What is PAHs
PAHs are polycyclic aromatic compounds composed of two or more fused aromatic rings with only carbon and hydrogen atoms.
The two main classes of PAHs are the LMW and HMW PAHs. The LMW PAHs (2–3 ring PAHs) such as naphthalene, fluorene, phenanthrene and anthracene are shown to have significantly less toxicity compared to the HMW PAHs of 4–7 rings (from chrysene to coronenes) which are recalcitrant and carcinogenic to humans.
Sources of PAHs
PAHs are ubiquitous in the environment and the sources can be divided into natural and anthropogenic sources. Natural sources include volcanic eruptions, forest and grassland fires. Existing studies show that PAHs in the environment are mostly derived from human activities, such as the incomplete combustion or pyrolysis of coal, petroleum and other mineral raw materials, biomass fuels, petroleum products and other hydrocarbons. PAHs emitted by natural and human activities enter the atmosphere, water and soil environment. Due to their hydrophobic characteristics, PAHs migrate and transform into sediments and soil.
Hazards of PAHs
PAHs are carcinogenic, teratogenic and mutagenic. They can cause a variety of cancers, and even harm the reproductive system and immune system of organisms Most PAHs not only have "Three Pathogenic" effects, but also have neurotoxicity. PAHs exhibits deleterious effects to the human health based on the rate of exposure and innate toxicity of different compounds which causes carcinogenicity (ability or tendency to induce cancer), genotoxicity (ability to induce non-transmissible DNA damage), cytotoxicity (the ability of being toxic to cells), nephrotoxicity (damage to the kidney), cardiotoxicity (capacity to cause damage to heart muscles, ocular toxicity (ability to induce eye disorders) and etc.
Our Team
Our team from Xi 'an, China, a city also in the northwest, noticed that PAHs were widely distributed around us, and people didn't have the same awareness of PAHs as common pollutants. Therefore, we established this project this year, aiming to degrade it through synthetic biology means, and promote the public's awareness of the dangers of PAHs through HP.
Our Plan
We realized the heterologous expression of degradation enzymes in Escherichia coli through synthetic biological methods, aiming to eliminate this gap, strengthen the adaptability of microorganisms to the environment, and achieve the broad spectrum degradation of PAHs.
