Production of polyhydroxyalkanoate (pha) by pseudomonas aeruginosa (ol405443) using agrowastes as carbon source

Abstract

The search for cost-effective substrates for the manufacturing of valuable products has led to the use of agrowastes as alternative sources of reducing sugar. Numerous bacteria build up polyhydroxyalkanoates (PHAs) as storage materials. This research aimed to produce PHA from Pseudomonas aeruginosa using agrowastes as carbon sources. The agrowastes (corncob, plantain peduncle and sugarcane bagasse) were treated with 1 % NaOH and analysed. The agrowastes were hydrolysed using cellulase produced by Aspergillus niger isolated from agrowastes dumpsite. The agrowaste hydrolysate was used in place of glucose for PHA production in a submerged fermentation. Nile blue A test and Sudan black test showed positive results for the isolate with a bright orange fluorescence on irradiation with UV light and was identified as Pseudomonas aeruginosa (accession number 0L405443). Sugarcane bagasse gave the highest potential for PHA production with PHA values of 5.86 mg/mL, followed by corn cob (5.29 mg/mL) and the least was obtained in plantain peduncle with a yield of 3.58 mg/mL. The findings using response surface methodology (RSM) for optimization show that all the four factors (carbon source, pH, temperature and incubation time) were statistically significant (P < 0.05) for PHA production. The optimum PHA production was attained under culture conditions of 24 h, 38 °C, pH 6.5, and 3 % carbon source. The PHA produced from 10 L of MSM was quantified to be 10.57 g under these conditions. The study revealed that Pseudomonas aeruginosa 0L405443 is a local bacterial strain utilized for the production of PHA using affordable, sustainable and easily available agrowastes hydrolysate as substrate.

Keywords

• Agrowastes
• Polyhydroxyalkanoates
• Bacteria
• Aspergillus niger
• Pseudomonas aeruginosa
• Reducing sugar