Microbiology -Scholarly Publications

Permanent URI for this collection

https://ir.unilag.edu.ng/handle/123456789/3396

Browse

Browsing Microbiology -Scholarly Publications by Subject "Agricultural soil"

Now showing 1 - 2 of 2
  • Item
    Open Access
    Effects of cadmium perturbation on the microbial community structure and heavy metal resistome of a tropical agricultural soils
    (Bioresources and Bioprocessing (BIOB) Springer Open, 2020) Salami, L.B; Obayori, O.S; Ilori, M.O; Amund, O.O
    The effects of cadmium (Cd) contamination on the microbial community structure, soil physicochemistry and heavy metal resistome of a tropical agricultural soil were evaluated in field-moist soil microcosms. A Cd-contaminated agricultural soil (SL5) and an untreated control (SL4) were compared over a period of 5 weeks. Analysis of the physicochemical properties and heavy metals content of the two microcosms revealed a statistically significant decrease in value of the soil physicochemical parameters (Pā€‰<ā€‰0.05) and concentration of heavy metals (Cd, Pb, Cr, Zn, Fe, Cu, Se) content of the agricultural soil in SL5 microcosm. Illumina shotgun sequencing of the DNA extracted from the two microcosms showed the predominance of the phyla, classes, genera and species of Proteobacteria (37.38%), Actinobacteria (35.02%), Prevotella (6.93%), and Conexibacter woesei (8.93%) in SL4, and Proteobacteria (50.50%), Alphaproteobacteria (22.28%), Methylobacterium (9.14%), and Methylobacterium radiotolerans (12,80%) in SL5, respectively. Statistically significant (Pā€‰<ā€‰0.05) difference between the metagenomes was observed at genus and species delineations. Functional annotation of the two metagenomes revealed diverse heavy metal resistome for the uptake, transport, efflux and detoxification of various heavy metals. It also revealed the exclusive detection in SL5 metagenome of members of RND (resistance nodulation division) protein czcCBA efflux system (czcA, czrA, czrB), CDF (cation diffusion facilitator) transporters (czcD), and genes for enzymes that protect the microbial cells against cadmium stress (sodA, sodB, ahpC). The results obtained in this study showed that Cd contamination significantly affects the soil microbial community structure and function, modifies the heavy metal resistome, alters the soil physicochemistry and results in massive loss of some autochthonous members of the community not adapted to the Cd stress.
  • Item
    Open Access
    Impact of spent engine oil contamination on the antibiotic resistome of a tropical agricultural soil
    (Springer Link, 2021) Salam, L.B; Obayori, O.S; Ilori, M.O; Amund, O.O
    Profiling of hydrocarbon-contaminated soils for antibiotic resistance genes (ARGs) is becoming increasingly important due to emerging realities of their preponderance in hydrocarbon-inundated matrices. In this study, the antibiotic resistome of an agricultural soil (1S) and agricultural soil contaminated with spent engine oil (AB1) were evaluated via functional annotation of the open reading frames (ORFs) of their metagenomes using the comprehensive antibiotic database (CARD) and KEGG KofamKOALA. CARD analysis of AB1 metagenome revealed the detection of 24 AMR (antimicrobial resistance) gene families, 66 ARGs, and the preponderance (69.7%) of ARGs responsible for antibiotic efflux in AB1 metagenome. CARD analysis of 1S metagenome revealed four AMR gene families and five ARGs. Functional annotation of the two metagenomes using KofamKOALA showed 171 ARGs in AB1 and 29 ARGs in 1S, respectively. Majority of the detected ARGs in AB1 (121; 70.8%) and 1S (16; 55.2%) using KofamKOALA are responsible for antibiotic efflux while ARGs for other resistance mechanisms were also detected. All the five major antibiotic efflux pump systems were detected in AB1 metagenome, though majority of the ARGs for antibiotic efflux belong to the RND (resistance-nodulation-cell division) and MFS (major facilitator superfamily) efflux systems. Significant differences observed in the ARGs recovered from 1S and AB1 metagenomes were statistically validated (P < 0.05). SEO contamination is believed to be responsible for ARGs increase in AB1 metagenome via mechanisms of cross-resistance especially with efflux pumps. The detection of these ARGs is of great public health concern in this era of multidrug resistant isolates resurgence.