Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
Laboratory of Biopolymer and Derivatives, Institute of Tropical Forestry and Forest Products (INTROP), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
J Microbiol Biotechnol. 2024 Sep 28;34(9):1877-1889. doi: 10.4014/jmb.2406.06034. Epub 2024 Jul 19.
Rhamnolipid (RL) is renowned for its efficacy in bioremediating several types of organic and metal contaminants. Nevertheless, there has been a scarcity of studies specifically examining the relationship between this substance and metals, especially in terms of their impact on RL formation and the underlying interaction processes. This study addresses this gap by investigating the RL mechanism in Cr (VI) remediation and evaluating its effect on RL production in RW9. In this study, RW9 was grown in the presence of 10 mg l Cr (VI). We monitored RL yield, congeners distribution, and their ratios, as well as the transcriptional expression of the RL-encoded genes: , , and . Our results revealed that RL effectively reduced Cr (VI) to Cr (III), with RL yield increasing threefold, although with a slight delay in synthesis compared to control cells. Furthermore, Cr (VI) exposure induced the transcriptional expression of the targeted genes, leading to a significant increase in di-RL production. The findings confirm that Cr (VI) significantly impacts RL production, altering its structural compositions and enhancing the transcriptional expression of RL-encoded genes in RW9. This study represents a novel exploration of Cr (VI)'s influence on RL production, providing valuable insights into the biochemical pathways involved and supporting the potential of RL in Cr (VI) bioremediation.
鼠李糖脂（RL）以其有效生物修复多种有机和金属污染物的能力而闻名。然而，专门研究该物质与金属之间关系的研究很少，特别是在它们对 RL 形成和潜在相互作用过程的影响方面。本研究通过研究 Cr（VI）修复中的 RL 机制并评估其对 RW9 中 RL 生产的影响来填补这一空白。在这项研究中，RW9 在存在 10mg/L Cr（VI）的情况下生长。我们监测了 RL 的产量、同系物分布及其比率，以及 RL 编码基因的转录表达：、、和。我们的结果表明，RL 有效地将 Cr（VI）还原为 Cr（III），尽管与对照细胞相比，RL 的产量增加了两倍，但合成略有延迟。此外，Cr（VI）暴露诱导了目标基因的转录表达，导致二 RL 的产量显著增加。这些发现证实了 Cr（VI）对 RL 生产有显著影响，改变了其结构组成，并增强了 RW9 中 RL 编码基因的转录表达。本研究代表了对 Cr（VI）对 RL 生产影响的新探索，为涉及的生化途径提供了有价值的见解，并支持 RL 在 Cr（VI）生物修复中的潜力。
