, Thomas; Tischler, Dirk

doi:10.1016/bs.aambs.2019.12.003

Cited by 13 publications

(15 citation statements)

References 100 publications

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“…WS11 lacks glutathione biosynthesis genes in the isoprene gene cluster. Glutathione is important in many bacteria as a means of protection against toxic and oxidative stresses during aerobic growth, but Gram-positive bacteria typically use alternative low molecular weight thiols such as mycothiol, and do not produce glutathione [72]. Despite this, previous work strongly indicated the importance of glutathione in isoprene degradation by Rhodococcus sp.…”

Section: The Genome Of Variovorax Sp Ws11 Encodes Multiple Putative mentioning

confidence: 99%

Isoprene Oxidation by the Gram-Negative Model bacterium Variovorax sp. WS11

et al. 2020

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Plant-produced isoprene (2-methyl-1,3-butadiene) represents a significant portion of global volatile organic compound production, equaled only by methane. A metabolic pathway for the degradation of isoprene was first described for the Gram-positive bacterium Rhodococcus sp. AD45, and an alternative model organism has yet to be characterised. Here, we report the characterisation of a novel Gram-negative isoprene-degrading bacterium, Variovorax sp. WS11. Isoprene metabolism in this bacterium involves a plasmid-encoded iso metabolic gene cluster which differs from that found in Rhodococcus sp. AD45 in terms of organisation and regulation. Expression of iso metabolic genes is significantly upregulated by both isoprene and epoxyisoprene. The enzyme responsible for the initial oxidation of isoprene, isoprene monooxygenase, oxidises a wide range of alkene substrates in a manner which is strongly influenced by the presence of alkyl side-chains and differs from other well-characterised soluble diiron monooxygenases according to its response to alkyne inhibitors. This study presents Variovorax sp. WS11 as both a comparative and contrasting model organism for the study of isoprene metabolism in bacteria, aiding our understanding of the conservation of this biochemical pathway across diverse ecological niches.

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Section: The Genome Of Variovorax Sp Ws11 Encodes Multiple Putative mentioning

confidence: 99%

Isoprene Oxidation by the Gram-Negative Model bacterium Variovorax sp. WS11

et al. 2020

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“…During the last decades, biomaterials, ne chemicals, nutraceuticals, nanomaterials, and pharmaceutically relevant compounds have become increasingly biosynthesized by different microorganisms Cui et al, 2019;Hassan et al, 2019). Glutathione (γ-glutamyl-L-cysteinyl-glycine) is non-protein-thiol containing tripeptide; which is widely distributed in living organisms, and mainly in eukaryotic cells (Meister and Anderson, 1983;Lienkamp et al, 2020). Glutathione (GSH) is an essential molecule for cells in the protection mechanisms against UV, xenobiotics, and heavy metals (Penninckx, 2002; 2.1.…”

Section: Introductionmentioning

confidence: 99%

Bioprocess optimization of glutathione production by Saccharomyces boulardii: biochemical characterization of glutathione peroxidase

et al. 2021

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The well-known probiotic GRAS Saccharomyces boulardii (CNCM I-745) was used for the rst time to produce glutathione (GSH). The culture conditions affecting GSH biosynthesis were screened using a Plackett-Burman design (PBD). Analyzing the regression coe cients for 12 tested variables; 6 of them, including yeast extract, glucose, peptone and cysteine; temperature and agitation rate had a positive signi cant effect on GSH production with a maximum production of 192 mg/L. The impact of addition time of cysteine was investigated in 19 experiments during the growth time course (0-36 h), the best addition time was 8h post-inoculation producing 235 mg/L of GSH. The most signi cant variables were further explored at 5-levels using Central Composite Rotatable Design (CCRD), giving a maximum production of GSH (552 mg/L). Using ba ed asks, the GSH was increased to 730 mg/L, i.e 1.32-folds increment than obtained using CCRD. The two rate-limiting genes of GSH biosynthesis "γ-glutamyl cysteine synthetase (gsh1) and GSH-synthetase (gsh2) were ampli ed and sequenced to validate the GSH biosynthetic potency of S. boulardii. The sequences of genes showed 99% similarity with gsh1 and gsh2 genes of S. cerevisiae. Glutathione peroxidase was puri ed and characterized from S. boulardii with molecular mass and subunit structure of 80 kDa and 35 kDa as revealed from native and SDS-PAGE, ensuring its homodimeric identity. The activity of GPx was reduced by 2.5-folds upon demetallization con rming its metalloproteinic identity. The enzyme was strongly inhibited by hydroxylamine and DTNB, ensuring the implication of surface lysine and cysteine residues on the enzyme active site domains.

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“…Further steps in the metabolism of GMBA have not been confirmed, but it is likely that the glutathione moiety is subsequently removed and β-oxidation of the intermediates of isoprene metabolism enables growth on isoprene as the sole carbon and energy source. Detoxification of epoxyisoprene by conjugating with glutathione may be a feature common to all isoprene degraders, and this mechanism is especially intriguing in Gram-positive bacteria, in which glutathione synthesis is an unusual feature [70]. In Rhodococcus AD45, the megaplasmid carrying iso genes contains duplicate copies of isoGHIJ, and also duplicate copies of gshA encoding glutamate cysteine ligase, which catalyses the first step of glutathione biosynthesis.…”

Section: Aerobic Metabolism Of Isoprenementioning

confidence: 99%

Microbial metabolism of isoprene: a much-neglected climate-active gas

2020

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The climate-active gas isoprene is the major volatile produced by a variety of trees and is released into the atmosphere in enormous quantities, on a par with global emissions of methane. While isoprene production in plants and its effect on atmospheric chemistry have received considerable attention, research into the biological isoprene sink has been neglected until recently. Here, we review current knowledge on the sources and sinks of isoprene and outline its environmental effects. Focusing on degradation by microbes, many of which are able to use isoprene as the sole source of carbon and energy, we review recent studies characterizing novel isoprene degraders isolated from soils, marine sediments and in association with plants. We describe the development and use of molecular methods to identify, quantify and genetically characterize isoprene-degrading strains in environmental samples. Finally, this review identifies research imperatives for the further study of the environmental impact, ecology, regulation and biochemistry of this interesting group of microbes.

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Glutathione: A powerful but rare cofactor among Actinobacteria

Cited by 13 publications

References 100 publications

Isoprene Oxidation by the Gram-Negative Model bacterium Variovorax sp. WS11

Isoprene Oxidation by the Gram-Negative Model bacterium Variovorax sp. WS11

Bioprocess optimization of glutathione production by Saccharomyces boulardii: biochemical characterization of glutathione peroxidase

Microbial metabolism of isoprene: a much-neglected climate-active gas

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