Simplified engineering design towards a competitive lipid-rich effluents valorization
Metadatos
Mostrar el registro completo del ítemEditorial
Elsevier
Materia
Bioprocess Mixed microbial culture Triacylglyceride Polyhydroxyalkanoate Waste lipids
Fecha
2022-06-09Referencia bibliográfica
Lucía Argiz... [et al.]. Simplified engineering design towards a competitive lipid-rich effluents valorization, Journal of Environmental Management, Volume 317, 2022, 115433, ISSN 0301-4797, [https://doi.org/10.1016/j.jenvman.2022.115433]
Patrocinador
Spanish Government (AEI, Spain) through the TREASURE project CTQ 2017-83225-C2-1-R operative program FSE Galicia 2014-2020; European CommissionResumen
Medium- and long-chain fatty acids and glycerol contained in the oily fraction of many food-industry effluents
are excellent candidates to produce biobased high-value triacylglycerides (TAGs) and polyhydroxyalkanoates
(PHAs). The typical process configuration for TAGs recovery from lipid-rich streams always includes two steps
(culture enrichment plus storage compounds accumulation) whereas, for PHAs production, an additional pretreatment
of the substrate for the obtainment of soluble volatile fatty acids (VFAs) is required. To simplify the
process, substrate hydrolysis, culture enrichment, and accumulation (TAG and PHA storage) were coupled here
in a single sequencing batch reactor (SBR) operated under the double growth limitation strategy (DGL) and fed in
pulses with industrial waste fish oil during the whole feast phase. When the SBR was operated in 12 h cycles, it
was reached up to 51 wt % biopolymers after only 6 h of feast (TAG:PHA ratio of 50:51; 0.423 CmmolBIOP/
CmmolS). Daily storage compound production was observed to be over 25% higher than the reached when
enrichment and accumulation stages were carried in separate operational units. Increasing the feast phase length
from 6 to 12 h (18 h cycle) negatively affected the DGL strategy performance and hence system storage capacity,
which was recovered after also extending the famine phase in the same proportion (24 h cycle). Besides, the
carbon influx during the feast phase was identified as a key operational parameter controlling storage compounds
production and, together with the C/N ratio, culture selection. The different cycle configurations tested
clearly modulated the total fungal abundances without no significant differences in the size of the bacterial
populations. Several PHA and TAG producers were found in the mixed culture although the PHA and TAG
productions were poorly associated with the increased relative abundances (RAs) of specific operational taxonomic
units (OTUs).