Research Article Synthesis of Poly-(R-hydroxyalkanoates) by Cupriavidus necator ATCC 17699 Using Mexican Avocado (Persea americana) Oil as a Carbon Source Araceli Flores-Sánchez, 1 Ma. del Rocío López-Cuellar, 2 Fermín Pérez-Guevara, 3 Ulises Figueroa López, 1 José Mauricio Martín-Bufájer, 1 and Berenice Vergara-Porras 1 1 Escuela de Ingenier´ ıa y Ciencias, Tecnol´ ogico de Monterrey, Campus Estado de M´ exico, Carretera Lago de Guadalupe Km 3.5, Margarita Maza de Ju´ arez, Atizap´ an de Zaragoza, MEX, Mexico 2 Cuerpo Academico de Biotecnolog´ ıa Agroalimentaria, Instituto de Ciencias Agropecuarias, Universidad Aut´ onoma del Estado de Hidalgo, Pachuca, HGO, Mexico 3 Departamento de Biotecnolog´ ıa y Bioingenier´ ıa, Centro de Investigaci´ on y Estudios Avanzados (CINVESTAV), Avenida IPN 2508, Zacatenco, Gustavo A. Madero, Ciudad de M´ exico, Mexico Correspondence should be addressed to Berenice Vergara-Porras; vergarabp@itesm.mx Received 20 April 2017; Accepted 14 June 2017; Published 21 August 2017 Academic Editor: Rafaele Cucciniello Copyright © 2017 Araceli Flores-S´ anchez et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Poly-R-hydroxyalkanoates (PHAs) are polymers produced by a vast number of bacterial species under stress conditions. PHAs exhibit diferent thermal and mechanical properties that depend on their molecular structure. In this work, PHAs were produced using avocado oil as the carbon source. Cupriavidus necator H16 was cultured in three-stage fermentation using fructose during the cell growth stages and avocado oil during the PHA synthesis stage. Diferent concentrations of avocado oil were used during the third stage to test the incorporation of various monomeric units into the PHAs. Biomass and PHA production were measured during the fermentation. DSC, FTIR, and gas chromatography analysis aided the PHA characterization. Diferent proportions of 3-hydroxyvalerate were present in the 3-hydroxybutyrate main chain depending on the concentration of avocado oil. Te results suggest that avocado oil is a viable new substrate for PHA production. 1. Introduction Poly-R-hydroxyalkanoates (PHAs) are polymers synthesized by a large number of bacterial species as a response to unbalanced nutritional conditions [1]. PHAs are thermoplas- tic polyesters of R-hydroxy alkanoic acids and accumulate intracellularly as granules that exhibit diferent properties depending on their chemical composition [2, 3]. A single monomer that forms the chain of PHAs typically contains from 3 to 15 carbon atoms [4], but the fnal chemical compo- sition of PHAs is related to the synthesizer microorganism, the carbon source, the culture conditions, and the specifcity of the PHA-synthase enzyme [5–7]. Homopolymers, copoly- mers, or terpolymers of PHAs can be obtained; for example, PHA copolymers can be synthesized from a combination of diferent substrates [8]. Te thermal properties of PHAs, such as melting temperature and degree of crystallinity, depend on the length of the PHA monomeric units. Monomers con- taining more than fve carbon atoms signifcantly decrease the polymer melting temperature, as well as the degree of crystallinity [9]. Many PHAs have main chains formed from monomers with diferent numbers of carbon atoms. Short-length-chain PHAs (PHA slc ) consist of monomers ranging from 3 to 5 carbons, whereas medium-length-chain PHAs (PHA mlc ) are formed from monomers containing 6 to 14 carbon atoms [4, 8]. One PHA slc , poly(3-hydroxybutyrate) (PHB), is the most common PHA and was frst identifed by Maurice Lemoigne in 1926 [1, 4]. PHB biodegradability and bio- compatibility make it an attractive material; however, its Hindawi International Journal of Polymer Science Volume 2017, Article ID 6942950, 10 pages https://doi.org/10.1155/2017/6942950