Showing 4 results for Soil
Hr Pordeli, Sj Hashemi Hazaveh, M Jamshidian, M Bayat,
Volume 7, Issue 2 (7-2013)
Abstract
Abstract Background and objective: Soil bacteria, particularly Bacillus genus have the potential of producing a range of bioactive substances with antimicrobial and antifungal properties. They have the ability to produce hundreds of active and effective biologic compound against microorganisms. Therefore, it seems to be a proper candidate in the biocontrol of fungal pathogenesis. Material & Methods: In this study, soil samples were collected from different parts of Gorgan in order to isolate Bacillus and to determine their antifungal activity against T.mentagrophytes. The Isolates that had the highest antifungal effects were analyzed by PCR and 16s rRNA sequencing. Results: of 54 strains, 14 have antifungal activity. The Isolates, S4 and S12, identified as B.cereus and B.thuringiensis respectively show the highest antidermatofit effect. These isolates based on 16s rRNA sequence analysis show 97% homology with Bacillus cereusstrain KU4 and Bacillus thuringiensisstrain ucsc27. Conclusion: According to the results, it seems that the soil Bacilli have biocontrol potential against dermatophytic agents such as T.mentagrophytes. Keywords: Antifungal effects, Bacillus, Rhizospheric soil, T.mentagrophytes
M Rasouli Nasab, Sh Habibnia, P Heidarieh, Mr Pourmand, M Fatahi, Ss Eshraghi,
Volume 7, Issue 5 (2-2014)
Abstract
Abstract
Background and Objective: The Isolation of Nocardia species is complex and time-consuming, which is due to rapid growth of adjacent bacteria. Because of the importance of a specific medium with the ability of controlling intrusive microorganisms, this study aimed at comparing three laboratory methods to introduce the reliable isolation technique for Nocardia species.
Material and Methods: The soil samples were collected from different regions of Tehran province, Iran, and carefully transferred to the laboratory. The samples were cultured in three different media including Paraffin Baiting,Humic acid vitamin B agar and Paraffin agar, and incubated for 3-4 weeks at 35 °C.
Results: Of 110 soil samples, 31 Nocardia isolates (28.18%) were obtained from the media including Paraffin Baiting, (19 17.27%), Humic acid and vitamin B agar (4 3.63%), and Paraffin agar, (8 7.27%).
Conclusion: because of high rate of isolation, low cost and the clearance of colonies suspected nocardia, Paraffin Bait technique is more reliable and efficient compared to the other methods.
Key words: Nocardia Soil Paraffin Baiting Humic Acid Vitamin B
Aj Eiri, Aa Nasrollahi Omran, Hr Pordeli,
Volume 7, Issue 5 (2-2014)
Abstract
Abstract
Background and Objective: Chitin, which is a linear polymer of N-acetyl glucosamine residues, has been the most abundant polymer in nature after cellulose. In recent decades, Chitinases have received increased attention because of their wide range of applications, especially in biological control against fungi.
Material and Methods: the isolation of bacilli producing chitinolytic enzymes was performed by collecting 40 soil samples from various regions of Gorgan, northern of Iran. The chitinolytic potential of the isolates was indicated by observation of clear zone in colloidal chitin agar medium. Identification of selected strains was performed by polyphasic taxonomy, and subtler identification and sequensing were carried out by extraction DNA. Antifungal effect was evaluated by well method against Candida albicans (ATCC 10231) Aspergillusniger (ATCC 2029)،Aspergillusflavus (IR6) Fusariumoxyporum (PTCC 5115) and Alternariaalternata (PTCC 5224).
Results: Nine colonies of chitinase positive bacillus were isolated on choloidal Chitin Agar (CCA) and five of them had antifungal effect. R6 strain had the highest, and R2 and R3 had the lowest effect on fungi. The 16S rRNA sequence of these isolations in comparison with the known bacteria has 95-97% similarity.
Conclusion: Some of the soil bacteria can have antagonestic effects on human and phytopathogenic agents existed in soil.
Keywords: Bacillus Chitinase Soil Antifungal
Yaghoobi Avini, M, Daraei, M, Ebrahimipour, Gh,
Volume 8, Issue 5 (1-2015)
Abstract
Abstract Background and Objective: The bacteria living in the specific ecological conditions are among the most promising antimicrobial producers. This study aimed at isolating antimicrobial producing bacteria from soils contaminated with crude oil. Material and Methods: the samples were obtained from crude oil contaminated soils around Dezful located in Khuzestan province, Iran, and antimicrobial producing bacteria were isolated using disc diffusion and cross streak culture. Then, the best bacterium was selected and its antimicrobial potency was studied against indicator microorganisms. The isolate was also characterized based on biochemical properties and phylogenetic analysis. Results: based on the results, the highest antimicrobial activity of isolated bacterium was related to Candida albicans, Aspergillus niger, Bacillus subtilis, E. coli and Klebsiella pneumonia. An intermediate effect was determined against Serratia marcesens and Staphylococcus aureus, whereas no effect was observed against three strains of Enterococcus. Using biochemical characteristics and phenotypic traits, the isolate was identified as Alcaligenes faecalis. Conclusion: given that the isolate has broad spectrum activity against a various range of microorganisms and in comparison with some antimicrobial compounds produced by other Alcaligenes species, it seems the novelty of this antimicrobial compound. Keywords: Antimicrobial Compound, Oil Contaminated Soil, Alcaligenes faecalis
