Optimizing recombinant production of L-asparaginase 1 from Saccharomyces cerevisiae using response surface methodology

L-asparaginase is an essential enzyme used in cancer treatment, but its production faces challenges like low yield, high cost, and immunogenicity. Recombinant production is a promising method to overcome these limitations. In this study, response surface methodology (RSM) was used to optimize the production of L-asparaginase 1 from Saccharomyces cerevisiae in Escherichia coli K-12 BW25113. The Box-Behnken design (BBD) was utilized for the RSM modeling, and a total of 29 experiments were conducted. These experiments aimed to examine the impact of different factors, including the concentration of isopropyl-b-LD-thiogalactopyranoside (IPTG), the cell density prior to induction, the duration of induction, and the temperature, on the expression level of L-asparaginase 1. The results revealed that while the post-induction temperature, cell density at induction time, and post-induction time all had a significant influence on the response, the post-induction time exhibited the greatest effect. The optimized conditions (induction at cell density 0.8 with 0.7 mM IPTG for 4 h at 30 °C) resulted in a significant amount of L-asparaginase with a titer of 93.52 μg/mL, which was consistent with the model-based prediction. The study concluded that RSM optimization effectively increased the production of L-asparaginase 1 in E. coli, which could have the potential for large-scale fermentation. Further research can explore using other host cells, optimizing the fermentation process, and examining the effect of other variables to increase production.

Assessing occupational exposure of airborne PMs and TVOCs in the nail salons in Tehran city, Iran

There are concerns about the health of nail salon technicians due to the inherently harmful agents such as volatile organic compounds (VOCs) and released particles in the salons. For this reason, this study was conducted to investigate the occupational exposure of nail salon technicians to VOCs and particulate matters (PMs) in the nail salons in Tehran, Iran. In this cross-sectional study, indoor air quality and measurement continually Total VOCs and PMs in the various size of PM1-PM10 using PhoCheck Tiger and particle counter device investigated, respectively. site observation, and an interview with the manager in 49 salons in Tehran. Data was analyzed using SPSS software (version 22). Mean concentrations of PM1 with 2.56 μɡ/m3 was the lowest amount and PM10 with 346.86μɡ/m3 had the highest concentration. Also, the mean concentration of TVOCs was equal 2.61 ppm. The results of the regression model showed that there is a statistically significant between the number of services with airborne PMs (PM2.5), (p-Value≤0.050). In salons only with nail activities, the concentration of PM4 was less than the others, although this correlation was statistically significant just for PM1 (p-Value = 0.010). By implementing effective local exhaust ventilation systems equipped with dust collectors and utilizing safe products, the emission of particles and chemical compounds within salons can be significantly reduced.

Exposure assessment to BTEX in the air of nail salons in Tehran city, Iran

The nail salon industry has grown considerably, but there are serious concerns about the health risks associated with working in this field. Therefore, the purpose of this study was to investigate the exposure of nail technicians to BTEX. A cross-sectional study was conducted on 49 salons, and NIOSH Method 1501 was used to measure the concentration of BTEX in the breathing zone of technicians. The EPA method was used to assess health risks. Statistical analysis was conducted using SPSS software. The mean concentrations of toluene were (82.65 ± 198.84µg/m³)µg/m³, followed by benzene (10.58 ± 9.62µg/m³), p-xylenes (20.77 ± 37.79µg/m³), o-xylene (13.79 ± 25.70µg/m³), and ethylbenzene (29.35 ± 58.26µg/m³) , that lower than the permissible exposure limits suggested by NIOSH. Among the BTEX, toluene (82.65 ± 198.84µg/m³) has the most concentration in the nail salons. It was also discovered through multiple linear regression analysis that humidity had a significant effect on increasing the concentration of toluene (Beta = 0.50, P-value = 0.001) and ethylbenzene (Beta = 0.16, P = 0.049), while there was a considerable association between the number of services performed and benzene concentration (Beta = 0.34, P = 0.010). The average inhalation lifetime cancer risk for benzene (4.9 × 10 ^-5±4.5 × 10^-5) was higher than the recommended value set by the US EPA. Although the concentrations of BTEX were lower than the maximum permissible limits, the results of the cancer risk assessment for benzene showed that working in nail salons with poor ventilation is hazardous. Therefore, exposure can be minimized by ensuring appropriate ventilation in the workplace and using safe products.

The relationship between emotional intelligence, personality traits and safety behaviors in metal industries workers; confirmatory factor analysis

BACKGROUND

Human errors cause accidents in the workplace. Screening workers at employment can prevent future accidents from happening. Two important tools that can be helpful in screening are determining the emotional intelligence score and personality traits score of the workers.

OBJECTIVE

The purpose of this study was to evaluate the relationship between Emotional Intelligence, Personality Traits and safety behaviors in metal Industries workers.

METHODS

This is a cross-sectional survey. Confirmatory factor analysis was performed to determine the relationship between the components of emotional intelligence, unsafe behaviors, and personality. To collect data for this study, Five -factor Goldberg questionnaire, BAR-ON Emotional questionnaire and Safety behavior questionnaire were used. The collected data were entered into software (SPSS version22) and refined.

RESULTS

The results of this study showed that there was a significant positive correlation between personality traits, emotional intelligence and safe behaviors (P-Value = 0.000). The confirmatory factor analysis showed that personality traits influence safe behaviours. Also, studies have shown that emotional intelligence has a positive effect on safe behaviours. The amount indicators of goodness of fit (GFI), Comparative Fit Index (CFI), Tucker-Lewis index (TLI) and root mean square error approximation (RMSEA) were 0.944, 0.970, 0.965 and 0.061, respectively.

CONCLUSIONS

The results of this study suggest that personality traits and emotional intelligence influence safe behaviours in the workplace. Employers can use these two tools in the employment phase and prevent future human-related accidents.

Colorectal cancer treatment using bacteria: focus on molecular mechanisms

BACKGROUND

Colorectal cancer which is related to genetic and environmental risk factors, is among the most prevalent life-threatening cancers. Although several pathogenic bacteria are associated with colorectal cancer etiology, some others are considered as highly selective therapeutic agents in colorectal cancer. Nowadays, researchers are concentrating on bacteriotherapy as a novel effective therapeutic method with fewer or no side effects to pay the way of cancer therapy. The introduction of advanced and successful strategies in bacterial colorectal cancer therapy could be useful to identify new promising treatment strategies for colorectal cancer patients.

MAIN TEXT

In this article, we scrutinized the beneficial effects of bacterial therapy in colorectal cancer amelioration focusing on different strategies to use a complete bacterial cell or bacterial-related biotherapeutics including toxins, bacteriocins, and other bacterial peptides and proteins. In addition, the utilization of bacteria as carriers for gene delivery or other known active ingredients in colorectal cancer therapy are reviewed and ultimately, the molecular mechanisms targeted by the bacterial treatment in the colorectal cancer tumors are detailed.

CONCLUSIONS

Application of the bacterial instrument in cancer treatment is on its way through becoming a promising method of colorectal cancer targeted therapy with numerous successful studies and may someday be a practical strategy for cancer treatment, particularly colorectal cancer.

Zingiber officinale ameliorates Alzheimer's disease and Cognitive Impairments: Lessons from preclinical studies

Alzheimer's disease (AD) is a neurodegenerative condition mostly communal in people of advanced years accompanying various dysfunctionalities especially cognitive impairments. A number of cellular damages, such as amyloid-beta aggregation, tau protein hyperphosphorylation, some neurotransmitter imbalances, apoptosis, oxidative stress, and inflammatory responses are responsible for AD incidence. As a reason for inadequate efficacy, side effects, and pharmacokinetic problems of conventional drugs used for AD, the discovery of novel therapeutic agents with multi-targeted potential is desirable. Protective properties of phytochemicals combat numerous diseases and their vast acceptance and demand in human beings encouraged scientists to assess their effective activities. Zingiber officinale, gingerol, shogaol, and borneol were evaluated against memory impairments. Online databases including; Web of Science, Scopus, Embase, Pubmed, ProQuest, ScienceDirect, and Cochrane Library were searched until 3th February 2020. In vitro, in vivo, and clinical studies are included after screening their eligibility. Mostly interventive mechanisms such as; oxidative stress, neuroinflammation, and apoptosis are described. Correlation between the pathogenesis of AD and signaling pathways is explicated. Results and scores of cognition measurements are clarified due to in vivo studies and clinical trials. Some traditional aspects of consuming ginger in AD are also mentioned in the present review. In accumulation ginger and its components possess great potency for improving and abrogating memory dysfunctions but conducting further studies to evaluate their pharmacological and pharmaceutical aspects is required.

Garlic (Allium sativum) improves anxiety- and depressive-related behaviors and brain oxidative stress in diabetic rats

This study investigated the effects of garlic on anxiety- and depression-related behaviors and brain oxidative markers in streptozotocin (STZ)-induced diabetes in rats. Fifty-six male Wistar rats were randomly divided into seven experimental groups (n = 8/group): control, diabetic + saline, diabetic + garlic, diabetic + imipramine, and diabetic + diazepam groups. Animals received garlic homogenate (0.1, 0.25, and 0.5 g/kg) for 10 days. At the end of the treatments, anxiety- and depressive-related behaviors were evaluated by elevated plus maze (EPM) and forced swimming test (FST), respectively. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and malondialdehyde (MDA) levels were measured in the brain. Diabetic + garlic (0.5 g/kg) group showed lower anxiety- and- depressive-like behaviors as compared to the diabetic rats. Furthermore, garlic treatment (0.5 g/kg) attenuated MDA levels and enhanced SOD and GPx activities in the brain. Our findings indicate that garlic alleviates anxiety- and depression-related behaviors in the diabetic rats possibly by attenuation of brain oxidative stress.

Polycyclic Aromatic Hydrocarbons Degradation by Aquatic Bacteria Isolated from Khazar Sea, the World’s Largest Lake

Background: Aquatic microorganisms have an important role in the bioremediation of environmental pollutants. Polycyclic Aromatic Hydrocarbons (PAHs) are described as dangerous pollutants that can bind covalently to the nucleic acids, causing mutations. Therefore, they have carcinogenic and toxic properties. Also, are involved in diseases such as asthma, lung dysfunction, and chronic bronchitis. This study aimed to isolate and characterize aquatic bio-degrading bacteria from the world’s largest lake, Khazar, with the ability to use PAHs as only carbon source. Methods: Samples were taken from the estuary of Siah Rud River (Mazandaran province, Iran) and Fereydunkenar beach leading to isolation of twenty-three bacteria on marine agar and sea water media. The isolates were cultured on separate ONR7a medium, each supplemented with only one PAH; as the sole carbon source; including naphthalene, phenanthrene, and anthracene. Results: Eleven bacterial isolates were able to grow on supplemented media: TBZ-E1, TBZ-E2, TBZ-E3, TBZ-S12, TBZ-S16, TBZ-E20, TBZ-SF2, TBZ-F1, TBZ-F2, TBZ-F3 and TBZ2. These isolates belong to Alteromonas, Marivivens, Pseudoalteromonas, Vibrio, Shewanella, Photobacterium, Mycobacterium and Pseudomonas genera. The qualitative analysis showed that the consortium of isolates TBZ-F1, TBZ-F2, TBZ-F3, TBZ-SF2, and TBZ2 displayed the highest degradation rate for phenanthrene and naphthalene. Naphthalene, phenanthrene, and anthracene were potently degraded by TBZ2 and TBZ-SF2 and accordingly were subjected to measure degradation potential of mentioned PAHs. Conclusion: The bacterial isolates of Caspian lake have a critical duty in biodegradation of PAHs. These isolates are representative samples of the bacterial population of this lake, participating in the purification process of this habitat.

Pseudomonas khazarica sp. nov., a polycyclic aromatic hydrocarbon-degrading bacterium isolated from Khazar Sea sediments

A novel Gram-negative, aerobic, motile and rod-shaped bacterium with the potential to biodegrade polycyclic aromatic hydrocarbons, was isolated from Khazar (Caspian) Sea. Strain TBZ2^T grows in the absence of NaCl and tolerates up to 8.5% NaCl. Growth occurred at pH 3.0-10.0 (optimum, pH 6.0-7.0) and 10-45 °C (optimum, 30 °C). The major fatty acids are C_18:1ω7C, C_16:1ω7C/ C_15:0 iso 2-OH, C_16:0, C_12:0, C_10:0 3-OH, C_12:0 3-OH. The major polar lipids include diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and the predominant respiratory quinone is ubiquinone Q-9. The 16S rRNA gene sequence analysis showed that strain TBZ2^T is a member of the genus Pseudomonas with the highest similarity to P. oleovorans subsp. oleovorans DSM 1045^T (98.83%), P. mendocina NBRC 14162^T (98.63%), P. oleovorans subsp. lubricantis RS1^T (98.61%) and P. alcaliphila JCM 10630^T (98.49%) based on EzBioCloud server. Phylogenetic analyses using housekeeping genes (16S rRNA, rpoD, gyrB and rpoB) and genome sequences demonstrated that the strain TBZ2^T formed a distinct branch closely related to the type strains of P. mendocina and P. guguanensis. Digital DNA-DNA hybridisation and average nucleotide identity values between strain TBZ2^T and its closest relatives, P. mendocina NBRC 14162^T (25.3%, 81.5%) and P. guguanensis JCM 18146^T (26.8%, 79.0%), rate well below the designed threshold for assigning prokaryotic strains to the same species. On the basis of phenotypic, chemotaxonomic, genomic and phylogenetic results, it is recommended that strain TBZ2^T is a novel species of the genus Pseudomonas, for which the name Pseudomonas khazarica sp. nov., is proposed. The type strain is TBZ2^T (= LMG 29674^T = KCTC 52410^T).