Phenotypic identification of soil bacterial and fungal communities inhabiting an archaeological monument at Augustine University, Ilara Epe, southwest Nigeria

*Ajayi, A. A., Onipede, G. O., Okafor, B. C., Adepoju, K. A., and Nwabuenu, J. C.
Department of Biological Sciences, Augustine University, Ilara Epe, Lagos State, Nigeria

*Correspondence to: adesola.ajayi@augustineuniversity.edu.ng

Abstract:
Background: The Sungbo Eredo Monument is an ancient public work with a system of defensive walls and ditches located in Eredo Local Council Development Area of Epe, Lagos State, southwest Nigeria. A huge section of the monument cuts through the Augustine University campus, forming two-sided vertical walls with a deep ridge in-between. The objective of this investigative study is to determine the microbial profile of soil samples from the monument in the University campus.

Methodology: Soil samples were collected from the topsoil at a depth of 7.5cm from four randomly selected points along the edge of the monument. The samples were transported to the microbiology laboratory of the Department of Biological Sciences of Augustine University for analysis. Samples were cultured on Nutrient agar (NA) and incubated aerobically for 24-48 hours for bacteria isolation and on Sabouraud’s Dextrose agar (SDA) for 72 hours for fungi isolation. Bacterial colonies on NA were preliminarily identified to genus level by Gram reaction and conventional biochemical test scheme for Gram-positive (catalase, coagulase, starch hydrolysis) and Gram-negative isolates (oxidase, urease test, indole, methyl red, Voges Proskauer and sugar fermentation tests). Fungi colonies on SDA were identified using conventional macroscopic and microscopic characteristics. Antibiotic susceptibility test of the bacterial isolates to selected antibiotics was done using the Kirby Bauer disc diffusion method. Continue reading “Phenotypic identification of soil bacterial and fungal communities inhabiting an archaeological monument at Augustine University, Ilara Epe, southwest Nigeria”

Comparative study of microbial, proximate and heavy metal compositions of some gastropods, bivalve and crustacean seafood

S Oranusi, E.D. Effiong, N.U. Duru

 

Abstract

Background: Seafood are known to be nutritionally rich, however, water bodies from where these foods are harvested are often burdened with wastes from industries, household and run-offs. Thus seafood can harbor pathogenic microorganisms and heavy metals which can pose a serious health hazard to consumers.

Materials and Methods: In this study, 5kg each of Littorina littorea, Achatina fulica,Tympanotonos fuscatusDorsanum miran, Egeria radiateand Penaeus notialis were investigated for microbial, proximate and heavy metal qualities using standard microbiological and chemical methods of analysis.

Results: The gastropod mollusks Tympanotonos fuscatusLittorina littorea and Achatina fulica had significantly (p≤0.05) higher microbial loads compared to other samples. All the samples had significantly (p≤0.05) higher coliform counts compared to standard specifications. The microbial isolates from the samples included species of BacillusKlebsiellaeCitrobacterProvidenciaPseudomonasStaphylococcus aureusEscherichia coli and Aspergillus nigerAspergillus flavus, yeasts, AlternariaAbsidia, Rhizopus, and Mucor. Antibiogram of the isolates revealed multiple resistances with 79.55% and 66.67% resistance to antibacterial and antifungal agents respectively. The seafood was rich in protein (8.0±0.03 to 46.0±0.03%) and fat (0.6±0.01 to 8.8±1.00%) but low in carbohydrate (1.18±0.84 to 3.81±0.86%).The heavy metal compositions of the seafood were generally low except for manganese 6.36±0.03ppm in Dorsanum miran and nickel 0.81±0.50 ppm in Penaeus notialis.

Conclusion: The microbial loads of the seafood are significantly (p≤0.05) higher in gastropods and more than acceptable standard, effective protection of water bodies for food cultivation and constant monitoring of seafood is necessary. Adequate processing and employing good manufacturing practices can reduce the microbial loads to an acceptable level and prevent food borne hazards that could be associated with seafood consumption.

Keywords: Seafood, Heavy metals, Microbial profile, proximate compositions

Download full journal in PDF below

Comparative study of microbial, proximate and heavy metal compositions of some gastropods, bivalve and crustacean seafood