Abstract:
The selection of oleaginous bacteria, potentially applicable to biotechnological approaches, is usually carried out by different expensive and time-consuming techniques. In this study, we used Oil Red O (ORO) as an useful dye for staining of neutral lipids (triacylglycerols and wax esters) on thin-layer chromatography plates. ORO could detect minimal quantities of both compounds (detection limit, 0.0025 mg of tripalmitin or 0.005 mg of cetylpalmitate). In addition, we developed a specific, rapid, and inexpensive screening methodology to detect triacylglycerol-accumulating microorganisms grown on the agar plate. This staining methodology detected 9/13 strains with a triacylglycerol content higher than 20% by cellular dry weight. ORO did not stain polyhydroxyalkanoates-producing bacteria. The four oleaginous strains not detected by this screening methodology exhibited a mucoid morphology of their colonies. Apparently, an extracellular polymeric substance produced by these strains hampered the entry of the lipophilic dye into cells. The utilization of the developed screening methodology would allow selecting of oleaginous bacteria in a simpler and faster way than techniques usually used nowadays, based on unspecific staining protocols and spectrophotometric or chromatographic methods. Furthermore, the use of ORO as a staining reagent would easily characterize the neutral lipids accumulated by microorganisms as reserve compounds. KEY POINTS: • Oil Red O staining is specific for triacylglycerols • Oil Red O staining is useful to detect oleaginous bacteria • Fast and inexpensive staining to isolate oleaginous bacteria from the environment.
摘要:
产油细菌的选择,可能适用于生物技术方法,通常是通过不同的昂贵和耗时的技术进行。在这项研究中,我们使用油红O(ORO)作为有用的染料,用于在薄层色谱板上染色中性脂质(三酰甘油和蜡酯)。ORO可以检测到最小量的两种化合物(检测限,0.0025毫克三棕榈素或0.005毫克十六烷基棕榈酸酯)。此外,我们开发了一个特定的,快速,和廉价的筛选方法,以检测在琼脂平板上生长的三酰基甘油积累微生物。该染色方法检测到9/13个菌株的三酰甘油含量高于按细胞干重计的20%。ORO不染色产生聚羟基链烷酸酯的细菌。通过这种筛选方法未检测到的四种含油菌株表现出它们的菌落的粘液形态。显然,由这些菌株产生的细胞外聚合物阻碍亲脂性染料进入细胞。利用已开发的筛选方法将允许以比现在通常使用的技术更简单和更快的方式选择含油细菌。基于非特异性染色方案和分光光度或色谱方法。此外,使用ORO作为染色试剂可以很容易地将微生物积累的中性脂质表征为储备化合物。关键点:•油红O染色对三酰基甘油具有特异性•油红O染色可用于检测含油细菌•快速且廉价的染色以从环境中分离含油细菌。