South Asian Journal of Research in Microbiology

Effect of Fermentation on Bacteria Isolates and Phytochemical Properties of Cocoa (Theobroma cacao) Beans

2020-09-18T07:24:43+00:00

This investigation was carried out to assess the bacteria associated with cocoa beans at different stages of fermentation and determine the changes in the phytochemical constituents of the fermenting beans. The pour plate technique was used for bacterial isolation while phytochemicals were assessed based on standard qualitative chemical reactions. The total bacterial count on the cocoa beans reduced during fermentation from the initial 86.2±0.02 x 10⁵ CFU/g (day 0) to 1.00±0.00 x 10⁵ CFU/g on day 5. However, there was an increase in the lactic acid bacteria count from 48.7±0.03 x 10⁵ CFU/g (day 0) to 111.7±0.03 x 10⁵ CFU/g on day 3, then reduced to 51.4±0.01 x 10⁵ CFU/g on day 5. Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis, Lactobacillus fermentum, Lactobacillus plantarum and Lactobacillus acidophilus were isolated from the cocoa beans at different stages of the fermentation. There was a gradual increase in the temperature of the fermenting cocoa mass from the initial 25.6°C recorded at the beginning of the fermentation to 42.8°C recorded on day 5. Also, the pH of the fermenting cocoa beans reduced significantly from 6.1 at the commencement of the fermentation to 3.2 on day 5. In the total titratable acidity assay, the acidity of the cocoa beans increased from 3.12% at the beginning of the fermentation to 7.12% on day 5. Further, in the phytochemical screening, only alkaloids, phenols, steroids and flavonoids were detected in the beans throughout fermentation period whereas tannin and saponin were not found in the beans at any stage of fermentation. The preset phytochemicals got reduced in intensity as fermentation advanced. From these results, it can therefore be concluded that fermentation helps to improve the taste quality and phytochemical properties of Nigerian cocoa beans.

Microbial Load of Domestic Water Sources Treated with Moringa oleifera and Jatropha curcas Seed Powder

2020-09-18T07:24:43+00:00

Aim: Microbial load of domestic water sources treated with Moringa oleifera and Jatropha curcas seed powder.

Study Design: The container test method was used for the treatments. One gram (1.0 g) each of the plant seed (Moringa oleifera and Jatropha curcas seeds) powder was weighed and added separately into 1000 ml of water sample. The mixture was stirred rapidly for 3 minutes and allowed to stand undisturbed for 1 hour and 3 hours, after which the top water was decanted.

Place and Duration of Study: Advanced Research Laboratory, Department of Microbiology, Gregory University Uturu, from May to September 2017.

Methodology: Tenfold serial dilutions were used for processing of the domestic water samples, after which 0.5 ml of the water sample was cultured on the media using the spread plate method. This was incubated appropriately and other standard microbiological methods were employed to determine microbial loads and characterize the isolates.

Results: The microbial counts were generally high, 0.6×10¹– 2.5×10²cfu/ml (borehole), 0.8×10¹– 6.3×10³cfu/ml (well), 2.0×10¹– 1.4×10⁴cfu/ml (stream), while the total potential pathogenic bacteria counts (TPPBC) were the least in occurrence. Treatment with Moringa oleifera and Jatropha curcas seed powders showed a significant decrease in the microbial load. After treatment with 1.0g of the seed powder for one hour, an apparent decrease in the microbial load was noticed. When allowed for three hours (3 hrs), the counts further reduced to no growth for potential pathogenic bacteria (TPPBC) especially for water samples that had low counts.

Conclusion: Moringa and Jatropha seeds powder showed efficiency as a biocoagulant and thus can be used for water treatment. Moringa seed powder had a greater potential to serve as an alternative coagulant for water treatment. The intervention improved the quality of water and will provide significant benefits to the health of the consumer rural populace.

Antimicrobial Activities of Moringa, Neem and Ginger Plant Extracts against Bacteria Associated with the Spoilage of Fruit Juice

2020-09-18T07:24:41+00:00

Aim: This study aims to evaluate the antibacterial activity of Moringa, Neem, and Ginger plant extracts on the bacteria species isolated from fruit juice samples.

Place and Duration of Study: Department of Microbiology, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria, between October 2019 and November 2019.

Methods: The fruit juice sample was prepared and cultured on Mannitol Salt Agar (MSA), Eosin Methylene Blue (EMB), Salmonella Shigella Agar (SSA), and Blood Agar using streak plate techniques. Four (4) bacteria species were isolated and identified from the fruit juice sample. These organisms served as the test isolates. Two (2) solvents (methanol and water) were used to get a comparative result. Disc diffusion method was used to determine the antibacterial effects of the Moringa, Neem, and Ginger on the test organisms.

Results: The methanolic extract of Moringa, Neem and Ginger was found to exhibit high degrees of antibacterial activities against the test isolates. This was shown by the clear zones of inhibition produced by the methanolic extract on the test microorganisms. The highest in-vitro antibacterial activity is 16 mm, which was exhibited by the methanolic extract of Moringa at the highest concentration of 200 mg/ml against Staphylococcus aureus. In comparison, the Methanolic extract exhibited no antibacterial activity (0.0 mm) at the lowest concentration of 50 mg/ml against all the test organisms. The minimum bactericidal concentration from this study revealed that methanolic and aqueous extract was active against Staphylococcus aureus, Shigella species, Bacillus species, and Escherichia coli. However, the water extract of Moringa demonstrated more significant antibacterial activity on Shigella species, Bacillus species, and Escherichia coli with the range of 200 mg/ml each. In contrast, methanol extract of neem demonstrated antibacterial activity on Shigella species alone, with the range of 200 mg/ml each.

Conclusion: Moringa, Neem, and Ginger extract had both a bacteriostatic and bactericidal activity when tested in vitro using methanolic and aqueous preparation of Moringa, Neem, and Ginger extract. Therefore, these plants may be used successfully for treating illness caused by Staphylococcus aureus.

Monitoring the Presence of Bacteria, Fungi and Parasitic Pathogens Associated with Swimming Pools in Port Harcourt Metropolis

2020-09-19T02:14:46+00:00

Aims: Ideal water for swimming should meet the portable water standard by being transparent, odorless, and tasteless. However, these qualities can be affected by the presence of infectious agents which directly or indirectly contaminate pool water. This study aims at monitoring the microorganisms (bacteria, fungi and protozoa parasites) and pH associated with swimming pool water.

Study Design: A random sampling technique was adopted to select the five (5) swimming pools for the study based on accessibility and visitation.

Place and Duration of Study: The study was carried out in Port Harcourt Metropolis, Port Harcourt Local Government Area, Rivers State between March 2016 to August 2017.

Methodology: Five (5) outdoor swimming pools attached to hotels in Port Harcourt Metropolis, Port Harcourt Local Government Area of Rivers State, Nigeria were randomly selected for the study. Water samples were aseptically collected in duplicates and analyzed for total heterotrophic bacterial count, total heterotrophic fungal count, protozoa and pH using appropriate techniques.

Results: The results show that swimming pools with sodium thiosulphate pentahydrate had a mean THBC range from 4x10¹cfu/ml - 1.58x10³ cfu/ml, mean THFC, 0 cfu/ml - 8x10¹ cfu/ml and mean pH, 5.9-6.4; for samples without sodium thiosulphate pentahydrate, the mean THBC ranged from 0 cfu/ml - 9.2x10¹ cfu/ml, mean THF, 0 cfu/ml - 8x10¹ cfu/ml and mean pH, 5.6-6-2. Protozoa (parasites) were absent in all water samples analyzed. The results further reveals that 95.9% and 100% of the swimming pools samples failed to the meet the <100 cfu/ml and 7.0 – 7.8 World Health Organisation Standards for THBC and pH respectively. The bacteria identified are Bacillus spp., Escherichia coli, Stapylococcus aureus while the fungi identified are Aspergillus spp., Rhizopus spp. and Penicillium spp.

Conclusion: The study finds the levels of THBC in the samples with sodium thiosulphate pentahydrate, the presence of Escherichia coli and the pH range a threat to health of bathers. Therefore, the owners should ensure routine decontamination and assessment of water quality.