New PHA products using unrelated carbon sources

Abstract

Polyhydroxyalkanoates (PHA) are natural polyesters stored by a wide range of bacteria as carbon source reserve. Due to its chemical characteristics and biodegradability PHA can be used in chemical, medical and pharmaceutical industry for many human purposes. Over the past years, few Burkholderia species have become known for production of PHA. Aside from that, these bacteria seem to be interesting for discovering new PHA compositions which is important to different industrial applications. In this paper, we introduce two new strains which belong either to Burkholderia cepacia complex (Bcc) or genomovar-type, Burkholderia cepacia SA3J and Burkholderia contaminans I29B, both PHA producers from unrelated carbon sources. The classification was based on 16S rDNA and recA partial sequence genes and cell wall fatty acids composition. These two strains were capable to produce different types of PHA monomers or precursors. Unrelated carbon sources were used for growth and PHA accumulation. The amount of carbon source evaluated, or mixtures of them, was increased with every new experiment until it reaches eighteen carbon sources. As first bioprospection experiments staining methods were used with colony fluorescent dye Nile Red and the cell fluorescent dye Nile Blue A. Gas chromatography analysis coupled to mass spectrometry was used to evaluate the PHA composition on each strain cultivated on different carbon sources. The synthesized polymers were composed by short chain length-PHA (scl-PHA), especially polyhydroxybutyrate, and medium chain length-PHA (mcl-PHA) depending on the carbon source used.

Polyhydroxybutyrate and polyhydroxydodecanoate produced byBurkholderia contaminansIPT553

“…). Comparing to this work, B. contaminans IPT 553 (Matias and Rodrigues ) could accumulate blends of PHB, PHV/PHO and PHDd when cultivated in sucrose or glucose as sole carbon source. It is interesting that the combination scl‐PHA/mcl‐PHA, for example, PHB‐PHDd, is not usual in any bacterial group, and it was found in this work without supplemental carbon source related to the PHA obtained.…”

“…The bacterium was isolated from soil in 2000, according to Matias et al (2009) and called I29B strain. After been identified as Burkholderia contaminans, the strain was deposited in São Paulo State Technological Research Institute (from Portuguese Instituto de Pesquisas Tecnol ogicas do Estado de São Paulo-IPT) and received the number 553 (Matias and Rodrigues 2011). For maintenance and first PHA accumulation screening, solid ISP9 medium (Shirling and Gottlieb 1966) was used with glucose (1% w/v), as the principal carbon source, and hydrolysed casein (0Á1% w/v), as second carbon and nitrogen source.…”

“…); (iv) or blends of mcl‐PHA and scl‐PHA as described for actinobacteria strains (Matias et al . ) and Burkholderia representatives (Matias and Rodrigues ).…”

“…Only few PHAs can be produced from carbon sources, which are structurally unrelated to the constituents. Some examples are (i) 3-hydroxyvalerate (3HV)-containing PHAs produced by species of the genus Rhodococcus (Pieper and Steinb€ uchel 1992); (ii) PHAs consisting of medium chain length 3-hydroxyalkanoates (mcl-3HA) occurring in fluorescent pseudomonads (Timm and Steinbuchel 1990); (iii) Burkholderia strains that were found to accumulate a PHA blend composed of the two homopolyesters poly(3-hydroxybutyrate), poly(3HB) and poly(3hydroxy-4-pentenoate), poly(3H4PE) (Rodrigues et al 1995);(iv) or blends of mcl-PHA and scl-PHA as described for actinobacteria strains (Matias et al 2009) and Burkholderia representatives (Matias and Rodrigues 2011).…”

Mathematical Modelling as a Tool to Optimize PHA Production by Massilia spp

“…(PHAs) are biopolyesters, accumulated under nutrient limiting conditions (nitrogen and/or phosphorous) and excess of carbon [1]. Apart from being biocompatible and biodegradable, they possess properties similar to conventional plastic [2].…”