School of Food Science and Environmental Health, Technological University Dublin, Grangegorman, Dublin 7, D07 ADY7, Ireland.
Biotechnol Lett. 2022 Oct;44(10):1139-1147. doi: 10.1007/s10529-022-03284-5. Epub 2022 Aug 25.
The emerging biobased economy will require robust, adaptable, organisms for the production and processing of biomaterials as well as for bioremediation. Recently, the search for solvent tolerant organisms and solvent tolerant enzymes has intensified. Resilient organisms secreting solvent stable lipases are of particular interest for biotechnological applications.
Screening of soil samples for lipase-producing organisms was carried out on Rhodamine B plates. The most productive lipase-producing organisms were further screened for their resistance to solvents commonly used in biotechnological applications.
In the course of screening, one of the isolated organisms that exhibited extracellular lipase activity, was identified as the human pathogen Listeria monocytogenes through 16S rRNA sequencing. Further exploration revealed that this organism was resistant to solvents ranging from log P - 0.81 to 4.0. Moreover, in the presence of these solvents, L. monocytogenes secreted an extracellular, solvent tolerant, lipase activity. This lipase retained approximately 80% activity when incubated in 30% (v/v) methanol for 24 h.
These findings identify L. monocytogenes as a potentially useful organism for biotechnological applications. However, the fact that Listeria is a pathogen is problematic and it will require the use of non-pathogenic or attenuated Listeria strains for practical applications. Nonetheless, the ability to adapt to rapidly changing environmental conditions, to grow at low temperatures, to resist solvents and to secrete an extracellular solvent tolerant lipase are unique and highly useful characteristics. The potential application of L. monocytogenes in wastewater bioremediation and plastics degradation is discussed.
新兴的生物基经济将需要能够生产和加工生物材料以及进行生物修复的强大、适应性强的生物体。最近，人们对耐溶剂生物体和耐溶剂酶的搜索加强了。能够分泌耐溶剂脂肪酶的弹性生物体对于生物技术应用具有特别的兴趣。
在罗丹明 B 平板上对产脂肪酶的土壤样品进行了筛选。对最具生产力的产脂肪酶生物体进行了进一步筛选，以检测它们对生物技术应用中常用溶剂的抗性。
在筛选过程中，通过 16S rRNA 测序鉴定了一种具有细胞外脂肪酶活性的分离生物体，该生物体为人病原体李斯特菌。进一步探索表明，该生物体能够抵抗从 log P -0.81 到 4.0 的溶剂。此外，在这些溶剂存在下，李斯特菌分泌出一种细胞外耐溶剂的脂肪酶活性。该脂肪酶在 30%（v/v）甲醇中孵育 24 小时后保留了大约 80%的活性。
这些发现将李斯特菌鉴定为一种具有潜在生物技术应用价值的生物体。然而，李斯特菌是一种病原体，这是一个问题，因此需要使用非病原体或减毒李斯特菌菌株来进行实际应用。尽管如此，适应快速变化的环境条件、在低温下生长、耐溶剂和分泌细胞外耐溶剂脂肪酶的能力是独特且非常有用的特性。讨论了李斯特菌在废水生物修复和塑料降解中的潜在应用。
