Desalter effluent is a difficult to treat wastewater stream emerging from petroleum refining operations. In this study, an osmotolerant and halotolerant yeast, Debaryomyces hansenii, was investigated for the first time for its use in removing phenol from simulated and actual desalter effluent. D. hansenii was able to degrade phenols at substrate COD concentrations ranging from 300–1200 mg L−1, whereas the substrate inhibition was noted as COD increased from 2000–4000 mg L−1. Three kinetic models (Andrews, Aiba, and Edward) were applied as unstructured mathematical models to simulate substrate inhibition kinetics with respect to phenol COD. Among all models, the Edward model best simulated the yeast growth on phenol. Using the Edward model, the model parameters were μmax 0.21 h−1, KS 633.95 mg · L−1, and KI 1263.61 mg · L−1, respectively. The results in this study confirmed that D. hansenii has a high tolerance toward phenols and other organic compounds and salt found in desalter effluent. This yeast is therefore suggested to serve as an appropriate system from biological treatment of phenolic wastes in difficult to treat effluents such as desalter effluent.

Cinnamon and its extracts have been used as herbal remedies for many ailments, including for reducing insulin resistance and diabetes complications. Type 2 diabetes mellitus (T2DM) is a rapidly growing health concern around the world. Although many drugs are available for T2DM treatment, side effects and costs can be considerable, and there is increasing interest in natural products for managing chronic health conditions. Cinnamon may decrease the expression of genes associated with T2DM risk. The purpose of this study was to evaluate the effects of cinnamon water extract (CWE) compared with metformin on T2DM-related gene expression. HepG2 human hepatoma cells, widely used in drug metabolism and hepatotoxicity studies, were treated with different concentrations of metformin or CWE for 24 or 48 h. Cell viability was assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and glucose uptake was compared in untreated and CWE-or metformin-treated cells under highglucose conditions. Finally, total RNA was extracted and analyzed by RNA sequencing (RNA-seq), and bioinformatics analyses were performed to compare the transcriptional effects of CWE and metformin. We found cell viability was better in cells treated with CWE than in metformin-treated cells, demonstrating that CWE was not toxic at tested doses. CWE significantly increased glucose uptake in HepG2 cells, to the same degree as metformin (1.4-fold). RNA-seq data revealed CWE and metformin both induced significantly increased (1.3-to 1.4-fold) glucose uptake gene expression compared with untreated controls. Transcriptional differences between CWE and metformin were not significant. The effects of 0.125 mg mL −1 CWE on gene expression were comparable to 1.5 mg mL −1 (9.5 mM) metformin. In addition, gene expression at 0.125 mg mL −1 CWE was comparable to 1.5 mg mL −1 (9.5 mM) metformin. Our results reveal that CWE's effects on cell viability, glucose uptake, and gene expression in HepG2 cells are comparable to those of metformin, suggesting CWE may be an effective dietary supplement for mitigating T2DMrelated metabolic dysfunction.

Desalter effluent (DE) is typically discharged into a petroleum wastewater treatment plant, but its high salt concentration deteriorates the biological treatment. This study used various dilution rates to investigate the treatment of a synthetic DE containing dodecane under saline conditions using a halotolerant yeast, Debaryomyces hansenii, to determine the optimum substrate concentration for use in continuous stirred‐tank reactors (CSTRs). A literature review indicated that this study was the first to examine the biological treatment of DE using D. hansenii in a CSTR system. At a low dodecane substrate concentration, DE did not inhibit D. hansenii growth, and the experimental data approached the Monod model, with μmax and Ks selected as 0.08 h−1 and 1575 mg L−1, respectively. The optimum removal of chemical oxygen demand (95.7% and 85%) was obtained at dilution rates of 0.007 and 0.026 d−1. Using D. hansenii in a CSTR system appeared to be a sustainable approach for the biological treatment of DE. Scale‐up of these laboratory findings to the industrial scale is required to confirm that petroleum DE can be treated using equalization and filtration tanks as a continuous bioreactor. Adjusting the dilution rate can provide sufficient time for biodegradation and hydrocarbon removal from high salt DE by halotolerant yeasts like D. hansenii.

Cinnamon and its extracts have been used herbal remedies including reducing insulin resistance and diabetic complications. T2DM is a rapidly growing health concern around the world[[1]](#ref-0001). While many drugs are now available for T2DM treatment, side effects and costs can be considerable, and there is increasing interest in natural products for managing chronic health conditions[2]. Cinnamon may decrease the expression of genes associated with type 2 diabetes (T2DM) risk. The purpose of this study was to evaluate the effects of cinnamon water extract (CWE) and metformin on T2DM-related gene expression. The HepG2 human hepatoma cell line is widely used in drug metabolism and hepatotoxicity studies. HepG2 cells were treated with different concentrations of metformin or CWE for 24 or 48 h. Cell viability was assessed by MTT assay, and glucose uptake was compared between untreated and CWE- or metformin-treated cells under high-glucose conditions. Finally, total RNA was extracted and analyzed by RNA sequencing (RNA-Seq), and bioinformatics analysis was performed to compare the transcriptional effects of CWE and metformin. We found that cell viability was higher in cells treated with CWE than in metformin-treated cells, demonstrating that the cinnamon extract was not toxic at the tested doses. CWE significantly increased glucose uptake in HepG2 cells to the same degree as metformin (1.4-fold). RNA-Seq data revealed that CWE and metformin both induced significant changes (1.3- to 1.4-fold increases) in glucose uptake gene expression compared with untreated controls, but that transcriptional differences between CWE and metformin conditions were not significant. The effects of 0.125 mg mL CWE on gene expression were comparable to those seen with 1.5 mg mL (9.5 mM) metformin. We found that gene expression at 0.125 mg mL-1 CWE was comparable to 1.5 mg mL-1 (9.5 mM) metformin. Our results reveal that CWE’s effects on cell viability, glucose uptake, and gene expression in HepG2 cells are comparable to those of the widely used antidiabetic drug metformin, suggesting that CWE may be an effective dietary supplement for mitigating T2DM-related metabolic dysfunction.

The effluent from a petroleum desalting unit contains salts, emulsifiers, hydrocarbons (mainly n‐dodecane), and other contaminants. Conventional wastewater treatment cannot be used to treat this salt‐containing effluent; thus, alternative approaches must be explored. In this study, a halo‐tolerant yeast, Debaryomyces hansenii, was investigated for the removal of varying concentrations of n‐dodecane in a simulated desalter effluent (SDE). Then, the removal of n‐dodecane was optimized using response surface methodology (RSM). The effects of pH, salt, temperature, and n‐dodecane concentration were evaluated, and a mathematical model was developed and verified. The results showed that complete removal of n‐dodecane was achieved at 20°C and a salt concentration of 1–5 g L−1. The main factors in COD removal are temperature, n‐dodecane concentration, pH, and the interaction between n‐dodecane and temperature. Salt concentration does not affect COD removal or the growth rate of D. hansenii in a SDE. Applying RSM suggested that interactional effects among the operational variables include temperature, n‐dodecane concentration, and pH on the yeast's removal rate. Overall, it can be concluded that the use of D. hansenii could be a viable solution at a wide range of salt concentrations (1–5 g L−1) for desalter wastewater treatment in petroleum refining.