Hot springs are fascinating extreme environments for the isolation of polyextremophilic microorganisms with extraordinary characteristics. Since polyextremophilic bacterial growth are not as high as routine bacteria, the objective of this study was to investigate the effect of some environmental factors on biomass and metabolites productions in the newly isolated strain, from Larijan hot spring in Iran. The strain was identified as Aeribacillus pallidus Lhs-10 and deposited as CCUG 72355 and IBRC-M 11202 in Sweden and Iran, respectively. This thermoalkaliphilic strain can grow best at 50 °C, pH 8 and in the presence of 25 g/l NaCl. The physiological characterization of this strain show that [Ca/Mg] ratio affect its growth and biomass production with the best results obtained at the ratio of 2.5. Moreover, lactic and acetic acids production by this strain was affected by pH, aeration, and temperature, where a metabolic shift was detected from lactate to acetate production when the culture was aerated. Besides, its spores could tolerate heating at 80, 85, 90, 95 and 98 °C for 30 min without any reduction in the initial spore population, whereas D-value was defined 50 min at 98 °C. This newly lactic acid-producing strain of A. pallidus can be a promising strain that can be used in the harsh conditions in industrial processes.

中文翻译：

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钙镁比对具有高耐热孢子的新型热嗜碱苍白杆菌菌株的生物质生产的影响

温泉是用于分离具有非凡特性的多嗜极端微生物的迷人极端环境。由于多嗜极端细菌的生长不如常规细菌高，本研究的目的是研究一些环境因素对来自伊朗拉里詹温泉的新分离菌株的生物量和代谢物产生的影响。该菌株被鉴定为苍白杆菌Lhs-10，并分别在瑞典和伊朗保藏为CCUG 72355和IBRC-M 11202。这种嗜碱菌株在 50 °C、pH 8 和 25 g/l NaCl 的条件下生长最好。该菌株的生理特征表明，[Ca/Mg] 比率影响其生长和生物量生产，在比率为 2.5 时获得最佳结果。而且，该菌株的乳酸和乙酸生产受 pH 值、通气和温度的影响，当培养物通气时，检测到从乳酸到醋酸的代谢转变。此外，它的孢子可以耐受在 80、85、90、95 和 98°C 下加热 30 分钟，而初始孢子数量没有任何减少，而 D 值定义为 98°C 下 50 分钟。这种新的产乳酸菌株苍白球可能是一种很有前途的菌株，可用于工业过程中的恶劣条件。而 D 值定义为 98 °C 下 50 分钟。这种新的产乳酸菌株苍白球可能是一种很有前途的菌株，可用于工业过程中的恶劣条件。而 D 值定义为 98 °C 下 50 分钟。这种新的产乳酸菌株苍白球可能是一种很有前途的菌株，可用于工业过程中的恶劣条件。