Showing 4 results for Emtiazi
Volume 9, Issue 1 (Number 1 - 2007)
Abstract
Various basidiomycetes and deuteromycetes, grown in liquid and solid culture media, were compared for their laccase-producing ability and for the inducing effect of soil and agricultural residues on laccase production. Laccase activity in extracts of all solid media was higher than that of the liquid media. In liquid cultures, fungal laccase activity in ex-tracts of pea (Pisum sativum) straw-treated media compared with the other agricultural residue-treated media was significantly low. The laccase-producing ability of Polyporus sp. compared with the other fungi was significantly high whereas that of Trichoderma reesei was markedly low. Laccase activity of Phanerochaete chrysosporium under liquid conditions was strikingly low, however, under solid conditions it increased more than that of the other fungi. With the addition of soil to wheat and rice straw-treated solid media, fungal laccase activity increased significantly.
M.s. Borhani , Z. Etemadifar , G. Emtiazi , E. Jorjani ,
Volume 9, Issue 4 (Fall 2018)
Abstract
Aims: Alkaline protease is one of the most important groups of industrial enzymes with many applications. The aim of this study was to determine the physicochemical parameters affecting the production of alkaline protease enzyme produced by Bacillus pseudofirmus MSB22 by one-factor-at-a-time (OFAT) method and optimize the production of this enzyme by the response surface methodology (RSM) in the form of a rotatable central composite design.
Materials and Methods: In the present experimental study, the isolation of microorganism producing alkaline protease from wastewater from sausage and lunch meat factories in Isfahan was carried out. The morphological and biochemical characteristics of the strain were performed according to the Bergey's book and amplification of 16S rRNA gene sequences. Detection of metalloproteinase gene and alkaline serine protease was done by polymerase chain reaction (PCR) reaction and enzyme activity measurement was performed by Folin reagent. Screening of variables effective in enzyme production was done, using one-factor-at-a-time method and optimization was performed by response surface methodology. MEGA 6 software was used for phylogenetic analyses. To analyze the data, the Design Expert 7 software and the one-way analysis of variance were used.
Findings: The maximum protease production, which was 1.85 times higher than that of OFAT method and 3.45 times higher than unoptimized conditions was obtained, using 1% w/v xylose, 3% w/v beef extract, 4% v/v inoculation size, pH 10, and 30°C. The established quadratic model had a great ability to predict responses to new observations due to a high value of the predicted determination coefficient.
Conclusion: OFAT and RSM strategies are useful screening and optimization methods, respectively and sub I and sub II genes (alkaline serine protease genes) are detected in Bacillus pseudofirmus MSB22.
Giti Emtiazi, Soheila Abbasi,
Volume 11, Issue 4 (fall 2020)
Abstract
The trend toward sustainable development of the environment and economy has led to a large-scale debate on the use of seafood wastes. In recent years shrimp has been a major part of the food industry. The accumulated waste of shrimp without proper use has resulted in the destruction of the resources and problems of waste disposal and environmental pollution. Shrimp waste fermentation with microorganisms is a method for recovering biologically active material. Bacterial chitinase is considered as a degenerate enzyme .In this study, chitin degrading bacteria were isolated from different environment and then the most efficient strain was selected. The isolate identified by Microscopic, physiological and molecular characteristics and sequencing the 16SrRNA gene and compared with the Bacillus licheniformis strain, the highest rate of chitinase has been reported so far. The isolated strain identified as Bacillus altitudinis can ferment shrimp shell as the only sources of energy and produce high-temperature chitinase, with a 5.1 U/mL activity of over a period of 4 days, and 65.6 mg/l protein on semisolid shrimp shell. While it does not grow on the agar under normal conditions, therefore, its use can't cause pollution to the environment. As a result, the activity of chitinase, its simple and inexpensive method of concentration by heat, high enzyme resistance at high temperatures, activity in a wide range of pH and the use of cheap shrimp shell substrate show the superior functional quality of this strain in shrimp shell fermentation.
Volume 14, Issue 5 (9-2012)
Abstract
Bacteria of the genus Azospirillum are well known as plant growth promoting rhizobacteria. The ability to synthesize phytohormones is considered one of the most important mechanisms to promote plant growth and is widely distributed among plant-associated rhizobacteria.The most important phytohormone produced by Azospirillum is the auxin indole-3-acetic acid, with the L-tryptophan as the precursor. In the present study, we evaluate the capacity of eight Azospirillum strains isolated from rice and wheat, to produce in vitro auxins using plant exudates. Our results show that isolates produced auxins in tryptophan free media, but, generally, the amount produced increased when the tryptophan concentration increased. Some plants root exudates had a similar effect to tryptophan for the auxin production. In this sense, bean, rice and canola root extracts produced, respectively, 93.3%, 96.2%, and 88.31% more auxin than L-tryptophan. Azospirillum sp. isolate A3 had the maximal capacity to produce auxin. Therefore, the effect of cell free supernatant was studied on rice root development. Statistical analysis did not show any significant difference between root number and dry weight of the treated and control seedlings. However, significant differences were observed in root length and wet weight at α=0.01 and α=0.05, respectively.
