Biology subjects

Xiu, Z.

Publications and source records attributed to Xiu, Z..

3 recordsLinked to original sources

bioRxiv2026

Microbial Reductive Dechlorination of Hexachlorobutadiene by Dehalococcoides

Hexachlorobutadiene (HCBD), a persistent organic pollutant (POP), poses a significant threat to ecological environments and human health. While anaerobic microbial transformation is a promising remediation strategy, the specific microorganisms and metabolic mechanisms involved have remained poorly understood. This study demonstrates the successful enrichment of an anaerobic microbial consortium from river sediment, with lactate as an electron donor, capable of transforming HCBD. Within 240 days, 62.5 mol of HCBD was sequentially dechlorinated through pentachlorobutadiene (PCBD), tetrachlorobutadiene (TeCBD), trichlorobutadiene (TCBD), and dichlorobutadiene (DCBD) to chlorobutadiene (CBD). Co-amendment with HCBD and trichloroethene (TCE) resulted in complete removal of both compounds. 16S rRNA gene sequencing and quantitative PCR showed enrichment of Dehalococcoides, linking its population growth to HCBD and TCE dechlorination. This study demonstrates that Dehalococcoides growth was associated with HCBD transformation in the enrichment cultures, broadens our understanding of the metabolic capabilities of Dehalococcoides, and identifies a candidate gene for this important environmental process, offering valuable insights for the bioremediation of sites contaminated with HCBD.

microbiology↗

bioRxiv2026

Allyl chloride respiration by Dehalobacter shapes the fate of 1,2,3-trichloropropane

The synthetic compound 1,2,3-trichloropropane (1,2,3-TCP) is a persistent groundwater contaminant and probable human carcinogen for which effective detoxification pathways remain limited. Under anoxic conditions, microbial transformation of 1,2,3-TCP typically stalls at the intermediate allyl chloride, preventing complete detoxification. Here, we report the enrichment and characterization of Dehalobacter restrictus strain XRTCP, a bacterium capable of coupling dichloroelimination of 1,2,3-TCP with subsequent hydrogenolysis of allyl chloride to propene. While dichloroelimination to allyl chloride has been previously observed, the ability to utilize allyl chloride as a respiratory electron acceptor represents a previously unrecognized metabolic capability. This transformation was linked to microbial growth, with cell densities increasing by up to 74-fold during 1,2,3-TCP reduction and 15.8-fold during allyl chloride transformation. Metagenomic and metaproteomic analyses revealed a diverse repertoire of reductive dehalogenases (RDases), with expression patterns that differed between 1,2,3-TCP and allyl chloride amendments. Notably, a tcpA-like RDase was expressed under both 1,2,3-TCP and allyl chloride conditions, while distinct RDases were preferentially expressed under each substrate, indicating functional specialization within the dechlorination pathway. Despite this metabolic capability, propene formation remained limited due to rapid abiotic transformation of allyl chloride, primarily via reactions with reduced sulfur species, highlighting a critical branching point between biotic and abiotic pathways. These findings demonstrate that allyl chloride can function as a growth-supporting respiratory electron acceptor. More broadly, this work reveals how interactions between microbial metabolism and geochemical processes govern contaminant fate, with implications for improving both monitored natural attenuation and engineered bioremediation strategies for chlorinated solvents.

microbiology↗

bioRxiv2019

Transcriptome Profile Analysis of Twisted Leaf Disease Response in Susceptible Sugarcane with Narenga porphyrocoma Genetic Background

Sugarcane is an important industrial crop with a high sugar yield that has become a leading energy crop worldwide. It is widely cultivated in tropical and subtropical regions. Various diseases beset the cultivation of sugarcane. The molecular study of disease resistance in sugarcane is limited by its complicated genome. In our study, RNA-seq was employed to detect the mechanism of twisted leaf disease tolerance in modern cultivar sugarcane, which derived from Narenga porphyrocoma. We completed high-throughput transcriptomic sequencing of 12 samples, including three stages of a susceptible (NSBC1_T \"H3-8\") and an unsusceptible cultivar (NSBC1_CK \"H-19\") with two biological repeats, respectively. Using the Saccharum spontaneum genome as reference, the average mapping ratio of the clean data was over 70%. Among the differentially expressed genes between H3-8 and H3-19, we focused on the analysis of hormone pathways and resistance (R) genes. The results showed that twisted leaf disease triggers hormone networks and around 40% of R genes conditioned lower expression in the susceptible cultivar. One of the possible reasons for H3-8 being susceptible to twisted leaf disease might be the null/retarded response of R genes, especially in pre-onset stage (46% down-regulated) of pathogens infection.

genomics↗