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Isolation of PHA–Producing Bacteria from Date Syrup Waste
Author(s) -
Ataei Seyed Ahmad,
VasheghaniFarahani Ebrahim,
Shojaosadati Seyed Abbas,
Tehrani Hossein Abdul
Publication year - 2008
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200850903
Subject(s) - polyhydroxyalkanoates , polyhydroxybutyrate , bacteria , food science , staining , chemistry , dry weight , microorganism , biomass (ecology) , bacterial growth , biology , botany , genetics , agronomy
Since the major problem associated with the industrial production of Polyhydroxyalkanoates (PHAs) is their high production cost, this study was carried out using date syrup as the major carbon source to decrease the production cost and also help to supply other nutrient requirements. To isolate PHA–producing bacteria for this purpose, microorganisms were isolated from the syrup waste of a local date factory. These purified colonies were screened for intracellular granules by staining with Sudan Black. The positive‐staining strains were grown for production of PHAs in 5% date syrup as carbon source supplemented with mineral salt medium. The culture was incubated at 30 °C with shaking at 140 rpm for 60 h. Among positively stained bacteria, the best PHA producers were selected on the basis of cell growth, cell dry weight, PHA content and the monomer composition of PHA. One of them could utilize date syrup for growth and produce the homopolymer of Polyhydroxybutyrate (PHB) with a cell density of about 5.1 g/L and maximum concentration of PHB equal to 3.6 g/L which is 71% of cell dry weight. Another one produces copolymer of Poly (hydroxybutyrate‐hydroxyvalerate) in date syrup media with a maximum concentration of 2.2 g/L containing 10 wt % valerate in shake flask cultivation.