Sogol Tavanaeian, Javad Hamedi, Setareh Haghighat,
Volume 7, Issue 1 (4-2020)
Abstract
Exopolymers (EPS) are high-molecular-weight polymers secreted by some micro-organisms and have several applications in food, pharmaceutical, packaging and agricultural industries, as well as medicine. Actinobacteria are valuable bacteria in biotechnology and many commercial drugs such as antibiotics, antioxidants and immune-suppressant agents are derived from Actinobacteria. Recently, their other capabilities such as exopolymer production have been taken into consideration. Due to the high potential of actinobacteria in producing various compounds and increased prevalence of infections by antibiotic-resistant pathogens, the aim of the present study was to evaluate the potential of isolated Actinobacteria from various locations of Iran to produce EPS with antimicrobial activity. Appropriate dilutions of the samples were, therefore, cultured in ISP2 medium after treatment. The isolates were primarily identified by morphological tests. Then, their ability to produce EPS was investigated in BHI medium with 5% sucrose. The exopolymers of the most efficient strain were analyzed by UV-visible spectroscopy and FT-IR. Finally, the most efficient isolate was molecularly identified. Of the 120 isolates, 38 were able to produce EPS, and six had significant capability of producing EPS (10-14 g/L) and showed antibiotic activity against Staphylococcus aureus, Bacillus subtilis and Aspergillus niger. The EPS of the strain So49 had high absorbance in 190-230 nm, but did not have absorbance in 260-280 nm. Therefore, it does not have any protein impurity. The EPS has hydroxyl and carboxyl functional groups, according to FT-IR analysis. 16S rRNA gene analysis showed that the most efficient isolate had 99.68% similarity to Promicromonospora xylanilytica.
Mehrdad Ghiasvand, Ali Makhdoumi, Maryam Moghaddam Matin, Jamil Vaezi,
Volume 8, Issue 2 (7-2021)
Abstract
Regarding the rising rate of esophageal cancer in some parts of Asia, including northern and northeastern regions of Iran, the identification of new anti-cancer compounds is essential to combat the disease. The relation between some plants metabolites and these endophytic microorganisms are well characterized. In the current study, the potentials of Ephedra endophyte bacteria for the inhibition of esophageal cancer cell line (KYSE-30) proliferation were investigated. A total of 54 endophyte bacteria (out of 70) were obtained from the sterilized surfaces of two medicinal plants, i.e., Ephedra intermedia and Ephedra foliata. Bacterial strains were then cultured in Tryptic soy broth (TSB) medium and, after 72 h incubation, the produced secondary metabolites were extracted by chloroform. Anticancer effects of secondary metabolites from theses bacteria on esophageal cancer cell line KYSE-30 were evaluated after 24, 48 and 72 h by MTT method. MTT assay results showed that only strain A1 had a cytotoxic effect on KYSE-30 cells. The IC50 amounts of this strain against KYSE-30 cell lines were equaled (µg/ml) to 346.4, 192.8 and 121.3 after 24, 48, and 72 hours, respectively. The molecular identification of strain A1 revealed that Microbacterium maritypicum (99.8% similarity) was the closest identified taxon to the strain studied. According to the promising ability of strain A1 to inhibit the growth of KYSE-30 cell line, the use of natural compounds produced by this bacterium to treat esophageal cancer was found to be applicable. However, more experiments are needed to confirm these results after purifying the ingredients, as well as conducting studies in animal cancer models.
Raheleh Ahmadpour, Roya Ghalavand, Saeed Reza Hosseinzadeh, Nezam Armand,
Volume 9, Issue 4 (3-2023)
Abstract
Successful germination is the main factor in proper establishment and seedling yield. Information on seed germination, in the face of temperature changes at the time of planting, is a way to identify more suitable cultivars for cultivation at the planting site. For this purpose, a factorial experiment was performed based on completely randomized design with 3 replications. This experiment was conducted to investigate the temperature changes on the germination and growth indicators of lentil cultivars at Khatam Al-Anbia University of Behbahan. The studied treatments included five lentil cultivars of Gachsaran, Kimia, Robat, Ziba and Bilehsevar, and the temperature levels were 20, 25 and 30 °C, similar to the autumn conditions of Khuzestan Province. The results showed that all the seedlings of investigated cultivars cultivated at temperatures of 20 and 30 °C had a significant decrease in all the investigated traits, i.e., germination percent, germination rate, germination vigor, seed vigor index, endosperm consumption, plumule length, radicle length, seedling length, plumule dry weight and radicle dry weight, in comparison with those seedlings cultivated in 25 °C. The study of the interaction of cultivar-temperature effects showed that Bilehsevar cultivar had the highest germination and growth indices at 25°C compared to other investigated cultivars. This increase in traits such as germination rate, germination vigor, seed vigor index, plumule dry weight and radicle length was more significant in Bilehsevar cultivar compared to other cultivars. The second rank of the highest germination and growth indices was assigned to Gachsaran cultivar under 25°C conditions, which had a significant increase compared to other cultivars (Kimia, Robat and Ziba). Considering the autumn cultivation of lentils and the changes of temperature in that season (temperature range of 20 to 30 °C) in the studied area, the use of Bilehsevar and Gachsaran cultivars under the temperature of 25 °C, due to their higher germination indicators compared to the other cultivars, i.e., Ziba, Kimia and Robat, could be recommended.
