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Pseudomonas aeruginosa to Hydrocarbon-Rich Jet Fuel
Published in Kenneth Wunch, Marko Stipaničev, Max Frenzel, Microbial Bioinformatics in the Oil and Gas Industry, 2021
The formation of a biofilm in P. aeruginosa is regulated by numerous regulators including Quorum Sensing (QS), secondary regulatory system - bis-(3′-5′)-cyclic diguanosine monophosphate (c-di-GMP) molecules and small RNA (sRNA). Quorum sensing plays a key role in modulating the biofilm expression genes of polycyclic aromatic hydrocarbons (PAHs) in P. aeruginosa N6P6 (Mangwani et al., 2015). The degradation of the PAH compounds, phenanthrene and pyrene, was directly affected by biofilm growth and expression of lasI genes, which plays a role in synthesis and the use of N-(3-oxo-dodecanoyl)-L-homoserine lactone (3OC12-HL). Cyclic di-GMP is central to the post-transcriptional regulation of biofilm formation. For example, PelD is a c-di-GMP receptor and binding to c-di-GMP is essential for Pel polysaccharide production (Lee et al., 2007). In addition, the RNA-binding protein RsmA negatively controls biofilm formation. For example, RsmA post-transcriptionally regulated Psl biosynthesis by binding to psl mRNA and inhibits translation (Irie et al., 2010). However, two small non-coding RNAs (ncRNAs), RsmY and RsmZ, sequester the translational repressor RsmA and de-repress biofilm formation by increasing cyclic di-GMP level (Jimenez et al., 2012). Biofilm formation in fuel tanks are a significant concern because biofilms can clog fuel lines and fuel filters. Scientists are developing approaches to inhibit microbial biofilm formation and keep bacteria in planktonic growth state as single cells, which are more susceptible to biocides or antimicrobial agents.
Pathogen contamination of groundwater systems and health risks
Published in Critical Reviews in Environmental Science and Technology, 2023
Yiran Dong, Zhou Jiang, Yidan Hu, Yongguang Jiang, Lei Tong, Ying Yu, Jianmei Cheng, Yu He, Jianbo Shi, Yanxin Wang
With the capacity to remove particles of size down to nanometer scale or even less, membrane filtration techniques (e.g., ultrafiltration, reverse osmosis, and nanofiltration) can effectively remove bacteria and viruses, and thus has been widely employed in large-scale waste water treatment plants and point-of-use household systems (Venugopal et al., 2020). However, membrane filtration has been challenged by biofouling caused by undesirable microbial attachment and growth (Gray, 2014). Recent studies have improved membrane performance by coating nanomaterial or supplying anti-biofouling microorganisms on the membranes (Vries et al., 2021). For example, a novel quorum quenching and light-responsive biofilm entrapping engineered bacterial cells were developed to mitigate biofouling on water purification membranes with the aid of synthetic biology. The cells containing a dichromatic and optogenetic cyclic di-GMP (c-di-GMP) gene circuit can mediate the growth and dispersal of biofilm when exposed to light with different wavelength (Mukherjee et al., 2018).