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Engineering a predatory bacterium as a proficient killer agent for intracellular bio-products recovery: The case of the polyhydroxyalkanoates.

Martínez V, Herencias C, Jurkevitch E, Prieto MA - Sci Rep (2016)

Bottom Line: This work examines the potential of the predatory bacterium Bdellovibrio bacteriovorus HD100, an obligate predator of other Gram-negative bacteria, as an external cell-lytic agent for recovering valuable intracellular bio-products produced by prey cultures.The bio-product targets to be recovered were polyhydroxyalkanoates (PHAs) produced naturally by Pseudomonas putida and Cupriavidus necator, or by recombinant Escherichia coli strains.B. bacteriovorus with a mutated PHA depolymerase gene to prevent the unwanted breakdown of the bio-product allowed the recovery of up to 80% of that accumulated by the prey bacteria, even at high biomass concentrations.

View Article: PubMed Central - PubMed

Affiliation: Environmental Biology Department, Centro de Investigaciones Biológicas, CSIC, C/Ramiro de Maeztu 9, 28040 Madrid, Spain.

ABSTRACT
This work examines the potential of the predatory bacterium Bdellovibrio bacteriovorus HD100, an obligate predator of other Gram-negative bacteria, as an external cell-lytic agent for recovering valuable intracellular bio-products produced by prey cultures. The bio-product targets to be recovered were polyhydroxyalkanoates (PHAs) produced naturally by Pseudomonas putida and Cupriavidus necator, or by recombinant Escherichia coli strains. B. bacteriovorus with a mutated PHA depolymerase gene to prevent the unwanted breakdown of the bio-product allowed the recovery of up to 80% of that accumulated by the prey bacteria, even at high biomass concentrations. This innovative downstream process highlights how B. bacteriovorus can be used as a novel, biological lytic agent for the inexpensive, industrial scale recovery of intracellular products from different Gram-negative prey cultures.

No MeSH data available.


Related in: MedlinePlus

Molecular characterization of PHA and PHB polymers obtained from 24 h co-cultures with B. bacteriovorus strains.(a) Polydispersity index (PDI) values of the PHA obtained from the co-cultures of B. bacteriovorus HD100 and Bd3709 strains preying on PHA-accumulating P. putida KT2440 or KT42Z. (b) PDI values of the PHB obtained from B. bacteriovorus HD100 and Bd2637 strains preying on PHB-accumulating E. coli ML35 (pAV1). Polymer granules were directly isolated from the co-cultures sediments with chloroform (PHA) or dichloromethane (PHB). As an experimental control, the polymer was extracted from the prey culture (without predator) by breaking the cells with a French press. The results of one experiment are shown; the values were reproducible in three separate experiments with standard deviations of <10%. Error bars mean the variation of three technical replicates.
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f4: Molecular characterization of PHA and PHB polymers obtained from 24 h co-cultures with B. bacteriovorus strains.(a) Polydispersity index (PDI) values of the PHA obtained from the co-cultures of B. bacteriovorus HD100 and Bd3709 strains preying on PHA-accumulating P. putida KT2440 or KT42Z. (b) PDI values of the PHB obtained from B. bacteriovorus HD100 and Bd2637 strains preying on PHB-accumulating E. coli ML35 (pAV1). Polymer granules were directly isolated from the co-cultures sediments with chloroform (PHA) or dichloromethane (PHB). As an experimental control, the polymer was extracted from the prey culture (without predator) by breaking the cells with a French press. The results of one experiment are shown; the values were reproducible in three separate experiments with standard deviations of <10%. Error bars mean the variation of three technical replicates.

Mentions: The PHA recovered from the B. bacteriovorus Bd3709/P. putida KT2440 co-culture was compared to that recovered from the B. bacteriovorus HD100/P. putida KT2440 co-culture and that from the P. putida KT2440 culture (as control experiment, extracted by subjecting the cells to lysis using a French press). The PHA extracted from B. bacteriovorus Bd3709/P. putida KT2440 co-culture showed a profile with a higher weight-average molecular weight (Mw) and number-average molecular weight (Mn), and a lower polydispersity index (PDI) than the PHA recovered from the B. bacteriovorus HD100/P. putida KT2440 co-culture (Fig. 4a and Supplementary Table 2). This indicates that, in the latter co-culture the biopolymer was partially degraded, increasing the heterogeneity of the polymer chains in terms of their molecular mass.


Engineering a predatory bacterium as a proficient killer agent for intracellular bio-products recovery: The case of the polyhydroxyalkanoates.

Martínez V, Herencias C, Jurkevitch E, Prieto MA - Sci Rep (2016)

Molecular characterization of PHA and PHB polymers obtained from 24 h co-cultures with B. bacteriovorus strains.(a) Polydispersity index (PDI) values of the PHA obtained from the co-cultures of B. bacteriovorus HD100 and Bd3709 strains preying on PHA-accumulating P. putida KT2440 or KT42Z. (b) PDI values of the PHB obtained from B. bacteriovorus HD100 and Bd2637 strains preying on PHB-accumulating E. coli ML35 (pAV1). Polymer granules were directly isolated from the co-cultures sediments with chloroform (PHA) or dichloromethane (PHB). As an experimental control, the polymer was extracted from the prey culture (without predator) by breaking the cells with a French press. The results of one experiment are shown; the values were reproducible in three separate experiments with standard deviations of <10%. Error bars mean the variation of three technical replicates.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834554&req=5

f4: Molecular characterization of PHA and PHB polymers obtained from 24 h co-cultures with B. bacteriovorus strains.(a) Polydispersity index (PDI) values of the PHA obtained from the co-cultures of B. bacteriovorus HD100 and Bd3709 strains preying on PHA-accumulating P. putida KT2440 or KT42Z. (b) PDI values of the PHB obtained from B. bacteriovorus HD100 and Bd2637 strains preying on PHB-accumulating E. coli ML35 (pAV1). Polymer granules were directly isolated from the co-cultures sediments with chloroform (PHA) or dichloromethane (PHB). As an experimental control, the polymer was extracted from the prey culture (without predator) by breaking the cells with a French press. The results of one experiment are shown; the values were reproducible in three separate experiments with standard deviations of <10%. Error bars mean the variation of three technical replicates.
Mentions: The PHA recovered from the B. bacteriovorus Bd3709/P. putida KT2440 co-culture was compared to that recovered from the B. bacteriovorus HD100/P. putida KT2440 co-culture and that from the P. putida KT2440 culture (as control experiment, extracted by subjecting the cells to lysis using a French press). The PHA extracted from B. bacteriovorus Bd3709/P. putida KT2440 co-culture showed a profile with a higher weight-average molecular weight (Mw) and number-average molecular weight (Mn), and a lower polydispersity index (PDI) than the PHA recovered from the B. bacteriovorus HD100/P. putida KT2440 co-culture (Fig. 4a and Supplementary Table 2). This indicates that, in the latter co-culture the biopolymer was partially degraded, increasing the heterogeneity of the polymer chains in terms of their molecular mass.

Bottom Line: This work examines the potential of the predatory bacterium Bdellovibrio bacteriovorus HD100, an obligate predator of other Gram-negative bacteria, as an external cell-lytic agent for recovering valuable intracellular bio-products produced by prey cultures.The bio-product targets to be recovered were polyhydroxyalkanoates (PHAs) produced naturally by Pseudomonas putida and Cupriavidus necator, or by recombinant Escherichia coli strains.B. bacteriovorus with a mutated PHA depolymerase gene to prevent the unwanted breakdown of the bio-product allowed the recovery of up to 80% of that accumulated by the prey bacteria, even at high biomass concentrations.

View Article: PubMed Central - PubMed

Affiliation: Environmental Biology Department, Centro de Investigaciones Biológicas, CSIC, C/Ramiro de Maeztu 9, 28040 Madrid, Spain.

ABSTRACT
This work examines the potential of the predatory bacterium Bdellovibrio bacteriovorus HD100, an obligate predator of other Gram-negative bacteria, as an external cell-lytic agent for recovering valuable intracellular bio-products produced by prey cultures. The bio-product targets to be recovered were polyhydroxyalkanoates (PHAs) produced naturally by Pseudomonas putida and Cupriavidus necator, or by recombinant Escherichia coli strains. B. bacteriovorus with a mutated PHA depolymerase gene to prevent the unwanted breakdown of the bio-product allowed the recovery of up to 80% of that accumulated by the prey bacteria, even at high biomass concentrations. This innovative downstream process highlights how B. bacteriovorus can be used as a novel, biological lytic agent for the inexpensive, industrial scale recovery of intracellular products from different Gram-negative prey cultures.

No MeSH data available.


Related in: MedlinePlus