Forest soil bacteria able to produce homo and copolymers of polyhydroxyalkanoates from several pure and waste carbon sources

Abstract

Two bacterial strains able to produce polyhydroxyalkanoates (PHAs) from a wide variety of pure carbon sources (dextrose, xylose, sucrose, lactose and glycerol) were isolated from forest soils and identified as Achromobacter mucicolens and Stenotrophomonas rhizophila. Achromobacter mucicolens also produced poly(3‐hydroxybutyrate) (PHB) from different wastes (cheese whey, molasses, agave bagasse hydrolysate, nejayote and mango waste pulp). Stenotrophomonas rhizophila, produced the copolymer poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHB‐co‐HV) from glycerol (7·7 mol% of HV), and from sucrose with addition of propionic or valeric acid (4·5 and 25 mol% of HV, respectively). The copolymers presented a lower melting point (145, 156 and 127°C) and crystallinity (23, 26 and 16%) than PHB. The maximum biopolymer accumulation (PHB) for each strain growing in pure carbon source was as follows: 31·3 g per 100 g dry cell weight (DCW) for A. mucicolens from xylose; and 13·7 g per 100 g DCW for S. rhizophila from sucrose. Regarding the waste carbon sources, the highest PHB accumulation was obtained from agave bagasse hydrolysate (20·4 g per 100 g DCW) by A. mucicolens. The molecular weights of the biopolymers obtained ranged from 200 to 741 kDa. Significance and Impact of the Study The economic cost of the carbon source for the culture of polyhydroxyalkanoates (PHAs)‐producing microorganisms is one of the main process limitations. Therefore, it is vital to find versatile microorganisms able to grow and to accumulate homo and copolymers of PHAs from low‐cost substrates. In this research, we report two bacterial strains that produce poly(3‐hydroxybutyrate), poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) or both from at least five pure and five waste carbon sources. These results, by such bacterial strains have not been reported, especially the production of copolymer from glycerol without addition of precursors by Stenotrophomonas rhizophila and the production of PHB from xylose and agave bagasse hydrolysate by Achromobacter mucicolens.

Biodegradability and improved mechanical performance of polyhydroxyalkanoates/agave fiber biocomposites compatibilized by different strategies

“…Polyhydroxyalkanoates (PHA) are biopolyesters synthesized via fermentation from bacteria that intracellularly accumulate the biopolymer under nutritional stress conditions 1–3 . The most common PHA are polyhydroxybutyrate (PHB) and the copolymer with polyhydroxyvalerate (PHBV), which have similar physico‐mechanical properties than petroleum‐based polymers such as polypropylene 4 . They also have good moisture resistance and good barrier properties to gases 3 .…”

Dynamics of PHA-Accumulating Bacterial Communities Fed with Lipid-Rich Liquid Effluents from Fish-Canning Industries

“…The dominant genera previously described as PHA-accumulating bacteria were Acidovorax [ 72 ], Acinetobacter [ 73 ], Alkaliphilus [ 74 ], Azospirillum [ 11 ], Calothrix [ 13 ], Comamonas [ 75 ], Corynebacterium [ 76 ], Gemmobacter [ 77 ], Leifsonia [ 78 ], Lysobacter [ 79 ], Novosphingobium [ 80 ], Oscillochloris [ 81 ], Pandoraea [ 82 ], Polynucleobacter [ 83 ], Pseudomonas [ 84 ], Rhizobium [ 85 ], Roseiflexus [ 86 ], Stenotrophomonas [ 87 ], and Tsukamurella [ 55 ]. Moreover, species of the diazotrophic genus Niveispirillum were formerly classified within the well-known PHA-accumulating genus Azospirillum [ 88 ].…”

Effect of culture medium composition on the growth and biopolyesters production by the marine bacterium Saccharophagus degradans

“…Por lo tanto, la limitación combinada de nutrientes pudo activar varios mecanismos de acumulación. Sin embargo, no se detectó la producción de biopolímero a partir de xilosa, lo cual es común ya que han sido reportadas pocas bacterias son capaces de crecer y producir el polímero a partir de este azúcar (Clifton et al, 2020). En cuanto al porcentaje de acumulación de polímero alcanzado en este estudio, está dentro del rango de muchas cepas nativas cultivadas bajo condiciones sin optimizar como en este caso (Clifton et al, 2020).…”

“…Sin embargo, no se detectó la producción de biopolímero a partir de xilosa, lo cual es común ya que han sido reportadas pocas bacterias son capaces de crecer y producir el polímero a partir de este azúcar (Clifton et al, 2020). En cuanto al porcentaje de acumulación de polímero alcanzado en este estudio, está dentro del rango de muchas cepas nativas cultivadas bajo condiciones sin optimizar como en este caso (Clifton et al, 2020). Por lo tanto, sería de importancia seguir investigando el efecto de diferentes factores nutricionales y ambientales, así como estrategias de cultivo para optimizar la acumulación de PHB.…”