Display omitted •Feedstocks govern PHA production schemes and enrichment conditions.•Synergistic impact of OLR, cycle length and SRT on enrichment conditions.•Nitrogen supplement associates with growth of PHA accumulators in the MC.•Uncoupled C/N supply and extended cultivation are strategies to improve PHA productivity.•Future work focusing in impact of F/F regime combined nitrogen supply on PHA production. PHA production using a combination of mixed culture and carbon wastes has been demonstrated as a cost-reducing solution compared to the use of expensive pure culture process. Continuous research has been conducted with the aim to further reduce the production cost by simplifying the production scheme, as well as enhancing the performance of mixed culture in PHA production. Selection of the carbon feedstock and enrichment strategies needs to be essentially considered to obtain a culture enriched with PHA accumulators for a stable PHA production. Most of the studies implementing mixed culture process applied the feast-famine regime with periodical supply of carbon for culture enrichment. Results have revealed that the enriched culture showed a comparable performance with pure culture, in terms of PHA content (30–80%) and yield (0.4–0.8 g PHA/g S). However, a low productivity is the hindering factor to produce PHA at industrial scale by using mixed culture, which could be overcome by improvising the enrichment strategies. This review zooms into the evaluation of two step and three step processes in PHA production by utilising different feedstocks. Critical parameters to be considered for PHA production such as the suitable feedstocks, enrichment conditions, stability of the enriched culture and nutrient supplementation are being highlighted. The possible enrichment strategies that include uncoupled C and N supply and extended cultivation in overcoming the issue of low productivity are presented. The impact of different enrichment strategies on microbial community, characteristics of PHA produced as well as PHA production performance is worth investigating in future.