Huang Lili, Zhang Yehui, Du Xinmei, An Ran, Liang Xingguo
College of Food Science and Engineering, Ocean University of China, Qingdao, China.
Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Front Microbiol. 2022 Jun 28;13:894849. doi: 10.3389/fmicb.2022.894849. eCollection 2022.
Is DNA or RNA a good nutrient? Although scientists have raised this question for dozens of years, few textbooks mention the nutritional role of nucleic acids. Paradoxically, mononucleotides are widely added to infant formula milk and animal feed. Interestingly, competent bacteria can bind and ingest extracellular DNA and even integrate it into their genome. These results prompt us to clarify whether bacteria can "eat" DNA as food. We found that can grow well in the medium with DNA as carbon and nitrogen sources. More interestingly, in the presence of glucose and DNA, bacteria grew more rapidly, showing that bacteria can use DNA as an excellent nitrogen source. Surprisingly, the amount of DNA in the culture media decreased but its length remained unchanged, demonstrating that ingested long DNA directly. The gene expression study shows that mainly ingests DNA before digestion and digests it in the periplasm. can also use DNA as the nitrogen source for growth, but not efficiently as . This study is of great significance to study DNA metabolism and utilization in organisms. It also lays a foundation to understand the nutritional function of DNA in intestinal flora and human health.
DNA或RNA是一种良好的营养物质吗？尽管科学家们已经提出这个问题数十年了，但很少有教科书提及核酸的营养作用。矛盾的是，单核苷酸被广泛添加到婴儿配方奶粉和动物饲料中。有趣的是，有能力的细菌能够结合并摄取细胞外DNA，甚至将其整合到它们的基因组中。这些结果促使我们去阐明细菌是否能将DNA作为食物“食用”。我们发现[具体细菌名称]能在以DNA作为碳源和氮源的培养基中良好生长。更有趣的是，在有葡萄糖和DNA存在的情况下，细菌生长得更快，这表明细菌能够将DNA作为一种优质的氮源。令人惊讶的是，培养基中DNA的量减少了但其长度保持不变，这表明[具体细菌名称]直接摄取了长链DNA。基因表达研究表明，[具体细菌名称]主要在消化前摄取DNA并在周质中进行消化。[另一种细菌名称]也能将DNA用作生长的氮源，但不如[具体细菌名称]高效。这项研究对于研究生物体中DNA的代谢和利用具有重要意义。它也为理解DNA在肠道菌群和人类健康中的营养功能奠定了基础。
