Open Access Original Research Article

Occurrence and Diversity of Soil Microflora in Potato Fields of Bangladesh

M. A. Nitu, M. Rahaman, F. M. Aminuzzaman, N. Sultana

Journal of Advances in Microbiology, Page 1-15
DOI: 10.9734/jamb/2020/v20i930277

Microflora from potato rhizosphere soil was isolated from different potato fields of Bangladesh. Seventeen soil samples were analyzed for the presence of microflora in selected potato field soils. Seven fungal species and one bacterium species were morphologically characterized using soil dilution and streak plate methods. The predominant fungi isolated including Alternaria sp., Aspergillus sp., Penicillium sp., Rhizopus sp., Bipolaris sp., Phytophthora sp., Fusarium sp. and one bacterium was identified as Ralstonia solanacearum. Individual colonies of fungi and bacteria were counted on Potato Dextrose Agar (PDA), V8 juice Agar and their presence in soil was compared in respect of different locations of potato fields. The occurrence of Phytophthora sp. was medium in Tongibari and lower in Singair Union, Sonargaon, Matlab Dakshin, Gobindaganj, Palashbari, Gopinathpur and Bagmara. The highest counts of R. solanacearum were found in Singair Union, Tongibari and Daudkandi and the lowest counts were made in Palashbari and Bagmara. This was the first reported examination of the microbial diversity of soil microflora in some selected potato fields of Bangladesh.

Open Access Original Research Article

Microbiological Analysis and Identification of Pathogenic Microorganisms on Currency Notes (Congolese Francs) in Kinshasa, Democratic Republic of the Congo

Jeff Bekomo Iteku, Donel Moswala Likabo, Aaron Lelo Pambu, Gédéon Ngiala Bongo, Ruth Katunda, Octavie Metila Lunguya, Joseph Kasali Lumande

Journal of Advances in Microbiology, Page 16-30
DOI: 10.9734/jamb/2020/v20i930278

Aims: The incidence of infectious diseases is still a vital concern in developing countries. Recently, hygienists have focused on the risk of transmitted diseases through currency notes. This study aims at the determination of potential pathogenic microorganisms found on the Congolese Francs currency notes circulating in Kinshasa, Democratic Republic of the Congo.

Place and Duration of the Study: This study was carried out in Kinshasa city, in the Democratic Republic of the Congo between September 3 and 29, 2019 at the Bacteriology Laboratory of the National Institute for Biomedical Research.

Methods: During this study, 36 currency notes of different denominations have been used for microbiological analysis. Currency notes were collected from vendors of the Central market and currency note dealers at Kintambo Magasin market in Kinshasa. The identification of microorganisms (bacteria and fungi) was performed using gram staining and biochemical analyses. Results: The findings reveal the presence of following microorganisms, namely Bacillus spp, Staphylococcus aureus, Staphylococcus spp., Enterobacter spp, Escherichia coli, Serratia spp, Citrobacter spp, Salmonella enteritidis as well as molds on the Congolese currency notes. It should be observed that circulated currency notes in Kinshasa are contaminated by bacteria and fungi. The contamination rate was based on the fact, that money is new, clean or dirty.

Conclusion: Congolese currency notes constitute the potential sources of infectious disease transmission if hygienic conditions are not respected. Molecular studies are required in order to determine the antibiotic resistance gene of these microorganisms. As the population does not know how to store these notes properly, their contamination would eventually become a major public health hazard. Therefore, a need of an awareness of the population in order to apply hygienic rules while handling currency notes. This is for the first time that such a study is being carried out in the Democratic Republic of the Congo.

Open Access Original Research Article

Production and Characterization of Polyhydroxyalkanoates from Lactic Acid Bacteria Isolated from Dairy Wastewater, Fermented Cow Milk and ‘Ogi’

Wakil Sherifah Monilola, Oluwatobi Esther Makinde

Journal of Advances in Microbiology, Page 31-46
DOI: 10.9734/jamb/2020/v20i930279

Aims: This study aimed at screening, producing and characterizing polyhydroxyalkanoates (PHA) from lactic acid bacteria (LAB) isolated from dairy wastewater, fermented cow milk and “ogi”.

Place and Duration of Study: Department of Microbiology, Faculty of Science, University of Ibadan, Ibadan between August 2018 and February 2019.

Methodology: The initial screening of isolated LAB was carried out by Sudan Black staining method followed by secondary screening on liquid medium. Isolates that tested positive for Sudan Black stain and had the highest PHA yield from liquid medium was used for further analysis. The cell walls of selected isolates were lysed with sodium hypochlorite and PHA extracted using chloroform. Optimization of PHA production was carried out using different carbon and nitrogen sources, incubation temperature, pH and agitation speed. Extracted PHA was characterized by FTIR spectroscopy and the microstructure and surface morphology were observed using Scanning Electron Microscope.

Results: Seven isolates tested positive for Sudan Black stain of which two isolates identified as Lactobacillus plantarum CW10 and Lactobacillus casei WWD3 had the highest PHA yield from liquid medium. From the optimization experiment, highest PHA production was observed in Lactobacillus plantarum CW10 (20.5%) and Lactobacillus casei WWD3 (19.7%) when glucose and ammonium sulphate was used as carbon and nitrogen sources respectively, and at pH 6, agitation speed of 200 rpm and incubation temperature of 35oC and 40oC. The spectra of extracted PHA as characterized by FTIR showed absorption peaks for the carbonyl, C-H, -OH, aliphatic -CH3 and ester groups that are characteristics of PHA. The microstructure and surface morphology shows grains that are pseudo-spherical in shape with fairly regular distribution.

Conclusion: There is an appreciable production of PHA from the Lactobacillus strains and can be considered as part of the choice of organisms for PHA production in commercial quantity.

Open Access Original Research Article

Production, Preservation and Shelf-Life Evaluation of Wine from Banana Fruit (Musa acuminata Colla)

O. P. Obiekezie, B. J. O. Efiuvwevwere, O. C. Eruteya

Journal of Advances in Microbiology, Page 47-61
DOI: 10.9734/jamb/2020/v20i930280

Aims: The investigation focused on production, preservation and shelf-life study of wine from banana fruit (Musa acuminata).

Study Design: This work is based on completely randomized design with two replications and the average values calculated for mean comparison.

Place and Duration of Study: Food and Industrial Microbiology laboratory, Department of Microbiology, University of Port Harcourt, Nigeria, September, 2018 to March, 2019.

Methodology: Analyses performed using standard methods were microbiological, physicochemical and sensory evaluations. Sodium benzoate concentrations of 5 and 25 ppm were used for shelf life studies. Banana ‘must’ was analyzed at 4 day intervals for 12 days while produced wine was analyzed at 5 day intervals for 25 days during storage.

Results: Changes in total heterotrophic counts (THCs), total coliform counts (TCCs) and fungal counts (FCs) occurred during fermentation, resulting in maximum THCs of 5.02, TCCs of 3.60 and FCs of 8.87 log10 cfu ml-1 on days 4, 4 and 8 respectively. Acetobacter and Saccharomyces were pronounced in wine without preservative (control) throughout storage. Mean pH of ‘must’ was 5.8±0.30 while alcohol content was 0.28±0.03% on day 0 but as fermentation progressed, mean pH was reduced while mean alcohol content increased. Mean pH of wine preserved with 5 ppm varied slightly throughout storage but mean pH of control and 25 ppm preserved wine decreased from 3.7±0.20 on day 0 to 3.2±0.23 on day 25. Sensory attributes (overall acceptability) on day 12 was most preferred while during shelf-life studies, significant difference in overall acceptability of the different wines at P=.05 occurred. Wine preserved with 5 ppm had the best organoleptic quality but 25 ppm preserved wine showed the most acceptable microbial quality.

Conclusion: Findings show that banana is a good substrate for wine production and 5 ppm sodium benzoate retained the qualities of the wine.

Open Access Original Research Article

Antifungal Resistance Pattern of Candida Species Isolated from High Vaginal Swabs of Women Attending a Hospital in Enugu State, Nigeria

Joachim Ohiakwu Ezeadila, Ikechukwu Okoli, Christie Amaechi Oyeka

Journal of Advances in Microbiology, Page 62-72
DOI: 10.9734/jamb/2020/v20i930281

There is an increase in non-albicans Candida (NAC) vulvovaginal candidiasis which is attributed to overuse of antifungal therapy and this has led to antifungal resistance. This study was aimed at determining the antifungal resistance pattern of some clinical isolates of Candida species. Eighty-eight (88) isolates were used which included Candida tropicalis (34), Candida Parapsilosis (21), Candida albicans (20), Candida krusei (7) and Candida glabrata (6). The drugs used were Fluconazole (25µg), Ketoconazole (10µg), Voriconazole (1µg), Nystatin (100Units), Amphotericin B (20µg), Flucytosine (1µg), Clotrimazole (10µg) and Itraconazole (50µg). The susceptibility testing was carried out using the M44-A standard method for yeast disk diffusion testing. Results showed that the percentages of Candida species resistant to Fluconazole, Ketoconazole, Voriconazole, Amphotericin B, Flucytosine, Clotrimazole and Itraconazole and Nystatin were 52.3%, 61.9%, 35.2%, 19.3%, 86.4%, 34.1%,  45.5% and 44.3%,  with inhibition zone diameters ≤14mm, ≤20mm, ≤13mm, <10mm, ≤11mm, ≤11mm, ≤13mm and no inhibition zone diameter respectively. Candida krusei was the most resistant species with 100% resistance to each of Fluconazole, Ketoconazole and Flucytosine. Candida tropicalis was the species with the highest susceptibility (79.4%) to Amphotericin B followed by Candida parapsilosis with inhibition zone diameters ≥15mm. While Candida glabrata showed 100% resistance to each of Flucytosine and Itraconazole, Candida albicans showed 100% resistance to Flucytosine only. Candida glabrata was the only Candida species with 0% resistance to Amphotericin B. The drug to which most of the Candida species were susceptible was Amphotericin B followed by Voriconazole while Flucytosine was the drug with the highest resistance followed by Ketoconazole and Fluconazole. The highest number of susceptible-dose dependent Candida isolates was observed with Ketoconazole (25%), followed by Clotrimazole and Itraconazole, each recording 23.9%. Based on the findings of the present study, Voriconazole is recommended for vaginal candidiasis especially in the study area and also especially for infections caused by Fluconazole-resistant Candida species. This suggests that routine sensitivity testing is pertinent to guiding the choice of antifungal therapy. Thus, indiscriminate use of antifungal drugs should be avoided to reduce the development and spread of resistance.

Open Access Original Research Article

Predicting the Toxicities of Ternary Mixtures of two Metals and Sodium Dodecyl Sulfate to Serratia marcescens (SerEW01) from Otamiri River Water

Reuben N. Okechi, Edna I. Chukwura, Christian O. Nweke

Journal of Advances in Microbiology, Page 73-86
DOI: 10.9734/jamb/2020/v20i930282

Background: Otamiri river server as a source of water for domestic activities, urban farming, recreation, aquatic foods in Owerri and environs. It also receives untreated domestic, industrial and agricultural waste water and run offs from the municipality. Seepages from solid wastes dumps at the river banks and sand mining activity going on in the river could also constitute environmental hazards

Aims: This study aims at evaluating the interactive effects of the ternary mixtures of sodium dodecyl sulfate (SDS) and some divalent metals on preponderant bacterium (Serratia marcescens (SerEW01)) from the river.

Study Design: Fixed ratio ray design was used for the study, with inhibition of dehydrogenase activity as end point.

Place and Duration of Study:    Owerri, Imo State, Nigeria, June – December, 2019.

Methodology: The bacterium was earlier isolated as the preponderant bacterium isolate from the river water. Fixed ratio ternary mixtures (Equieffect concentration (EEC50) and arbitrary concentration (ABCR) ratios), SDS + Pb + Zn, SDS + Cd +Zn, SDS + Pb +Ni, SDS + Ni + Cd, SDS + Co + Pb and SDS + Co + Cd were designed to evaluate the combined toxicities of these toxicants. Toxicities predicted by concentration addition (CA) and independent action (IA) models were compared with the experimentally observed toxicities.

Results: The EC50S observed ranged from 0.046 ± 0.003 mM (Zn) to 2.329 ± 0.092 mM (SDS). The EC50S of the toxicants were statistically different from each other (P<0.05). The order of increasing toxicities were SDS >Pb >Ni > Co > Cd(II) >Zn. Concentration-dependent toxicities with progressive inhibition of the dehydrogenase activity as the concentration increased were observed.. In all ternary mixtures, both the experimentally derived, CA and IA-predicted EC50S were statistically different from each other. Both models predicted lower toxicities compared to the experimental data. The Toxic Index and Model Deviation Ratio indicated synergistic interaction of SDS and metal ions against S. marcescens (SerEW01)

Conclusion: This study could constitute base line information towards assessing the possible environmental hazards associated with co-contamination of the environment by SDS and divalent heavy metals, more so when both pollutants are common aquatic pollutants.

Open Access Original Research Article

Investigation on Microbiological, Organoleptic and Shelf Life Characteristics of Wheat-cassava Bread

C. L. Okoli, B. J. O. Efiuvwevwere, O. C. Eruteya

Journal of Advances in Microbiology, Page 87-106
DOI: 10.9734/jamb/2020/v20i930283

Aim: Microbiology, sensory and shelf life evaluation of wheat-cassava bread from raw materials to finished products.

Study Design: Completely randomized design with two replications and average values calculated for mean comparison.

Place and Duration of Study: Food/Industrial Laboratory, Department of Microbiology, University of Port Harcourt, Nigeria and Department of Medical Laboratory Science, Niger Delta University, Nigeria, from June 2018 to March, 2019.

Methodology: Microbiological, proximate, physicochemical, sensory and shelf-life characteristics of wheat-cassava bread produced using different formulations (90:10; 80:20; 70:30; 60:40) and control 100% wheat-bread were investigated during storage at 32±2°C, using standard methods. Bread were baked at 180°C and 200°C. Two independent determinations were analyzed using ANOVA and significance of the mean differences determined at P=.05.

Results: Mean total heterotrophic counts (THC) of raw flour samples increased from 5.41 to 7.62 log10 cfu g-1; total coliform from, 1.08 to 1.90 log10 cfu g-1; and total fungal counts from 2.46 to 4.88 log10 cfu g-1 with increasing cassava flour substitution. Mean values for THC and total fungal counts of baked bread samples increased from 1.88 to 7.73 log10 cfu g-1 and 0.48 to 4.05 log10 cfu g-1 respectively from day 0 to day 6. However, coliforms were not detected in baked bread. The predominantly isolated bacteria were: Bacillus, Aerococcus and Staphylococcus while fungi were: Aspergillus, Penicillium and Fusarium. Proximate composition showed that carbohydrate and ash contents increased from 46.07 to 55.29% and 1.35 to 3.79% respectively while crude protein and moisture contents decreased from 14.01 to 8.08% and 29.0 to 23.8% respectively and pH from 6.59 to 6.14 with increasing cassava flour substitution.

Conclusion: The overall acceptability of the wheat/cassava bread reduced with increasing cassava flour concentration, however, there was no significant difference (P=.05) in the overall acceptability of the 100% wheat bread and that of 90:10% till day four.

Open Access Original Research Article

Microbial Diversity of Acetic Acid Producing Bacteria from Protein-Rich Residues

G. C. Onyenegecha, F. S. Ire, O. K. Agwa

Journal of Advances in Microbiology, Page 107-120
DOI: 10.9734/jamb/2020/v20i930284

Background: Acetic acid bacteria (AAB) are concrete sets of organism which act as precursor for acetic acid production. Acetic acid is a colorless liquid with strong pungent and sour smell. It is synthesized from oxidation of ethanol by AAB. Vast studies have been made from sugary sources in the isolation of AAB.

Aim: The needs to study and utilize our protein-rich residues (PRR) for AAB presence spurn this study.

Place and Duration of Study: Department of Microbiology, University of Port Harcourt, between June and December 2018.

Methodology: The samples (beans, groundnut and powdered milk) used in this study were surface-sterilized, homogenized, pre-enriched (in balsam medium) and serially diluted with inoculum size (0.1ml) inoculated on sterilized glucose yeast peptone agar, Mannitol agar and low glycemic index (LGI) media and incubated at 30oC for 48 h using the spread plate technique. A total of 11 bacterial isolates were obtained and screened for acetic acid production in brain heart infusion and yeast glucose ethanol acetic acid broth at 30oC for 14 days and positive isolates were identified by titration method. AAB isolates with the highest acetic acid concentration were selected for molecular identification and further studies.

Results: Two Acetic acid bacteria identified in this study were Acetobacter and Gluconobacter. The result of this study indicated that Acetobacter had acetic acid concentration of 3.6g/100ml while Gluconobacter had 1.8g/100 ml. However, molecular identification highlighted Acetobacter as Bacillus cereus with Genbank accession number MK 332142; whereas Gluconobacter was Stenotrophomonas maltophilia MK 332143. The neighbor-joining phylogenetic tree and bioinformatics revealed B. cereus and S. maltophilia as 97% and 96% similarity index, 854 and 883 nucleotide sequencing letters as well as 450 and 410 base pairs.

Conclusion: This finding implied that S. maltophilia” and “B. cereus” are predominant Acetic acid bacteria in spoilt beans and groundnut; and can act as potential strains with industrial importance to man and environment.

Open Access Original Research Article

Evaluation of Nutritional, Microbial and Sensory Attributes of Rice Tuwo Flour Fortified with Soy and Plantain Flour Blends

Noah Abimbola. A, Omoyeni Serah. E

Journal of Advances in Microbiology, Page 121-129
DOI: 10.9734/jamb/2020/v20i930303

Aims: The aim of the work is to investigate the effect of soybean and Plantain flour fortification on the nutritional, microbial and sensory qualities of rice flour paste (Tuwo) fortified with soy and plantain flour blends.

Methodology: White rice was cleansed, sorted and soaked in water for 12hrs and dried at 60OC for 12hrs.  White rice was fortified with soybean and plantain flour at 10, 15, 20, 25% respectively while 100% white rice flour serve as the control. Nutrient, microbial and sensory qualities of the samples were determined using standard methods.

Results: There were significant differences (p≤.05) and increase in values of all the nutritional properties with increase in substitution of soy-plantain flour. The protein content ranges from (2.19 – 21.46%), Fat content (1.67 – 18.51%), Fiber (0.68 – 6.78%), Ash content (1.37 - 2.26%), Moisture content (10.16 – 12.47%) of the blends respectively, while the carbohydrate contents of the blends was significantly lower to that of the control sample. The mineral content increased where the abundant mineral was potassium (29.22 – 45.57 mg/100g) and zinc (2.66 – 3.34 mg/100g) been the least mineral element. The microbial analysis shows a lower microbial counts of prepared tuwo samples, which makes it safe for consumption. Mean total viable count range from 1.10 to 3.50 x102 cfu/g, Staphylococcus count range from 0.00 to 1.03 x102 cfu/g. fungi count range from 0.00 to 0.60  102 cfu/g with no growh of salmonella from all the samples respectively. The sensory evaluation result shows that the sample from whole rice was highly rated but sample B with 80% rice flour, 10% soy flour and 10% plantain flour has the highest preference in terms of taste, colour, aroma, texture, smoothness and overall acceptability.

Conclusion: This fortification highly improve its nutrient contents and slightly improves microbial and organoleptic properties of rice tuwo, which can serve as alternative protein supplement.