Production of Bioplastic (Polyhydroxybutyrate) with Local Bacillus megaterium Isolated from Petrochemical Wastewater
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ABSTRACT: Background:
Polyhydroxybutyrate is a biodegradable plastic produced by some bacteria and can completely be replaced with petroleum based non-degradable plastics. Objectives:
This study was done to isolate and identify one local strain with a high-production ability for industrial purposes. Material and Methods:
The sampling from petrochemical wastewater was done. The existence of polyhydroxybutyrate in isolates was studied with Sudan Black staining. Using the Sudan Black B plate assay method
SUBMITTER: Amiri Kojuri S
PROVIDER: S-EPMC8590724 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The identification of novel bacterial strains with a high production potential of polyhydroxybutyrate (PHB) to substitute the bioplastics with non-biodegradable plastics and reducing environmental pollution is really effective. The present study was done with the purpose of PHB bioplastic production using a novel bacterial strain. Twenty-one different bacterial isolates were obtained from petrochemical wastewater, which among them, 10 isolates were PHB positive. The presence of PHB granules was detected in the isolates using Sudan Black B staining. The most excellent PHB-accumulating bacterium with a maximum yield of PHB (61.53%) was selected and identified as Bacillus cereus saba.zh, based on morphological, biochemical, and molecular techniques. 16S rRNA nucleotide sequence of the bacterium was assigned accession number: MT975245 in the NCBI database. The phylogenetic tree data showed that the closest type strain to the Bacillus cereus saba.zh is the Bacillus cereus SDB4 (91%). The three genes (phaA, phaB, and phaC) responsible for the PHB biosynthesis were amplified using the specific oligonucleotide primers by PCR technique. The highest PHB yield was achieved when the culture medium was supplemented with 3% sugarcane molasses as a carbon source, ammonium sulfate as the nitrogen source, at pH 7, and temperature of 30 °C. The characterization of the extracted polymer by FTIR and 1H NMR spectroscopy proves the presence of methyl, methylene, methine, hydroxyl, and ester carbonyl groups and confirmed the structure of biopolymer as PHB. The novel strain Bacillus cereus saba.zh has good potential as an appropriate candidate for low-cost industrial production of bioplastic.
| S-EPMC8578562 | biostudies-literature
Project description:The synthesis of bioplastic from marine microbes has a great attendance in the realm of biotechnological applications for sustainable eco-management. This study aims to isolate novel strains of poly-β-hydroxybutyrate (PHB)-producing bacteria from the mangrove rhizosphere, Red Sea, Saudi Arabia, and to characterize the extracted polymer. The efficient marine bacterial isolates were identified by the phylogenetic analysis of the 16S rRNA genes as Tamlana crocina, Bacillus aquimaris, Erythrobacter aquimaris, and Halomonas halophila. The optimization of PHB accumulation by E. aquimaris was achieved at 120 h, pH 8.0, 35 °C, and 2% NaCl, using glucose and peptone as the best carbon and nitrogen sources at a C:N ratio of 9.2:1. The characterization of the extracted biopolymer by Fourier-transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (NMR), and Gas chromatography-mass spectrometry (GC-MS) proves the presence of hydroxyl, methyl, methylene, methine, and ester carbonyl groups, as well as derivative products of butanoic acid, that confirmed the structure of the polymer as PHB. This is the first report on E. aquimaris as a PHB producer, which promoted the hypothesis that marine rhizospheric bacteria were a new area of research for the production of biopolymers of commercial value.
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Project description:BackgroundPolyhydroxybutyrate (PHB) is a biopolymer formed by some microbes in response to excess carbon sources or essential nutrient depletion. PHBs are entirely biodegradable into CO2 and H2O under aerobic and anaerobic conditions. It has several applications in various fields such as medicine, pharmacy, agriculture, and food packaging due to its biocompatibility and nontoxicity nature.ResultIn the present study, PHB-producing bacterium was isolated from the Dirout channel at Assiut Governorate. This isolate was characterized phenotypically and genetically as Bacillus cereus SH-02 (OM992297). According to one-way ANOVA test, the maximum PHB content was observed after 72 h of incubation at 35 °C using glucose and peptone as carbon and nitrogen source. Response surface methodology (RSM) was used to study the interactive effects of glucose concentration, peptone concentration, and pH on PHB production. This result proved that all variables have a significant effect on PHB production either independently or in the interaction with each other. The optimized medium conditions with the constraint to maximize PHB content and concentration were 22.315 g/L glucose, and 15.625 g/L peptone at pH 7.048. The maximum PHB content and concentration were 3100.799 mg/L and 28.799% which was close to the actual value (3051 mg/l and 28.7%). The polymer was identified as PHB using FTIR, NMR, and mass spectrometry. FT-IR analysis showed a strong band at 1724 cm- 1 which attributed to the ester group's carbonyl while NMR analysis has different peaks at 169.15, 67.6, 40.77, and 19.75 ppm that were corresponding to carbonyl, methine, methylene, and methyl resonance. Mass spectroscopy exhibited molecular weight for methyl 3- hydroxybutyric acid.ConclusionPHB-producing strain was identified as Bacillus cereus SH-02 (OM992297). Under optimum conditions from RSM analysis, the maximum PHB content and concentration of this strain can reach (3100.799 mg/L and 28.799%); respectively. FTIR, NMR, and Mass spectrometry were used to confirm the polymer as PHB. Our results demonstrated that optimization using RSM is one of the strategies used for reducing the production cost. RSM can determine the optimal factors to produce the polymer in a better way and in a larger quantity without consuming time.
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Project description:Polyhydroxybutyrate (PHB) is a biodegradable biopolymer which is useful for various applications including packing, medical and coating materials. An endospore-forming bacterium (strain BP17) was isolated from composted soil and evaluated for PHB production. Strain BP17, taxonomically identified as Bacillus drentensis, showed enhanced PHB accumulation and was selected for further studies. To achieve maximum PHB production, the culture conditions for B. drentensis BP17 were optimized through response surface methodology (RSM) employing central composite rotatable design (CCRD). The final optimum fermentation conditions included: pineapple peel solution, 11.5% (v/v); tryptic soy broth (TSB), 60 g/L; pH, 6.0; inoculum size, 10% (v/v) and temperature, 28°C for 36 h. This optimization yielded 5.55 g/L of PHB compared to the non-optimized condition (0.17 g/L). PHB accumulated by B. drentensis BP17 had a polydispersity value of 1.59 and an average molecular weight of 1.15x105 Da. Thermal analyses revealed that PHB existed as a thermally stable semi-crystalline polymer, exhibiting a thermal degradation temperature of 228°C, a melting temperature of 172°C and an apparent melting enthalpy of fusion of 83.69 J/g. It is evident that B. drentensis strain BP17 is a promising bacterium candidate for PHB production using agricultural waste, such as pineapple peel as a low-cost alternative carbon source for PHB production.
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Project description:First transcriptome analyses of Bacillus megaterium DSM319 grown under mild and severe salt stress (up to 1.8 M NaCl) to analyse the addaptation of the organism on transcriptome level
2020-01-13 | GSE110712 | GEO
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Project description: Not available
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