Production of Polyhydroxybutyrate (PHB) using Bacillus sp. (in: Bacteria) KUMBNGBT-35 associated with Low-Cost Substrate

Abstract

Polyhydroxybutyrate (PHB) is a biodegradable polymer produced by bacteria and archaea as carbon and energy reserves, belonging to the polyester family. Four strains (PHB 1, PHB 2, PHB 3 and PHB 4) of bacteria were collected from Ajjampura, Chikkamagaluru district, Karnataka, India and one was chosen to produce PHB. PHB 3 reported the highest PHB output at 4.3 g/L of CDW (Concentration of Dry Weight). The novel bacterial strain's 16s rRNA gene analysis indicated 100% similarity to the Bacillus sp. (in: Bacteria) and was assigned accession no MW048987. Additionally, the greatest PHB production was linked to the following factors: nutrient broth medium, 72 h of incubation, 37°C temperature, pH 7.0, glucose as the carbon source, ammonium chloride as the nitrogen source and a carbon-nitrogen ratio of 4:1. The largest amount of PHB production was observed in feed stock hydrolysate which was one of the several low-cost substrates used in the large-scale manufacture of PHB. The generation of PHB is measured and confirmed by the UV-visible spectrophotometric analysis which gives a λ-max of 0.073 nm. These results demonstrate that the isolated Bacillus sp. is a unique bacterial strain that produces a sizable amount of PHB that can be used to make PHB biopolymers in large quantities.