Limits...
Extracellular Polyhydroxyalkanoate Depolymerase by Acidovorax sp. DP5.

Vigneswari S, Lee TS, Bhubalan K, Amirul AA - Enzyme Res (2015)

Bottom Line: The highest degradation activity of P(3HB) was also observed with depolymerase enzyme of DP5 in mineral salt medium containing P(3HB).Based on biochemical characterization and 16S rRNA cloning and sequencing, isolate DP5 was found to belong to the genus Acidovorax and subsequently named as Acidovorax sp.The highest extracellular depolymerase enzyme activity was achieved when 0.25% (w/v) of P(3HB) and 1 g/L of urea were used as carbon and nitrogen source, respectively, in the culture media.

View Article: PubMed Central - PubMed

Affiliation: Malaysian Institute of Pharmaceuticals and Nutraceuticals, NIBM, MOSTI, 11700 Penang, Malaysia ; Institute of Marine Biotechnology, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Malaysia.

ABSTRACT
Bacteria capable of degrading polyhydroxyalkanoates (PHA) by secreting extracellular depolymerase enzymes were isolated from water and soil samples collected from various environments in Malaysia. A total of 8 potential degraders exhibited clear zones on poly(3-hydroxybutyrate) [P(3HB)] based agar, indicating the presence of extracellular PHA depolymerase. Among the isolates, DP5 exhibited the largest clearing zone with a degradation index of 6.0. The highest degradation activity of P(3HB) was also observed with depolymerase enzyme of DP5 in mineral salt medium containing P(3HB). Based on biochemical characterization and 16S rRNA cloning and sequencing, isolate DP5 was found to belong to the genus Acidovorax and subsequently named as Acidovorax sp. DP5. The highest extracellular depolymerase enzyme activity was achieved when 0.25% (w/v) of P(3HB) and 1 g/L of urea were used as carbon and nitrogen source, respectively, in the culture media. The most suitable assay condition of the depolymerase enzyme in response to pH and temperature was tested. The depolymerase produced by strain Acidovorax sp. DP5 showed high percentage of degradation with P(3HB) films in an alkaline condition with pH 9 and at a temperature of 40°C.

No MeSH data available.


Related in: MedlinePlus

Effect of various pH values on the degradation of P(3HB) films in an aqueous solution of depolymerase at 37°C. Values are mean of two replicates.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4664802&req=5

fig5: Effect of various pH values on the degradation of P(3HB) films in an aqueous solution of depolymerase at 37°C. Values are mean of two replicates.

Mentions: Besides microbial population and the properties of the plastic materials, surrounding temperature and pH have been found to have a strong influence on the rate of biodegradation of PHA polymers. It was previously reported that the optimum activity of depolymerase enzyme was achieved in alkaline conditions [22]. In this study, the effect of various pH values in the alkaline region ranging from 7.5 to 10.5 towards the degradation process of P(3HB) films was evaluated. Varying pH conditions revealed different surface erosion of P(3HB) films by the extracellular depolymerase of DP5 microorganism. Based on results obtained in Figure 5, pH 9 gave the highest percentage of degradation up to 42% of P(3HB) film. At this pH, the degradation reached around 35% at 24 h, whereas, with other pH values, the degradation was only in the range of 10–25%. It was observed that the degradation of P(3HB) film was the lowest at pH 10.5. Hence, it could be concluded that the most suitable pH required by depolymerase for maximum activity is at 9.


Extracellular Polyhydroxyalkanoate Depolymerase by Acidovorax sp. DP5.

Vigneswari S, Lee TS, Bhubalan K, Amirul AA - Enzyme Res (2015)

Effect of various pH values on the degradation of P(3HB) films in an aqueous solution of depolymerase at 37°C. Values are mean of two replicates.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4664802&req=5

fig5: Effect of various pH values on the degradation of P(3HB) films in an aqueous solution of depolymerase at 37°C. Values are mean of two replicates.
Mentions: Besides microbial population and the properties of the plastic materials, surrounding temperature and pH have been found to have a strong influence on the rate of biodegradation of PHA polymers. It was previously reported that the optimum activity of depolymerase enzyme was achieved in alkaline conditions [22]. In this study, the effect of various pH values in the alkaline region ranging from 7.5 to 10.5 towards the degradation process of P(3HB) films was evaluated. Varying pH conditions revealed different surface erosion of P(3HB) films by the extracellular depolymerase of DP5 microorganism. Based on results obtained in Figure 5, pH 9 gave the highest percentage of degradation up to 42% of P(3HB) film. At this pH, the degradation reached around 35% at 24 h, whereas, with other pH values, the degradation was only in the range of 10–25%. It was observed that the degradation of P(3HB) film was the lowest at pH 10.5. Hence, it could be concluded that the most suitable pH required by depolymerase for maximum activity is at 9.

Bottom Line: The highest degradation activity of P(3HB) was also observed with depolymerase enzyme of DP5 in mineral salt medium containing P(3HB).Based on biochemical characterization and 16S rRNA cloning and sequencing, isolate DP5 was found to belong to the genus Acidovorax and subsequently named as Acidovorax sp.The highest extracellular depolymerase enzyme activity was achieved when 0.25% (w/v) of P(3HB) and 1 g/L of urea were used as carbon and nitrogen source, respectively, in the culture media.

View Article: PubMed Central - PubMed

Affiliation: Malaysian Institute of Pharmaceuticals and Nutraceuticals, NIBM, MOSTI, 11700 Penang, Malaysia ; Institute of Marine Biotechnology, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Malaysia.

ABSTRACT
Bacteria capable of degrading polyhydroxyalkanoates (PHA) by secreting extracellular depolymerase enzymes were isolated from water and soil samples collected from various environments in Malaysia. A total of 8 potential degraders exhibited clear zones on poly(3-hydroxybutyrate) [P(3HB)] based agar, indicating the presence of extracellular PHA depolymerase. Among the isolates, DP5 exhibited the largest clearing zone with a degradation index of 6.0. The highest degradation activity of P(3HB) was also observed with depolymerase enzyme of DP5 in mineral salt medium containing P(3HB). Based on biochemical characterization and 16S rRNA cloning and sequencing, isolate DP5 was found to belong to the genus Acidovorax and subsequently named as Acidovorax sp. DP5. The highest extracellular depolymerase enzyme activity was achieved when 0.25% (w/v) of P(3HB) and 1 g/L of urea were used as carbon and nitrogen source, respectively, in the culture media. The most suitable assay condition of the depolymerase enzyme in response to pH and temperature was tested. The depolymerase produced by strain Acidovorax sp. DP5 showed high percentage of degradation with P(3HB) films in an alkaline condition with pH 9 and at a temperature of 40°C.

No MeSH data available.


Related in: MedlinePlus