Production and maximization of polyhydroxybutyrate from diazotrophic cyanobacteria isolated from inland waters of Turkey

Abstract

Plastic has an essential importance in our lives. However, the disposal of these non-biodegradable plastics poses a threat to our environment. In addition to their chemical and physical properties, biocompatible and biodegradable polyhydroxyalkanoates (PHA) have the potential to be alternative to petroleumbased plastics. Polyhydroxybutyrate (PHB), which is the most common derivative of PHA, is generated as an alternative petrochemical plastics due to their biodegradable qualifications. In this thesis, twelve Cyanobacteria species from the paddy fields of Edirne were isolated, and with twelve Cyanobacteria species from the IMU culture library, which were also collected from Turkey’s inland waters have been identified on morphologic and genomic base. Studied diazotrophic Cyanobacteria have been investigated for their PHB contents, which is biodegradable, renewable, biologically suitable, non-toxic, and environmentally friendly bioplastics. The best culture medium selection has been performed, and Calothrix sp. IMU10, Nostoc sp. IMU11, and Anabaena sp. IMU18 have been selected as the best diazotrophic PHB producer Cyanobacteria. Also, PHB analysis methods and the maximization of extraction technics have been investigated. Furthermore, valuable Cyanobacterial by-products such as fatty acid methyl ester and tri acyl glycerol, saccharide, chlorophyll-a, carotenoid, riboflavin, protein, and phycobiliprotein have been measured.