مجله پژوهش های سلولی مولکولی (زیست شناسی ایران)
سال بیست و هفتم شماره 3 (پاییز 1393)

The rising popularity of natural aroma products has triggered off significant research activities to use biocatalysts for the production of natural flavor compounds. Vanillin is of major interest for the flavor and fragrance industry. It has been widely used as a flavoring agent in foods، perfumes، beverages، pharmaceuticals and medical industries. Two main approaches for the production of natural vanillin are direct extraction from botanical sources and microbial bioconversion. Considering the various applications of vanillin and increasing consumer-led demand for natural vanillin and also due to the fact that the extraction from botanic sources is very time consuming، expensive and does not satisfy the worldwide demand، alternative biotechnological methods for its production are being constantly explored. Microbial bioconversion has been extensively exploited to make modifications in the structure of the organic compounds. Microbial cells can be efficiently used as a eco-friendly biocatalyst in the conversion of substrates as precursors into value-added products. The current review emphasizes the microbial bioconversion routes involved biological production of natural vanillin based on the microbial conversion of henylpropanoids.

In this research، for the first time identification of moderate halophile microorganism of the genus Salinivibrio was studied، which leaded to identification of novel strains of this genus. Urmia Lake is a hypersaline lake located at the north-west region of Iran and it is the saltiest perennial lake of Iran and one of the rare perennial hyper saturation lakes in the world. At first، samples were collected from different sites of Urmia Lake and transferred to the laboratory under sterile conditions. After enrichment and culture of samples under defined conditions، repeated cultures were carried out to achieve pure cultures. Then selected strains were studied regarding phenotypic and phylogenetic (by sequencing 16S rRNA technique) characteristics. From total strains which were belonged to Salinivibrio sp.، 57% and 43% of the strains showed closest similarity with S. costicola subsp. alcaliphilus and S. sharmensis، respectively. This study is attempted to present of novel genetic pools from great microbial sources of Urmia Lake and especially Salinivibrio sp. that they are the base of wide applications in biotechnological science.

Oily Wastewater causes severe environmental pollution and damage to aquatic life. Different methods for treating the wastewater are applied to one of the most important biological methods. Enzymatic treatment of wastewater is also an example of the ways in which biological research has attracted much attention. The purpose of this study، isolation of bacteria producing lipase enzyme and then use them in the oily wastewater treatment. Two separate locations، including Abadan refinery soil and the Behshar Industrial town sewage treatment plant. Among the isolated bacteria، two strains of bacteria belonging to Staphylococcus and Flavobacter was used for subsequent studies. They ranged between 0. 6 to 3. 25 u/ml of lipase activity. The removal of the oil was measured using gravimetric، for concentrations less than 4 grams per liter to about 95% and for concentrations greater than 4 gr/l ranged from 20 to 50 percent.

In this study، we introduced a new biosensor for measurement of glucose by using of glucose oxidase enzyme، cadmium oxide nanoparticles and carbon paste electrode. Size of cadmium oxide nanoparticles were about 43 nm. The results indicated that produced carbon paste electrode modified with cadmium oxide nanoparticles، can facilitates electron transfer in stabilized glucose oxidase enzyme on the electrode surface. In addition، the reduced form of glucose oxidase enzyme could oxidize by solutions oxygen with an electro catalytic reaction، that this oxidation، due to reaction between the oxidized form of glucose and glucose oxidase and this reaction inhibited by glucose. Based on electro catalytic decrease of glucose oxidase enzyme in saturated oxygen solution in the presence of glucose، a new sensor was designed for glucose. Designed sensor has high sensitivity and in linear range of 20 µM to 360 µM and can be used to determine glucose. This biosensor also has very good stability.

Metal salen complexes have been widely studied as potentially pharmaceutical substances with antioxidant and anti cancer effects. In this investigation the salen ligand was synthesized and injected in the air sac of the eggs. The liver and fibroblast cell cultures were treated by the compound and the proportion of the live cells was recorded. The survival fraction of the embryos was 23. 5% in the uppermost concentration of the compound and the LD50 was 91. 8 μM/egg. The morphological studies showed clubfoot، the abnormality of beak and ectopic viscera، and the skeletal staining showed the deletion and unosification of the caudal vertebrates، the brevity and the bending of tibia. The compound inhibited the growth of liver and fibroblast cells with the IC50 of 1159. 3 and 964. 7 μM، respectively. The treated cells were round، the inter-cellular connection became loose، the proliferation was inhibited، and the granules in the cytoplasm were increased. The compound significantly affected the proliferative cells compared with the cells were arrested in growth.

H+-ATPase proton pump is one of the major proteins found in plasma membrane of plants which plays an important role in molecular physiology of stress response. Aeluropus littoralis grass due to resistance to some environmental stresses like salinity and heavy metals is a good model for studying the structure and function of the plasma H+ATPase pump. In this study as a starting point، the complete coding sequence of the gene were identified and cloned from Aeluropus littoralis halophyte. Preliminary data showed that nucleotide sequence of A. littoralis plasma membrane proton pump contains a 2856 bp full-length ORF region that shared a significant homology with Sorghum bicolor، Oryza sativa and Zea mays. Also the predicted peptide of this gene consists of 165 amino acid residues with a molecular weight of 104567 Da which is in terms of domains type and structure، consistent with most plant and fungal plasma membrane H + ATPase protein type III (type III) from a large family pump ATPase p-type. Comparative alignment of amino acid sequence of A. littoralis plasma membrane H+ATPase with some species indicated that nucleotide substitutions did not targeted critical and functional positions of protein and these regions remained conserved. At last the sequence was submitted to GenBank with accession number of GI: 346230720.

Complex of enzymes in the name of Ligninase are involved in lignin degradation. Special properties of Laccase among the lignin degradation enzymes make them more important. Oxidation of wide range of substrates، high heat tolerance and acidic isoelectric pH are main properties of laccase. Identification of new microorganism with higher production and secretion laccase is very valuable. In this research، laccase producing fungi was isolated، screened and identified from bagass and sugarcane rhizosphere. In order to screen laccase producing strains malt extract agar medium containing 0. 1gl-1 ABTS or 0. 5mMl-1 Guaiacol was used. Laccase activity was determined as described by Niku-Paavola et al. In this study، among 22 fungi screened، Alternaria alternata and Retroconis sp isolates were identified with the highest laccase production. Two species were identified using PCR amplification and sequencing of the internal transcribed spacer ‘ITS’regions of the ribosomal DNA and by basic morphology. In this research laccase activity has been determined in agitation and stationary state. These results showed that agitation and stationary conditions had different effects on laccase production rate of these isolates.

Chemotherapy has been used for centuries in cancer therapy. Different compounds and drugs are used in chemotherapy; each is applied for a specific type of cancer. Among them; plant compounds including lignans، have been used in medicine for a long time. Podophyllutoxin is a member of lignans family that is mostly extracted from Podophyllum species. It has multiple biological properties such as antiviral، antifungal and anticancer properties. Considering anticancer property of podophyllutoxin، it is used in Wilm`s tumor and genital tumors treatment. Also، it has been shown that podophyllutoxin causes apoptosis in ovary carcinoma cell line (Hela). There is not yet any report of the effect of podophyllutoxin on bladder carcinoma cell line such as 5637. In this study، we have evaluated the effect of podophyllutoxin on cell viability and apoptosis of 5637 cell line، and we have shown that podophyllutoxin causes apoptosis and death of these cells. It seems that podophyllutoxin can be an active agent to induce apoptosis of cancer cells.

Petroleum pollution is the most important soil pollution. Bioremediation is an effective and usable technology for remediation of polluted soils. Some microorganisms have bioremediation potency for petroleum compounds. In this research Tabriz city was selected as a cold area of Iran for studying of native bacteria with biodegradation potency of crude oil. Soil samples were collected from polluted soils of Tabriz refinery and their bacteria were accommodated to crude oil. The bacterial strains exited in the samples were isolated، grouped and determined. The growth ability and petroleum removal efficiency were evaluated for the each bacterium at the different crude oil concentrations during a month. In this research، seven bacterial species were found that are well accommodated to crude oil. The highest petroleum removal efficiency (98%) was determined for Pseudomonas aerogenesis at concentration of 0. 5%. Biological removing of crude oil with high efficiency is possible by soil bacterial flora، as an environmental friendly method، even for soil cleaning of the industrial areas in cold temperature regions.

The effects of feeding strategy of broiler breeder hens on reproductive performance and ovarian morphology from 42 to 54 week of age were studied with using 50 Ross 308 broiler breeder hens. Hens were randomly divided to 2 groups of restricted (160 g/d) and ad libitum (208 g/d) feeding. Ad libitum fed hens had 630 g heavier body weight than restricted hens. Egg production rate decreased 23. 3% during the first 2 weeks of experiment in ad libitum fed hens compared to restricted hens. Egg weight was increased quickly during first 5 week of experiment in ad libitum fed hens and then continued slowly. Percentage of fertility and hatchability significantly decreased in ad libitum fed hens compared to restricted hens (P≤0. 05). Ad libitum fed hens had more atretic and third follicles (P≤0. 05). However، there were no significant difference in ovary weight between the two feeding group، oviduct weight was lower in ad libitum fed hens (P≤0. 05). Abdominal fat pad weight، liver weight، percentage of liver lipids and cholesterol was higher in ad libitum fed hens compared to restricted hens (P≤0. 05). Microscopic examination of liver tissue revealed huge vacuoles of fat which was not detected in restricted hens. Results indicate that ad libitum feeding of broiler breeder hens by increasing of fat deposit in abdomen and liver، reduce reproductive performance.

RNA molecule plays important and fundamental roles in many biological processes. In the most times، activities of RNAs are determined by their structures. In notice to complexity and costly of laboratory methods to predict RNAs structure، computational approaches are used. There are variety of algorithms to predict RNA secondary structure. In this paper، a genetic algorithm called RNAG is presented to predict the RNA secondary structure based on minimum free energy (MFE). In this algorithm، each individual of population includes some stems. The individuals are increasingly ranked based on fitness value of MFE from stems and loops، and in the follow، crossover and mutation operations are done on individuals to make a new population، respectively. Process of population generation continues until an individual with proper MFE is produced. Finally، this individual is selected as an optimal RNA secondary structure. The proposed algorithm is performed on some RNAs in the bacteria. Results of the paper show that RNAG algorithm has a high accuracy in comparison with the other related methods.

Dimethylsulfoxide (DMSO) is one of the cryoprotectants utilizing in freezing and long term maintenance of the cells. In this study، the mechanism of protection of this mater in relation with cell death and autophagy is envisaged. Study of the expression level of autophagic genes (atg5، lc3، beclin1، dram و p53)، using real time RT-PCR، indicated that at the lowest concentration of DMSO the genes involved in autophagy are over-expressed، thus regarding to death autophagy induction، the cells have lower viability relative to those cells which are freezed at the higher concentrations of cryoprotectant. Increasing cell viability، at the greater concentrations of DMSO (over than 10%)، occurs because of the converting of death autophagy to cytoprotective one which is supported by means of over-expression of the genes involved in the survival pathway. Simultaneous study of autophagy and AKT/mTOR pathway can be utilized as a separating method for death and survival autophagy.

In this study، expression of mature Hepatitis C virus core protein (HCVC173)، consistent with a viral isotype isolated in Iran، was studied in E. coli. The 20 kDa- HCVC173 protein was expressed while it contains 18% of total expressed proteins in which a part was partially soluble but the main part was expressed in insoluble inclusion body. However، the produced inclusion body has not shown the expected purity and HCVC173 has been aggregated with the host proteins. Moreover، during refolding of insoluble HCVC173، notable aggregation of the protein was undesirable phenomena. Intramolecular evaluation of target expressed protein predicted two irregularity area in the HCVC173 which may aggregate the expressed protein. Consequently، HCVC173 has the features of the intrinsically unstructured proteins. This character may justify its aggregation during refolding. Moreover، the approach presented in this paper is an alternative solution to overcome the expression limitation of mature form of the HCVC protein.