Effect of pH control and uncoupled carbon and nitrogen feeding strategy on enrichment of mixed microbial culture for polyhydroxyalkanoates production

Abstract Polyhydroxyalkanoates (PHA) production via a combination of mixed microbial culture (MMC) and waste carbon substrate has shown to be more economical solution compared pure process. Although crude glycerol been proven as promising feedstock, there are still limited study on the effect operating conditions such pH nutrient feeding strategy PHA using glycerol. This aims investigate feasibility enrichment accumulators in without control when uncoupled nitrogen was implemented. Enrichment conducted sequencing batch reactor (SBR) with cycle duration 24 hr organic loading rate (OLR) 1000 mg C/(L.d). Feast famine successfully implemented, feast/famine (F/F) ratio 0.43 indicating good storage response. The cyclic profile concentration also successful implementation F/F regime. Biomass 779 mg/L obtained by end week 5 content 16.2% g PHA/g VSS. During cycle, between 6 8 recorded which suggests that extreme acidic or alkaline condition detrimental cultivation not observed this study. demonstrates is feasible controlled under C N strategy.