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Author Cabrera, F.; Torres-Aravena, A.; Pinto-Ibieta, F.; Campos, J.L.; Jeison, D. doi  openurl
  Title On-Line Control of Feast/Famine Cycles to Improve PHB Accumulation during Cultivation of Mixed Microbial Cultures in Sequential Batch Reactors Type
  Year 2021 Publication International Journal of Environmental Research and Public Health Abbreviated Journal Int. J. Environ. Res. Public Health  
  Volume 18 Issue 23 Pages 12611  
  Keywords PHB; bioplastics; SBR; dissolved oxygen; feast; famine  
  Abstract Production of polyhydroxyalkanoates (PHA) has generated great interest as building blocks for bioplastic production. Their production using mixed microbial cultures represents an interesting alternative, since it enables the use of organic wastes as a carbon source. Feast/famine strategy is a common way to promote selection of microorganisms with PHA accumulation capacity. However, when using waste sources, changes in substrate concentration are expected, that may affect performance and efficiency of the process. This study showed how the dissolved oxygen level can be used for online control of the cycle time, ensuring that the desired feast/famine ratio is effectively applied. An operation strategy is presented and validated, using sequential batch reactors fed with acetate as the carbon source. Production of polyhydroxybutyrate (PHB) was studied, which is the expected type of PHA to be synthetized when using acetate as substrate. Two reactors were operated by applying the proposed control strategy, to provide F/F ratios of 0.2 and 0.6, respectively. A third reactor was operated with a fixed cycle time, for comparison purposes. Results showed that the reactor that operated at an F/F ratio of 0.6 promoted higher biomass productivity and PHB content, as a result of a better use of available time, preventing unnecessary long famine times. The application of the tested strategy is a simple a reliable way to promote a better performance of feast/famine-based bioreactors involving mixed microbial cultures for PHB production.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1660-4601 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000734924900001 Approved  
  Call Number UAI @ alexi.delcanto @ Serial 1523  
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Author Palmeiro-Sanchez, T.; Campos, J.L.; Mosquera-Corral, A. doi  openurl
  Title Bioconversion of Organic Pollutants in Fish-Canning Wastewater into Volatile Fatty Acids and Polyhydroxyalkanoate Type
  Year 2021 Publication International Journal of Environmental Research and Public Health Abbreviated Journal Int. J. Environ. Res. Public Health  
  Volume 18 Issue 19 Pages 10176  
  Keywords acidogenic fermentation; fish-canning wastewater; mixed culture; polyhydroxyalkanoates (PHAs); saline conditions; volatile fatty acids (VFAs)  
  Abstract The wastewater from the cookers of a tuna-canning plant was used as feedstock for the process. It was acidified in a continuous stirred tank reactor (CSTR) of 1.5 L to produce a mixture of volatile fatty acids (VFAs). The effluent contained 28.3 & PLUSMN; 8.7 g CODS/L and 25.0 & PLUSMN; 4.6 g CODVFA/L, 4.4 & PLUSMN; 1.6 g NH4+/L, and 10.9 & PLUSMN; 4.0 g Na+/L, which corresponds to about 28 g NaCl/L approximately. This was used to feed a PHA production system. The enriched MMC presented a capacity to accumulate PHAs from the fermented tuna wastewater. The maximum PHA content of the biomass in the fed-batch (8.35 wt% PHA) seemed very low, possibly due to the variable salinity (from 2.2 up to 12.3 g NaCl/L) and the presence of ammonium (which promoted the biomass growth). The batch assay showed a PHA accumulation of 5.70 wt% PHA, but this is a much better result if the productivity of the reactor is taken into account. The fed-batch reactor had a productivity of 10.3 mg PHA/(L h), while the batch value was about five times higher (55.4 mg PHA/(L h)). At the sight of the results, it can be seen that the acidification of fish-canning wastewater is possible even at high saline concentrations (27.7 g NaCl/L). On the other hand, the enrichment and accumulation results show us promising news and which direction has to be followed: PHAs can be obtained from challenging substrates, and the feeding mode during the accumulation stage has an important role to play when it comes to inhibition.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1660-4601 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000709111100001 Approved  
  Call Number UAI @ alexi.delcanto @ Serial 1479  
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