Review on extraction of polyhydroxyalkanoates and astaxanthin from food and beverage processing wastewater

The recovery of value-added products from food and beverage processing wastewater, polyhydroxyalkanoates, and astaxanthin, via various chemical and microbiological extraction techniques has been summarized in this contribution. While wastewaters from several food industries like olive oil, brewery, starchy, and agro-cultural have been utilized to produce polyhydroxyalkanoates as an alternative to the petrochemical sources, seafood wastewaters such as mussel processing, shrimp cooking, and chitin production have been used to recover astaxanthin. In these studies, the wastewater's carbon content has been found as an essential parameter for the recovery of polyhydroxyalkanoates and astaxanthin. The type of additional nitrogen source, microorganism properties, ambient conditions, and polymer extraction methods were mostly examined parameters for the polyhydroxyalkanoate recovery. Olive oil mill wastewater has been presented as one of the most promising industries for the recovery of polyhydroxyalkanoate with the highest polymer yield of 4.93 g L-1. Shrimp cooking wastewaters provide one of the highest astaxanthin yields as 10-13 mu g mL(-1). In addition to summarizing polyhydroxyalkanoates and astaxanthin yields from various wastewaters, technological obstacles and solutions regarding efficient extraction and large scale production have been discussed in this review.