Volume 36, Issue 2 (6-2025)
Studies in Medical Sciences 2025, 36(2): 114-122 |
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Ethics code: IR.IAU.PS.REC.1403.159
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Mohammadi M, Falsifi S, Amini K. Identification of the met Gene and Kinetic Analysis of Methionine Synthesis in Soil Thermophilic Bacilli. Studies in Medical Sciences 2025; 36 (2) :114-122
URL: http://umj.umsu.ac.ir/article-1-6402-en.html
URL: http://umj.umsu.ac.ir/article-1-6402-en.html
Department of Microbiology, Faculty of Basic Sciences, Medical Sciences Branch, Islamic Azad University, Tehran, Iran , Dr.sfalsafi@gmail.com
Abstract: (211 Views)
Background Methionine, an essential sulfur-containing amino acid, plays a critical role in detoxification via methylation and must be obtained through the diet, as humans cannot synthesize it. This study aimed to identify the met gene and analyze the kinetics of methionine synthesis in soil-derived thermophilic bacteria.
Methods Two hundred soil samples were collected from tree-adjacent areas along Khordin Boulevard, Tehran. After heat treatment and culturing, isolates underwent microscopic, biochemical, and molecular characterization. DNA was extracted using a specialized kit, and the met gene was identified via multiplex PCR and gel electrophoresis. Gene expression was quantified using quantitative real-time PCR (qRT-PCR) under three temperatures (25°C, 35°C, 45°C) with ammonium nitrate (nitrogen source) and glucose (carbon source). Data were analyzed by one-way ANOVA using SPSS v.22 and reported as mean ± SD at a significance level of p < 0.05.
Results Bacilli accounted for 30% of isolates from Tehran’s urban soil. The met gene was detected in only 6.66% of bacilli. Significant differences in met expression were observed between treated and control groups across all temperatures and nutrient conditions (p < 0.05). The most excellent suppression of met expression occurred at 45°C (2.342-fold decrease), while 25°C showed the least reduction (1.649-fold). Glucose and ammonium nitrate synergistically reduced expression (1.914- and 1.834-fold, respectively).
Conclusion Temperature and carbon/nitrogen sources modulate met gene expression, thereby influencing methionine synthesis in soil bacilli. Optimal suppression occurred at 45°C with a combination of glucose/ammonium nitrate, suggesting environmental regulation of this metabolic pathway. In contrast, the lowest suppression of met expression was observed at 25°C.
Methods Two hundred soil samples were collected from tree-adjacent areas along Khordin Boulevard, Tehran. After heat treatment and culturing, isolates underwent microscopic, biochemical, and molecular characterization. DNA was extracted using a specialized kit, and the met gene was identified via multiplex PCR and gel electrophoresis. Gene expression was quantified using quantitative real-time PCR (qRT-PCR) under three temperatures (25°C, 35°C, 45°C) with ammonium nitrate (nitrogen source) and glucose (carbon source). Data were analyzed by one-way ANOVA using SPSS v.22 and reported as mean ± SD at a significance level of p < 0.05.
Results Bacilli accounted for 30% of isolates from Tehran’s urban soil. The met gene was detected in only 6.66% of bacilli. Significant differences in met expression were observed between treated and control groups across all temperatures and nutrient conditions (p < 0.05). The most excellent suppression of met expression occurred at 45°C (2.342-fold decrease), while 25°C showed the least reduction (1.649-fold). Glucose and ammonium nitrate synergistically reduced expression (1.914- and 1.834-fold, respectively).
Conclusion Temperature and carbon/nitrogen sources modulate met gene expression, thereby influencing methionine synthesis in soil bacilli. Optimal suppression occurred at 45°C with a combination of glucose/ammonium nitrate, suggesting environmental regulation of this metabolic pathway. In contrast, the lowest suppression of met expression was observed at 25°C.
Type of Study: Research |
Subject:
میکروبیولوژی
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