Production of Polyhydroxyalkanoate Co-polymer by Bacillus thuringiensis

Abstract

Integrative processes for the production of bioenergy and biopolymers are gaining importance in recent years as alternatives to fossil fuels and synthetic plastics. In the present study, Bacillus thuringiensis strain EGU45 has been used to generate hydrogen (H 2 ), polyhydroxybutyrate (PHB) and new co-polymers (NP). Under batch culture conditions with 250 ml synthetic media, B. thuringiensis EGU45 produced up to 0.58 mol H 2 /mol of glucose. Effluent from the H 2 production stage was incubated under shaking conditions leading to the production of PHB up to 95 mg/l along with NP of levulinic acid up to 190 mg/l. A twofold to fourfold enhancement in PHB and up to 1.5 fold increase in NP yields was observed on synthetic medium (mixture of M-9?GM-2 medium in 1:1 ratio) containing at 1-2 % glucose concentration. The novelty of this work lies in developing modified physiological conditions, which induce bacterial culture to produce NP.

Synthesis of Silver and Gold Nanoparticles Using Cashew Nut Shell Liquid and Its Antibacterial Activity Against Fish Pathogens

“…A recent study describes, when irradiation applied at 4 kGy without Ag NPs and at 2 kGy with Ag NPs against total aerobic mesophilic bacteria, Enterobacteriaceae, Escherichia coli and Clostridium perfringens shows greater inhibition zones in antimicrobial treatments of the packaging films using Ag NPs impregnation and gamma irradiation [20][21][22]. The CSNL mediated synthesized Ag and Au NPs with bactericidal activity might became an alternative to antibiotics used in fishery and aquaculture industry [22][23][24]. In the fact of controlling chemical toxicity in the environment, occurred through the antibiotic used in aquaculture industry can be replaced by eco-friendly biosynthesized Ag NPs [25].…”

Challenges and Opportunities for Customizing Polyhydroxyalkanoates

“…3HHx. PHAs varying from PHB, P(3HB:3HV), P(3HB:3HHx), P(3HB:4HB:3HHx) to P(3HB:6HHx:3HHx) depending upon the substrate [3,4,30,32,33]. Bacillus provides a robust option as potential PHA producer under more stringent conditions [3,4].…”

“…Integration of PHA production with H 2 may yield an improved and efficient PHA. During the process, the shift in the reactor from anaerobic static bioreactor to shake conditions, a modified composition was observed [17,33,42,44,78].…”

EVALUATION OF POLYHYDROXYALKANOATES PRODUCING BACTERIA ISOLATED FROM SOILS WITH WASTES OF Cocos nucifera

“…The production of this strain was high compared with other producing bacteria (Reddy et al 2003, Gao et al 2013, Singh et al 2013, Yun et al 2013. Its PHAs accumulation started at the end of the exponential growth and continued during the stationary phase, (Gumel et al 2013 Fig.…”

“…The best PHAs producer obtained in this study was the strain S15 that was identified as Bacillus megaterium. Particularly, many PHAs producers can accumulate a high number of granules in cytoplasm such as, Alcaligenes, Azotobacter, Bacillus, Pseudomonas, Enterobacter, Necator, Rhodobacter, Aeromonas, Ralstonia and Cupriavidus (Reddy et al 2003, Gao et al 2013, Singh et al 2013, Yun et al 2013.…”