Open Access Original Research Article

Phytochemical Analysis and Antibacterial Efficacy of Mentha piperita (L) Ethanolic Leaf Extract against Clinical Isolates of Uropathogens

Sowjanya Pulipati, O. Sai Koushik, P. Srinivasa Babu

Microbiology Research Journal International, Page 1-5
DOI: 10.9734/BMRJ/2016/24031

Aim: The present study was designed to evaluate the antibacterial activity of Mentha piperita (L) leaf extract against clinical isolates of urinary tract infections.

Introduction: M. piperita L. (Peppermint) is a strongly scented herb belonging to family Lamiaceae. The plant is stimulant, aromatic and used for headache, vomiting and allaying nausea. In India the leaves are used to relieve sore throat. The most common form of bacterial infections is urinary tract infections (UTIs). They affect people of all age groups throughout their lifespan.

Methodology: The M. piperita ethanolic extract (MPEE) was prepared by cold maceration. The presence of phytoconstituents was determined using standard protocols. Clinical isolates of UTI pathogens such as Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were isolated from urine samples and identified by biochemical tests. The antibacterial property was determined by agar well diffusion method.

Results and Discussion: The preliminary phytochemical screening revealed the presence of amino acids, carbohydrates, alkaloids, proteins, glycosides, steroids, tannins and flavonoids. MPEE exhibited pronounced antibacterial activity against tested microorganisms. The extract exhibited antibacterial activity at 1000 µg concentration against S. aureus (21.50±1.22 mm), E. coli (19.33±0.81 mm), P. aeruginosa (15.33±1.69 mm) from high to low respectively. The minimum inhibitory concentration was ranged from 62.5 to 125 mg/ml.

Conclusion: The results of antibacterial studies confirm that MPEE was found to contain bioactive constituents that exhibited notable antibacterial activity. However, further isolation and characterization of phytoconstituents will be needed to evaluate the antimicrobial activities against a wider range of microbial pathogens.

Open Access Original Research Article

Bioavailability and Toxicity of Plastic Contaminants to Soil and Soil Bacteria

E. I. Atuanya, U. Udochukwu, A. O. Dave-Omoregie

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/BMRJ/2016/25128

Aim: The bioavailability and toxicity of plastic contaminants to soil and soil bacteria was investigated to detect the presence of plastic contaminants in the soil and to evaluate the toxic effects of plastic contaminants to soil and soil bacteria. 

Methodology: Five plastic composted soil samples were collected from different locations within the Edo State Waste Management site located at Iyowa in Benin City which were merged together to form a composite sample. The physico-chemical characteristics of the soil samples were analysed. The soil was analysed for the presence of plastic components using the Perkin Elmer Gas Chromatograph model Auto-system XL. Nitrobacter acute toxicity test was carried out. The median effective concentrations (EC50) and the median lethal concentration (LC50) values were calculated using the probit analysis.   

Results: The gas chromatography revealed that the control soil sample had zero concentration for chlorobenzene, dichlorobenzene, and benzene. The physico-chemical analysis for the plastic composted soil and the control soil had electrical conductivity  245.00, 61.00 us/cm, chloride 66.15, 16.00 mg/kg, potassium 171.50, 4.27 mg/kg, nickel  1.00, 0.25 mg/kg,  vanadium 0.44, 0.23 mg/kg, and moisture 5.32, 7.21% and  total organic carbon 5.26, 71.0.% respectively. The bacteriological analysis for the plastic composted soil and the control soil had growth ranging from 1.0x 101±0.16 to 4.0 x 102±0.11 cfu/g and 2.0 x 103±0.20 to 11.0 x 103±0.86 cfu/g respectively. The average turbidity result showed a normal bacteria growth curve when plotted for the control soil. There was significant difference (P<0.05) in the bacterial counts from the control soil sample. The toxicity analysis revealed higher percentage utilization of nitrite with EC50 values of 52.00, 81.72, 111.31 and 123.13 and higher bacteria inhibition with LC50 values of 25.04, 23. 93, 15.94 and 13.39.

Conclusion: The result obtained from this study suggest that autotrophic transformation by nitrifying bacteria which enhances soil fertility may be hindered in an ecosystem polluted with these plastics as nitrification process will be reduced.

Open Access Original Research Article

Molecular Identification and Characterization of Heavy Metal Resistant Bacteria and Their Role in Bioremediation of Chromium

Nusrat Jahan, Muhammad Idrees, Muhammad Tariq Zahid, Nazish Mazhar Ali, Mudassar Hussain

Microbiology Research Journal International, Page 1-11
DOI: 10.9734/BMRJ/2016/22909

In this study two bacterial strains Bacillus thuringiensis (Cr-S1) and Bacillus pumilus (Cr-S2) were isolated on Cr+6 enriched nutrient agar plates at the concentration of 100 µg/ml. Minimum inhibitory concentration of chromium for Cr-S1 was 500 µg/ml while for Cr-S2 was 400 µg/ml. Maximum growth of Cr-S1 and Cr-S2 was noticed at 37ºC and at 8.0 and 7.0 pH, respectively. After careful phenotypic and biochemical characterization, confirmation was done by 16S rRNA gene amplification and sequencing. Partial sequencing results of 16S rDNA of Cr-S1 showed 97% homology with Bacillus thuringiensis while Cr-S2 showed 99% homology with Bacillus pumilus. Both the bacterial strains, B. thuringiensis (Cr-S1) and B. pumilus (Cr-S2) were assessed for their bioremediation potential in culture medium containing 100µg/ml of chromium  showed 87.04% and 90.1% Cr+6 uptake at 37ºC within 24 hours. This research suggests use of B. thuringiensis and B. pumilus to remove elevated levels of, not only, chromium but also other heavy metals from polluted waters from industry.

Open Access Original Research Article

Isolation and Screening of Microorganisms Associated with Locust Bean (IRU) for the Ability to Ferment Soya Bean to Produce Soy Iru

F. Titilayo Afolabi, M. Abdulkadir, A. Abiodun Onilude

Microbiology Research Journal International, Page 1-10
DOI: 10.9734/BMRJ/2016/24593

Aims: This study was conducted to isolate, identify and screen microorganisms associated with soy iru for the ability to be used as starter in the fermentation of soya bean (Glycine max) to produce soy iru.

Study Design: To control the fermentation of soya bean (Glycine max) to produce soya iru using functional starter culture in order to improve the quality of the product.

Place and Duration of Study: Soybeans (Glycine max) samples were collected from markets in Ibadan, in Oyo State Nigeria. Analyses of the samples were conducted in the Department of Microbiology, University of Ibadan and Central Multidisciplinary Research Laboratory in the University of Ibadan, Nigeria. The sampling and analyses were done between August 2014 to January 2015.

Methodology: Soybean (Glycine max) seeds were purchased from markets, in Ibadan, Oyo State, Nigeria. Spontaneously fermented locust bean iru samples were also purchased from iru seller from markets, Ibadan, Oyo State and they were analysed using Nutrient agar, DeMann Rogosa and Sharpe medium (MRS), MacConkey Agar and Malt Extract Agar and isolates were also screened for enzymatic activity. The antibacterial activity of LAB metabolites against some indicator organisms was also determined;

Results: A total of thirty eight (38) strains of bacteria were isolated, seven (7) isolates from locust bean iru (LBI) and thirty one (31) isolates from soya bean iru (SBI). Bacillus subtilis SBI 13 and Leuconostoc mesenteroides SBI 15 produced the three enzymes and the highest protease activity was produced by Bacillus subtilis SBI 13. All the isolated LAB produced antimicrobial compounds; lactic acid, diacetyl and hydrogen peroxides with Leuconostoc mesenteroides SBI 15 producing the highest quantity of diacetyl (0.91 g/l) and hydrogen peroxide (1.10 g/l) while the highest quantity of lactic acid (1.61 g/l) was produced by Lactobacillus plantarum. Bacillus subtilis SBI 13 and Leuconostoc mesenteroides SBI 15 were chosen as starter cultures for further study.

Conclusion: Bacillus subtilis and Leuconostoc mesenteroides exhibit the best potentials of a good starter so they can be used as starter culture in the fermentation of soya beans to produce Soy Iru.

Open Access Original Research Article

Bacteria Associated with Selected Rivers in Akure, Nigeria and their Alkysulphatase Activity/Production

D. J. Arotupin, A. Yusuf

Microbiology Research Journal International, Page 1-7
DOI: 10.9734/BMRJ/2016/23198

Aims: To isolate, characterize and identify surfactant degrading bacteria from selected rivers in Akure, Nigeria and also to compare and quantify the biodegrading potentials of each of the bacterial isolates.                                     

Place and Duration of Study: Akure metropolis, Ondo state, Nigeria, between June and November, 2013.

Methodology: Surfactant degrading bacteria were isolated from the water samples by supplementing culture media with test surfactant. The bacteria isolated were later subjected to the alkylsulphatase enzyme assay to quantify their various enzyme production/activity.

Results: The total bacterial load of the water samples range from 7.20±0.69 x103 cfu/ml to 40.0±2.31 x103 cfu/ml, while the surfactant degrading bacteria counts was within the range of 3.30±0.02 x102 cfu/ml to 5.37±2.3 x103cfu/ml. Pseudomonas putida and Exiguobacterium profundum were able to produce more of the alkylsulphatase enzyme amongst the isolated surfactant degrading bacteria.

Conclusion: It can be concluded that the set of bacteria isolated from the selected aquatic environments are capable of carrying out biodegradation of surfactants and that they are abundant in the selected environments. Pseudomonas putida and Exiguobacterium profundum have higher biodegrading potentials and they can be exploited in the bioremediation of water bodies polluted with surfactants.

Open Access Review Article

Leptospirosis; Diagnosis, Treatment and Prevention: A Review

Ozgur Aslan

Microbiology Research Journal International, Page 1-5
DOI: 10.9734/BMRJ/2016/24924

Leptospirosis is one of the most common and zoonotic infections on earth, induced by Leptospira genus spirochetes. Although leptospirosis is defined as a zoonotic infection induced by Leptospira interrogans serotypes and characterized by jaundice, high fever and hemoglobinuria, it exhibits a complex clinical picture and difficult to diagnose only with clinical pictures. It could be confused with diseases such as meningitis, typhoid fever, brucella, tuberculosis and pneumonia. Definitive diagnosis of leptospirosis is established by the isolation of microorganism in clinical samples accompanied with clinical symptoms, determination of seroconversion or observation of a four-fold or more increase in antibody titer.