Impact of long-term cultivation with crude oil on wetland microbial community shifts and the hydrocarbon degradation potential

Abstract

ABSTRACT Microbial community shifts of a freshwater wetland with crude oil pressure were investigated fully as a function of cultivation time, using the enrichment procedure and high-throughput sequencing. Bacterial structures and biodegradation capabilities were apparently altered over different cultivation periods. Flavobacterium was the dominant genus in the original water sample, followed by hgcl_clade and Limnobabitans. However, during a long-term successional cultivation with crude oil, a potential microbial consortium was successfully rebuilt that was mainly composed of hydrocarbon-degrading genera, such as Pseudomonas, Rhodococcus, and Nocardia. Furthermore, the cultivation time was a significant factor that contributed to the complexity and relative stability of the bacterial community. Additionally, the majority of crude oil fractions were degraded by the enriched consortium. For example, n-alkanes (m/z 85) in the crude oil were fully depleted, and polycyclic aromatic hydrocarbons, such as naphthalenes, decalins, fluorenes, phenanthrenes, dibenzothiophenes, and chrysenes, were partially degraded from 10% to 100%. Moreover, the degree of biodegradation varied during different cultivation periods and within compound families. The microbial consortium of hydrocarbon degradation can be constructed from the freshwater wetland and this finding is useful when considering bioremediation of petroleum contamination in natural wetlands.