Open Access Original Research Article

Antioxidant and Antimicrobial Activities of Various Extracts from Safou (Dacryodes edulis) Cultivated in Côte d’Ivoire

Andrée Emmanuelle Sika, Romuald Léonce Kadji, Lacinan Ouattara, Soumaïla Dabonné, Rose Koffi-Nevry

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/mrji/2021/v31i830336

Safou (Dacryodes edulis) is a fruit with very interesting nutritional and pharmacological properties. However, this fruit remains rather unknown to the Ivorian population.

Aims: The objective of this study was to highlight the antioxidant and antimicrobial potential of the seed and pulp of Safou (Dacryodes edulis) cultivated in Côte d'Ivoire for its valorization.

Study Design: Microbiological and biochemical studies

Place and Duration of Study: Laboratory of Biotechnology and Food Microbiology,Abidjan, Côte d’Ivoire, between September 2020 and February 2021.

Methodology: Aqueous, ethanolic and methanolic extracts of the pulp and seed of Safou were prepared. Moisture content, pH, yield, total polyphenols,diphényl-2-picrylhydrazyle (DPPH) radical scavenging testof the different extracts were determined.Aqueous, ethanolicand methanolicextracts of the seed and pulp at varying concentrations of 200 mg/mL, 100 mg/mL, 50 mg/mL, 25 mg/mL, 12.5mg/mL and 6.25 mg/mL was tested against human pathogens such asEscherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiellapneumoniae, Proteus mirabilis, Aspergillus fumigatus and Penicilliumchrysogenum.

Results: pH, moisture content and yield ranged from 3.16 to 4.74; 9 to 18.30%; and 10.79 to 18.78%, respectively. Total polyphenol content ranged from 1.45 mgEAG/g to 4.56 mgEAG/g. The highest levels of total polyphenols were observed for the methanolic extracts of pulp. The different extracts strongly scavenged the DPPH radical with percentages of anti-free radical activity that varied from 50.76 to 64.43%.The antimicrobial susceptibility results of the methanolic extracts of D. edulis seed showed highest zones of inhibition to the microbial isolates tested. The microorganisms were resistant to the aqueous extracts of pulp and seed.

Conclusion: The presence of bioactive compounds and the antimicrobial activity of Safou extracts could justify its use in the food and pharmaceutical fields.

Open Access Original Research Article

Isolation, Identification and Antibiotic Susceptibility of Escherichia coli Isolated from Raw Meat from Modake and Ile-Ife, Osun State, Nigeria

Wilkie Eunice Damilola, Oluduro Anthonia Olufunke, Ezeani Chidinma Vivian, Sotala Toyosi Teniola

Microbiology Research Journal International, Page 9-13
DOI: 10.9734/mrji/2021/v31i830337

The study reported isolation, identification and antibiotic susceptibility of Escherichia coli isolated from raw meat from Modakeke and Ile-ife, Osun State, Nigeria, with the view to determining the antibiogram profiling of the bacterial isolates. 

In this study, five samples of fresh meat were collected from different abattoirs in Ile-Ife and Modakeke, Osun State. Isolates of Escherichia coli were isolated, identified morphologically based on their growth on nutrient agar and subjected to antibiotic susceptibility test on Mueller Hinton agar. The mean microbial load from the meat samples ranged from 8.85 x 102cfu/ml to 5.77 x 104cfu/ml. A total of 69 E. coli isolates were recovered from the meat sampled. All the isolates appeared cream, translucent, entire, convex, circular, smooth and glistering. The isolates were identified as Gram negative rods, non-motile, lactose fermenters, positive for indole test and negative for citrate utilization test. All the E. coli isolates were resistant to augmentin, ceftriazone, nitrofurantoin and gentamycin. 98.55% of E. coli isolated was resistant to amoxillin and the least resistant was recorded in ofloxacin (8.70%). However, 91.30% of the E. coli isolates was sensitive to ofloxacin, 81.16% to ciprofloxacin and 36.23% to pefloxacin while none was sensitive to augmentin, ceftriazone, nitrofurantoin and gentamycin. A total of 19 different multiple antibiotic resistance patterns were observed among the isolates. Thirty isolates (43.48%) showed multiple antibiotic resistance to 5 and 10 different antibiotic types each.

The study concluded that occurrence of E. coli infection is high in the study area with high level of multiple antibiotic resistance.

Open Access Original Research Article

Physicochemical Indices of Phyto Remediated Hydrocarbon Polluted Soil and the Effect of Bio-nutrient Amendment

J. O. Dasetima-Altraide, D. N. Ogbonna, T. K. S. Abam, A. E. Gobo

Microbiology Research Journal International, Page 14-33
DOI: 10.9734/mrji/2021/v31i830338

Aim: To assess the Physicochemical indices of Phytoremediated Crude Oil polluted amended soil using grass plant Cyperus esculentus (Cyp) and Phyllanthus amarus (Phy).

Study Design: The study employs experimental design, statistical analysis of the data and interpretation.

Place and Duration of Study: Rivers State University demonstration farmland in Nkpolu- Oroworukwo, Mile 3 Diobu area of Port Harcourt, was used for this study. The piece of land is situated at Longitude 4°48’18.50” N and Latitude 6ᵒ58’39.12” E measuring 5.4864 m x 5.1816 m with a total area of 28.4283 square meter. Phytoremediation process monitoring lasted for 240 days; analyses were carried out monthly at 30 days’ interval.

Methodology: The study was carried out on Crude Oil Polluted soil (PS) amended with bio-nutrient supplements (Spent Mushroom Substrate (SMS) and selected fungi (Aspergillus niger(AN) andMucor racemosus (MR)) used to stimulate and augment the indigenous microbial population present in a crude oil polluted soil thereby enhancing hydrocarbon reduction in pari per sue with phytoremediation (uptake of Crude oil by test plants) over a period of 240 days. Ten (10) experimental plots (two Control (Unpolluted and polluted soil without amendment) and eight polluted amended/treated plots) employing Randomized Block Design (each having dimensions: 100 x 50 x 30 cm LxBxH); formed and mapped out on agricultural soil and left fallow for 6 days before contamination on the seventh day; after which it was allowed for 21 days for proper contamination and exposure to natural environmental factors (to mimic soil crude oil spill site); thereafter nutrients/organics (biostimulating agents) and bioaugmenting organisms were applied. Baseline studies were carried out on soil profile before and after contamination, major parameters monitored and assayed were Total Petroleum Hydrocarbon (TPH) uptake by plant roots and stem, Polycyclic Aromatic Hydrocarbons (PAHs) and TPH reduction in soil. Other physicochemical properties analyzed in the soil from different plots were pH, Electrical Conductivity, Moisture Content, Total Nitrogen, Available Phosphorus, Potassium, Total Organic Carbon, Plant Height, Iron, Lead and Zinc at regular intervals; days 1, 60, 90, 120, 150, 180, 210 & 240. The rate of phytoremediation was estimated from percentage (%) uptake of Total petroleum hydrocarbon (TPH) in plant roots and stem from day 1 -240; while percentage (%) reduction of TPH and PAHs in soil was estimated from day 1 to the residual at day 240.

Results: The test plants decreased significant amount of crude oil as revealed in TPH uptake in their roots and Stem. Mean amount and percentage Total Petroleum Hydrocarbon (TPH) uptake by Cyperus esculentus roots and stem were; 152.33±50.34mg/kg, 12.57±4.16% and 201.13±8.80mg/kg, 13.27±0.58% respectively; while that of Phyllanthus amarusroots and stem were 141.50±35.62mg/kg, 11.68±2.94% and 174.44±19.98mg/kg, 11.51±1.32% respectively; revealing higher Uptake of TPH in plant stem than roots. From the initial TPH contamination value of 5503.00mg/kg, it was observed that plots planted with Cyperus esculentus (TPH 5492.75±76.36mg/kg) showed higher reduction of TPH from soil than those planted with Phyllanthus amarus(TPH 5449.72±18.27mg/kg); while PAHs degradation/reduction showed a reverse trend with plots planted with Phyllanthus amarus (PAHs 28.72±2.74mg/kg; 60.46±5.77%) higher than plots planted with Cyperus esculentus

s (PAHs 25.77±2.12mg/kg, 54.24±4.47%).

Conclusion: Plots planted with Cyperus esculentus showed higher reduction of TPH from soil than those planted with Phyllanthus amarus while PAHs degradation/reduction in plots planted with Phyllanthus amarus was higher than plots planted with Cyperus esculentus. TPH uptake was higher in plant stems than roots; more so, plots amended with nutrient supplements showed significant higher percentage reduction in hydrocarbon in the polluted soil than unamended polluted soil. It is therefore recommended that Cyperus esculentus is a suitable plant species for phytoremediation of crude oil contaminated soil with high TPH value while Phyllanthus amarusis the best option in phytoremediation of polluted soil with high PAHs value, both in combination with bio-nutrient supplement.