Abstract

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are environmental contaminants of concern. We previously described biodegradation of two PFAS that represent components and transformation products of aqueous film-forming foams (AFFF), 6:2 fluorotelomer sulfonamidoalkyl betaine (6:2 FTAB) and 6:2 fluorotelomer sulfonate (6:2 FTSA), by Gordonia sp. strain NB4-1Y. To identify genes involved in the breakdown of these compounds, the transcriptomic response of NB4-1Y was examined when grown on 6:2 FTAB, 6:2 FTSA, a non-fluorinated analog of 6:2 FTSA (1-octanesulfonate), or MgSO₄, as sole sulfur source. Differentially expressed genes were identified as those with ± 1.5 log₂-fold-differences (± 1.5 log₂FD) in transcript abundances in pairwise comparisons. Transcriptomes of cells grown on 6:2 FTAB and 6:2 FTSA were most similar (7.9% of genes expressed ± 1.5 log₂FD); however, several genes that were expressed in greater abundance in 6:2 FTAB treated cells compared to 6:2 FTSA treated cells were noted for their potential role in carbon–nitrogen bond cleavage in 6:2 FTAB. Responses to sulfur limitation were observed in 6:2 FTAB, 6:2 FTSA, and 1-octanesulfonate treatments, as 20 genes relating to global sulfate stress response were more highly expressed under these conditions compared to the MgSO₄ treatment. More highly expressed oxygenase genes in 6:2 FTAB, 6:2 FTSA, and 1-octanesulfonate treatments were found to code for proteins with lower percent sulfur-containing amino acids compared to both the total proteome and to oxygenases showing decreased expression. This work identifies genetic targets for further characterization and will inform studies aimed at evaluating the biodegradation potential of environmental samples through applied genomics.

Graphic Abstract

中文翻译：

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Gordonia sp。的转录组反应。当提供6：2含氟端粒磺酰胺基烷基甜菜碱或6：2含氟端粒磺酸盐作为唯一硫源时，菌株NB4-1Y

摘要

全氟烷基和多氟烷基物质（PFAS）是令人关注的环境污染物。我们先前曾描述过两种由Gordonia降解的PFAS的生物降解，它们代表水性成膜泡沫（AFFF），6：2氟调聚物磺酰胺基烷基甜菜碱（6：2 FTAB）和6：2氟调聚物磺酸盐（6：2 FTSA）的成分和转化产物。sp。菌株NB4-1Y。为了鉴定参与这些化合物分解的基因，在6：2 FTAB，6：2 FTSA，6：2 FTSA（1-辛烷磺酸）的非氟化类似物上生长时，检查了NB4-1Y的转录组反应。 MgSO ₄作为唯一的硫源。差异表达的基因被鉴定为差异为±1.5 log ₂倍的基因（±1.5 log ₂成对比较中转录本丰度的FD）。在6：2 FTAB和6：2 FTSA上生长的细胞的转录组最为相似（7.9％的基因表达±1.5 log ₂ FD）。然而，与6：2 FTSA处理的细胞相比，在6：2 FTAB处理的细胞中表达更高的几个基因因其在6：2 FTAB中碳氮键裂解中的潜在作用而被指出。在6：2 FTAB，6：2 FTSA和1-辛烷磺酸盐处理中观察到对硫限制的响应，因为与MgSO ₄相比，在这些条件下20个与全球硫酸盐胁迫响应相关的基因表达更高。治疗。发现在6：2 FTAB，6：2 FTSA和1-辛烷磺酸盐处理中，表达更高的加氧酶基因编码的蛋白质与总蛋白质组和表现出降低的加氧酶相比，含硫氨基酸的百分比更低。这项工作确定了可进一步表征的遗传目标，并将为旨在通过应用基因组学评估环境样品的生物降解潜力的研究提供信息。

图形摘要