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Showing 2 results for Bacterial Strain
Reduction of BOD and COD of waste water by native bacteria isolated from herbal distillation industry
Mohammad Goodarzi, Hossain-Ali Rafiee-Pour, Fereshteh Jookar Kashi,
Volume 11, Issue 1 (3-2020)
Abstract
The waste produced by households, industry and factories to use as wash water and cooling systems and equipment, is caused environmental complications. Waste created a suitable environment for the growth of odor and pathogenic bacteria. This study aimed to isolate microorganisms in the wastewater and use them for the reduction of BOD (biochemical oxygen demand) and COD (chemical oxygen demand).The samples were collected aseptically from different parts of wastewater of herbal distillation industry. The bacterial strains were isolated from the samples in LB media. The isolates were distinguished based on the morphology and biochemical characteristics. Among the total 69 isolates, four isolates were selected to measure the ability to reduce BOD and COD and added to the waste water. Reduction of BOD was measured using BOD meter. Also, COD was determined by titration method. The isolates were identified by biochemical tests. The amount of BOD and COD reduction after adding selected strains to wastewater was 47.43 - 71.82% and 44.79 - 56.5% respectively. Also, the consortium of bacterial strains showed better ability to reduce BOD and COD (38.32-57.29%and 76.6-83.21% respectively). The results determined that wastewater contains bacterial strains which have shown significant reduction in BOD and COD and organic matter decomposition in wastewater and reuse it in agricultural and industrial sectors. Therefore, we can use these bacteria for wastewater treatment.
Screening of isolated bacteria from Persian Gulf petroleum sediments with capability of poly hydroxybutyrate production and identification of the physicochemical structure of the produced biopolymer
Neda Sinaei, Davod Zare, Mehrdad Azin,
Volume 12, Issue 1 (12-2020)
Abstract
Background and Objective: Polyhydroxyalkanoates (PHAs) are polymers with biodegradable and biocompatible properties that are produced by some bacteria. In the present study, petroleum sediments were applied to screen PHA-producing bacteria.
Method: The industrial culture medium of petroleum effluent was used as a low-cost and economical medium for isolating and identifying the superior PHA-producing strain. Finally, the chemical and physical properties of the extracted biopolymer were investigated by Fourier-transform infrared spectroscopy, differential scanning calorimetry, and proton nuclear magnetic resonance.
Results: In general, 11 out of 76 isolated bacterial strains could produce biopolymers among which, the Sb8 strain was selected as the best PHA-producing strain in the industrial medium with the cell dry weight of 44.13% and 1.2 g/l in 27 h. This strain was identified as Citreicella thiooxidans by sequencing determination. Eventually, the results of physicochemical analyses revealed that polyhydroxybutyrate (PHB) was the extracted biopolymer.
Conclusion: The present study is the first report on PHB production by Iranian native Citreicella thiooxidans strain by focusing on identifying and separating producing bacteria, as well as determining the type of the produced biopolymer and the production capability in a low-cost culture medium of the petroleum effluent. Considering the production of the biopolymer with a relatively high yield percentage without adding any supplement to the petroleum effluent medium, the isolated wild strain has the potential to produce PHB.

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