Quantification of Chemotaxis-Related Alkane Accumulation in Acinetobacter baylyi Using Raman Microspectroscopy

Abstract

Alkanes are one of the most widespread contaminants in the natural environment, primarily as a consequence of biological synthesis and oil spills. Many indigenous microbes metabolize alkanes, and the chemotaxis and accumulation in some strains has been identified. For the first time, we apply Raman microspectroscopy to identify such chemotaxis-related affinity, and quantify the alkane concentrations via spectral alterations. Raman spectral alterations were only found for the alkane chemoattractant bacteria Acinetobacter baylyi ADP1, not for Pseudomonas fluorescence,

4-Nonylphenol effects on rat testis and sertoli cells determined by spectrochemical techniques coupled with chemometric analysis

“…The half-left testis of each rat were fixed in 4% PFA at 4 o C overnight, embedded in paraffin, sectioned for 10 μm thickness and then transferred onto a slide covered with aluminum foil (Li et al, 2017). The paraffin-embedded testicular sections were routinely de-paraffinized with xylene and a graded series of ethanol (100%, 90%, 80% and 70%) for 2 min each.…”

“…Testicular sections were air-dried at room temperature for 24 h and analysed by Raman spectroscopy. Raman spectra of testicular interstitial tissue were recorded using an InVia Renishaw Raman spectrometer with a 785 nm diode laser (Renishaw plc, UK), which has recently been described in more detail (Butler et al, 2016;Li et al, 2017). Briefly, the Raman system was calibrated using the 520 cm -1 band of a silicon wafer for assessing wavenumber shifts.…”

“…All point spectra were collected using 100% laser power (26 mW at sample), 15 s exposure time and 1 accumulation within the 1800~900 cm −1 spectral range, and approximately 100 spectra were obtained from different sites of testicular interstitial tissue from each rat. Each acquired raw spectrum was pre-processed by rubberband baseline correction and normalization to the Amide I peak using MATLAB (Butler et al, 2016;Li et al, 2017).…”

Differential Protein Expression During Growth on Medium Versus Long-Chain Alkanes in the Obligate Marine Hydrocarbon-Degrading Bacterium Thalassolituus oleivorans MIL-1

“…Similarly alkN appears to encode a MCP in P. putida GPo1 (van Beilen et al, 2001). Raman microspectroscopy showed chemotaxis in Acinetobacter baylyi toward alkanes is highly specific and the chemotaxis proteins therefore follow the same behavior (Li et al, 2017). For example, the coupling protein CheW2 is from A. dieselolei was found to be only induced by long-chain alkanes (Wang and Shao, 2014).…”

Fingerprinting microbiomes towards screening for microbial antibiotic resistance

“…When coupled with conventional microscopy, biospectroscopy can be used to reproduce cell architecture from both the visual and biochemical perspective by the passing of spectral data through a variety of computational algorithms and capture of pictures simultaneously 69,72 . It allows visualized monitoring and spectral interrogation undertaken in-situ in real-time, which is very helpful towards understanding the actual interactions between microbes and physical environment 66,69,72,77,80,93,94 . In the history of microbiological research, the microbiome is a particular hotspot in microbial ecology, challenging to all approaches to investigate it but bringing possibilities for biospectroscopy to be applied.…”