Bibi Shazia, Oualha Meriam, Ashfaq Mohammad Yousaf, Suleiman Muhannad T, Zouari Nabil
Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University PO Box 2713 Doha Qatar
Department of Civil and Environmental Engineering, Lehigh University USA.
RSC Adv. 2018 Feb 6;8(11):5854-5863. doi: 10.1039/c7ra12758h. eCollection 2018 Feb 2.
Biomineralization plays a key role in modifying the geological properties of soil, thereby stabilizing it against wind erosion, especially in areas characterized by harsh weather and harsh soil (calcareous and arid); Arabic Gulf region. Among soil microorganisms, ureolytic bacteria are capable of modifying soil characteristics and thus, inducing biomineralization. This research investigated the occurrence and diversity of ureolytic bacteria in Qatari soils, specifically to study their acquired potential to adapt to harsh conditions exhibiting ureolytic activity. Soil samples were collected from various locations in Qatar and were used to isolate the indigenous ureolytic bacteria. It was noticed that most of the ureolytic bacteria in Qatari soil belong to the genus mainly . Identification and differentiation of 18 ureolytic isolates were performed using MALDI-TOF MS techniques while ribotyping (16S rRNA) molecular technique was used mainly for 6 selected strains. This study not only shows the diversity of species of ureolytic bacteria in Qatari soil but also shows the diversity in their protein profiles, which confirms that bacteria have adapted well to the harsh environment. In addition, the strains were evaluated based on a newly modified screening method in this work; production of arbitrary urease activity (AUA). Thus, the strains showing the highest AUA, exhibited the highest capability to produce urease enzymes induced by urea. Analysis of calcium carbonate precipitation utilizing SEM-EDX showed that the ureolytic bacteria also play a significant role in the precipitation of minerals such as CaCO, in the presence of urea in soil. Therefore, this research showed a high occurrence of indigenous bacteria in Qatari soil that can perform biomineralization and thus can be helpful, if properly stimulated, in enhancing soil stabilization, and for other local applications as well, since they are adapted to these soil and weather conditions.
生物矿化在改变土壤地质性质方面起着关键作用，从而使其抵御风蚀，特别是在天气恶劣和土壤条件严酷（钙质和干旱）的地区，如阿拉伯湾地区。在土壤微生物中，尿素分解菌能够改变土壤特性，进而诱导生物矿化。本研究调查了卡塔尔土壤中尿素分解菌的存在情况和多样性，特别是研究它们适应表现出尿素分解活性的恶劣条件的潜在能力。从卡塔尔的不同地点采集土壤样本，用于分离本地尿素分解菌。注意到卡塔尔土壤中的大多数尿素分解菌主要属于 属。使用基质辅助激光解吸电离飞行时间质谱技术对18株尿素分解分离株进行鉴定和区分，而核糖体分型（16S rRNA）分子技术主要用于6株选定菌株。这项研究不仅显示了卡塔尔土壤中尿素分解菌物种的多样性，还显示了它们蛋白质谱的多样性，这证实细菌已很好地适应了恶劣环境。此外，根据本研究中新修改的筛选方法对菌株进行评估；任意脲酶活性（AUA）的产生。因此，显示出最高AUA的菌株表现出最高的由尿素诱导产生脲酶的能力。利用扫描电子显微镜 - 能谱仪（SEM - EDX）对碳酸钙沉淀的分析表明，在土壤中存在尿素的情况下，尿素分解菌在诸如CaCO₃等矿物质的沉淀中也起着重要作用。因此，这项研究表明卡塔尔土壤中存在大量能够进行生物矿化的本地 细菌，如果得到适当刺激，它们有助于增强土壤稳定性，也适用于其他当地应用，因为它们适应了这些土壤和天气条件。
