Microbial Insights into Shale Gas Wastewater from the Sichuan Basin: Diversity, Potential Functions, and Implications

Shale
gas flowback and produced water (SGFPW) represent a reservoir
of diverse and valuable halophilic microbial resources with profound
implications for both shale gas production and SGFPW treatment strategies.
However, current research is limited, especially in China. To address
this gap, we conducted an extensive study of the microbial community
compositions within SGFPW originating from three prominent shale gas
blocks in the Sichuan Basin, China. Our findings underscored the coexistence
of halotolerant and halophilic bacteria, methylotrophic archaea, and
eukaryotes within SGFPW, revealing a remarkably intricate microbial
ecosystem. Intriguingly, the archaeal community structure exhibited
striking similarity across all SGFPW samples, implying a consistent
composition in this regard. Moreover, salinity was identified as a
pivotal factor shaping the bacterial community structure in SGFPW.
Although divergence in species and abundance of core microbial genera
was observed among distinct SGFPW samples, their dominant potential
functions remained remarkably consistent. These functions encompassed
sulfate reduction, methane production, denitrification, acid production,
and degradation of characteristic organic matter of SGFPW. Our comprehensive
study significantly advances the comprehension of the microbial community
structure within SGFPW, thereby offering valuable insights to augment
the overall efficiency of SGFPW management and develop efficient SGFPW
biological treatment technologies.