Showing 3 results for Screening
Saide Afrisham, Arastoo Badoei-Delfard, Abdolhamid Namaki Shoushtari, Zahra Karami, Saeid Malek-Abadi,
Volume 4, Issue 4 (12-2017)
Abstract
Alpha-amylases are the most important amylases used in industry. Among them, thermophilic alpha-amylases are of particular importance, which is due to their activity and stability in high temperatures. These enzymes produced by thermophile micro-organisms including bacteria. These thermophilic alpha-amylases are used in various industries such as processing of starch as well as production of detergents and biofuels. In this research, the bacteria which produce the thermophilic alpha-amylases were isolated and characterized in hot springs of Gorooh village in Kerman province. According to the results of screening on the specific liquid and solid media, AT59 was selected as the best strain. Morphological and biochemical characterization of the isolated strain indicated that it belonged to Bacillus sp. and was gram-positive, catalase positive, casein hydrolyzing and acid producing from lactose and sucrose. The results obtained from the optimization of the enzyme production medium showed that among the carbon, nitrogen and ion sources investigated, starch (1 gr/l), gelatin (2 g/l) and magnesium sulfate (1 g/l) had the most increasing effect on the production of AT59 alpha-amylase. Moreover, the highest enzyme production was obtained at pH 5. This enzyme also demonstrated the highest degree of activity and stability in 80 and 70 ℃, respectively. These findings suggested that this enzyme has a considerable potential for use in starch industry.
Ehsan Azin, Hamid Moghimi,
Volume 7, Issue 3 (11-2020)
Abstract
The extensive application of dyes in the textile industries and their discharge in the wastewaters leads to numerous environmental pollutions; therefore, treating these wastewaters by efficient and eco-friendly methods is a necessity. In this study, potent strains were isolated by the enrichment technique according to their maximum dye sorption at the lowest possible time at 500nm. Consequently, the best isolate was selected and the dye removal was investigated in different concentrations of Congo red. Therefore, 50 different fungal strains were isolated in this study, of which 10 were able to dye removal. According to the results, isolate ADH8 was selected as the best strain with 94% of dye sorption. Moreover, during 48 hours, 80% of dye content was removed at all dye concentrations by this isolate, and the most growth rate and dye removal was achieved at 1000 mg/l. The results showed that different salt concentrations have no effect on dye sorption of the selected isolate. Molecular identification of ADH8 revealed that this isolate have a 100% similarity to Mucor circinelloides which was deposited under the accession number of UTMC5032 in the University of Tehran Microorganisms Collection. The results obtained from the dye removal of textile wastewater showed that the most amount of dye sorption by M. circinelloides UTMC5032 was 35-60% during three hours of biomass treatment as compared with the control sample. The obtained results indicated that, M. circinelloides UTMC5032 is highly capable in azo dyes sorption and could be utilized in the biosorption of dye in the textile industries wastewaters for the first time.
Ensieh Salehghamari,
Volume 9, Issue 3 (12-2022)
Abstract
Saline rhizospheric areas are untouched environments for isolating actinomycetes with the potential of valuable salt tolerant enzyme production. In this study, we isolated and evaluated a total number of of 26 actinomycete strains from plant rhizosphere of the periphery of Dasht-e-Kavir desert. Isolated actinomycetes produced different enzymes. Among them 50, 46, 39, 27, 10 and 7 % of the isolates produced amylase, lipase, protease, gelatinase, lecithinase and urease, respectively. The most frequently produced enzymes among the isolates were amylase, lipase and protease. Combined hydrolytic activity was also detected in some actinomycete strains. Among the isolates, strains Q1, Q4 and Q11 with the most diverse enzymes production, were identified and their 16s rRNA analysis showed that they are mostly similar to the Streptomyces scopiformis, Streptomyces argenteolus and Streptomyces manipurensis, respectively. Finally, due to the enzymatic diversity obtained and the valubility of the halophilic bacterial enzymes in industry, it seems that actinomycetes isolated from this saline habitat are potentially suitable for biotechnological applications.
