Fabrication of Nano Ester Fibrs by pure PHB from wild typeAzospirillum brasilense

Background and Aim : Concern about environmental pollution by synthetic plastics, whichconstitutes a major part of environmental pollution in industrialized and developing countries, newresearch has emerged to synthesis bioplastics with high biodegradability and with a formula thatis friendly to the environment. Biodegradable biopolymers such as PHA and its homopolymerPHB have the ability to replace plastics and be included in the biological cycle. PHAs are bacterialpolymers that are formed as naturally occurring storage polyesters by a wide range ofmicroorganisms usually under unbalanced growth conditions. Azospirillum brasilense is arhizosphere microorganism with potential use as an inoculant for promot-ing crop plant growthMethods : In this study Azospirillum brasilense was isolated from para-nodule of wild weed andidentified by ۱۶s rRNA sequencing. The production of high yield polymer performed in two stagesby Taguchi experimental design. The feeding time to high yield biomass were obtained andfollowed by addition of glucose, K۲HPO۴ in ammonium depletion media. The pure PHB extractedfrom biomass and analyzed first by UV spectrophotometer and finally it was characterized byFTIR, NMR and HPLC. In addition, extracted PHB and polyacrilonitryle were mixed together,Then the electrospun PHB/polyacrilonitryle nanocomposite scaffold were fabricated. Thenanocomposite were characterized and confirmed by AFM and FTIRResults : Azospirillum brasilense was isolated from para- nodule of wild weed, showed a goodcapacity for high growth and production of PHB. For this isolate PHB synthesis was favored underoxygen limitation and high C/N ratio or ammonium starvation for PHB synthetase enzyme inducer.At the end of exponential growth the production of PHB enhanced up to ۷۶% of the cell dry weight.As a result of electrospinning, fibers with a diameter of ۲-۱۰ micrometers were obtained.Conclusion : The feeding time make the industrial production of this polymer valuable. Therefore,the proposed PHB scaffolds prepared in this study can be considered as good candidates in surgeryas sutures to repair wounds and blood vessels and bone tissue engineering applications. Also, thebiodegradability of PHAS and their compatibility with vital systems have caused them to be usedin the controlled release of drugs, tissue engineering, and veterinary medicine.

کلیدواژه ها:

PHB ، Bioplastic ، Biopolymer ، Azospirillum ، HPLC ، NMR