Document Details

Document Type : Thesis 
Document Title :
Production of a natural biodegradable polymer of Polyhydroxy alkanoates from bacteria and its biodegradation compared to commercial product
انتاج بوليمر طبيعي قابل للتحل بوليهيدروكسي الكانيات من البكتريا ودراسه تكسيره بالمقارنة مع االمنتج تجاريا
 
Subject : Faculty of Science 
Document Language : Arabic 
Abstract : The natural biopolymers Polyhydroxy alkanoates (PHAs) are produced by many prokaryotic organisms as reserve material, when excess carbon source and nutrient limitation are available in the medium. Polyhydroxy butyrate (PHB) is the most famous class from PHAs. Bacteria (42 isolates) from different soil samples, collected from agriculture fields in 5 cities were obtained and screened for PHB production on modified nutrient agar medium (with 1% glucose as carbon source). All isolates were grown in modified nutrient broth medium for 2 days at 30ᵒC. Growth and % of PHB were calculated. The quantity of PHB was determined by UV-VIS spectrophotometer. Out of 42 isolates, 17 (31%) produced PHB with accumulation percentage ranged from 6-48 % of the cell dry weight. Excellent growth and high percentage of PHB was obtained by isolate SM23. Using morphological and physiological characters in addition to 16S rRNA, the isolate SM23 was identified as Bacillus subtilis SM23 with 95% similarity with B. subtilis strain X-01, Bacillus sp. K7SC-9A, B. velezensis UUS-1. Bacillus Subtilis SM23 was the most active isolate in PHB production and accumulation. Maximum PHB accumulation was obtained in modified nutrient broth medium containing 2% glucose. For the maximum PHB accumulation by the isolate B. subtilis SM23, the best incubation temperature was recorded to be 30ᵒC and the best medium pH was pH 6.5. Addition of any yeast extract to the medium decreased PHB accumulation. Production of PHB by the isolate SM36 was studied as described before. It was identified as Bacillus velezensis. The PHB sheet was degraded by different fungi. The most active fungal isolate was identified using molecular technique as Aspergillus fumigates MM 11. The growth and PHB deration of the selected fugal isolate MM11 were studied. The Spectra of PHB were determined. Effect of different factors on degradation process and depolymerase activity was studied. In conclusion, Bacillus isolates obtained from soil, showed excellent PHB production and improving growth conditions enhanced accumulation percentage. PHB was characterized and degraded easily. 
Supervisor : Prof. Dr. Magda Mohammed Aly Prof 
Thesis Type : Doctorate Thesis 
Publishing Year : 1441 AH
2020 AD 
Co-Supervisor : Dr. Fardos Marouf Bokhari 
Added Date : Friday, May 22, 2020 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
سها عبدالله الحربيAlharbi, Suha AbdullahResearcherDoctorate 

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