Open Access Original Research Article

Proximate and Mineral Composition of Bread Fortified with Mushroom (Plerotus ostreatus and Calocybe indica)

V. O. Oyetayo, R. R. Oyedeji

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/MRJI/2017/32133

The proximate and mineral composition of two mushrooms (Pleurotus ostreatus and Calocybe indica) was firstly determined. The mushrooms was dried and milled into powder. The Mushroom Powder (MP) was used to substitute wheat flour in bread formulation at 0%, 5%, 10%, 15% and 20%. The 0% inclusion served as the positive control while bread obtained    from the market served as the negative control. The proximate and mineral properties of the bread were determined before and after storage using standard methods. The study revealed that the ash content, fiber and protein content increased significantly with increase in the addition of the mushroom powder. Protein content increased from 9.12% in the negative control to 18.7% with 5% MP inclusion and 25.1% with 20% MP inclusion. Potassium, sodium, calcium, magnesium, manganese, copper, zinc and iron content of the bread increased significantly (P≤0.05) with increase in the mushroom powder. The results from this study revealed mushroom could be used to improve the nutritional value of bread and this may help in the reduction of protein and mineral malnutrition prevalent in Nigeria and other developing countries.

Open Access Original Research Article

Correlation of Methanotrophs and Soil Enzymes with Available Nutrients in Long Term Green Manured Rice Rhizospheric Soil

Jaspreet Kaur, S. K. Gosal, S. S. Walia

Microbiology Research Journal International, Page 1-10
DOI: 10.9734/MRJI/2017/32326

The indiscriminate use of chemical fertilizers in agriculture decreases the soil fertility as well as soil health and their adverse effects are clearly visible on soil microflora, soil function and structure. This scenario necessitates the need to adopt the integrated organic farming which maintains the soil health and sustainability. So, the present study was conducted during kharif season 2013 at Department of Microbiology and Agronomy, Punjab Agricultural University, Punjab, India to assess the effect of green manure application along with variations in plant density on methanotrophic populations, soil enzymatic activity and their correlation with available nutrient status of the soil. Highest methanotrophic population (176×105 cfu/g) was observed in the treatment having green manure (15 t/ha) + 44 plants/m2 + recommended NPK at 90 DAT. The highest soil dehydrogenase (50 µg Triphenyl formazon/g soil/hr) and urease activity (855 µg/g soil/h) was found in the treatment having green manure (15 t/ha) + 33 plants/m2 + recommended NPK whereas, alkaline phosphatase (21.9 µg p-nitro phenol/g soil/h) were observed in the treatment having green manure+ 44 plants/m2 + recommended NPK. A highly significant positive correlation was observed between methanotrophs and available nutrient content in soil. Similarly, the soil enzymatic activities were also positively correlated with the soil nutrients and organic carbon in soil. The study suggested that application of green manure along with increased plant density improves the soil health and fertility hence, increases the sustainability of cropping system.

Open Access Original Research Article

Characterization of Psychrotrophic Molds from Indigenous Fermented Dairy Products

Basavabharati ., N. Suchitra, R. Prabha

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/MRJI/2017/33106

Aim: The aim of the study was to establish the number and type of psychrotrophic molds in Indigenous Fermented Dairy Products (IFDP) of Bengaluru market, Karnataka, India.

Methodology: The study was taken up in the Department of Dairy Microbiology, Dairy Science College, KVAFSU, Hebbal, Bengaluru, 560 024, Karnataka, India  between June 2014 to June 2015 as part of post graduate research work. The samples used in the study were unbranded (n=6) and branded (n=15) IFDP such as Mishtidoi, Shrikhand, Lassi and Buttermilk collected from Bengaluru markets. The market samples of IFDP were subjected for isolation on poured sterile malt extract agar of pH 3.5. The isolates  were obtained by pour-plate technique on malt extract agar (pH 3.5). The mold isolates were identified by colony morphology, microscopic examination for cell morphology and specific biochemical tests.

Results: Out of total of 21 psychrotrophic mold isolates, 6 and 15 isolates were obtained from unbranded and branded samples, respectively. Based on the preliminary identification, the isolates were characterized as Penicillium spp. (n=3), Mucor spp. (n=2) and Cladosporium spp. (n=1) from unbranded samples while branded IFDP samples showed Penicillium spp. (n=9 and Alternaria spp. (n=6) were isolated from branded samples. According to pheno and genotypic characterization, the isolates were identified as P. chrysogenum(57.12%) followed by A. alternata (28.56%), C. cladosporioides (4.76%) and M. mehei (9.52%) at the species level.

Conclusion: Except unbranded mishitdoi, all types of IFDP samples were found to contain psychrotrophic molds. P. chrysogenum was the most abundant species especially in branded butter milk indicating longer refrigeration may lead to selection of psychrotrophic molds due to low temperature storage and pH of the IFDP samples.

Open Access Original Research Article

Degradation of Polycyclic Aromatic Hydrocarbons and Aroma Oxidation of Fermented Locust Bean Seeds ‘Iru’ by Laccase Enzyme Produced by Kluyveromyces dobzhanskii DW1 and Pichia manshurica DW2

Wakil Sherifah Monilola, Eyiolawi Seun Andrew, Salawu Kehinde Olamide, Onilude Abiodun Anthony

Microbiology Research Journal International, Page 1-13
DOI: 10.9734/MRJI/2017/31135

Laccases (EC.1.10.3.2 are multi-phenolics and non-phenolic oxidizing enzymes) have received much attention in their use for environmental bioremediation, food quality and functionality improvement. This work was aimed at degrading polycyclic aromatic hydrocarbons and aroma oxidation of fermented locust beans seeds ‘iru’ by laccase produced by yeast strains. Kluyveromyces dobzhanskii DW1 and Pichia manshurica DW2 were the yeast strains employed for the production of laccase enzyme. The enzymes were used in the crude, partially purified and agar-gel immobilized forms. The percentage laccase immobilization of Kluyveromyces dobzhanskii DW1 and Pichia manshurica DW2 were 65.2% and 73.1% respectively. The PAHs degraded were Naphthalene and Phenanthrene which were degraded by 50.1%, 23.3%, 18.2% and 65.0%, 54.4%, 39.1% respectively by the crude, partially purified and immobilized laccases fromKluyveromyces dobzhanskii DW1 while the following degradation percentages; 43.6%, 14.6%, 37.1% and 62.5%, 40.4%, 60.1% for the respective compounds were obtained for Pichia manshurica DW2 laccase. The use of the crude, partially purified and immobilized laccases from Kluyveromyces dobzhanskii DW1 and Pichia manshurica DW2 resulted in aroma oxidation by 78.6%, 51.4%, 31.4% and 62.8%, 57.2%, 45.7% respectively. Chemical analysis of flavour-oxidized ‘iru’ by crude laccase from Kluyveromyces dobzhanskiiDW1 showed an increase in protein and tocopherol contents by 9.38% and 30.46% respectively. From this study, the crude laccase from strains worked best in the degradation of Naphthalene and Phenanthrene as well as the aroma flavour oxidation of ‘iru’ which confers economic benefit to the laccase as additional cost of purification and immobilization of enzyme is not required.

Open Access Original Research Article

P. pentosaceus Administration Attenuates the Severity of Dextran Sulfate Sodium-Induced Colitis and Improve the Intestinal Permeability

Lorena Torres-Aguilar, Lourdes Rodríguez-Fragoso, Jorge Reyes-Esparza

Microbiology Research Journal International, Page 1-12
DOI: 10.9734/MRJI/2017/33126

Aims: To evaluate the effect of different doses of P. pentosaceus on colitis symptoms as well as in the intestinal barrier function in an in vivo model of acute ulcerative colitis induced with dextran sodium sulfate (DSS). 

Study Design: Experimental.

Place and Duration of Study: Laboratory of Pharmacology, Toxicology and Immunomodulators, Facultad de Farmacia, Universidad Autonoma del Estado de Morelos, Mexico, between march 2015 and December 2015.

Methodology: Acute colitis was induced in BALB/c mice via the administration of 3.5% DSS in drinking water administered ad libitum for 7 days. On day 2 during the induction of colitis, four groups received different doses of Pediococcus pentosaceus (1×107, 1×108, 1×109, and 1×1010 Colony Forming Units (CFUs)) via gastric tube once per day. We assessed the severity of colitis based on disease activity index (DAI), colon length and histological damage; colonic permeability to fluorescein isothiocyanate–dextran (FITC-dextran) was measured in vivo.  

Results: Treatment with P. pentosaceus at doses of 1x1010 significantly reduced the DAI compared with the DSS group (1.94± 0.93 vs. 3.54± 0.61) and decreased the diarrhea score and fecal blood score (1.53 ± 0.35 vs. 3.73). P. pentosaceus improved colon length (8.81 ± 0.95 cm vs. 7.26 ± 0.67 cm) and decreased intestinal permeability by 49.6% compared to the DSS group.

Conclusion: The administration of P. pentosaceus at a dosage of 1x1010 CFUs attenuates the severity of DSS-induced colitis and improves epithelial barrier function.