Feedstocks Used in PHA Production

Researchers in industry have also reported working on methods with which transgenic crops will be developed that express PHA synthesis routes from bacteria to produce PHA as energy storage in their tissues [16]. 

Different other wastes can also be considered [27], such as carbohydrates molasses, starch and whey [69], cellulose hydrolysates [e.g., paper industry waste) alcohols wastes from biodiesel production, methanol plus glycerol, methanol fats and oils lipids from plant and animal wastes organic acids lactic acid from the dairy industry. 

Except sources indicating that Biomatera Inc, Canada, is specialized in the manufacture of PHA by fermentation of agricultural residues [70], almost aforementioned efforts were mainly at the academic level. Nevertheless, they could have a very important Impact if transferred to the industry. Indeed the feedstock used such as sugar accounts for roughly 40% of the price of derived PHA [70]. 

The sugar market is dominated by Brazil and Asian countries and its price has been quite volatile in the last decade. As can be appreciated from Nasdaq markets reports [71], a ca. fivefold increase was observed from 2004 until 2011 and now, in 2014, the price is about 2.5 times its value in 2007. All this has a great impact on PHA price since as much as 4-5 kg of sugar is needed to produce 1 kg of PHA [72]. 

More than 300 types microorganism accumulating PHAs have been identified, e.g., E. coli fed with a range of oils [lipids, saccharides, etc.) as feedstock produces different compositions of P[3HB-co-HHx) R. eutropha fed with a combination of glucose and 

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