التصنيع الحيوي لمركب بولي هيدروكسي الكانويت المنتج من بكتريا Acinetobacter lwoffii وتوصيفه

الباحث

كرار كريم حميد

المشرف

امل علي حسين - ايمان هندي كاطع

الجامعة

الجامعة التكنولوجية

الكلية / القسم

قسم العلوم التطبيقية / التقنيات الأحيائية

الشهادة

ماجستير

السنة

2022

لغة الرسالة

انكليزي

الكلمات المفتاحية

Polyhydroxyalkanoate; Acinetobacter lwoffii; Biopolymers; Biodegradable plastics

الحيوية إلى 4.8 غم / لتر » على التوالي . ومن خلال الفحوصات التشخيصية للمنتج البكتيري تم التأكد من أن البوليمر المعزول هونوع من ال ‎PHA‏ ويكون بشكل بلورات بيضاء مائلة للاصفرارويتميز بنقطة انصهار تبلغ 177 درجة سيليزية. وباستخدام مقياس الطيف الضوئي تبين أن أفضل طول موجي للكشف عن البوليمر هو 235 نانوميتر. أثناء تحليل المنتج البكتيري باستخدام مطيافية الاشعة تحت الحمراء تم الكشف عن قمم مختلفة تشير إلى وجود مجموعات وظيفية ‎C = Oc CH :»0113 is‏ والتي توجد ‎Lal‏ في بنية ‎PHA‏ تم تشخيص إستر الميثيل لحمض أونديكانويك ومركبات حمض السداسي كانويك بواسطة تقنية كروموتوكرافيا الغاز-مطياف الكتلة ليؤكد على وجود البوليمر الناتج من العزلة البكتيرية والتي تم تحديدها كمجموعات وظيفية مثل بروتونات الميثان » بروتونات الميثيلين » -011) = ‎-CH‏ باستخدام مطياف الرنين المغناطيسي النووي. كانت النتيجة النهائية للدراسة هي أن استخدام العزلة البكتيرية//77/0/ 4 في تصنيع ‎PHA‏ يمكن أن يساعد في معالجة مشاكل التلوث البيئي الناجم عن استخدام البلاستيك الصناعي عن طريق استبداله ببديل ذو تاثيرغيرمحسوس وصديق للبيئة .

The most well-known degradable biopolymers are polyhydroxyalkanoates (PHAs), which are generated by several bacterial genera in unfavorable environments. It is widely acknowledged that PHA can be used in place of plastic to address one of the biggest environmental issues. In this investigation, samples of hydrocarbon-contaminated soil and environmental sources, such as landfills and waste dumping areas, were gathered from several sites in Baghdad, Iraq and (120) distinct localized bacterial isolates were isolated on enriched solid medium (L-Agar). After the bacterial isolates were stained with Gram stain, a microscopic examination under a light microscope revealed that (67) isolates are gram-negative. By employing Sudan black B as a stain; all bacterial isolates were examined for their ability to produce PHA. The tests focused on gram-negative bacterial isolates, as the results showed that (23) isolates are polymer-producing in varying proportions. Using the liquid production medium, it was found that five bacterial isolates were the most efficient in forming PHA inside their cells, ranging from (25-56%), which was accompanied by a rise in the dry weight of cells, which was between (1.20 and 3.53) gm/L . After 48 hours of incubation at 37 °C with a medium containing 10 gm/L glucose pH 7, the most active bacteria that produced a significant quantity of PHA were identified as Sphingomonas paucimobilis, Klebsiella pneumonia, Citrobacter braakii, Citrobacter sediakii, and Acinetobacter lowfii. The identification of A.lowffii as the most effective isolate in the synthesis of PHA was supported by morphological and physiological characteristics in addition to the Vitek test. In order to maximize the production of PHA, the focus of this study was also on evaluating spent cooking oil as a source of carbon. The experiments examined the key environmental factors in the culture medium that influence the growth of the experimental bacterial isolate and its capacity to make polymer. The cultivation of Acinetobacter lwoffii, which was previously studied and isolated from hydrocarbon-contaminated soil, showed the best production after 48 hours when it was incubated at 37 °C with an initial pH of 7.0 and 150 rpm of agitation. The optimum nutrient sources for concentrated PHA production were found to be corn oil waste as the source of carbon and urea as the source of nitrogen, with the best concentrations of carbon and nitrogen sources being 2 percent and 0.5 gm/L, respectively. The results demonstrated the significance of changing both the qualitative and quantitative components of the culture medium for the development of the indigenous A lwoffii. Results indicated a significant increase in PHA content ranging from 10% to 75% and the production of biomass to 4.8 gm/L, respectively . The isolate was confirmed to be a producer of PHA as yellowish white crystals with 177 °C melting point and the best wavelength for detecting the polymer is 235 using spectrophotometer .When the extracted molecule produced the characteristic C=O peak of PHA during FTIR-analysis and revealed various peaks indicating the presence of functional groups such as CH3, CH, which are also present in PHA structure. Methyl ester of undecanoic acid and hexadecanoic acid compounds were diagnosed by GCMS technology to pervade the presence of the polymer produced by the bacterial isolate which identified as Functional groups such as methane protons, methylene protons, –CH=CH– using NMR technique . The study's final finding was that the usage of bacterial isolate in the synthesis of PHA can help address the serious issue of environmental pollution by the use of industrial plastic by substituting it with an environmentally friendly and low- impact alternative.

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