Vol.:(0123456789) 1 3 Journal of Polymers and the Environment (2019) 27:1105–1111 https://doi.org/10.1007/s10924-019-01417-y ORIGINAL PAPER Physico-chemical Characterization of Poly(3-Hydroxybutyrate) Produced by Halomonas salina, Isolated from a Hypersaline Microbial Mat Emanuel Hernández‑Núñez 1  · Carolina Alejandra Martínez‑Gutiérrez 2  · Alejandro López‑Cortés 2  · Ma. Leopoldina Aguirre‑Macedo 3  · Carolina Tabasco‑Novelo 3  · Maria Ortencia González‑Díaz 4  · José Q. García‑Maldonado 1 Published online: 5 March 2019 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract In this work, the characterization of poly(3-hydroxybutyrate) PHB produced by Halomonas salina isolated from a hypersa- line microbial mat from Guerrero Negro, Baja California Sur, Mexico, is reported. The bacterial strain was able to produce isotactic PHB biopolymer with glucose (1%) as a single carbon source. The chemical structure of the polymer obtained was confrmed by Fourier-transform infrared (FTIR) and Nuclear magnetic resonance (NMR) spectroscopy. The polymer was thermally stable up to 225 °C and Diferential scanning calorimetry (DSC) analysis showed a melting temperature (T m ) of 173.6 °C. The obtained polymer presented a lower degree of crystallinity (39.3%) in comparison with PHB produced by other bacteria and polyhydroxyalkanoate co-polymers. Thus, the PHB biopolymer obtained in this study, could be recognized as more suitable for practical use, contributing to the repertoire of available bioplastics for further potential biotechnological applications, in which elastic polymers are needed. Keywords Poly(3-hydroxybutyrate) · Halomonas salina · Biopolymer · Hypersaline microbial mats Introduction Biopolymers have emerged as an environment-friendly alternative to the conventional plastics obtained from non- renewable petroleum resources [1]. Poly(hydroxyalkanoates) (PHAs) are a class of intracellular macromolecules synthesized by an extensive variety of microorganisms as a response to environmental stress and nutrient imbalance and which perform the function of a sink for carbon and energy [2–4]. PHAs show physical properties that are similar to those of common plastics such as polypropylene [2]. Due to their natural origin, many microorganisms in nature have the ability to degrade these compounds [5]. Currently, poly(3-hydroxybutyrate) (PHB) is the most common PHA stored by bacteria and is also the best char- acterized [2]. PHB has been proposed as a potential raw material for the production of fbers and biomedical items [6, 7]. However, PHB production, on a larger scale presents a higher cost in comparison with the production from petro- leum resources [8]. Diferent alternatives have been explored to decrease PHB production cost, including genetic engi- neering [9], the use of waste materials as substrate source [10, 11], improvements in the fermentation process [12] and the discovery of new PHA-producing bacterial strains which are able to tolerate extreme conditions regarding to cultivation parameters and to produce polymers with novel properties [13]. * Maria Ortencia González-Díaz maria.gonzalez@cicy.mx * José Q. García-Maldonado jose.garcia@cinvestav.mx 1 CONACYT - Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Departamento de Recursos del Mar, 97310 Mérida, Yucatán, Mexico 2 Centro de Investigaciones Biológicas del Noroeste S.C, La Paz, BCS, Mexico 3 Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Mérida, Mérida, Yucatán, Mexico 4 CONACYT - Centro de Investigación Científca de Yucatán A. C, Calle 43 No. 130, Chuburná de Hidalgo, 97205 Mérida, Yucatán, Mexico