scholarly journals Biosynthesis of Poly-ß-Hydroxybutyrate (PHB) from Different Bacterial Strains Grown on Alternative Cheap Carbon Sources

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3801
Author(s):  
Sherif M. El-Kadi ◽  
Mohssen Elbagory ◽  
Hassan A. H. EL-Zawawy ◽  
Hossam F. A. EL-Shaer ◽  
Adel A. Shoukry ◽  
...  

Thirty bacterial isolates were tested on three different media for Poly-ß-hydroxybutyrate (PHB) production. The best bacterial isolates for producing PHB were screened and identified based on molecular biology; then, using three different alternative carbon sources (dried whey, sugar beet molasses and date molasses), physical properties were evaluated by Infrared (IR) spectrometry and Gas chromatography–mass spectrometry (GC-MS/MS) analysis. Our results showed that the best isolates identified based on molecular biology were Bacillus paramycoides MCCC 1A04098, Azotobacter salinestris NBRC 102611 and Brevundimonas naejangsanensis BIO-TAS2-2. The addition of sugar beet molasses to the medium of A. salinestris increased the cell dry weight (CDW), PHB concentration, PHB% and conversion coefficient (4.97 g/L, 1.56 g/L, 31.38% and 23.92%, respectively). The correlation coefficient values between PHB g/L and CDW g/L varied between very strong and moderate positive correlation. IR of the produced PHB from B. paramycoides and A. salinestris showed similar bands which confirmed the presence of PHB; however, B. naejangsanensis showed weak bands, indicating lower PHB concentration. The chemical composition obtained showed that the GC-MS of the PHB extracted represents 2, 4-ditert-butylphenol for B. paramycoides and isopropyl ester of 2-butenoic acid for both of A. salinestris and Brevundimonas naejangsanensis. Therefore, PHB produced by microorganisms can be considered a biodegradable polyester, and represents a promising technique for the development of eco-friendly and fully biodegradable plastics.

2000 ◽  
Vol 882 (1-2) ◽  
pp. 329-334 ◽  
Author(s):  
Roland Ulber ◽  
Robert Faurie ◽  
Peter Sosnitza ◽  
Lutz Fischer ◽  
Egbert Stärk ◽  
...  

2018 ◽  
Vol 125 (1) ◽  
pp. 134-142 ◽  
Author(s):  
Vesna M. Vučurović ◽  
Vladimir S. Puškaš ◽  
Uroš D. Miljić

scholarly journals The effect of changes in opportunity costs and prices of some agricultural products such as sugar beet, corn,wheat etc. used for bioethanol production on the cost of bioethanol production is not adequately known in Turkey.. Therefore, it was aimed to determine the bioethanol production cost items and unit production costs and also to put forth the effects of variations in raw material prices on cost of bioethanol.. The research data were collected via personal interviews from active bioethanol plants in Turkey. The results of previous studies and documents of related institutions and organizations were also used. The study followed classical cost analysis approach to calculate production cost. Scenario analysis was performed when exploring the effect of raw material prices on bioethanol production cost. Research findings showed that production cost per litre bioethanol produced from sugar beet molasses, corn, wheat and corn-wheat mixture were 2.50 TL, 2.84 TL, 2.95 and 2.84 TL, respectively. The share of raw material expenses in bioethanol cost per liter varied associated with the crops used in the process, it was 28.55% for bioethanol produced from sugar beet molasses, 44.81% for bioethanol produced from corn-wheat mixture and 44.87% bioethanol produced from corn. The research results also showed that the changes that occur in raw material prices significantly affected the bioethanol production cost and opportunity cost of crops created difficulties in biomass supply. Implementing the suitable policies and strategies and making the necessary arrangements in legislation would enhance the economic sustainability of bioethanol production in Turkey.

2017 ◽  
Vol 32 (1) ◽  
pp. 16-16
Author(s):  
Selime Canan ◽  
Vedat Ceyhan

2016 ◽  
Vol 9 (1) ◽  
pp. 62-67 ◽  
Author(s):  
R. Jame ◽  
V. Zelená ◽  
B. Lakatoš ◽  
Ľ. Varečka

Abstract Five bacterial isolates were tested for their ability to generate hydrogen during anaerobic fermentation with various carbon sources. One isolate from sheep rumen was identified as Escherichia coli and four isolates belonged to Clostridium spp. Glucose, arabinose, ribose, xylose, lactose and cellobiose were used as carbon sources. Results showed that all bacterial strains could utilize these compounds, although the utilization of pentoses diminished growth yield. The excretion of monocarboxylic acids (acetate, propionate, formiate, butyrate) into medium was changed after replacing glucose by other carbon sources. Di- and tricarboxylic acids were excreted in negligible amounts only. Spectra of excreted carboxylic acids were unique for each strain and all carbon sources. All isolates produced H2 between 4—9 mmol·L−1 during the stationary phase of growth with glucose as energy source. This value was dramatically reduced when pentoses were used as carbon source. Lactose and cellobiose, starch and cellulose were suitable substrates for the H2 production in some but not all isolates. No H2 was produced by proteinaceous substrate, such as blood. Results show that both substrate utilization and physiological responses (growth, excretion of carboxylates, H2 production) are unique functions of each isolate.


2018 ◽  
Vol 97 (4) ◽  
pp. 947-954 ◽  
Author(s):  
Miljana Djordjević ◽  
Zita Šereš ◽  
Tatjana Došenović ◽  
Dragana Šoronja‐Simović ◽  
Nikola Maravić ◽  
...  

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