Influence of temperature on mixed microbial culture polyhydroxyalkanoate production while treating a starch industry wastewater

Abstract

Influence of temperature on mixed microbial culture polyhydroxyalkanoate production while treating a starch industry wastewater, Journal of Environmental Chemical Engineeringhttp://dx.Engineering (Brisbane, Queensland, Australia); 4 Promiko AB (Lomma, Sweden).Corresponding author: Alan Werker (alan@werker.se) Graphical abstractHighlights  Enrichment biomass at 15 and 25 °C gave similar PHA accumulation potential  PHA accumulation process robust to temperatures from 15 to 30°C  Kinetics change with temperature according to modified Arrhenius equation  Mixed culture PHA production is more efficient at lower temperatures  Bioprocess is adaptable to anticipated seasonal water temperature changes AbstractThe influence of temperature on the production of enrichment biomass and polyhydroxyalkanoates by activated sludge was evaluated within a practical case study. Two laboratory-scale sequencing batch reactors (SBRs) were operated in parallel over 131 days to treat a wastewater from a potatostarch modification facility, and produce surplus activated sludge biomass with PHA accumulation potential. The SBRs were operated similarly but at different temperatures (15 and 25°C).Temperature did not influence wastewater treatment performance (average 97% COD removal).Replicate PHA accumulation experiments were conducted on the SBR surplus biomass at 15, 20, 25 and 30°C. Surplus biomass accumulated PHA with acetic acid to between 60 and 65%, gPHA/gVSS for all temperatures tested and with estimated Arrhenius temperature coefficients (θ) of 1.048 for the PHA production, and 1.062 for the COD consumption specific rates. The MMC PHA production process was adaptable within a common range anticipated for seasonal fluctuation of temperature for the influent wastewater and PHA production feedstocks without loss of performance. This outcome suggests a broad range in the practical feasibility and reliability with MMC method and process implementations. PHA production was predicted to be more efficient at lower temperatures. Strategies can be engineered in the bioprocess design and operations to accommodate for temperature shifts in practical applications of PHA production as a route to resource recovery from organic waste management services.

Application of dissolved oxygen (DO) level control for polyhydroxyalkanoate (PHA) accumulation with concurrent nitrification in surplus municipal activated sludge

“…For PHA production, a much All these factors can alter mass transport conditions for diffusion [15,23]. PHA accumulation and nitrogen conversion rates are also temperature dependent [24,25]. Present data were obtained at 22°C and sensitivity to temperature was not explored as part of this investigation.…”

Functional bioplastics from food residual: Potentiality and safety issues

“…In anticipation of a scale‐up for the process of PHA accumulation, De Grazia et al. (2017) studied the influences of temperature on the conversion of activated sludge from potato starch wastewater with MMC and demonstrated that this parameter is not relevant for PHA productivity. Different results were reported by Setyawaty et al.…”

From Organic Wastes and Hydrocarbons Pollutants to Polyhydroxyalkanoates: Bioconversion by Terrestrial and Marine Bacteria

“…SBR is typically operated through a succession of cycles, whose duration can be adapted according to the characteristics of the fermented feedstock (e.g., VFA concentration) [59,60]. Such cycles guarantee the occurrence of the feast period (C source availability) during the feed phase and part of the reaction phase (feast), whereas the culture faces starvation in the rest of the cycle (famine) [61].…”

“…Such cycles guarantee the occurrence of the feast period (C source availability) during the feed phase and part of the reaction phase (feast), whereas the culture faces starvation in the rest of the cycle (famine) [61]. The ratio between the length of feast and the overall cycle length has been identified as the crucial parameter in establishing SBR is typically operated through a succession of cycles, whose duration can be adapted according to the characteristics of the fermented feedstock (e.g., VFA concentration) [59,60]. Such cycles guarantee the occurrence of the feast period (C source availability) during the feed phase and part of the reaction phase (feast), whereas the culture faces starvation in the rest of the cycle (famine) [61].…”