Limits...
Degradation of toluene by ortho cleavage enzymes in Burkholderia fungorum FLU100.

Dobslaw D, Engesser KH - Microb Biotechnol (2014)

Bottom Line: This means that 2-ML is an intermediate of toluene degradation and converted by specific enzymes.The conversion of 4-methylcatechol as a very minor by-product of toluene degradation in strain FLU100 resulted in the accumulation of 4-carboxymethyl-4-methylbut-2-en-4-olide (4-methyl-2-enelactone, 4-ML) as a dead-end product, excluding its nature as a possible intermediate.Thus, 3-methylcyclohexa-3,5-diene-1,2-diol, 3-methylcatechol, 2-methyl muconate and 2-ML were identified as central intermediates of productive ortho cleavage pathways for toluene metabolism in B. fungorum FLU100.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Waste Air Purification, Institute of Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Bandtäle 2, Stuttgart, D-70569, Germany.

Show MeSH

Related in: MedlinePlus

Concentration of 2-methylmuconolactone (2-ML) as intermediate of the conversion of 3-methylcatechol as well as sole substrate by whole cells of strain FLU100 pre-grown on toluene. To the second flask of each test row, chloramphenicol (CAP) as cytostatic drug was added to avoid induction of new enzymes. The optical density was OD546nm = 1.6. In all cases, 2-ML was transformed showing induction of relevant enzymes. Additionally, the concentration of 2-ML in a cell-free supernatant at a pH value of 1–2 as a blank row is presented.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4321380&req=5

fig03: Concentration of 2-methylmuconolactone (2-ML) as intermediate of the conversion of 3-methylcatechol as well as sole substrate by whole cells of strain FLU100 pre-grown on toluene. To the second flask of each test row, chloramphenicol (CAP) as cytostatic drug was added to avoid induction of new enzymes. The optical density was OD546nm = 1.6. In all cases, 2-ML was transformed showing induction of relevant enzymes. Additionally, the concentration of 2-ML in a cell-free supernatant at a pH value of 1–2 as a blank row is presented.

Mentions: However, transforming 3-methylcatechol by cells of strain FLU100 pre-grown on benzene or mono-halogen benzenes, nearly 55–65% of the provided 3-methylcatechol temporarily accumulated as 2-ML. Further transformation was observed after a lag phase of 2–3 h (Fig. 2). By contrast, no or only small concentrations of 2-ML accumulated in case of toluene-induced/growing cells (Fig. 3). This means that key enzymes for degradation of 2-ML were only induced after adaptation on toluene, but not on benzene or mono-halogen benzenes.


Degradation of toluene by ortho cleavage enzymes in Burkholderia fungorum FLU100.

Dobslaw D, Engesser KH - Microb Biotechnol (2014)

Concentration of 2-methylmuconolactone (2-ML) as intermediate of the conversion of 3-methylcatechol as well as sole substrate by whole cells of strain FLU100 pre-grown on toluene. To the second flask of each test row, chloramphenicol (CAP) as cytostatic drug was added to avoid induction of new enzymes. The optical density was OD546nm = 1.6. In all cases, 2-ML was transformed showing induction of relevant enzymes. Additionally, the concentration of 2-ML in a cell-free supernatant at a pH value of 1–2 as a blank row is presented.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4321380&req=5

fig03: Concentration of 2-methylmuconolactone (2-ML) as intermediate of the conversion of 3-methylcatechol as well as sole substrate by whole cells of strain FLU100 pre-grown on toluene. To the second flask of each test row, chloramphenicol (CAP) as cytostatic drug was added to avoid induction of new enzymes. The optical density was OD546nm = 1.6. In all cases, 2-ML was transformed showing induction of relevant enzymes. Additionally, the concentration of 2-ML in a cell-free supernatant at a pH value of 1–2 as a blank row is presented.
Mentions: However, transforming 3-methylcatechol by cells of strain FLU100 pre-grown on benzene or mono-halogen benzenes, nearly 55–65% of the provided 3-methylcatechol temporarily accumulated as 2-ML. Further transformation was observed after a lag phase of 2–3 h (Fig. 2). By contrast, no or only small concentrations of 2-ML accumulated in case of toluene-induced/growing cells (Fig. 3). This means that key enzymes for degradation of 2-ML were only induced after adaptation on toluene, but not on benzene or mono-halogen benzenes.

Bottom Line: This means that 2-ML is an intermediate of toluene degradation and converted by specific enzymes.The conversion of 4-methylcatechol as a very minor by-product of toluene degradation in strain FLU100 resulted in the accumulation of 4-carboxymethyl-4-methylbut-2-en-4-olide (4-methyl-2-enelactone, 4-ML) as a dead-end product, excluding its nature as a possible intermediate.Thus, 3-methylcyclohexa-3,5-diene-1,2-diol, 3-methylcatechol, 2-methyl muconate and 2-ML were identified as central intermediates of productive ortho cleavage pathways for toluene metabolism in B. fungorum FLU100.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Waste Air Purification, Institute of Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Bandtäle 2, Stuttgart, D-70569, Germany.

Show MeSH
Related in: MedlinePlus