Maldonado Desena Félix, De la Cruz Ceferino Navila, Gómez Cornelio Sergio, Alvarez Villagomez Carina, Herrera Candelario José Luis, De la Rosa García Susana
División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Carr. Villahermosa-Cardenas Km 0.5, Ranchería Emialiano Zapata, Villahermosa 86150, Tabasco, Mexico.
Ingeniería en Biotecnología, Universidad Politécnica del Centro, Carretera Federal, Villahermosa-Teapa Km 22.5, Tumbulushal Centro, Villahermosa 86290, Tabasco, Mexico.
Microorganisms. 2022 Jun 21;10(7):1264. doi: 10.3390/microorganisms10071264.
Halotolerant bacteria with biosurfactant (BS) and bioemulsifiers (BE) activity can coexist in Karstic sinkholes with marine influence. Two sinkholes in the Yucatan peninsula were selected to isolate bacteria with BE and BS activity stable in NaCl. The optimal time, the effect of nitrogen and carbon source in the medium, and the conditions (agitation, pH and salinity) for the production of BS and BE compounds in planktonic and sessile (stimulate the formation of biofilms in cell roller) culture were determined. Eighty strains showed the highest emulsification activity (EI ≥ 50%) and drop-collapse ≥ 4 mm. 87% of the strains are moderately halotolerant, and 21% bordered the limit of extreme halotolerance. Twenty-four strains maintained or improved their BS and BE activity under salinity conditions at 5% and 10%, being the most active genera , and , identified by sequencing of the 16S rRNA gene. The results show that the nitrogen source positively affects the BS and BE activity, regardless of the type of culture. The sessile culture markedly stimulated BS activity with significant differences. However, we did not find a greater influence on the culture conditions. The results suggest that halotolerant bacteria from sinkholes could be implemented in bioremediation and other biotechnological applications.
具有生物表面活性剂（BS）和生物乳化剂（BE）活性的耐盐细菌可共存于受海洋影响的岩溶天坑中。在尤卡坦半岛选择了两个天坑来分离在氯化钠中具有稳定BE和BS活性的细菌。确定了最佳时间、培养基中氮源和碳源的影响，以及浮游和固着（刺激细胞滚筒中生物膜形成）培养中产生BS和BE化合物的条件（搅拌、pH值和盐度）。八十个菌株表现出最高的乳化活性（EI≥50%）和液滴塌陷≥4毫米。87%的菌株为中度耐盐，21%接近极端耐盐极限。通过16S rRNA基因测序鉴定，有二十四个菌株在5%和10%的盐度条件下保持或提高了它们的BS和BE活性，它们是最活跃的属， 和 。结果表明，无论培养类型如何，氮源都对BS和BE活性有积极影响。固着培养显著刺激了BS活性，差异显著。然而，我们没有发现培养条件有更大的影响。结果表明，来自天坑的耐盐细菌可应用于生物修复和其他生物技术应用。
