The microbial growth of Mycobacterium aurum L1 on vinyl chloride with respect to inhibitory and limiting influence of substrate and oxygen

Hauschild, I.; Schröer, A.; Siedersleben, Matthias; Starnick, Jürgen

doi:10.2166/wst.1994.0459

Cited by 2 publications

(3 citation statements)

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“…For further characterization of MFT formation, clearer analytical results, and easier purification, a chemically defined mineral medium Hartmann de Bont (HdB) was tested for further process development as it was used before in several studies involving mycobacteria ( Hartmans et al, 1992 ; Hauschild et al, 1994 ; Song and Niederweis, 2011 ; Berney et al, 2012 ; Greening et al, 2014 ; Peña-Ortiz et al, 2020 ). Since previous experiments have proven the positive impact of oxygen limitation, oxygen-limited conditions were also chosen for the experiment presented in Figure 5 .…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, systematic development of the bioprocess for a scalable production was essential. Mycobacterium strains are considered strict aerobic or microaerophilic ( Moore and James, 1982 ; Dick et al, 1998 ; Realini et al, 1998 ; Lewis and Falkinham, 2015 ), and the few biotechnological processes available do indicate the importance of oxygen transfer rates (OTRs) in the final product ( Hauschild et al, 1994 ; Lo et al, 2002 ). Being a redox cofactor involved in aerobic pathways it was reasonable to assume that oxygen availability could have a direct impact on MFT production ( Clark and Bushell, 1995 ; Barberel and Walker, 2000 ; Gamboa-Suasnavart et al, 2018 ).…”

Section: Introductionmentioning

confidence: 99%

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Impact of Oxygen Supply and Scale Up on Mycobacterium smegmatis Cultivation and Mycofactocin Formation

Peña-Ortiz

Schlembach

Lackner

et al. 2020

Front. Bioeng. Biotechnol.

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Mycofactocin (MFT) is a recently discovered glycosylated redox cofactor, which has been associated with the detoxification of antibiotics in pathogenic mycobacteria, and, therefore, of potential medical interest. The MFT biosynthetic gene cluster is commonly found in mycobacteria, including Mycobacterium tuberculosis, the causative agent of tuberculosis. Since the MFT molecule is highly interesting for basic research and could even serve as a potential drug target, large-scale production of the molecule is highly desired. However, conventional shake flask cultivations failed to produce enough MFT for further biochemical characterization like kinetic studies and structure elucidation, and a more comprehensive study of cultivation parameters is urgently needed. Being a redox cofactor, it can be hypothesized that the oxygen transfer rate (OTR) is a critical parameter for MFT formation. Using the non-pathogenic strain Mycobacterium smegmatis mc2 155, shake flask experiments with online measurement of the oxygen uptake and the carbon dioxide formation, were conducted under different levels of oxygen supply. Using liquid chromatography and high-resolution mass spectrometry, a 4–8 times increase of MFT production was identified under oxygen-limited conditions, in both complex and mineral medium. Moreover, the level of oxygen supply modulates not only the overall MFT formation but also the length of the glycosidic chain. Finally, all results were scaled up into a 7 L stirred tank reactor to elucidate the kinetics of MFT formation. Ultimately, this study enables the production of high amounts of these redox cofactors, to perform further investigations into the role and importance of MFTs.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Impact of Oxygen Supply and Scale Up on Mycobacterium smegmatis Cultivation and Mycofactocin Formation

Peña-Ortiz

Schlembach

Lackner

et al. 2020

Front. Bioeng. Biotechnol.

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“…Mycobacterium strains JS60, JS61, JS616, and JS617 and Nocardioides strain JS614 exhibited low half‐velocity constants ( K s values) with respect to both VC (0.5–3.2 μM) and O 2 (0.03–0.3 mg L −1 ), indicating that they degrade VC to low levels under low oxygen tensions (Coleman et al ., 2002b). The growth of Mycobacterium strain L1 was optimal at low VC and oxygen concentrations, with high concentrations of VC and oxygen being inhibitory (Hauschild et al ., 1994). The results of these studies suggest that VC‐assimilating isolates are well adapted to low VC and oxygen concentrations and supports the argument that such bacteria are likely to be influential in natural attenuation.…”

Section: Introductionmentioning

confidence: 99%

Aerobic biodegradation of the chloroethenes: pathways, enzymes, ecology, and evolution

2010

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Extensive use and inadequate disposal of chloroethenes have led to prevalent groundwater contamination worldwide. The occurrence of the lesser chlorinated ethenes [i.e. vinyl chloride (VC) and cis-1,2-dichloroethene (cDCE)] in groundwater is primarily a consequence of incomplete anaerobic reductive dechlorination of the more highly chlorinated ethenes (tetrachloroethene and trichloroethene). VC and cDCE are toxic and VC is a known human carcinogen. Therefore, their presence in groundwater is undesirable. In situ cleanup of VC- and cDCE-contaminated groundwater via oxidation by aerobic microorganisms is an attractive and potentially cost-effective alternative to physical and chemical approaches. Of particular interest are aerobic bacteria that use VC or cDCE as growth substrates (known as the VC- and cDCE-assimilating bacteria). Bacteria that grow on VC are readily isolated from contaminated and uncontaminated environments, suggesting that they are widespread and influential in aerobic natural attenuation of VC. In contrast, only one cDCE-assimilating strain has been isolated, suggesting that their environmental occurrence is rare. In this review, we will summarize the current knowledge of the physiology, biodegradation pathways, genetics, ecology, and evolution of VC- and cDCE-assimilating bacteria. Techniques (e.g. PCR, proteomics, and compound-specific isotope analysis) that aim to determine the presence, numbers, and activity of these bacteria in the environment will also be discussed.

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The microbial growth of Mycobacterium aurum L1 on vinyl chloride with respect to inhibitory and limiting influence of substrate and oxygen

Cited by 2 publications

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Impact of Oxygen Supply and Scale Up on Mycobacterium smegmatis Cultivation and Mycofactocin Formation

Impact of Oxygen Supply and Scale Up on Mycobacterium smegmatis Cultivation and Mycofactocin Formation

Aerobic biodegradation of the chloroethenes: pathways, enzymes, ecology, and evolution

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