Characterization of Poly-β-Hydroxybutyrate Extracted from Different Bacteria

Abstract

different bacterial genera was studied with regard to its crystal structure, infrared absorption, intrinsic viscosity, and electron microscopy. All PHB samples precipitated from dilute chloroform solution gave identical X-ray diffractograms confirming uniformity of crystal structure, and uniformity of molecular structure, based on the similarity of the recorded infrared spectra, was also established. Crystal morphology was also similar, showing the reported "lath" shape structure for purified polymer from Bacillus cereus. Intrinsic viscosity ranged from 0.04 to 11.5 depending upon the polymer treatment; polymer molecular weights, based upon viscometry, could be estimated to range from 1,000 to 250,000. It is concluded that the same basic molecule is involved in all PHB present in the bacterial kindgom. ''no screen" X-ray film in a flat plate camera. Exposure times ranged from 1.5 to 15 hr, and film to-sample distance was 4 cm. For infrared-absorption analysis, enough poly-245

Quantitative analysis of the phospholipids of some marine bioluminescent bacteria

“…The precipitate was dissolved in chloroform and reprecipitated by the addition of 4 vol of methanol four more times, and was then dried in air. An IR spectrum of this material was identical to that of authentic poly@hydroxybutyrate (14). The combined supernatants, containing the lipids, were evaporated and taken up in chloroform-methanol 9:1 as above.…”

Topotactic crystallization of isolated poly(β-hydroxybutyrate) granules from Alcaligenes eutrophus

“…A portion of BXGOS was solubilized in reagent grade 1,1,2,2-tetrachloroethane and precipitated in lab grade hexane to form lamellar crystals [23]. Both the solvent and the non-solvent were obtained from Aldrich.…”

“…A Nicolet 6000 FTIR spectrometer was used to perform the infrared experiments in the 5000-400/cm region. Three polyester samples were examined: (i) freeze dried IH10/1EE, (ii) freeze dried IH10/1EE annealed for 18 h at 120°C, (iii) lamellar crystals [23] of BXG08. Each sample was first mixed with dry KBr, pressed under vacuum into thin disks and placed immediately into a magnetic sample holder for examination.…”

“…The extent of lamellar crystallization at the surface of the granule is a function of the severity of the isolation/purification treat-301 ment. Thus PHB granules isolated by a mild procedure involving enzyme treatment [10] show less crystallinity than granules isolated by the hypochlorite method [7] which causes some depolymerization [23].…”

The supramolecular architecture of the polyhydroxyalkanoate inclusions in Pseudomonas oleovorans

“…That polyhydroxyalkanoates (PHAs) could occur in an amorphous as well as a crystalline state was also first suggested by the initial works of Lemoigne. Work of Williamson and Wilkinson [2], and the laboratories of Merrick, Lundgren and Marchessault [3][4][5][6] demonstrated that in vivo or 'native granules' stain with Sudan Black, a characteristic fatty acid stain, but that isolated granules or purified polymer did not stain. They suggested that during isolation a lipid material was lost.…”