Production and characterization of poly(3-hydroxy butyrate-co-3 hydroxyvalerate) (PHBV) by a novel halotolerant mangrove isolate

• A mangrove isolate produces polyhydroxy butyrate-co-valerate, P(3HB-co-3HV).
• The Bacillus sp., is capable of utilizing varying carbon sources for polymer production.
• Culture has the ability to produce P(3HB-co-3HV) by propionate dependent and independent routes.
• The PHBV had a high 3-hydroxyvalerate fraction of 48 mol%.
• The culture can utilize the acid pretreated liquor of lignocellulosic biomass for PHBV production.

A halophilic mangrove isolate identified by 16S rRNA sequence as a Bacillus spp. was found to be capable of using a broad range of carbon sources including monosaccharides (glucose and fructose), disaccharides (sucrose), pentoses (xylose and arabinose), various organic acids (acetic acid, propionic acid and octanoic acid) and even the acid pre-treated liquor (APL) of sugarcane trash, a lignocellulosic biomass, for growth and the production of polyhydroxyalkanoates (PHAs) such as poly(3-hydroxybutyrate, P3HB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate, PHBV), and 4-hydroxyhexanoate, 4HHX). The study describes the innate ability of a wild-type culture for PHBV production by both propionate dependent and propionate independent pathways. The biopolymer was extracted and characterized physico-chemically. The PHBV yield from glucose was estimated to be 73% of biomass weight with a high 3-hydroxyvalerate fraction of 48 mol%. Thereafter, spherical homogenous PHBV nanoparticles of ∼164 nm size were prepared for future applications.

Metabolic pathways involved in the synthesis of P(3HB-co-3HV) copolymer.Figure optionsDownload as PowerPoint slide