The present study focused on the screening and optimization of biopolymer polyhydroxybutyrate (PHB) production by Bacillus spp. using cost-effective substrates. | Turkish Journal of Biology Research Article Turk J Biol (2017) 41: 992-1002 © TÜBİTAK doi: Efficient polyhydroxybutyrate production from Bacillus thuringiensis using sugarcane juice substrate 1,2, 1 1,2 Anon THAMMASITTIRONG *, Sudarat SAECHOW , Sutticha Na-Ranong THAMMASITTIRONG Department of Microbiology, Faculty of Liberal Arts and Science, Kasetsart University, Nakhon Pathom, Thailand 2 Microbial Biotechnology Research Unit, Faculty of Liberal Arts and Science, Kasetsart University, Nakhon Pathom, Thailand 1 Received: Accepted/Published Online: Final Version: Abstract: The present study focused on the screening and optimization of biopolymer polyhydroxybutyrate (PHB) production by Bacillus spp. using cost-effective substrates. Among 602 local Bacillus isolates, Bacillus thuringiensis B417-5 produced the highest amount of PHB ( g/L, of dry cell weight, DCW). 1H NMR and FTIR analyses of the extracted polymer revealed the characteristic peaks of PHB. The optimization results showed that the highest PHB accumulation ( g/L, of DCW) was achieved when culturing B. thuringiensis B417-5 in a nitrogen-deficient medium containing 1% total sugar from sugarcane juice and yeast extract, with a pH of and an incubation temperature of 37 °C for 48 h. B. thuringiensis B417-5 can thus be considered a good candidate for large-scale production of PHB. We are reporting for the first time that sugarcane juice is a promising carbon source for economical PHB production by B. thuringiensis. Key words: Bacillus thuringiensis, bioplastic, polyhydroxyalkanoate, polyhydroxybutyrate, sugarcane juice 1. Introduction Extensive use of petroleum-derived plastics (approximately 269 million tons used globally in 2015) increases the environmental concerns of nonbiodegradable wastes, including contamination with small fragments of toxic compounds leaching out of .
