Characterization of polyhydroxyalkanoate and the phaC gene of Paracoccus seriniphilus E71 strain isolated from a polluted marine microbial mat

Abstract

Polyhydroxyalakanote (PHA) was produced by the marine bacteria Paracoccus seriniphilus Strain E71. Three methods were used for screening PHA in this strain:(1) microscopic analysis, (2) specifically designed primers for amplify fragments of phaC gene from Gram negative bacteria, and (3) measurements using spectroscopy, calorimetry, thermogravimetry, and rheology. The polyhydroxyalkanoic acid synthase gene (phaC) sequence had 77% identity with the phaC gene of P. denitrificans PD1222 strain. Additionally, the translated sequence showed an 86% similarity with the amino acid sequence of the phaC gene N-terminal portion of the P. denitrificans PD1222 strain. Our phaC sequence was closely related to two phaC sequences that correspond to P. denitrificans; therefore, this is the first report of a sequence of phaC that codifies a poly-(3-hydroxyalkanoate) synthase class I, specifically a polybeta-hydroxybutyrate polymerase from the marine bacteria Paracoccus seriniphilus. The polymer PHA of E71 melts at 167.86°C (T m ), which corresponded to the fusion of the crystalline polymer and thermally degrades at 296.52°C, indicating that the biopolymer has good thermal stability. Rheology showed that this polymer behaves as a nonNewtonian fluid. All these characteristics suggest that the E71 strain produces a PHA that corresponds to the crystalline thermoplastic polymer PHB type.

Characterization of a polyhydroxyalkanoate obtained from pineapple peel waste using Ralsthonia eutropha

“…Likewise, Barbosa et al (2005) and Hong et al (1999) reported that 2928 cm −1 bands corresponded to C H group vibrations or extensions for PHB and PHAs obtained from fructose and different cell types. Lopez-Cortes et al (2010), Lopez-Cuellar et al, 2011;and Misra et al (2000) reported that the 1724 cm −1 band was the C O extension, which was to what was found in this investigation. Moreover, asymmetric CH bending, found in this study at 1452-1457 cm −1 and 1379-1384 cm −1 , corresponded to CH 2 and CH 3 groups, respectively, and was also reported by Oliveira et al (2007) and Gáscue et al (2000).…”

Degradation of corn stover by fungal cellulase cocktail for production of polyhydroxyalkanoates by moderate halophile Paracoccus sp. LL1

“…To obtain a prime region of phaC gene from the potent PHA producing strain, two degenerated primers reported by López-Cortés et al (2010) were used. PCR conditions for amplification of a region belonging to the phaC gene are given in MMS 6.…”

Antibiotics Sensitivity and Heavy Metals Resistance in PHB-Producing Bacilli Isolated from Eastern Province, Saudi Arabia

“…Moreover, PHB-producing bacilli are capable of rapid growth on a variety of cost-effective substrates, while gram-negative bacteria require expensive substrates which should be structurally related substrate to produce the PHAs polymer. Therefore, large numbers of bacilli are used in PHAs production and recommended for biomedical applications (Chen et al, 1991;Wu et al, 2001;Yilmaz et al, 2005;Valappil et al, 2007;Singh et al, 2009;Lopez-Cortes et al, 2010;Mizuno et al, 2010).…”