Production of polyhydroxyalkanoates by mixed microbial cultures

Reis, Maria A.M.; Serafim, Luísa S.; Lemos, Paulo C.; Ramos, A.M.; Aguiar, Filipe; Loosdrecht, M.C.M. van

doi:10.1007/s00449-003-0322-4

Cited by 256 publications

(157 citation statements)

References 40 publications

Supporting

Mentioning

148

Contrasting

Unclassified

Order By: Relevance

“…The first or acidogenic fermentation step (Temudo et al, 2007) aims to convert the waste organic carbon, primarily carbohydrates, to a mixture of volatile fatty acids. These acids are a more suitable substrate for PHA production (Reis et al, 2003) and will be used as such in the following two steps. In the second step, an open microbial community is enriched in bacteria with a high PHA storage capacity.…”

Section: -Or Recombinantmentioning

confidence: 99%

“…In the second step, an open microbial community is enriched in bacteria with a high PHA storage capacity. This enrichment step is performed in a sequencing batch reactor (SBR) operated under a feast-famine regime, as intermittent substrate availability creates a competitive advantage for bacteria that store substrate inside their cell as a reserve (Reis et al, 2003). Once a stable culture is obtained, the SBR will be operated as a biomass production step and the excess sludge used in step 3: maximization of the PHA content of the biomass in a (nitrogen-limited) fed-batch reactor (Johnson et al, 2009a).…”

Section: -Or Recombinantmentioning

confidence: 99%

“…PHA-rich biomass could also be harvested directly from the enrichment reactor (Dionisi et al, 2007;Reis et al, 2003). During the feast phase of each SBR cycle, external substrate is taken up and stored as PHA before it is used for growth.…”

Section: -Or Recombinantmentioning

confidence: 99%

See 2 more Smart Citations

Combining the enrichment and accumulation step in non-axenic PHA production: Cultivation of Plasticicumulans acidivorans at high volume exchange ratios

Marang

Loosdrecht

Kleerebezem

2016

Journal of Biotechnology

View full text Add to dashboard Cite

Section: -Or Recombinantmentioning

confidence: 99%

Section: -Or Recombinantmentioning

confidence: 99%

See 1 more Smart Citation

Combining the enrichment and accumulation step in non-axenic PHA production: Cultivation of Plasticicumulans acidivorans at high volume exchange ratios

Marang

Loosdrecht

Kleerebezem

2016

Journal of Biotechnology

View full text Add to dashboard Cite

“…A two-step process with a feast-famine regime has been demonstrated to enable the effective enrichment of a PHA-producing mixed microbial culture from the natural environment based on the ecological role of PHA (van Loosdrecht, 2000). However, the maximum PHA content of mixed cultures is in general lower than that of pure cultures (Reis et al, 2003;Dias et al, 2006). This increases the relative costs for downstream processing, and thereby increases the production costs of PHA (Mudliar et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Effect of temperature and cycle length on microbial competition in PHB-producing sequencing batch reactor

et al. 2010

View full text Add to dashboard Cite

The impact of temperature and cycle length on microbial competition between polyhydroxybutyrate (PHB)-producing populations enriched in feast-famine sequencing batch reactors (SBRs) was investigated at temperatures of 20 1C and 30 1C, and in a cycle length range of 1-18 h. In this study, the microbial community structure of the PHB-producing enrichments was found to be strongly dependent on temperature, but not on cycle length. Zoogloea and Plasticicumulans acidivorans dominated the SBRs operated at 20 1C and 30 1C, respectively. Both enrichments accumulated PHB more than 75% of cell dry weight. Short-term temperature change experiments revealed that P. acidivorans was more temperature sensitive as compared with Zoogloea. This is particularly true for the PHB degradation, resulting in incomplete PHB degradation in P. acidivorans at 20 1C. Incomplete PHB degradation limited biomass growth and allowed Zoogloea to outcompete P. acidivorans. The PHB content at the end of the feast phase correlated well with the cycle length at a constant solid retention time (SRT). These results suggest that to establish enrichment with the capacity to store a high fraction of PHB, the number of cycles per SRT should be minimized independent of the temperature.

show abstract

“…The major costs consist in the cost of pure culture fermentation and expensive pure substrates [3] . Recently, the production of PHB by activated sludge from the wastewater treatment plants has attracted attention [4][5][6][7] . The activated sludge can use cheap substrates (such as organic waste) and avoid the need of sterilization.…”

mentioning

confidence: 99%

Determination of optimum operating conditions for production of polyhydroxybutyrate by activated sludge submitted to dynamic feeding regime

Liu

2009

Chin. Sci. Bull.

View full text Add to dashboard Cite

Polyhydroxybutyrate (PHB) was produced by activated sludge in a two-stage process. In the first stage, the sludge with high storage potential was enriched in a sequencing batch reactor (SBR) operated by a dynamic feeding regime. The biosynthesis of PHB was sequentially accomplished in a batch reactor in the second stage. This article focused on the optimization of PHB content by evaluating the effects of three critical factors: Dissolved oxygen, pH and food-to-microorganism (F/M) ratio in the batch reactor. The results showed that the rate of substrate uptake, as well as the yield and content of PHB increased with the increase of dissolved oxygen concentration. The control of pH was not necessary under the weak alkaline condition for improvement of PHB content, except for the case in which the pH value was out of rang of 7.0 to 10.0. The enhanced F/M ratio favored PHB accumulation in the range of 1.0 to 4.5 C-mmol/C-mmol and the highest PHB content, 64%, was achieved at 4.5 C-mmol/C-mmol. When F/M ratio was enhanced to 6.0 C-mmol/C-mmol, the phenomenon of utilizing simultaneously intracellular PHB and external substrate by sludge was observed, which resulted in a sharp decrease of PHB content. The microscopic observation clearly confirmed that dynamic feeding regime was effective for selecting and enriching the sludge with a high storage potential.polyhydroxybutyrate, activated sludge, dynamic feeding regime, optimum operating conditions Conventional plastics have faced some severe problems, because of their persistency in the environment and non-biodegradability. Therefore, the biodegradable plastic has potentials in applications. Polyhydroxyalkanoates (PHAs) are the polyester of hydroxyalkanoates synthesized by numerous bacteria as intracellular carbon and energy storage compounds, and have similar mechanical properties to conventional plastics like polypropylene or polyethylene. Additionally, PHAs have the attractive features of being completely biodegradable, biocompatible, and produced from renewable sources. Polyhydroxybutyrate (PHB) is the most common and best characterized PHAs. For the economical production of PHAs, various bacterial strains, either wild-type or recombinant, and new fermentation strategies were developed with high content and productivity of PHAs [1,2]

show abstract

Production of polyhydroxyalkanoates by mixed microbial cultures

Cited by 256 publications

References 40 publications

Combining the enrichment and accumulation step in non-axenic PHA production: Cultivation of Plasticicumulans acidivorans at high volume exchange ratios

Combining the enrichment and accumulation step in non-axenic PHA production: Cultivation of Plasticicumulans acidivorans at high volume exchange ratios

Effect of temperature and cycle length on microbial competition in PHB-producing sequencing batch reactor

Determination of optimum operating conditions for production of polyhydroxybutyrate by activated sludge submitted to dynamic feeding regime

Contact Info

Product

Resources

About