Polyhydroxyalkanoates production by engineered Cupriavidus necator from waste material containing lactose

Whey Lactose as a Raw Material for Microbial Production of Biodegradable Polyesters

“…The recombinant strains obtained here were able to produce the polymer directly from lactose and from whey permeate. In addition, as reported above, the insertion of the lac operon within phaZ gene may reduce the amount of PHA depolymerised by the cell, thus improving the final polymer yield (Povolo et al, 2010). Catalán and coworkers (2007) constructed a modified strain of Herbaspirillum seropedicae Z69 carrying the lacZ, lacI and lacO genes of Escherichia coli for lactose conversion in plasmid pHM3.…”

“…Such a strategy could also face other metabolic bottle necks that can hamper a fast and complete substrate conversion by the selected strain. For instance, Cupriavidus necator, a well-known PHA producer, but unable to grow on lactose, has been genetically modified in order to construct a recombinant strain that can use lactose-containing waste material such as cheese whey, and one of the intracellular PHA depolymerases (phaZ1) was chosen to insert the lacZ, lacI and lacO genes of Escherichia coli (Povolo et al, 2010) This would have the effect to allow polymer production on lactose and, at the same time, to remove part of the PHA intracellular degradation system.…”

Making Green Polymers Even Greener:Towards Sustainable Production of Polyhydroxyalkanoates from Agroindustrial By-Products

“…Recently, the lacZ (encoding -galactosidase) and lacI (encoding the lac operon repressor protein) genes from Escherichia coli were introduced in the genome of R. eutropha interrupting phaZ1 (encoding an intracellular PHB depolymerase). Cell concentration reached values higher than 8 g · L -1 and the PHB content was about 20-25% (wt/wt), demonstrating the capability of this recombinant R. eutropha strain to use lactose (Povolo et al, 2010). …”

Exploring biodegradable polymer production from marine microbes

“…A wide range of industrial by-products has been used for PHAs production like agricultural, household waste materials, sugars, lignocellulosic raw materials, fats, and oils. Among those, extensive research is focused on wastes, sucrose [108], starch [109], glucose [110][111][112], soy molasses and hydrolysed soy [113,114], sugar cane molasses [115][116][117], waste rapeseed oil [118,119], sunflower meal hydrolysates [120], glycerol [121,122], rice bran and corn starch [74], lard oil, butter oil, and coconut oil [123], palm oil and its products [124], sugar beet molasses [125], spent palm oil [126], cellulose and cellulose hydrolysates [127], sugarcane bagasse hydrolysates [128,129], casein hydrolysate [130], rapeseed meal hydrolysates [131], triacylglycerides (TAG) [132], sugarcane liquor [133], acetic acid [111,134], corn steep liquor [135], fish peptone medium [136], galactose, mannose and rhamnose [137], cheese whey and hydrolysed whey [115,138,139], urea [117], oil [124], wheat based biorefinery [140,141], xylose [128], arabinose …”