Isolation and characterization of a bacteria of Cupriavidus genus from Indian Himalayan region and its evaluation for production of Poly-3-hydroxybutyrate

Abstract

A gram-negative, aerobic, rod-shaped bacterium, Cupriavidus basilensis 3.5A_LP, was isolated from a dry glacial lake bed in the Indian Himalayas. The isolate was characterized using phenotypic features, biochemical tests, and sequencing of its 16S rRNA gene and whole genome. The genome sequence analysis revealed that strain 3.5A_LP has a genome size of 8.94 Mb, an average G + C content of 65.03%, and 6397 protein coding sequences. Comparative genome analysis showed that strain 3.5A_LP is the closest relative to type strain Cupriavidus basilensis DSM 11853. Miniaturized growth experiments showed the accumulation of Poly-3-hydroxybutyrate (PHB) when grown on oleic acid and fructose as the sole carbon source. Cultivation experiments demonstrated that oleic acid supplemented cultures accumulated up to 73.67 ± 0.25% PHB (w/w) after 96 h-equivalent to ~ 7.55 g/L polymer. The polymer was extracted and confirmed as PHB, with an average molecular weight of 290 kDa and a maximum degradation temperature of around 277 °C. Cupriavidus basilensis 3.5A_LP has been isolated from the Himalayan region, a habitat normally exposed to extreme conditions. The strain can be a potential host for industrial production of PHB.

Keywords: Bioplastic production; Himalayan region; Poly-3-hydroxybutyrate; Soil bacteria; Whole genome sequencing.