Open Access Original Research Article

Effect of Micronutrients and Macronutrients on the Biodegradation of Phenol in Biological Treatment of Refinery Effluent

I. V. Agu, A. A. Ibiene, G. C. Okpokwasili

Microbiology Research Journal International, Page 1-12
DOI: 10.9734/MRJI/2017/30235

Background/Aim: Regulatory agencies in Nigeria and all over the world demand that refinery wastewater (RWW) meet stipulated regulatory limits before discharge into the environment. Biodegradation of toxic hydrocarbon constituents of these effluents, such as phenol, has remained a challenge with regards to compliance with regulatory requirements. This study investigated the effect of micronutrients and macronutrients on the biodegradation of phenol in RWW.

Methods: The micronutrients used in the study were CoSO4, MnSO­4, ZnSO4 and CuSO4 while the macronutrients comprised urea and NPK. Range-finding and optimum concentration tests were performed for each of the nutrients. The experiment was carried out in a 3L Erlenmeyer’s flask incubated in a rotary shaker under experimentally determined optimum cultural conditions, using a fractional factorial design. Phenol concentration (mg/ml) was monitored daily throughout the experiment using spectrophotometric method.

Results: The result obtained from the study revealed that a combination of CoSO4, MnSO­4 and NPK was most efficient in enhancing the degradation of phenol in the RWW. After three days of incubation, phenol concentration of 141.99 mg/ml was reduced to 0.1 mg/ml. This value is lower than the phenol concentration of 0.5 mg/ml recommended for discharge of RWW into the environment. The degradation model derived from the study can be represented with the equation, y = 8.4998e-2.302x and R² = 0.961. 

Conclusion: This study has revealed that the combination of CoSO4, MnSO­4 and NPK can efficiently enhance phenol degradation in RWW for effectual compliance with the regulatory discharge limit.

Open Access Original Research Article

Epidemiological Pattern of Non-fermenting Metallo Beta Lactamase Producing Bacterial Pathogens Isolated from Clinical Specimens in a Tertiary Care Hospital in Kakinada, India

Purimitla Usha Rani, Payala Vijayalakshmi

Microbiology Research Journal International, Page 1-10
DOI: 10.9734/MRJI/2017/30592

Background: Non-fermentative Gram negative bacilli are known causative pathogens responsible for hospital associated infection and responsible high morbidity and mortality rate across all genders and ages.

Objectives: This study examined the prevalence of Non-fermentative Gram negative isolates expressing Metallo beta-lactamase isolates (NFGNB-MBL) among carbapenem-resistant isolated from clinical specimens and the epidemiological pattern (Age, Sex and Source of infection).

Methodology: A total of 250 clinical specimens from diverse infections were collected and analyzed, using standard microbiological methods. For MBL detection, two previously described methods were employed i.e. Imipenem-EDTA combined disc test and Imipenem-EDTA double disc synergy test (DDST).

Results: Sixty (24%) NFGNB isolates were identified; highest of isolation was recovered from hospital associated infections (93.33%). Pseudomonas aeruginosa accounted for n=40 (66.67%) followed by Acinetobacter baumannii n=10 (16.67%), Alcaligenes faecalis n=6 (10%) and Stenotrophomonas maltophilia n=4 (6.66%) respectively. The isolates showed high sensitivity to imipenem and least sensitivity to Gentamicin. All the carbapenem resistant isolates of non-fermenters showed Metallo-beta lactamase production.

Conclusion: The prevalence of MBL producing isolates and association with hospital infection is of clinical concern and the therapeutic option in treatment and management of patients may be futhered worsen.

Open Access Original Research Article

Blood Stream Infections in Children with Malignancies: A Single Center Experience Risk Factors, Microbiological Isolates and Sensitivity Pattern

Wesam Hatem Amer, Shaymaa Mohamad Elrifaey, Radwa Mahmoud El Sharaby

Microbiology Research Journal International, Page 1-12
DOI: 10.9734/MRJI/2017/30595

Aim: To determine risk factors, microbiological isolates and antibiotic sensitivity pattern of blood stream infections of pediatric malignancies.

Study Design: A prospective single center cohort study included Children with malignancies that developed one or more episodes of septicemia during the period of their treatment and follow up.

Place and Duration of Study: We included 46 children who were admitted to the Pediatric oncology Unit of Tanta University Hospitals, Egypt, over the period of six months. The included children had a microbiologically confirmed blood stream infections.

Methodology: Positive blood cultures by BacT/ALERT were sub cultured on MacConkey agar, blood agar, chocolate agar, and sabouraud agar. VITEK 2TM Compact 15 was used for verification of bacterial identification and MIC determination.

Results: Sixty seven blood stream infections were detected in 46 patients. Hematological malignancies (67.4%) and neutropenia (69.7%) were the major risk factors. Gram positive bacteria represented (53.7%) including mainly coagulase negative Staphylococci (38.9%) and Streptococci (30.6%). Methicillin resistance was detected in all S. aureus, 71.4% of Coagulase negative Staphylococci that were sensitive to ciprofloxacin (85.7%, 100%), gentamycin (85.7%, 100%) and clindamycin (71.4%) respectively. Gram negative bacteria represent (46.3%) mainly Klebsiella pneumoniae (38.7%). ESBL in Enterobacteriaceae was (81.3%) with sensitivity to ciprofloxacin, amikacin, piperacillin/ tazobactam and sulbactam/ cefoperazone (100%, 100%, 69.2%, 53.8%) respectively. Carbapenem resistance was detected in one isolate of K. pneumoniae, two P. aeruginosa and two A. baumanii. Intestinal translocation of Klebsiella pneumoniae in (41.7%, 5/12) and P. aeruginosa (40%, 2/5), as well as in the four detected cases of central line blood stream infections.

Conclusion: The application of infection control guidelines and the strict antibiotic policy are mandatory for each institute. Selective digestive decontamination is considered to limit translocation. Carbapenem resistance was alarming and mandating more evaluation of β-lactam/β-lactamase inhibitors in treatment of ESBL Enterobacteriaceae.

Open Access Original Research Article

Detection and Enumeration of Moulds on Some Legumes and a Cereal Grain from Two Local Markets and Two Shopping Malls in the Accra Metropolis

Andrew Amegbedzi Minamor, Beatrice Adu Appiagyei

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/MRJI/2017/21883

This study detected and enumerated moulds associated with seeds and cereal grains under different packaging systems displayed for sale at two different purchasing sites; open market and supermarket. Two popular open markets and supermarkets were used for the investigation. The moulds were isolated on two mycological media, Malt Extract Agar (Oxoid CM545) and Dichloran Rose Bengal Chloramphenicol Agar (CM 041) using decimal Serial Dilution and Pour Plate methods. Four fungal genera, Aspergilus, Fusarium, Penicilium and Mucor were isolated on maize, cowpea, peanuts and bambara beans purchased from the two sampling points. Aspergilus sp predominated with 31.9% isolation followed by Fusarium verticillioide (= Fusarium moniliforme) with 20.1%, Penicilium digitatum, 8.1% and Mucor spp 0.2% isolation on the samples from the open markets. A similar trend was observed on the samples from the supermarkets with much lower percentage occurrence; Aspergillus sp. 12.2%, Fusarium sp. followed with 3.3%, and Penicilium sp. with 0.6% isolation. Mucor genus, however, was isolated only on bambara beans from one of the open markets. Five Aspergilus species namely; A. flavus ˃ A. niger ˃ A. fumigatus ˃A. ochraceus ˃ A. sulphureus in decreasing number of magnitude were isolated from the samples from the open markets. The samples from the supermarkkets also registered five Aspergillus sp. in this order of decreasing magnitude; A. flavus˃ A. niger =A. fumigatus ˃ A. sulphureus˃ A. ochraceusPenicillium digitatum and Fusarium verticillioide(=Fusarium moniliforme) were also isolated on the seed/grain from both open markets and the supermarkets. Most of the species isolated were mycotoxins producing moulds.

Open Access Original Research Article

Evaluation of Indigenous Biosurfactant-producing Bacteria for De-emulsification of Crude Oil Emulsions

Olugbenga Adebanjo Falode, Mariam Adebowale Adeleke, Adenike A. O. Ogunshe

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/MRJI/2017/29156

Conventional method of removing water from crude oil using chemicals is unfavourable from both the economic and environmental perspectives; so, this study aims at formulating economical and environmentally-friendly biosurfactant de-emulsifiers. Biosurfactant-producing bacteria isolated from oil-contaminated soil samples from Nigerian National Petroleum Corporation (NNPC) depot Apata, Ibadan, Oyo State of Nigeria were applied on crude oil emulsions for the purpose of separating water-in-crude oil emulsions. Thirty-five of 41 bacterial strains were further screened for ability to degrade (de-emulsify) hydrocarbon, using vapour transfer method. Highest displayed de-emulsification activities at 24 h were Pseudomonas sp. AGO1 (50.0%), Bacillus sp. DPK1A (50.0%), Bacillus subtilis AGO1A (50.0%), Pseudomonas aeruginosa DPK3A (55.7%) and Bacillus subtilis PMS1B2 (66.0%); and at 48 h were, Bacillus subtilis AGO1A (50.0%), Psaeruginosa DPK3A (60.0%) and Bacillus subtilis PMS1B2 (66.7%). Higher de-emulsification activities were recorded on supplementation of growth media, with Ps. aeruginosa DPK3A showing the highest de-emulsification activity of 66% when grown on growth media supplemented with glucose and yeast extract, at temperature of 60°C. In comparison with chemical de-emulsifier, microbial de-emulsifier produced 66%, 62% and 60% volume of water, while chemical de-emulsifier produced 63%, 60% and 66.2% volume of water. This study demonstrated that generally regarded as safe (GRAS), hydrocarbon-utilising, biosurfactant-producing bacteria, especially the Bacillus species isolated from crude oil-contaminated soils, when cultured on appropriate medium is effective in diesel degradation and treatment of water-in-crude oil emulsion; thus, reducing cost and environmental pollution.

Open Access Original Research Article

Exploring Textile Dye from Microorganisms, an Eco-friendly Alternative

Shovon Lal Sarkar, Prianka Saha, Nigarin Sultana, Selina Akter

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/MRJI/2017/29861

Aims: Being an ancient art, the concept of dyeing using natural resource is neither a noble issue. To develop a green and sustainable world, the natural resources are now common sought. In this study screening of pigment producing microorganisms and extraction of pigments were the prime concern.

Study Design: An environmental screening was performed to isolate pigmented microorganisms. Extractability of the pigments and dying capability of textiles were also evaluated.

Place and Duration of Study: Soil, water and air were sampled and cultured from different regions around Jessore, Bangladesh. Isolation and tests were performed at Jessore University of Science and Technology.

Methodology: Soil and water samples were inoculated on bacterial and fungal media. Media were exposed for 1h to air for air sampling. Pigmented isolates were cultured in bulk, dried and went through solvent extraction by ethanol and water. Soluble pigment producing isolates were identified and dying capability to cotton and silk were evaluated. Pigments were also tested for antimicrobial activity and allergic test to human skin to be used for medicated fabric.

Results: A few pigmented bacteria and several pigmented fungi were isolated. By solvent extraction, only two colors were extracted having greater solubility. The isolates were preliminarily identified as Aspergillus sp. and Penicillium sp., producing green and red color respectively. The dying capacity to cotton and silk fabrics were found satisfactory in respect to wash fastness. The extracted colors also showed antimicrobial activity against several pathogenic microorganisms. Pigments were also subjected to hypersensitivity test and found non allergic to human skin.

Conclusion: However, these dyes have the potentiality to be used in sophisticated garment for allergic patients to chemical dyes and infants. As the biomass yielding capability of pigmented fungi were very low in the designed media, further modification of media and growth conditions are to be optimized to maximize biomass and large-scale dye production.