Evaluation of short-chain-length polyhydroxyalkanoate accumulation in Bacillus aryabhattai

Abstract

This study was focused on the polyhydroxybutyrate (PHB) accumulation property of Bacillus aryabhattai isolated from environment. Twenty-four polyhydroxyalkanoate (PHA) producers were screened out from sixty-two environmental bacterial isolates based on Sudan Black B colony staining. Based on their PHA accumulation property, six promising isolates were further screened out. The most productive isolate PHB10 was identified as B. aryabhattai PHB10. The polymer production maxima were 3.264 g/L, 2.181 g/L, 1.47 g/L, 1.742 g/L and 1.786 g/L in glucose, fructose, maltose, starch and glycerol respectively. The bacterial culture reached its stationary and declining phases at 18 h and 21 h respectively and indicated growth-associated PHB production. Nuclear Magnetic Resonance (NMR) spectra confirmed the material as PHB. The material has thermal stability between 30 and 140 °C, melting point at 170 °C and maximum thermal degradation at 287 °C. The molecular weight and poly dispersion index of the polymer were found as 199.7 kDa and 2.67 respectively. The bacterium B. aryabhattai accumulating PHB up to 75% of cell dry mass utilizing various carbon sources is a potential candidate for large scale production of bacterial polyhydroxybutyrate.

Fed-batch production and characterization of polyhydroxybutyrate by Bacillus megaterium LVN01 from residual glycerol

“…On the other hand, the higher productivity of PHB (35.6 mg L -1 h -1 ) is again evidenced at 12 h (slightly higher than the 29.5 mg L -1 h -1 obtained with a culture volume of 5 L). These results are similar to PHB productivities reported with Bacillus strains using glycerol as a carbon source [21,22].…”

Microbial Polyhydroxyalkanoates Granules: An Approach Targeting Biopolymer for Medical Applications and Developing Bone Scaffolds

“…The characterization of the PHA granule can be performed using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, and X-ray diffraction, respectively. Size-exclusion chromatography is advised to understand the polydispersity index, the number-average molar mass, and weight-average molar mass (Mw) [5,11,12]. The PHA polymer can be further studied using proton nuclear magnetic resonance spectroscopy and 13 C-NMR spectra [5,12].…”

“…Biogenesis of PHA is aided by a close-knit network of enzymes such as acetyl-CoA-acetyltransferases, acetoacetyl-CoA-reductases, PHA synthases [ 4 ], and a gene cluster involving phaC, phaM, phaZ, etc. The research on this biopolymer has focused on the isolation of PHA proteinaceous granules accumulating in microbial bodies and optimizing culture conditions contributing to increment in yield and biomass production, which helps to identify the potential source of PHA [ 5 , 6 ]. The success of the PHA as a sustainable nanocomposite in various medical applications and product commercialization needs a clear understanding of its microbial source of production, industrialization, downstream processing, and utilization of PHA and its nanocomposites [ 1 ].…”

Draft Genome Sequence of Bacillus aryabhattai Strain PHB10, a Poly(3-Hydroxybutyrate)-Accumulating Bacterium Isolated from Domestic Sewerage

“…The strain efficiently valorizes cheap raw materials by converting them to poly(3-hydroxybutyrate) (PHB) (1), which is a biodegradable and biocompatible plastic material of great commercial importance (2). In the present study, we investigated the whole-genome sequence of strain PHB10 for novel enzymes involved in PHB biosynthetic pathways.…”