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Rapid short-term poly-beta-hydroxybutyrate production by Thiosphaera pantotropha in the presence of excess acetate

van Niel, Ed LU ; Robertson, L.A. and Kuenen, J.G. (1995) In Enzyme and Microbial Technology 17. p.977-982
Abstract
During substrate-limited growth, some strains of Thiosphaera pantotropha nitrify heterotrophically and denitrify aerobically. These processes are thought to be used as NADH overflow mechanisms, resulting from a restricted oxygen respiration capacity. In this study, the behavior of T. pantotropha regarding the NADH overflow in the presence of substantial concentrations of substrate was examined. Continuously grown (dilution rate 0.1 h−1), acetate-limited cultures of T. pantotropha (30–285 mg dry weight l−1) were exposed for short periods (10–90 min) to excess acetate in batch. After the transition from acetate limitation to acetate excess, the growth rate immediately increased from 0.1 to 0.2 h−1. The acetate uptake rate was 1.1–1.2 μmol... (More)
During substrate-limited growth, some strains of Thiosphaera pantotropha nitrify heterotrophically and denitrify aerobically. These processes are thought to be used as NADH overflow mechanisms, resulting from a restricted oxygen respiration capacity. In this study, the behavior of T. pantotropha regarding the NADH overflow in the presence of substantial concentrations of substrate was examined. Continuously grown (dilution rate 0.1 h−1), acetate-limited cultures of T. pantotropha (30–285 mg dry weight l−1) were exposed for short periods (10–90 min) to excess acetate in batch. After the transition from acetate limitation to acetate excess, the growth rate immediately increased from 0.1 to 0.2 h−1. The acetate uptake rate was 1.1–1.2 μmol min−1 mg protein−1, which would theoretically allow a growth rate of 0.35 h−1. Acetate appeared to be converted mainly to poly-β-hydroxybutyrate (PHB) (57% wt/wt−1). The initial PHB production rate was 27 μg PHB min−1 mg protein−1. Respiration measurements showed that only 29% of the total acetate taken up was oxidized. The remainder (14%) was used for biomass synthesis. After acetate (10 mm) was completely taken up, the cellular PHB content was 42% of the dry weight. During PHB synthesis no heterotrophic nitrification or aerobic dentrification could be detected. The results indicate that in acetate-limited cells when exposed to excess acetate, PHB formation serves as an NADH overflow metabolism. (Less)
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Contribution to journal
publication status
published
keywords
Thiosphaera pantotropha, poly-hydroxybutyrate
in
Enzyme and Microbial Technology
volume
17
pages
6 pages
publisher
Elsevier
ISSN
0141-0229
language
English
LU publication?
no
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bafd7a40-d152-4d73-b502-bb6388b0a26e
date added to LUP
2016-08-26 14:35:00
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2017-06-26 18:33:28
@article{bafd7a40-d152-4d73-b502-bb6388b0a26e,
  abstract     = {During substrate-limited growth, some strains of Thiosphaera pantotropha nitrify heterotrophically and denitrify aerobically. These processes are thought to be used as NADH overflow mechanisms, resulting from a restricted oxygen respiration capacity. In this study, the behavior of T. pantotropha regarding the NADH overflow in the presence of substantial concentrations of substrate was examined. Continuously grown (dilution rate 0.1 h−1), acetate-limited cultures of T. pantotropha (30–285 mg dry weight l−1) were exposed for short periods (10–90 min) to excess acetate in batch. After the transition from acetate limitation to acetate excess, the growth rate immediately increased from 0.1 to 0.2 h−1. The acetate uptake rate was 1.1–1.2 μmol min−1 mg protein−1, which would theoretically allow a growth rate of 0.35 h−1. Acetate appeared to be converted mainly to poly-β-hydroxybutyrate (PHB) (57% wt/wt−1). The initial PHB production rate was 27 μg PHB min−1 mg protein−1. Respiration measurements showed that only 29% of the total acetate taken up was oxidized. The remainder (14%) was used for biomass synthesis. After acetate (10 mm) was completely taken up, the cellular PHB content was 42% of the dry weight. During PHB synthesis no heterotrophic nitrification or aerobic dentrification could be detected. The results indicate that in acetate-limited cells when exposed to excess acetate, PHB formation serves as an NADH overflow metabolism.},
  author       = {van Niel, Ed and Robertson, L.A. and Kuenen, J.G.},
  issn         = {0141-0229},
  keyword      = {Thiosphaera pantotropha,poly-hydroxybutyrate},
  language     = {eng},
  pages        = {977--982},
  publisher    = {Elsevier},
  series       = {Enzyme and Microbial Technology},
  title        = {Rapid short-term poly-beta-hydroxybutyrate production by Thiosphaera pantotropha in the presence of excess acetate},
  volume       = {17},
  year         = {1995},
}