Preparation and characterization of astaxanthin-loaded biodegradable polyhydroxybutyrate (PHB) microbeads for personal care and cosmetic applications.

Due to its biodegradability and biocompatibility, polyhydroxybutyrate (PHB) has received attention as an alternative material for microbeads in personal care and cosmetic products (PCCPs). Here, PHB was produced from crude glycerol by an Escherichia coli JM109 strain harboring pUC19-23,119-phaCAB without isopropyl β-D-1-thiogalactopyranoside (IPTG), an inducing agent. Astaxanthin-loaded PHB microbeads were prepared through emulsification-solvent evaporation.

Strategies for Poly(3-hydroxybutyrate) Production Using a Cold-Shock Promoter in .

The present study attempted to increase poly(3-hydroxybutyrate) (PHB) production by improving expression of PHB biosynthesis operon derived from strain A-04 using various types of promoters. The intact PHB biosynthesis operon of A-04, an alkaline tolerant strain isolated in Thailand with a high degree of 16S rRNA sequence similarity with H16, was subcloned into pGEX-6P-1, pColdI, pColdTF, pBAD/Thio-TOPO, and pUC19 (native promoter) and transformed into JM109. While the gene was insoluble in most expression systems tested, it became soluble when it was expressed as a fusion protein with trigger factor (TF), a ribosome associated bacterial chaperone, under the control of a cold shock promoter.

Medium chain length polyhydroxyalkanoates consisting primarily of unsaturated 3-hydroxy-5-cis-dodecanoate synthesized by newly isolated bacteria using crude glycerol.

Background: Our study aimed to search for novel bacteria capable of producing polyhydroxyalkanoates (PHAs) using crude glycerol residue obtained from biodiesel production in which used cooking oils were the substrates.

Results: Newly isolated bacteria from soils in Thailand were screened for the efficient production of PHAs from crude glycerol. The bacterial strains were cultivated on glucose, refined glycerol, crude glycerol, or various cooking oils (canola oil, palm oil, soybean oil, sunflower oil, corn oil, grape seed oil, olive oil, rice bran oil, camellia seed oil) for growth and PHA production.