Advanced Journal of Microbiology Research

Advanced Journal of Microbiology Research Vol. 2011

Available online at http://internationalscholarsjournals.org/journal/ajmr

© 2011 International Scholars Journals 

Full Length Research Paper

Occurrence and identification of yeast species isolated from Egyptian Karish cheese

Neveen S. M. Soliman and Salwa A. Aly*

Department of Food Hygiene, Faculty of Veterinary Medicine, Cairo University, Egypt.

Accepted 8 April, 2011

Abstract

This study aims at identifying the diversity and abundance of yeast associated with Egyptian Karish cheese, employing comparison between conventional laboratory techniques and API20 kits techniques in yeast identification. A total of one hundred samples (fifty each) of Egyptian raw and pasteurized Karish cheese milk were randomly collected from farmers and markets in Cairo and Giza Districts. The occurrence of yeast in raw and pasteurized Karish cheese milk were 100 and 38% with a mean value of 7 ± 1.1 l and 1 ± 0.31 log₁₀ cfu g⁻¹, respectively. Yeast strains isolated from both raw and pasteurized karish cheese samples were identified and characterized using both conventional methods and API 20 C AUX as a commercial identification system. The most prevalent isolates belonged to Trichosporon cutaneum (25%), Candida catenulata (23%), Yarrowia lipolytica (13%), Debaryomyces hansenii (13%), Kluyveromyces lactis (6%), Geotrichum candidum (7%), Candida zeylanoides (5%), Candida lambica (3%), Candida albicans (2%), Cryptococcus formans (1%), Rhodotorula glabrata (1%) and Saccharomyces cerevisiae (1%). There was no significant difference (P 0.05) between the conventional method and the API20 kits test. However, the results of this study reveal that API 20 kits are simple, highly useful and are commercially available kits that considerably shorten the time required for the identification of yeast in cheese.

Key words: Yeast identification, Karish cheese, API 20 kits.

Advanced Journal of Microbiology Research Vol. 2011

Available online at http://internationalscholarsjournals.org/journal/ajmr

© 2011 International Scholars Journals

Full Length Research Paper

Modeling the action of technical mashing enzymes on extracts and free-amino nitrogen yields of the Madjeru sorghum cultivar

Zangué S. C. Desobgo², Emmanuel J. Nso¹* and Dzudie Tenin¹

¹Department of Process Engineering, National School of Agro- Industrial Sciences (ENSAI) of Ngaoundere, Cameroon.

²Department of Food Processing and Quality Control, University Institute of Technology (IUT) of Ngaoundere, Cameroon.

Accepted 18 April, 2011

Abstract

The action of three technical mashing enzymes (hitempase 2XL, bioglucanase-TX and brewers protease) on yields of extract and free amino nitrogen (FAN) of the worts of mashes of unmalted and malted Madjeru sorghum was modeled and analyzed using the response surface methodology. The analysis showed that increasing amounts of hitempase 2XL considerably increased yields of extract during mashing of unmalted Madjeru sorghum grist. The use of bioglucanase-TX was not indispensable, while Brewers’ protease contributed very little. Increasing amounts of hitempase contributed approximately 45% of the free amino nitrogen, while Brewers’ protease influence amounted to not more than 15%. Bioglucanase’s action was globally nil. Addition of the three enzymes into malted Madjeru sorghum mashes had no significant effect on the yields of extracts and FAN, but the milling operation singularly liberated more than 50% of FAN for both mash types. Optimization of the concerted actions of the three enzymes for extract yield for unmalted Madjeru sorghum mash gave a combination of (1960.5 U; 132.61 BGU and 28.86 mg) for hitempase, bioglucanase and brewers protease respectively). This gave a maximal extract yield of 16.55 °P. This combination was: 2610 U; 0 BGU and 40.44 mg for malted Madjeru sorghum mash, giving a maximal extract yield of 16.35 °P. Optimization for free amino nitrogen for unmalted Madjeru sorghum mash gave a combination of: 3000 U; 0 BGU and 100 mg for hitempase, bioglucanase and brewers protease respectively). This gave maximal FAN of 93.55 mg/L. The combination was: 3000 U; 0 BGU and 100 mg for malted Madjeru sorghum mash, giving a maximal FAN of 144.48 mg/L.

Key words: Modeling, technical mashing enzymes, yields of extract, free-amino-nitrogen, Madjeru, optimization.

Advanced Journal of Microbiology Research Vol. 2011

Available online at http://internationalscholarsjournals.org/journal/ajmr

© 2011 International Scholars Journals 

Review

Yeasts in marine and estuarine environments

Kathiresan Kandasamy*, Nabeel M. Alikunhi and Manivannan Subramanian

Centre of Advanced Study in Marine Biology, Annamalai University,

Parangipettai: 608502, Tamil Nadu, India.

Accepted 14 July, 2011

Abstract

Yeasts and other fungi are prevalent in marine and estuarine ecosystems where they play an important role in the food web. Marine yeasts are unique in performing fermentations under high salt concentrations. The mechanism underlying the high salt tolerance involves the ability to accumulate high concentrations of sodium without becoming intoxicated, and the exclusion of excessive sodium from the cytoplasm. Overall, the yeasts play major roles in fermentation, enzyme technology, pollution control, micro sensors, and in some medicinal and medical applications.

Key words: Marine yeast, deep sea, estuarine, mangrove, association.

Advanced Journal of Microbiology Research Vol. 2011

Available online at http://internationalscholarsjournals.org/journal/ajmr

© 2011 International Scholars Journals

Full Length Research Paper

Antimicrobial activity and physicochemical properties of oils from tropical macrofungi

David, O. M.¹*, Fagbohun, E. D.¹, Oluyege, A. O.¹ and Adegbuyi, A.²

¹Dapartment of Microbiology, Ekiti State University, Ado-Ekiti, Nigeria.

²Department of Pharmacy, University Teaching Hospital, Ado-Ekiti, Nigeria.

Accepted 13 July, 2011

Abstract

Nutriceutics potential and physicochemical properties of the oil extract from five species of macrofungi which include Ganoderma lucidium, Pleurotus tuberregium, Termytomyces robustus, Schizophyllum commune and Trametes versicolor were investigated using standard chemical and microbiological methods. The oil was extracted using Soxhlet method of extraction. Disc diffusion and agar dilution methods were used to test for the antibacterial and antifungal properties of the samples respectively. The extracted oils were tested against five clinical bacterial isolates: Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Serratia marcescens, Enterococcus faecalis and Escherichia coli. The susceptibility of three fungi genera to the oil samples was also tested. The potency of the extracts oils was determined at different concentrations. All the oils extracted from the mushroom were liquid at room temperature. The acid values of the oils ranged between 0.9 and 6.7 mg KOH/g in T. robustus and T. versicolor respectively. The high iodine values ranged between 39.8 in T. versicolor and 127.0 mg I₂/100 g. The saponification value was above 100 mg KOH/g except T. robustus. The aromabiogram of the oils from the mushroom had a pronounced effect on the Gram negative bacteria. Oil from S. commune has the least inhibitory effect on the bacteria. The antifungal assay of P. tuberregium was most effective against Aspergillus parasiticus, followed by that of G. lucidium. The least effective was oil from T. versicolor. The performance of oil from G. lucidium was the best out of all the samples. The inhibitory activities of the oils were concentration dependent. The oils tested were good sources of antimicrobials.

Key words: Mushroom, oil, nutriceutics, antimicrobial, pathogens, macrofungi.

Advanced Journal of Microbiology Research Vol. 2011

Available online at http://internationalscholarsjournals.org/journal/ajmr

© 2011 International Scholars Journals

Full Length Research Paper

Alternaria jacinthicola, a new fungal species causing blight leaf disease on water hyacinth [Eichhornia crassipes (Martius) Solms-Laubach]

Karim Dagno¹*, Julien Crovadore², François Lefort², Rachid Lahlali³, LudivineLassois¹ and M. Haïssam Jijakli¹

¹Unit of Plant Pathology, University of Liege, Gembloux Agro Bio Tech, Passage des Déportés 2, B-5030 Belgium.

²Plants and Pathogens Group, Institute Earth Nature and Landscape, University of Applied Sciences of Western Switzerland, 150 route de Presinge, Jussy, Geneva 1254, Switzerland.

³Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Place, S7N0X2, Canada.

Accepted 26 April, 2011

Abstract

Water hyacinth (Eichhornia crassipes) causes environmental, agricultural and health problems in Mali. This is particularly severe in the District of Bamako and the irrigation systems of the “Office du Niger” area. During two years survey for fungal pathogens of water hyacinth infested areas, isolate Mlb684 was collected from diseased plant. This fungal isolate was identified as a potential mycoherbicide for sustainable management for water hyacinth. The aim of this study was to characterize isolate Mlb684. The characterization was based on a morphological description and a DNA sequence analysis. Various genes amplified from isolate Mlb684 were compared to those existing in Genbank. These genes were 18S ribosomal rDNA gene, ITS rDNA gene, elongation factor-1 alpha (EF1a) gene, calmodulin and actin genes. DNA sequence comparisons and morphological description provided enough evidences to show that isolate Mlb684 belonged to the Alternaria genus and was distinct from any other known Alternaria species. Based on these evidences, the new fungal isolate was called “Alternaria jacinthicola Dagno & M.H. Jijakli”. A specimen culture has been deposited in the Gembloux Agro Bio Tech Plant Pathology unit fungal collection, with Mlb684 reference and in the Industrial Fungal and Yeast Collection (BCCM/MUCL, Belgium) under the accession number: MUCL 53159 and all DNA sequences were deposited in GenBank (NCBI).

Key words: ITS rDNA, 18S rDNA, actin, calmodulin, elongation factor, genetic characterization, Alternaria jacinthicola, Eichhornia crassipes, water hyacinth.

Advanced Journal of Microbiology Research Vol. 2011

Available online at http://internationalscholarsjournals.org/journal/ajmr

© 2011 International Scholars Journals

Full Length Research Paper

Physiological variability among isolates of Phomopsis azadirachtae from Tamil Nadu

K. Girish^1,2* and S. Shankara Bhat^1,3

¹Department of Studies in Microbiology, Manasagangotri, University of Mysore, Mysore – 570 006, Karnataka, India.

²Postgraduate Department of Microbiology, Maharani’s Science College for Women, JLB road, Mysore - 570 005, Karnataka, India.

³Labland Biodiesel Private Limited, # 98, 7th main, Jayalakshmipuram, Mysore -570 012, Karnataka, India.

Accepted 16 February, 2011

Abstract

16 isolates of Phomopsis azadirachtae, causing die-back of neem were isolated from 16 different geographical regions of Tamil Nadu. Their growth response to physical (temperature and pH) and chemical (carbon and nitrogen sources) factors were investigated. The toxicity of culture filtrate of each isolate on neem seed germination was also studied. Several isolates exhibited maximum growth at 35°C. Maximum growth of all the isolates was observed at pH 6.0. Many isolates preferred starch and a few, sucrose, as carbon sources. Ammonium sulphate formed the good nitrogen source for most of the isolates. However, all the isolates displayed significant differences among themselves in their growth response to each treatment. The culture filtrate of each isolate inhibited the germination of neem seeds but exhibited varying degree of toxicity. The results obtained suggest the existence of physiological variability within P. azadirachtae.

Key words: Die-back of neem, carbon source, culture filtrate, isolates, nitrogen source, pH, Phomopsis azadirachtae, temperature, variation.