Metagenomic Analysis Of San Jacinto River Microbial Soil Populations And Toxicity Resistance

As environmental pollution proves to remain a pervasive problem despite conservation efforts, the effects of this pollution on microbial soil populations are more important than ever. Pollution by PCBs, PCDD/Fs, and many more contaminants of concern, present since the 1960s, has been leaking into the San Jacinto River for over half a century. The San Jacinto River Waste Pits, the French Limited Superfund Site, The Highlands Acid Pits, the Sikes Disposal pits, and the Patrick Bayou Superfund Site, all lie in close proximity to the San Jacinto River, which in turn, weaves through many large communities in Southeast Houston, before finally emptying into the Galveston Bay. This paper will focus on the effects these toxins may be exerting on indigenous microbial populations, mostly bacteria, by monitoring their response to an amendment of a biphenyl solution. Utilizing soil samples from River Terrace Park, located on the western banks of the San Jacinto River just downstream from four of these Superfund Sites, the effect of this pollution on microbial populations was measured. Illumina shotgun sequencing and subsequent metagenomic analysis performed via MG-RAST revealed significant decreases in nearly all microbial populations following this amendment, confirming the deleterious effect these pollutants can exert on indigenous microorganisms. Nearly every phylum, class, order, as well as functional category experienced significant population loss when exposed to biphenyl. Houston is a sprawling metropolitan port city with a population of more than 2.3 million people. This massive community relies heavily on the waterways that support the area’s massive shipping and oil industries. The San Jacinto River is one of these waterways and understanding the influence more than half a century of pollution has had is vital in maintaining the growth and success the city has experienced for years, while protecting the environment that has allowed for such prosperity. The observed deleterious effect of biphenyl in this study, as well as the presence of multiple superfund sites acting as sources of other toxins such as PCDD/Fs illustrates that this region of southeast Texas is heavily affected by environmental pollutants and will require continued attention and testing for years to come