Sharif Sobia, Shah Asad Hussain, Fariq Anila, Jannat Sammyia, Rasheed Sajida, Yasmin Azra
Biotechnology Research Lab, Department of Biotechnology, University of Kotli, Azad Jammu and Kashmir, Pakistan.
School of Life Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Michal Smith Building, Oxford Road Manchester, UK.
Heliyon. 2023 Jan 18;9(1):e12901. doi: 10.1016/j.heliyon.2023.e12901. eCollection 2023 Jan.
Present study was aimed at screening and characterizing thermostable amylase-producing bacteria from water and sediment samples of unexplored hot spring of Tatta Pani Kotli Azad Kashmir. Four thermophilic isolates were characterized on morphological, biochemical, physiological basis and were authenticated by molecular analysis. By 16S rDNA sequencing, isolates were identified as (MBT001), (MBT002), (MBT004). Among all identified strains, MBT003 showed maximum homology with both and . Amylase activity was analyzed qualitatively in starch agar and quantitatively by DNS method. The optimal enzyme production was observed and authenticated by Response Surface Methodology at 7 pH, 70 °C, 1.25% substrate concentration, 300 μL of inocula volume after 48 h of incubation. Optimum amylase activity (4.4 U/mL) and stability (3.3 U/mL) was observed with 1.5% soluble starch at 70 °C. Maximum activity (3.7 U/mL) and stability (1.5 U/mL) was found at pH 8. Enzyme activity was increased in the presence of MgSO and CaCl. Amylase was stable with surfactants and commercial detergents for 30 min. Supplementation of the enzyme with commercial detergent improved the washing ability of the detergent. This investigation has revealed that these thermostable bacteria are excellent source of amylase which can be used commercially for generating economic activity on sustainable basis.
本研究旨在从克什米尔自由邦塔塔帕尼未开发温泉的水和沉积物样本中筛选并鉴定产耐热淀粉酶的细菌。对四株嗜热分离株进行了形态学、生物化学和生理学特征分析，并通过分子分析进行了鉴定。通过16S rDNA测序，分离株被鉴定为（MBT001）、（MBT002）、（MBT004）。在所有鉴定出的菌株中，MBT003与 和 均显示出最高的同源性。在淀粉琼脂中对淀粉酶活性进行了定性分析，并通过DNS法进行了定量分析。通过响应面法在7pH、70°C、1.25%底物浓度、300μL接种量、培养48小时后观察并验证了最佳酶产量。在70°C下，1.5%可溶性淀粉存在时观察到最佳淀粉酶活性（4.4U/mL）和稳定性（3.3U/mL）。在pH8时发现最大活性（3.7U/mL）和稳定性（1.5U/mL）。在MgSO和CaCl存在下酶活性增加。淀粉酶在表面活性剂和商用洗涤剂中稳定30分钟。向商用洗涤剂中添加该酶提高了洗涤剂的洗涤能力。这项研究表明，这些耐热细菌是淀粉酶的优质来源，可在可持续基础上用于商业生产以创造经济活动。
