Author : Jose A. Mallari
Publisher :
ISBN 13 :
Total Pages : 243 pages
Book Rating : 4.:/5 (989 download)
Book Synopsis Production of Biodegradable Poly-betahydroxybutyrate (PHB) from Indigenous Bacteria by Batch Fermentation by : Jose A. Mallari
Download or read book Production of Biodegradable Poly-betahydroxybutyrate (PHB) from Indigenous Bacteria by Batch Fermentation written by Jose A. Mallari and published by . This book was released on 2010 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polybeta-hydroxybutyrate (PHB) is a biodegradable close substitute for non-biodegradable synthetic plastic. Its production by 79 local bacteria obtained from dumpsite soils and sewage sludge was explored in the study, initially by clear zone formation indicative of both synthesis and degradation in PHB medium, staining of cultured cells with Sudan Black B and, finally, by the chemical method of Law & Slepecky (1961) followed by UV-Vis spectrophotometry at 235nm of yields from a chemically defined medium (FBM) used in batch fermentation. focus wwas on Burkholder cepacia (I-79), B pseudomallei (I-50), Stenotrophomonas maltophilia (I-69), Pseudomonas putida (I-68) and Synthrophomonas wolfei (I-78). Production by these isolates with 20g glucose and 0-4g (NH4)2HPO4 registered highest with no significant differences with sucrose and glucose at 30g and SCM and SWL at 35g. In fermentation runs at 30 degrees with continuous aeration (200rpm), the same amount of (NH4)2HPO4 and 20g glucose, sucrose, sugarcane molasses (SCM) and sulphite waste liquor (SWL) as C sources, yields were higher at pH 7 than at pH 5. Yields were consistently low on the 24th hr and peaked on the 48th hour with the N source at 2g for I-69 (S. maltophilia) and 4g for the other four isolates. Production by all five isolates also differed with the C sources, generally in decreasing order from sucrose, to glucos, SCM and SWL. Moreover prolonged fermentation up to 72 hr resulted in decreased yields by all isolates irrespective of C source and amount of N source. Similar changes in PHB production with fermentation time by the isolates other than I-69 were obtained in tests with increased levels of C sources (25-40g) and (NH4)2HPO4 (5-7g); yields were highest with no significant differences with sucrose and glucose at 30g and SCM and SWL at 35g. Dry biomass of the isolatews correlated in general with PHB yields, which, however, likewise did not differ significantly in further tests with these amounts of the C sources in combination with (NH4)Dry biomass of the isolates correlated in general with PHB yields, which, however, likewise did not differ significantly in further tests with these amounts of the C sources in combination with (NH4)2HPO4, (NH4)2MO4 or (NH2)2CO at 0-4g for I-69 and 4-7g for the other four bacterial isolates. Overall, I-79 (B. cepacia), a wild-type strain isolated from sewage sludge of Central Fermentation Corporation in Sulipan, Apalit, Pampanga, gave as much as 71% PHB yield equivalent to 4.25g per liter of FBM with 4g (NH2)2CO and 35g SCM at a minimal total cost of PhP 0.22 per 1% PHB.