Identification of over producer strain of endo-ß-1,4-glucanase in Aspergillus Species: Characterization of crude carboxymethyl cellulase

Cellulases are a group of hydrolytic enzymes capable of degrading cellulose to smaller sugar components like glucose units. These enzymes are produced by fungi and bacteria. The aim of this research was to identify a Aspergillus species with over production of endo-β-1,4-glucanase. Properties of endo-β-1,4-glucanase/carboxymethylcellulase (CMCase) from a culture filtrate of the Aspergillus sp. was also studied. Aspergillus sp. (R4) was selected as over producer of endo-β-1,4-glucanase among 13 different species. SDS-PAGE activity staining with 1% Congo Red solution revealed three protein bands showing cellulolytic activity. The molecular weights of these proteins were estimated to be approximately 18.5, 23 and 28 kD. Also, conservative region of endo-β-1,4-glucanase coding gene was studied by polymerase chain reaction (PCR). Amplified fragments with 1204 bp and 399 bp were confirmed by restriction pattern with HindII and PstI enzymes. Key Words: Aspergillus sp., Endo-β-1, 4-glucanase, CMCase, SDS-PAGE, PCR. African Journal of Biotechnology Vol.4(1) 2005: 26-3

The fifth developing plan of Iranian Fisheries Research Institute

Accurate scientific and practical plan for achieving the goals of the Islamic Republic of Iran within the framework of Vision development 1404, is the infrastructure achieving sustainable development of the country. Order to achieve the above mentioned objectives and in order to the comprehensive development plans in the country, Iranian fisheries research organization adjust the fifth developing plan for support of executive related departments in country with mobilization a large number researchers consists of several working groups of ifro affiliated research centers. The fifth developing plan consist of three chapters for report of the forth developing plan and intrudction of research, construction plans and financial support (budjet) for period of 2011-2014 A.C

Significant increase in cyanide degradation by Bacillus sp. M01 PTCC 1908 with response surface methodology optimization

Abstract Cyanide is used in many industries despite its toxicity. Cyanide biodegradation is affordable and eco-friendly. Sampling from cyanide-contaminated areas from the Muteh gold mine and isolation of 24 bacteria were performed successfully. The selected bacteria—‘Bacillus sp. M01’—showed maximum tolerance (15 mM) to cyanide and deposited in Persian Type Culture Collection by PTCC No.: 1908. In the primary experiments, effective factors were identified through the Plackett–Burman design. In order to attain the maximum degradation by Bacillus sp. M01 PTCC 1908, culture conditions were optimized by using response surface methodology. By optimizing the effective factor values and considering the interaction between them, the culture conditions were optimized. The degradation percentage was calculated using one-way ANOVA vs t test, and was found to have increased 2.35 times compared to pre-optimization. In all of the experiments, R2 was as high as 91%. The results of this study are strongly significant for cyanide biodegradation. This method enables the bacteria to degrade 86% of 10 mM cyanide in 48 h. This process has been patented in Iranian Intellectual Property Centre under Licence No: 90533

Investigating the relationship between stress and oral health-related behaviors changes in final year of high school students prior to university entrance exam

Background and Aims: Today, academic stress and subsequent test anxiety is one of the most important problems for the last year of high school students. In addition to systemic effects, stress can affect the level of oral health by disrupting oral health behaviors. The aim of this study was to investigate the relationship between stress and variables related to oral health in the final year of high school students prior to University entrance exam. Materials and Methods: In this descriptive-analytical study, the level of stress and variables related to oral health in 180 students of the final year of high school in Tehran, in three time periods during the academic year 2018-2019, were measured by a questionnaire and one clinical examination. Data were analyzed by Friedman, Bonferroni and Generalized Estimating Equations using SPSS software. Results: As the exam approaches, some variables related to the oral health, such as toothbrush usage pattern, daily sleep, fast food frequency, and sweet snack consumption, changed (P<0.05). Daily sleep changes were significantly associated with the stress changes (P=0.022). According to the results of the Repeated Measures Analysis, significant changes were observed between the average score of the "Cognitive Error" aspect of three times (P<0.001). Also, according to the results of the Bonferroni Test, significant changes related to the difference in the average score of "cognitive error" 6 months and 3 months before the entrance exam (P<0.001), 6 months and 1 month before the entrance exam (P<0.001), and 3 months and 1 month before the entrance exam (P<0.001) were observed. In all three cases, as the time of the entrance exam approaches, the score of "cognitive error" had decreased significantly. Considering that the lower score in this index indicates a higher level of test anxiety, the closer we get to the entrance exam, the higher the level of test anxiety in the "cognitive error" dimension Conclusion: The academic stress of the national university entrance exam can affect some oral health variables such as daily sleep, however, it is not related to other variables

Cyanide Biodegradation by <i>Trichoderma harzianum</i> and Cyanide Hydratase Network Analysis

Cyanide is a poisonous and dangerous chemical that binds to metals in metalloenzymes, especially cytochrome C oxidase and, thus, interferes with their functionalities. Different pathways and enzymes are involved during cyanide biodegradation, and cyanide hydratase is one of the enzymes that is involved in such a process. In this study, cyanide resistance and cyanide degradation were studied using 24 fungal strains in order to find the strain with the best capacity for cyanide bioremediation. To confirm the capacity of the tested strains, cyano-bioremediation and the presence of the gene that is responsible for the cyanide detoxification was assessed. From the tested organisms, Trichoderma harzianum (T. harzianum) had a significant capability to resist and degrade cyanide at a 15 mM concentration, where it achieved an efficiency of 75% in 7 days. The gene network analysis of enzymes that are involved in cyanide degradation revealed the involvement of cyanide hydratase, dipeptidase, carbon–nitrogen hydrolase-like protein, and ATP adenylyltransferase. This study revealed that T. harzianum was more efficient in degrading cyanide than the other tested fungal organisms, and molecular analysis confirmed the experimental observations