IOSR Journal Of Pharmacy And Biological Sciences (IOSR-JPBS) e-ISSN:2278-3008, p-ISSN:2319-7676. Volume 14, Issue 6 Ser. III (Nov –Dec 2019), PP 17-25 www.Iosrjournals.Org DOI: 10.9790/3008-1406031725 www.iosrjournals.org 17 | Page Isolation, characterization and Molecular identification of Polyhydroxybutyrate producing bacterium grown on cooking oil wastes Nouf Abdulaziz Almansour and Mona O. Albureikan Abstract: Disposal of petroleum based plastic is a threat to our environment and health since it is non degradable. Polyhydroxybutyrate (PHB) is the best type of biodegradable polymer that accumulated by genera of bacteria. These bacteria used it as a carbon and energy sources. The properties of PHB are identical to the petroleum based plastics. Twenty two bacterial isolates were obtained on nutrient agar and modified C2M agar media from different soil samples, collected from Jeddah, Kingdom of Saudi Arabia. All bacterial isolates used oil as carbon source. They were screened for PHB production using Sudan Black B stain. Three bacterial isolates accumulated PHB and the quantity of PHB was determined by UV-VIS spectrophotometer. The bacterial isolate NM17 is the best PHB producer which accumulates 50.10 % of the cell dry weight. The bacterial isolate NM17 was identified based on morphological, physiological, biochemical tests and 16s rRNA gene sequence as Bacillus funiculus. The best condition of PHB production were obtained using medium C2M at pH 6.5, incubation temperature at 37ᵒC and incubation period was 2 days. Keywords: petroleum based plastic, polyhydroxybutyrate, production, waste cooking oil, Bacillus --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 17-12-2019 Date of Acceptance: 31-12-2019 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction: Disposal of petroleum based plasticis a threat to our environment and health. Chemically, petroleum based plasticis synthetic polymers made of a long chains of molecules by petroleum and other fossil fuels (Tuominen et al., 2002). Unfortunately, these petroleum based plastics stick on the environment for a long time in a hard condition and remain protected from the damage of microorganisms and chemicals (Marjadi and Dharaiya, 2011). For this reason, the need to produced bioplastics for available and alternative technology has become important (Zargounet al., 2015).Biological material has a special type called bioplastics, their chemical nature is degradable and eco-friendly (Kamilah et al., 2011; Jain and Tiwari, 2015). Among different biodegradable plastic, polyhydroxylalkanoate, a biopolymer found as inclusion, used as both carbon and energy sources in bacteria, is the most famous (Zhang et al., 2003; Scheel et al., 2016). There are more than 155 polyhydroxylalkanoate (PHA) monomers had been identified (Agnew and Pfleger, 2013; Nielsen et al., 2017). Polyhydroxybutyrate that accumulated by numerous microorganisms isconsidered to bethe best characterized and the most studied of polyhydroxylalkanoate (Echo and Antimafia, 2010; Phanseet al., 2011). The high cost production of carbon source is the main reason for high cost of polyhydroxylalkanoate. There for, the need to investigate inexpensive substrates to make the polyhydroxylalkanoate production economically more attractive than petroleum based plastic (Povoloet al., 2010; Budde et al., 2011). Plants oils found as a possible substrate for polyhydroxylalkanoate production (Kahar et al., 2004; Alias and Tan 2005). Plants oils compared with sugar such as glucose or sucrose can increase the production of PHA and decrease the cost of the production (Daniel, 2006;Chenyu et al., 2012). Waste cooking oil is a cheaper sustainable source of plant oils that can be used in the production of polyhydroxylalkanoate (PHA) which can be easily collected from several of domestic communities (Zhang et al., 2003; Jiang et al., 2016). There are about 250 of different bacterial strains that can produce polyhydroxylalkanoate at different levels of quality, yield and efficiency under several conditions (Pollet and Averous, 2011).For example, Azotobacter, Bacillus, Archaebacteria, Methylobacteria and Pseudomonas (Lee, 1996).Moreover, Ralstonia eutropha (formerly Alcaligenes eitrophus) and Cupriavidus necator which are the most studied bacteria that can accumulate polyhydroxylalkanoate up to 80 per cent of the dry weight of PHA (Verlinden et al., 2007; ShzeMok et al., 2016). The aim of this study was isolation and characterization of the best polyhydroxybutyrate producers that used waste cooking oil as carbon source.