"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates" "uuid:a2e20356-1469-40c2-9750-0baddecd9b7e","http://resolver.tudelft.nl/uuid:a2e20356-1469-40c2-9750-0baddecd9b7e","Influence of silicate on enrichment of highly productive microalgae from a mixed culture","Mooij, P.R.; De Jongh, L.D.; Van Loosdrecht, M.C.M.; Kleerebezem, R.","","2015","Microalgae have the potential to supply a biobased society with essential feedstocks like sugar and lipids. Besides being productive, strains used for this purpose should grow fast, be resistant to predators, and have good harvestability properties. Diatoms, a class of siliceous algae, have these and other preferred characteristics. In this paper, we describe the enrichment of microalgae in sequencing batch reactors with and without supply of silicate. Both reactors were operated with a light–dark cycle. To maximize storage compound production, carbon fixation and nitrogen uptake were uncoupled by limiting the availability of nitrate to the dark phase. After ten cycles, a stable culture was established in both reactors. The diatom Nitzschia sp. dominated the silicate-rich reactor, and the green algae Chlamydomonas sp. dominated the silicate-depleted reactor. Over the remaining 27 cycles of the experiment, the microalgal community structure did not change, indicating a highly stable system. Although the dominant microalga was highly dependent on the presence of silicate, the performance of both microalgal enrichments was similar. Polymers of glucose were stored during the nitrogen-limited light period. On organic matter dry weight basis, the sugar content of the biomass increased during the light period from 17?±?4 to 53?±?4 % for the silicate-limited culture, and from 14?±?4 to 43?±?4 % (w w ?1) for the silicate excess culture. These results show that storage compound production can be achieved under various conditions, as long as a selective environment is maintained.","mixed cultures; selective environment; green algae; diatoms; storage compounds","en","journal article","Springer","","","","","","","","Applied Sciences","BT/Biotechnology","","","","" "uuid:e7e53762-55a7-4017-8d1e-3ea6ec649471","http://resolver.tudelft.nl/uuid:e7e53762-55a7-4017-8d1e-3ea6ec649471","Lipid recovery from a vegetable oil emulsion using microbial enrichment cultures","Tamis, J.; Sorokin, D.Y.; Jiang, Y.; Van Loosdrecht, M.C.M.; Kleerebezem, R.","","2015","Background Many waste streams have a relatively high vegetable oil content, which is a potential resource that should be recovered. Microbial storage compound production for the recovery of lipids from lipid-water emulsions with open (unsterilized) microbial cultures was investigated in a sequencing batch reactor using a diluted vegetable oil emulsion as model substrate. Results After feeding, triacylglycerides (TAG) were accumulated intracellular by the microbial enrichment culture and subsequently used for growth in the remainder of the sequencing batch cycle. Roughly 50% of the added TAG could be recovered as intracellular lipids in this culture. The maximum lipid storage capacity of the enrichment culture was 54% on volatile suspended solids (VSS) mass basis in a separate fed-batch accumulation experiment. The microbial community was dominated by a lipolytic fungus, Trichosporon gracile, that was responsible for intracellular lipid accumulation but also a significant fraction of lipolytic and long chain fatty-acid-utilizing bacteria was present. Conclusion Herewith, we demonstrate an effective strategy for enrichment of a microbial community that can accumulate significant amounts of lipids from wastewaters without the need for sterilization of substrates or equipment. Further optimization of this process will make recovery of lipids from wastewater possible.","vegetable oil; storage compounds; microbial enrichment culture; feast-famine; resource recovery; OA-Fund TU Delft","en","journal article","BioMed Central","","","","","","","","Applied Sciences","BT/Biotechnology","","","",""