Production and characterization of PHB‐HV copolymer by Bacillus thuringiensis isolated from Eisenia foetida

Abstract

Polyhydroxyalkanoates (PHAs) are one of the most important biopolyesters produced by vast number of microorganisms that exist in the environment. PHAs gained much attention due to its inherent biodegradable and biocompatible ability along with its physicochemical properties, which are similar to those of conventional petroleum-based plastics. In the present study, PHA producing bacterial strains was isolated from earthworm. Initially, four bacterial strains were selected based on the intensity of fluorescence from 80 non-clonal isolates. Bacillus thuringiensis (B.t.) E101 was identified as the bacterium producing highest yield of PHA (3.6 ± 0.04 g L −1 ) through biochemical and molecular techniques such as 16S rRNA gene sequence analysis. Growth parameters such as carbon, nitrogen sources, and incubation time were optimized with respect to higher PHA production. Both qualitative (Fourier transform infrared spectroscopy and nuclear magnetic resonance) and quantitative (GC-MS) characterizations revealed that the polymer produced by B.t.E101 contains the characteristic peaks for poly(3-hydroxybutyrate-co-3hydroxyvalerate) copolymer. This is the first report for the occurrence, successful isolation, and characterization of PHA producing Bacillus sp. from earthworm.

Polyhydroxyalkanoate production from rice straw hydrolysate obtained by alkaline pretreatment and enzymatic hydrolysis using Bacillus strains isolated from decomposing straw

“…PHA production by several Bacillus species such as B. subtilis, B. firmus, B. cereus, B. thuringiensis isolated from different ecosystems and using different carbon sources has been reported earlier (Singh et al 2009;Sindhu et al 2013;Gowda and Shivakumar 2014;Odeniyi and Adeola 2017;Mohandas et al 2018;Ponnusamy et al 2019;Mohammed et al 2020). Synthesis of both homo-and copolymers has been reported depending on the substrate (Singh et al 2009;Mohapatra et al 2017).…”

Wood Juice Valorization through Production of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Using Bacillus sp. G8_19

“…Usually, Bacillus species accumulate P­(3HB) homopolymer, but there are also some reports of P­(3HB- co - 3HV) accumulation. For example, Kumar et al and Ponnusamy et al reported synthesis of P­(3HB- co -3HV) by B. thuringiensis . In comparison to P­(3HB), P­(3HB- co -3HV) has lower stiffness and brittleness, higher elongation at fracture, and increased tensile strength .…”

Challenges for polyhydroxyalkanoates production: extremophilic bacteria, waste streams, and optimization strategies

“…1,[20][21][22][23] PHA biopolymers possess distinctive characteristics such as biodegradability, biocompatibility, non-toxicity and similar physicochemical properties to conventional petroleum-based plastics. 24,25 PHA can display a range of physicochemical properties, which vary based on the length of their chains and the composition of their monomers which make their material properties highly versatile. 21,23,26 Among scl-PHA, PHB and the copolyester poly(3hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) are best described.…”