Basic Medical Sciences Department, Al-Balqa' Applied University, Salt, Jordan.
Medical Laboratory Sciences Department, Al-Ahliyya Amman University, Amman, Jordan.
PLoS One. 2024 Apr 18;19(4):e0297217. doi: 10.1371/journal.pone.0297217. eCollection 2024.
This study focuses on isolated thermophilic Bacillus species' adaptability and physiological diversity, highlighting their ecological roles and potential industrial applications. We specifically investigated their capacity to thrive in extreme conditions by examining their environmental tolerances and adaptations at the metabolic and genetic levels. The primary objective is to evaluate the suitability of these species for biotechnological applications, considering their resilience in harsh environments. We conducted a comparative analysis of the environmental adaptability parameters for various Bacillus species. This included examining growth temperature ranges, pH tolerance, oxygen requirements, carbohydrate fermentation patterns, colony morphology, enzymatic activities, and genetic properties. Controlled laboratory experiments provided the data, which were then analyzed to determine patterns of adaptability and diversity. The research revealed that Bacillus species could endure temperatures as high as 73°C, with a generally lower growth limit at 43°C. However, strains TBS35 and TBS40 were exceptions, growing at 37°C. Most strains preferred slightly alkaline conditions (optimal pH 8), but TBS34, TBS35, and TBS40 exhibited adaptations to highly alkaline environments (pH 11). Oxygen requirement tests classified the species into aerobic, anaerobic, and facultative aerobic categories. Genetic analysis highlighted variations in DNA concentrations, 16s rRNA gene lengths, and G+C content across species. Although glucose was the primary substrate for carbohydrate fermentation, exceptions indicated metabolic flexibility. The enzymatic profiles varied, with a universal absence of urease and differences in catalase and oxidase production. Our findings underscore thermophilic Bacillus species' significant adaptability and diversity under various environmental conditions. Their resilience to extreme temperatures, pH levels, varied oxygen conditions, and diverse metabolic and genetic features emphasize their potential for biotechnological applications. These insights deepen our understanding of these species' ecological roles and highlight their potential industrial and environmental applications.
本研究聚焦于嗜热芽孢杆菌属的物种的适应性和生理多样性，重点探讨其生态角色和潜在的工业应用。我们通过研究其在代谢和遗传水平上的环境耐受和适应能力，特别考察了它们在极端条件下生存的能力。主要目标是评估这些物种在生物技术应用中的适用性，考虑它们在恶劣环境中的恢复能力。我们对各种芽孢杆菌属的环境适应性参数进行了比较分析。这包括考察生长温度范围、pH 值耐受、氧气需求、碳水化合物发酵模式、菌落形态、酶活性和遗传特性。受控的实验室实验提供了数据，然后对其进行分析以确定适应性和多样性模式。研究表明，芽孢杆菌属可以耐受高达 73°C 的温度，一般的最低生长温度为 43°C。然而，菌株 TBS35 和 TBS40 是例外，它们可以在 37°C 下生长。大多数菌株更喜欢略碱性的条件（最佳 pH 值 8），但 TBS34、TBS35 和 TBS40 适应了高碱性环境（pH 值 11）。氧气需求测试将这些物种分为需氧、厌氧和兼性需氧种类。遗传分析突出了不同物种之间的 DNA 浓度、16s rRNA 基因长度和 G+C 含量的差异。尽管葡萄糖是碳水化合物发酵的主要底物，但也存在代谢灵活性的例外。酶谱各不相同，普遍缺乏脲酶，而在过氧化氢酶和氧化酶的产生方面存在差异。我们的研究结果强调了嗜热芽孢杆菌属在各种环境条件下具有显著的适应性和多样性。它们对极端温度、pH 值、不同氧气条件以及多样的代谢和遗传特性的抵抗力强调了它们在生物技术应用中的潜力。这些发现加深了我们对这些物种生态角色的理解，并突出了它们在工业和环境应用方面的潜力。
