Maximum Polyhydroxyalkanoates Production Research Articles

Bioconversion of glycerol into polyhydroxyalkanoates through an atypical metabolism shift using Priestia megaterium during fermentation processes: A statistical analysis of carbon and nitrogen source concentrations

Polyhydroxyalkanoates (PHA) are bioplastics which are well known as intracellular energy storage compounds and are produced in a large number of prokaryotic species. These bio-based inclusions are biodegradable, biocompatible and environmental friendly. Industrial production of, short chain and medium chain length PHA, involves the use of microorganisms and their enzymes. Priestia megaterium previously known as Bacillus megaterium is a well-recognized bacterium for producing short chain length PHA. This study focuses to characterize this bacterium for the production of medium chain length PHA, and a novel blend of both types of monomers having enhanced properties and versatile applications. Statistical analyses and simulations were used to demonstrate that cell dry weight can be derived as a function of OD600 and PHA content. Optimization of growth conditions resulted in the maximum PHA production as: 0. 05 g. g-x. H−1, where the rate of PHA production was 0.28 g L−1. H−1 and PHA concentration was 4.94 g. L−1. This study also demonstrated FTIR to be a semi quantitative tool for PHA production. Moreover, conversion of scl-PHA to mcl-PHA with reference to time intermissions using GC-FID are shown.

Application of Immersed Membrane Bioreactor for Semi-Continuous Production of Polyhydroxyalkanoates from Organic Waste-Based Volatile Fatty Acids.

Volatile fatty acids (VFAs) appear to be an economical carbon feedstock for the cost-effective production of polyhydroxyalkanoates (PHAs). The use of VFAs, however, could impose a drawback of substrate inhibition at high concentrations, resulting in low microbial PHA productivity in batch cultivations. In this regard, retaining high cell density using immersed membrane bioreactor (iMBR) in a (semi-) continuous process could enhance production yields. In this study, an iMBR with a flat-sheet membrane was applied for semi-continuous cultivation and recovery of Cupriavidus necator in a bench-scale bioreactor using VFAs as the sole carbon source. The cultivation was prolonged up to 128 h under an interval feed of 5 g/L VFAs at a dilution rate of 0.15 (d-1), yielding a maximum biomass and PHA production of 6.6 and 2.8 g/L, respectively. Potato liquor and apple pomace-based VFAs with a total concentration of 8.8 g/L were also successfully used in the iMBR, rendering the highest PHA content of 1.3 g/L after 128 h of cultivation. The PHAs obtained from both synthetic and real VFA effluents were affirmed to be poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with a crystallinity degree of 23.8 and 9.6%, respectively. The application of iMBR could open an opportunity for semi-continuous production of PHA, increasing the feasibility of upscaling PHA production using waste-based VFAs.

Molecular Characterization, Optimization and Production of PHA by Indigenous Bacteria Using Alternative Nutrient Sources as Substrate

Polyhydroxyalkanoates (PHA) are renewable, biodegradable biopolymer intracellularly accumulated by wide array of microorganisms as carbon reserve. This study investigates the influence of various cultural conditions on PHA production by a recently isolated local species under submerged fermentation. Six PHA producing strains were identified by 16S rDNA gene sequencing and strain Priestia flexa OWO1 showed satisfactory PHA productivity. The effects of production parameters were investigated and extraction of PHA was carried out using sodium hypochlorite method and maximum amount was detected after 72h. Maximum PHA production was obtained at incubation period of 48h, pH of 7.0 and temperature of 30oC. Amongst the hydrolysate of agro waste used, brewers spent grain (BSG) gave maximum yield of 3.01g/L while beans bran powder gave the highest PHA yields of 3.9 g/L amongst the organic nitrogen sources tested. Analysis of the crude PHA by Fourier Transform Infrared Spectroscopy (FT-IR) showed the presence of methyl, methylene as well as carbonyl functional groups. PHA production was higher after optimizing the production conditions as compared to basal medium therefore the utilization of these cheap renewable resources as alternative substrates for production of PHA make the process cost effective and sustainable.

Bioconversion of Mixed Alkanes to Polyhydroxyalkanoate by Pseudomonas resinovornas: Upcycling of Pyrolysis Oil from Waste-Plastic.

Polyhydroxyalkanoate (PHA) is a biodegradable plastic that can be used to replace petroleum-based plastic. In addition, as a medium-chain-length PHA (mcl-PHA), it can be used to provide elastomeric properties in specific applications. Because of these characteristics, recently, there has been much research on mcl-PHA production using inexpensive biomass materials as substrates. In this study, mcl-PHA producers were screened using alkanes (n-octane, n-decane, and n-dodecane) as sources of carbon. The amount of PHA produced by Pseudomonas resinovorans using sole n-octane, n-decane, or n-dodecane was 0.48 g/L, 0.27 g/L, or 0.07 g/L, respectively, while that produced using mixed alkane was 0.74 g/L. As a larger amount of PHA was produced using mixed alkane compared with sole alkane, a statistical mixture analysis was used to determine the optimal ratio of alkanes in the mixture. The optimal ratio predicted by the analysis was a medium with 9.15% n-octane, 6.44% n-decane, and 4.29% n-dodecane. In addition, through several concentration-specific experiments, the optimum concentrations of nitrogen and phosphorus for cell growth and maximum PHA production were determined as 0.05% and 1.0%, respectively. Finally, under the determined optimal conditions, 2.1 g/L of mcl-PHA and 60% PHA content were obtained using P. resinovorans in a 7 L fermenter.

Polyhydroxyalkanoates production from short and medium chain carboxylic acids by Paracoccus homiensis

The aim of this study was to evaluate an effect of short and medium chain carboxylic acids (CAs) rich stream derived from acidogenic mixed culture fermentation of acid whey on polyhydroxyalkanoates (PHAs) synthesis by Paracoccus homiensis and compare it with the impact of individual synthetic CAs. The obtained results confirmed that the analyzed bacterium is able to metabolize synthetic CAs as the only carbon sources in the growth medium with maximum PHAs production yields of 26% of cell dry mass (CDM). The replacement of the individual CAs by a CAs-rich residual stream was found to be beneficial for the Paracoccus homiensis growth. The highest biomass concentration reached about 2.5 g/L with PHAs content of 17% of CDM. The purified PHAs were identified as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by applying gas chromatography coupled with mass spectrometry, Fourier transform infrared spectroscopic spectra and UV–Vis spectra. Furthermore, a differential scanning calorimetric, thermogravimetric and water contact angle analysis proved that the extracted copolymers have useful properties. The obtained data are promising in the perspective of developing a microbial PHAs production as a part of an integrated valorization process of high CAs content waste-derived streams.

Utilization of crude paper industry effluent for Polyhydroxyalkanoate (PHA) production

Paper industry generates a large amount of effluent which contains unused organic carbon from the raw materials used. Utilization of the unused carbon may lead to remediation of the effluent by lowering the BOD. Polyhydroxyalkanoates are microbial polymers which accumulate in various bacteria in carbon rich conditions. The present study is focused on the utilization of untreated crude paper industry effluent (PIE) as a substrate for Polyhydroxyalkanoates (PHA) production to utilize the unused carbon and develop a feasible production process. To achieve this, indigenous PHA-producing bacterial strains were screened for their ability to utilize different concentrations of PIE as a substrate. One of the isolates, ART_41, was able to utilize different concentrations of PIE for growth. ART_41 was characterizedas a Gram-negative strain belonging to Ancylobacter sp. by 16s rRNA sequencing. Maximum PHA production (41.7%) was achieved when using 30% PIE. FTIR and DSC-TGA analysis validated the extracted polymer as Poly-3-hydroxybutyrate (PHB). Thus, this study concludes that crude paper industry effluent could be utilized as a substrate when the correct bacterial strain is employed; allowing sustainable PHA production.

Simultaneous nitrification and denitrification in microbial community-based polyhydroxyalkanoate production

Microbial community-based polyhydroxyalkanoate (PHA) production has been demonstrated repeatedly at pilot scale. Ammonium, normally present in waste streams, might be oxidized by nitrifying bacteria resulting in additional aeration energy demand. The use of low dissolved oxygen (DO) concentrations allowed to reduce nitrifying rates by up to 70% compared to non-oxygen limiting conditions. At lower DO concentrations nitrate was used as alternative electron acceptor for PHA production and therefore, a constant PHA production rate could only be maintained if nitrate was sufficiently available. An optimum DO concentration (0.9 mgO2/L) was found for which nitrification was mitigated but also exploited to supply requisite heterotrophic nitrate requirements that maintained maximum PHA production rates. PHA accumulations with such DO control was estimated to reduce oxygen demand by about 18%. This work contributes to establish fundamental insight towards viable industrial practice with the control and exploitation of nitrifying bacteria in microbial community-based PHA production.

Production of polyhydroxyalkanoates (PHAs) by Bacillus megaterium using food waste acidogenic fermentation-derived volatile fatty acids

ABSTRACT High production costs still hamper fast expansion of commercial production of polyhydroxyalkanoates (PHAs). This problem is greatly related to the cultivation medium which accounts for up to 50% of the whole process costs. The aim of this research work was to evaluate the potential of using volatile fatty acids (VFAs), derived from acidogenic fermentation of food waste, as inexpensive carbon sources for the production of PHAs through bacterial cultivation. Bacillus megaterium could assimilate glucose, acetic acid, butyric acid, and caproic acid as single carbon sources in synthetic medium with maximum PHAs production yields of 9–11%, on a cell dry weight basis. Single carbon sources were then replaced by a mixture of synthetic VFAs and by a VFAs-rich stream from the acidogenic fermentation of food waste. After 72 h of cultivation, the VFAs were almost fully consumed by the bacterium in both media and PHAs production yields of 9–10%, on cell dry weight basis, were obtained. The usage of VFAs mixture was found to be beneficial for the bacterial growth that tackled the inhibition of propionic acid, iso-butyric acid, and valeric acid when these volatile fatty acids were used as single carbon sources. The extracted PHAs were revealed to be polyhydroxybutyrate (PHB) by characterization methods of Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The obtained results proved the possibility of using VFAs from acidogenic fermentation of food waste as a cheap substrate to reduce the cost of PHAs production.

Polyhydroxyalkanoate biosynthesis and characterization from optimized medium utilizing distillery effluent using Bacillus endophyticus MTCC 9021: a statistical approach

Use of expensive raw material and inefficient extraction method has limited the production of biopolymers at pilot scale compared to commercial plastics. Hence, this research work spotlights on production of polyhydroxyalkanoate (PHA) using Bacillus endophyticus MTCC 9021 in different dilutions of untreated distillery effluent (10–25%) among which 10% dilutions exhibited maximum PHA production. Statistical optimization through Response surface methodology yielded a maximum PHA of 6.45 ± 0.07 g/L. The obtained PHA was analysed by FTIR and NMR which confirms the polymer to be polyhydroxybutyrate. The extracted PHA was reduced to nanoscale to develop PHA nanosheet which exposed higher oil absorption and retention ability than normal PHA sheet. Further the rapid degradation of PHA nanosheet with synthetic plastics in garden soil emphasises their unique application in wide sectors.

Production of polyhydroxyalkanoates by halotolerant bacteria with volatile fatty acids from food waste as carbon source.

In this study, a halotolerant strain was isolated from high salinity leachate and identified as Bacillus cereus NT-3. It can produce a high concentration of polyhydroxyalkanoates (PHAs) with no significant changes when NaCl concentration is up to 50 g/L. FTIR and NMR spectra of PHAs synthesized by Bacillus cereus NT-3 were similar to the standard or previous results. Effluent from acidogenic fermentation of food waste and pure volatile fatty acids (VFAs) mixture was used as carbon source to check the effect of non-VFAs compounds of the effluent on PHAs production. The maximum PHAs production was 0.42 g/L for effluent fermentation, whereas it was 0.34 g/L for pure VFAs fermentation, indicating that bacteria could use actual effluent in a better way. Furthermore, a mathematical model was established for describing kinetic behavior of bacteria using different carbon sources. These results provided a promising approach for PHAs biosynthesis with a low-cost carbon source.

An investigation for recovery of polyhydroxyalkanoates (PHA) from Bacillus sp. BPPI-14 and Bacillus sp. BPPI-19 isolated from plastic waste landfill

Bio-plastic synthesis from renewable and cheap agro-based materials is a sustainable solution for replacing conventionally produced plastic with environmental contamination. The current study was aimed at screening and characterization of Polyhydroxyalkanoates (PHA) producing bacterial isolates, evaluation of their potential and recovery of PHA using the isolates. The PHA compounds were characterized using FT-IR. Based on 16SrRNA sequence analyses the isolates were designated as Bacillus sp. BPPI-14 and Bacillus sp. BPPI-19. The isolates were gram-positive, rod-shaped, endospore former, and citrate test positive. Intracellular PHA granules were observed when these isolates were stained with Sudan black B (SBB) and Nile blue A (NBA) preliminary and specific staining dyes, respectively. Effect of pH, temperature and carbon sources on the PHA production by the isolates BPPI-14 and BPPI-19 was studied. Maximum PHA production was recorded for Glucose (49.46±2.79%) by Bacillus sp. BPPI-14 and followed by molasses (45.86±2.17%) by Bacillus sp. BPPI-19, respectively at 37°C and pH7. The obtained PHA polymers were confirmed by preparation of plastic films for both the isolates. Fourier transform infrared spectrum for BPPI-14 and BPPI-19 showed the peak (carboxylic acid group) at 1706–1719.39cm−1 was a characteristic feature of PHA and corresponds functional group (C=O).

Reconsideration on the effect of nitrogen on mixed culture polyhydroxyalkanoate production toward high organic loading enrichment history

In most of the operating strategies for mixed microbial cultures polyhydroxyalkanoate (PHA) production, moderate organic loads and low nitrogen concentrations are used, however, the real waste streams contain variable concentrations of carbon and nitrogen. To evaluate the effect of enrichment history on PHA producer and production the various carbon and nitrogen levels were utilized during the accumulation phase. Different operating strategies were applied in three sequencing batch reactors (SBRs) subjected to aerobic dynamic feeding. The maximum PHA production of the enriched cultures under nutrient excess, limitation and starvation (Cmol/Nmol ratio of 8, 40 and 1, respectively) was evaluated in batch assays. A higher PHA content and biomass growth were achieved in the nutrients presence in comparison to the nutrient starvation condition. The cultures from the SBR treated under short sludge retention time, high organic loading rate, short cycle length (SBR#3) and nutrient excess reached the maximum PHA content (54.9%) and biomass increase (38.9%). Under nutrient limitation, the negative biomass growth was observed under nutrient starvation because of the sampling loss. The succession of microbial communities in SBRs and batch assays was analyzed using terminal restriction fragment length polymorphism. The SBR#3 had the best overall PHA production performance considering its high PHA content and productivity in all nutrient content, it indicates that nitrogen has a substantial impact on PHA yield especially when high organic loading rate enrichment history is involved.

Construction of Efficient Platform Escherichia coli Strains for Polyhydroxyalkanoate Production by Engineering Branched Pathway.

Polyhydroxyalkanoate (PHA) is a potential substitute for petroleum-based plastics and can be produced by many microorganisms, including recombinant Escherichia coli. For efficient conversion of substrates and maximum PHA production, we performed multiple engineering of branched pathways in E. coli. We deleted four genes (pflb, ldhA, adhE, and fnr), which contributed to the formation of byproducts, using the CRISPR/Cas9 system and overexpressed pntAB, which catalyzes the interconversion of NADH and NADPH. The constructed strain, HR002, showed accumulation of acetyl-CoA and decreased levels of byproducts, resulting in dramatic increases in cell growth and PHA content. Thus, we demonstrated the effects of multiple engineering for redirecting carbon flux into PHA production without any concerns regarding simultaneous deletion.

Bioconversion of plant biomass hydrolysate into bioplastic (polyhydroxyalkanoates) using Ralstonia eutropha 5119

Pretreatment of lignocellulosic biomass results in the formation of byproducts (furfural, hydroxymethylfurfural [HMF], vanillin, acetate etc.), which affect microbial growth and productivity. Furfural (0.02%), HMF (0.04%), and acetate (0.6%) showed positive effects on Ralstonia eutropha 5119 growth and polyhydroxyalkanoate (PHA) production, while vanillin exhibited negative effects. Response optimization and interaction studies between the variables glucose, ammonium chloride, furfural, HMF, and acetate using the response surface methodology resulted in maximum PHA production (2.1 g/L) at optimal variable values of 15.3 g/L, 0.43 g/L, 0.04 g/L, 0.05 g/L, and 2.34 g/L, respectively. Different lignocellulosic biomass hydrolysates (LBHs), including barley biomass hydrolysate (BBH), Miscanthus biomass hydrolysate (MBH), and pine biomass hydrolysate (PBH), were evaluated as potential carbon sources for R. eutropha 5119 and resulted in 1.8, 2.0, and 1.7 g/L PHA production, respectively. MBH proved the best carbon source, resulted in higher biomass (Yx/s, 0.31 g/g) and PHA (Yp/s, 0.14 g/g) yield.

Production of polyhydroxyalkanoates (PHA) from a non‐lignocellulosic component of sugarcane bagasse: fueling a biobased economy

AbstractThe present study examines the use of residual sugar from sugarcane bagasse for the production of polyhydroxyalkanoates (PHA), a class of biodegradable microbial polymers. To achieve this, 26 bacterial isolates were screened for PHA production. From the strains isolated, ART_MKT2E was found to produce PHA and was selected to discover its capability to use a bagasse‐based medium (BGM). To date, the lignocellulosic component of bagasse has been used as a substrate by treating bagasse with acids. This study demonstrates the use of residual sugar from bagasse as a substrate for PHA production. The concentration of bagasse filtrate was found to be optimum at 60%, along with yeast extract and additional salts (pH 7.0 ± 0.5). The maximum PHA production (w/w) was 55%. These results indicate the successful use of non‐lignocellulosic BGM. The remaining lignocellulosic component of bagasse could be fed as a substrate for another production process, promoting a sustainable, biobased economy. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd

Variation analysis of bacterial polyhydroxyalkanoates production using saturated and unsaturated hydrocarbons.

Polyhydroxyalkanoates (PHA) are efficient, renewable and environment friendly polymeric esters. These polymers are synthesized by a variety of microbes under stress conditions. This study was carried out to check the suitability of waste frying oil in comparison to other oils for economical bioplastic production. Six bacterial strains were isolated and identified as Bacillus cereus (KF270349), Klebsiella pneumoniae (KF270350), Bacillus subtilis (KF270351), Brevibacterium halotolerance (KF270352), Pseudomonas aeruginosa (KF270353), and Stenotrophomonas rhizoposid (KF270354) by ribotyping. All strains were PHA producers so were selected for PHA synthesis using four different carbon sources, i.e., waste frying oil, canola oil, diesel and glucose. Extraction of PHA was carried out using sodium hypochlorite method and maximum amount was detected after 72 h in all cases. P. aeruginosa led to maximum PHA production after 72 h at 37 °C and 100 rpm using waste frying oil that was 53.2% PHA in comparison with glucose 37.8% and cooking oil 34.4%. B. cereus produced 40% PHA using glucose as carbon source which was high when compared against other strains. A significantly lesser amount of PHA was recorded with diesel as a carbon source for all strains. Sharp Infrared peaks around 1740–1750 cm−1 were present in Fourier Transform Infrared spectra that correspond to exact position for PHA. The use of waste oils and production of poly-3hydroxybutyrate-co-3hydroxyvalerate (3HB-co-3HV) by strains used in this study is a good aspect to consider for future prospects as this type of polymer has better properties as compared to PHBs.

Production of Single Cell Protein and Polyhydroxyalkanoate from Carica papaya Waste

Carica papaya waste represents an ideal candidate for production of single cell proteins (SCP) and polyhydroxyalkanoates (PHA) due to its high carbohydrate content. Bioconversion of papaya waste in to microbial biomass protein or SCP and PHA paves way to tackle global issues raised due to protein caloric malnutrition and synthetic plastic disposal, respectively. In this work, acid hydrolyzed papaya waste was employed as substrate for PHA and SCP production. Maximum PHA production (4.2 g/L) was observed with papaya peel under optimized conditions of temperature (37 \({^{\circ }}\)C), pH (7), carbon source (sucrose) and nitrogen source (ammonium sulfate) on 72 h of fermentation using Bacillus subtilis NCDC0671. The extracted polymer was characterized through FTIR spectroscopy. SCP production using Saccharomyces cerevisiae NDRI 364 was sequentially optimized for maximizing biomass yield. Maximum SCP production was achieved at 25 \({^{\circ }}\)C (4.67 g/L), pH 5 (4.65 g/L), incubation period of 120 h (4.86 g/L). Screening for best carbon and nitrogen source revealed that maximum SCP was produced using sucrose (4.26 g/L) and beef extract (4.56 g/L) as carbon and nitrogen source, respectively. HPTLC profile of the SCP revealed a significant amount of both essential and non-essential amino acids suggesting its possible incorporation as a feed ingredient.

Optimization and Characterization of Polyhydroxyalkanoates and its Copolymers Synthesized by Isolated Yeasts

The present study investigates the role of yeasts, isolated from different environments for its abilities to synthesize biodegradable polymer, Polyhydroxyalkanoates (PHA) and its copolymers. Serial dilution method and spread plate technique had been used for the isolation of yeasts from different samples. Screening had been done by crotonic assay followed by UV Spectrophotometric analysis. Growth parameters such as effect of carbon sources, incubation period, inoculum percentage, incubation temperature and pH of the production medium were optimized for each of the screened isolates. Characterization of PHA was done by FTIR and GC-MS analysis. Maximum PHA produced was observed after 96 hours of incubation period inoculated with 2% (v/v) of inoculum in minimal media of pH 8 containing various carbon sources viz. 5% sucrose for Isolate1; 5% glucose for Isolate 2; 3% starch for Isolate 3 and 5% Lactose for Isolate 4. Incubation temperature was maintained at 37°C. Maximum PHA production was noted as 40 % in Isolate 1, 33% in Isolate 2, 29% in Isolate 3and 25% in Isolate 4 respectively on the basis of dry cell weight under optimized condition. Prominent peaks obtained through FTIR analysis at wavelength 3273, 2922, 1739 and 1462 cm -1 showed the presence of stretching bands of –OH-,-CH-, -C=O- and –CH3- group which are the characteristic peaks of PHA polymer. GC-MS chromatogram detected the peaks at retention time 3.063 and 19.25 min were corresponding to the derivatized products of butanoic acid (polyhydroxybutyrate) and octadecanoic acid (polyhydroxyoctadecanoate).The present study demonstrated that yeast Isolate 1 could produce high amount of PHA (40% on dry cell weight basis ) with hydroxybutyrate (HB) and hydroxyoctadecanoate (HOD) as its main constituents.

Optimization and characterization of PHA from isolate Pannonibacter phragmitetus ERC8 using glycerol waste

Polyhydroxyalkanoates (PHAs) have been considered as a good alternative for petrochemical based polymers due to its biodegradability. However, a high production cost limits their acceptance in industries. In present work, efforts have been made to optimize the production of PHA by Pannonibacter phragmitetus ERC8 using glycerol waste as a sole carbon source, with enhanced polymer production in a cost effective way. To check the possibility of growth and polymer accumulation potential of P. phragmitetus ERC8, various low cost substrates such as food waste, mutton tallow, whey, sugarcane bagasse, corn steep liquor and glycerol waste were used. Optimum concentration of selected factors obtained as response of statistical experimental design were 0.8% (v/v) glycerol waste, 0.26% (w/v) BHM and 1.25%OD as an inoculum for the maximum PHA production. The suggested model was validated and maximum 1.36g/L of PHA production was obtained after 96h. PHA production of 1.87g/L was achieved in 5L (working volume 3L) lab scale bioreactor with the suggested media components by RSM (Response Surface Methodology). Characterization of the PHA by NMR spectroscopy revealed that the polymer was a hetromonomer of (R)-3-hydroxybutyrate and medium chain length 3HA[(R)-3-hydroxyalkanoate] monomers.

Characterization of Polyhydroxyalkanoates Produced by Contaminated Soil Bacteria using Wastewater and Glucose as Carbon Sources

Purpose: To isolate polyhydroxyalkanoates (PHA)-producing bacterial strains from contaminated soil using industrial wastewater and glucose as carbon soured by Macrogen sequencing. Two different sources, namely, glucose and wastewater were used to ces.Methods: The strains were isolated and identified as Pseudomonas, Bacillus, Enterobacter, Exiguobacterium and Stenotrophomonas using biochemical tests and further confirmevaluate and compare the use of wastewater as a carbon source for PHA production. The biomass obtained was analyzed by Fourier transform infra-red (FTIR) to identify the presence of PHA in it. Afterwards, PHA extraction was carried out and then gas chromatography (GC) performed to identify PHA monomers.Results: Utilization of glucose resulted in the production of PHB, while wastewater yielded copolymers poly-3 hydroxybutyrate-co-3hydroxyvalerate P(3HB-co-3HV) due to its content of volatile fatty acids such as acetic acid, propionic acid and butyric acid, which led to the production of different types of polymers. The maximum PHA production was 41 ± 0.22 % obtained for Stenotrophomonas (SM03) using 2 % glucose as carbon source while for wastewater, maximum production was achieved by the Pseudomonas strain (SM01).Conclusion: Wastewater is produced in large quantities daily during various activities and therefore can be used as a cheap carbon source for the production of valuable products such as PHA.Keywords: Polyhydroxyalkanoates, Wastewater, Glucose, Pseudomonas strain, Stenotrophomonas