Open Access Short Research Article

Isolation and Characterization of a Non-Saccharomyces Yeast with Improved Functional Characteristics for Ethanol Production

Sandeep Kaur, Harinder Singh Oberoi, Rajpal Phutela

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/mrji/2018/v26i430073

Aim: To isolate a thermotolerant yeast strain with fermentation potential at elevated temperatures.

Study Design: Lab experimental design was used in the study.

Methodology: Yeasts were isolated from over-ripened fruits and naturally fermenting sugarcane juice. Four isolates showing relatively higher fermentation ability were screened for their fermentation potential. The selected strain was tested for its thermotolerance, osmotolence as well as to work at varied pH.

Results: Isolate Y-4 produced relatively higher ethanol than the other isolates from 15 gl-1 glucose. Scanning electron micrographs (SEM) of isolate Y-4 showed oval to spherical cells with diameter ranging from 4.5 to 6.2 µm. On the basis of the SEM images and 28s rRNA gene sequencing, isolate Y-4 was identified as Pichia kudriavzevii and designated as P. kudriavzevii SK1. P. kudriavzevii SK1 metabolized glucose, galactose, mannose, maltose and fructose. It showed the potential to grow at a glucose concentration of 300 gl-1 and ferment at 45°C, though the best results were obtained from 15-20 gl-1 glucose at 35°C. Reference strain Saccharomyces cerevisiae MTCC 11815 produced low concentrations of ethanol under similar conditions. With 200 gl-1 initial glucose concentration 86.1 and 87.9 gl-1 ethanol was obtained in shake flasks and laboratory batch fermenter experiments, respectively at pH 5 at 35°C. This study revealed that P. kudriavzevii SK1 could be utilized for pilot scale fermentation for high gravity fermentations.

Open Access Original Research Article

Evaluation of Functional Properties of Spontaneous and Starter Culture Fermented Sweet Potato Flour

O. I. Ajayi, C. P. Onyemali, T. E. Akinwale, T. A. Okedina, M. J. Bamidele, J. Ehiwuogu-Onyibe, A. K. Lawal, G. N. Elemo

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/MRJI/2018/46910

Sweet potato tubers obtained from a local market were sorted, washed processed into fermented and unfermented sweet potato flour. The samples obtained were analysed for their functional properties (swelling power, solubility index, water absorption capacity, dispersibility and bulk density) using standard laboratory procedures. A significant difference (p > 0.05) was observed in the loose and packed bulk density with values ranging from 0.488 to 0.607 g/mL and 0.701 to 0.801 g/mL respectively but there was no significant difference (p > 0.05) in the water absorption capacity, oil absorption capacity and dispersibility. There was no significant difference (p > 0.05) in the swelling power but numerically the swelling power increased with increase in temperature. A significant difference in the solubility index above 75°C and increase in solubility with increase in temperature was observed. The result of this study showed that fermentation had no significant effect on the functional properties of the sweet potato flour except its effect on the porosity of the granules as shown in the result of the bulk density. The functional properties of these flours showed their uniqueness which can be useful for food application processes.

Open Access Original Research Article

Prevalence and Control of Multi Drug Resistant (MDR) Nosocomial Pathogens Isolated from Hospital Wards (Surgical, Medical, Paediatric and Labor Unit)

Aqsa Jamil, Nain Taara Bukhari, Yasmeen Lashari, Urooj Rajput, Tasmia Anis, Anum Muneer, Atiya Hussain, Arif Jamil Khan, Hamid Hussain Khan, Shahana Urooj Kazmi

Microbiology Research Journal International, Page 1-12
DOI: 10.9734/MRJI/2018/45312

Introduction: Nosocomial infection have increased and gained attention because of high isolation rates of multi drug resistant (MDR) organism in admitted and out patients in hospitals with complicated infectious ailments. The spread of multi drug resistant organisms among critically ill, hospitalized patients and subsequent epidemics, have become an increasing cause of concern. A recent manifestation of multi drug resistant organisms that has attracted public attention due to high mortality and morbidity rate is alarming.

Aims: To access the prevalence of multidrug resistant nosocomial pathogens in hospitalized patients.

Materials & Methods: This was a hospital based cross sectional study from January 2013 to December 2017.Almost 700 hospitalized and out patients who acquired nosocomial infections (NI) were enrolled, with the permission of ethical and research review committee and with the informed consent to the patient and attendant. Clinical samples were analysed for antibiotic sensitivity pattern by Kirby Baur method according to CLSI guidelines [15].

Results: Data analysis showed that 63% were female patients and 37% were male patients included. Almost 37% prevalence of etiological agents was found. Predominant were E.coli, followed by Klebsiella pneumoniae, Acinetobacter spp, and Staphylococcus aureus. Antibiotic resistance rate was found very high i.e up to 55 - 90% against commonly prescribed antibiotics in hospitalized and out patients having nosocomial infection resulting complicated infections.

Conclusion: Emergence of MDR strains in nosocomial infection (NI) is a matter of great concern and warrant investigation. There is need to adopt infection control strategies in public and private secondary tertiary care hospitals.

Open Access Original Research Article

Validity of Combined Serodiagnostic Assays; Galactomannan, Mannan Antigens and Panfungal PCR in Diagnosis of Invasive Fungal Infection

Azza Z. Labeeb, Azza M. Abd-Allah, Ahmed M. Zahran

Microbiology Research Journal International, Page 1-10
DOI: 10.9734/MRJI/2018/45534

Background: The development of reliable and rapid techniques for accurate diagnosis of invasive fungal infection (IFI) is an important goal that could help in effective treatment. Among the new promising methods used in diagnosis of IFI, pan-fungal PCR for detection of fungal DNA and measurement of serum Mannan and Galactomannan antigens.

Objectives: Our aim was to assess the performance of combined seroassays in diagnosis of IFI; Mannan plus Galactomannan antigens assays and the pan-fungal PCR with Galactomannan antigen tests compared to the culture based method.

Methodology: This study included 76 patients with suspected IFIs, (50 liver transplant recipients and 26 haematologic malignancy patients). Selected cases were subjected to complete diagnostic work-up (complete history, clinical, laboratory and radiological assessment). Blood samples were collected from all 76 cases, were divided into 2 parts; first part was inoculated into blood culture bottle for fungal isolation, serum was separated from the second part. Serum Mannan and Galactomannan antigens were measured by enzyme immunoassay (EIAs). Pan- fungal PCR technique was performed for molecular diagnosis.

Results: Among 76 of IFI patients, pure fungal growth was encountered in 16 cases (21.1%), which were 7 Aspergillus spp. and 9 Candida spp. Pan fungal PCR could diagnose 27/76 (35.5%) IFI cases; whereas, 29/76 (38.2%) cases were positive by combined GM (13.2%) plus MN (25%) EIAs. Sensitivity of combined antigen tests (100%) was higher than Pan- PCR (87.5%) assay alone and was the same as combined GM and PCR, while specificity was the same (78.3%). Blood culture method was considered as the gold standard. Sixteen (21%) patients were confirmed as proven IFI, ten (13.2%) were probable, 19 (25%) were possible and 31 (40.8%) were non-IFI. Unfavorable outcome was encountered in 9/76 (11.8%) patients (5 proven, 2 probable and 2 no-IFI), all of them were PCR positive.

Conclusion: Combinations of GM plus MN or PCR plus GM assays had high diagnostic performance in IFI patients. Both provided 100% sensitivity and NPV and 78.3% specificity. Consequently, these combinations will limit the time for deciding effective treatment strategies or empirical antifungal therapy.

Open Access Original Research Article

An Electron Microscopic Study of the Effect of (Saccharomyces cerevisiae) on the Ability of E. coli 0157:H7 to Attach and Efface Healthy Young Broilers

M. S. Shathele Abdullah, Sharif M. Hassan, A. A. Alaqil

Microbiology Research Journal International, Page 1-15
DOI: 10.9734/mrji/2018/v26i430074

The present study was carried out to determine the influence of dietary probiotic source feed (fungal-yeast; Saccharomyces cerevisiae) on the ability of E. coli 0157:H7 to attach and efface healthy young broilers at different feeding periods (7, 10, 14, 21, and 28 days of age). There were reductions in bacterial attachment of broilers fed various yeast levels. Twenty one days post-challenging about 87% of the (G1); positive control, chicks fed control diet containing 0.00% baker yeast and challenged with E. coli 0157:H7, showed both cecal attachment and effacement. On the other hand  37% of the (G2); chicks fed control diet containing 0.75% baker yeast and challenged with E. coli 0157:H7, showed cecal attachment. And only 16% of the (G3); chicks fed control diet containing 1.00% baker yeast and challenged with E. coli 0157:H7  showed cecal attachment. The results of this study suggest adding yeast at 1.0% into broilers diets causing a significant (P<0.005) decrease in bacterial attachment and may enhance the productive performance and nutrients utilization via the inhibitory effect of yeast against pathogenic bacteria E. coli 0157:H7.