نشریه زیست شناسی کاربردی
سال سی و چهارم شماره 1 (بهار 1400)

This study aimed to find morphological traits to discriminate four species of the genus Cobitis in Iran using geometric morphometric method. For this purpose, a total of 65 specimens were captured from Sefid (C. saniae), Siah (C. faridpaki), Maloosjan (C. linea) and Gamasiab (C. avicennae) rivers using electrofishing device. To extract the body shape data of the studied taxa, 14 Landmarks-point were defined and digitized using tpsDig2 software. Data after generalized procrust analysis were analyzed using principal component analysis, multivariate analysis of variance /canonical variate analysis and cluster analysis.  The results showed a significant difference in the body shape between the studied species (p < 0.001). Cluster analysis positioned C. avicennae in one clade, distinguish from others. The results also revealed that the members of this genus can adapt themselves to the environmental parameters of their habitats by alternations in the body depth, head size and snout position, length of the caudal peduncle and positions of the dorsal, anal and pectoral fins.

Probiotics are living microorganisms that have an important role in prevention and treatment of diseases. The aim of this study was isolate yeast with probiotic properties due to the importance of probiotic yeasts. Sampling was performed from different parts of human skin. Growth ability of isolated yeast at concentrations of 0.3, 0.5 and 1% oxgall, 2, 4 and 6% NaCl, pHs of 2, 4, 5.8, 9 and 11 and temperature 37, 40 and 42°C were investigated. The activity of amylase, protease, pectinase, cellulase, lipase, urease, catalase, citratase and hemolysin was investigated. The yeast was able to grow in 0.3% oxgall, concentrations of 2, 4 and 6% NaCl, pHs of 2, 4, 5.8, 9 and 11 and also at a temperature of 37°C. The isolated yeast has the primary properties of probiotics and can be used in future studies.

Invasive species are globally endangered for ecosystems, and ecologists are increasingly concerned about them. Pteridium aquilinum is one of the most invasive species widely distributed in the world. This study investigated the phytochemical of Pteridium aquilinum species in different altitude gradients. So, random sampling was performed from vegetation and soil in three altitudes (0-700, 700-1400 and 1400-2100 meters) with three replications for both growth and reproduction stages. In the growth stage, the composition of Linalool was the highest value (1.09) in the altitude of 0-700m. During the reproductive stage, Sabinene and –α Thujene had the highest values in the altitude of 0-700m with 0.15 and 0.13%, respectively. The amount of oil in the growth stage is more than the reproductive stage, so it can be concluded that the growth stage will have a significant effect on the amount of oil compounds.

Plantago major L.  is one of the most important medicinal plants used in traditional medicine worldwide. This study was conducted to investigate the effect of ecological and edaphic factors on the active ingredients of this plant. For this purpose, the Plantago major was collected from different regions of Mazandaran province, namely Shorab, Pain Kola, and Panbeh Zar Koti. Phenol and flavonoid levels from acidic methanol extract of plant samples were calculated using standard curve of Gallic acid and Quercetin, respectively. Antioxidant activity of the samples were investigated by three methods of DPPH, Nitric oxide and Reducing power. Our results showed that all of the Plantago major not only have a total phenol, flavonoid content, and antioxidant activity but also they have a biological activity of the extract depends on its phenol and flavonoid content. On the other hand, the antioxidant function of Plantago major species is affected by weather conditions as well as habitat characteristics and edaphic factors. On the basis of these findings, it is suggested that the identification of the potential of the Plantago major extract and selection of optimal phenological habitat and phases is essential and enables the extraction of effective ingredients in the applied of the products and the ability to enhance the medicinal yield of the plants.

Increasing demand for industrial applications of various natural polymers has led to increased attention to the use of exopolysaccharides made by microorganisms. Since most lactic acid bacteria (LAB) are food-grade microorganisms with GRAS status (Generally Recognized As Safe), the use of the secreted EPS as natural alternatives to produce all-natural food products without additives from LAB has received increased attention. In this research, carbon and nitrogen sources suitable for the production of exopolysaccharides (EPSs) by Leuconostoc dextranicum, as GRAS bacterium, were investigated. The results showed that glucose (Glu) produced more EPSs in the medium compared to other sugars and peptone compared to other nitrogen sources. Therefore, only glucose and peptone were used to optimize the production conditions of EPSs. In order to investigate the effect and optimization of EPS production conditions, three parameters of temperature, pH and incubation time, each was selected at five levels and optimized separately. Then, optimization was performed to determine the levels at which independent variables attain the best production. Results showed that the best laboratory condition for EPSs production would be yielded at the incubation temperature of 40 °C, pH of 5.5 and fermentation time of 48 hours. In summary, the results of this study showed the potential of Leu. dextranicum as a native microorganism and the cheap culture medium of skimmed milk for producing such a valuable product.

Polygonum is one of the most widespread weeds in the world. To determine the best dormancy- breaking treatment, five dormancy-breaking treatments consisted of 10 and 20 min soaking in sulfuric acid, 0.2% nitrate potassium, wet chilling and 200 ppm gibberellic acid were studied. At second experiment germination percentage was evaluated under different alternating temperature and light regimes. seeds of ten populations were exposed to three levels of light (24 h darkness, 16 h light/8 h darkness and continuous light) and five alternating day/night temperature regimes 15/5°C, 20/10°C, 25/15°C , 30/20°and 35/25 ºC for 21 days. For third experiment, seven depths ( 0, 2, 4, 6, 8, 10 and 12 cm) were investigated. Results showed that best treatment for dormancy breaking was wet chilling for Prostrate knotweed and Lady’s thumb and sulfuric acid 20 min for Wild buckwheat. Germination of Polygonum species seeds occurred over a wide range of alternating temperatures but there were inter- and intraspecific differences in optimal temperature. Wild buckwheat was not dependent to light for germination. Seedling emergence decreased exponentially with increasing burial depth with highest emergence for unburied seeds. The influence of burial depth was extremely dependent on population. High seedling emergence of Prostrate knotweed and Lady’s thumb on the soil surface could be suggesting light requirements. Therefore, spreading of these species would be higher in fields with no-tillage or minimum-tillage practices. Increasing of tillage depth could be an effective weed management strategy to reduce seedling emergence of Prostrate knotweed and Lady’s thumb.

Kardeh River is one of the most important permanent rivers of Khorasan Razavi province Which supplies a large part of Mashhad's drinking and agricultural water. Multivariate analysis was used to find out the quality of Kardeh River in this study and to understand the impact of macroinvertebrates community structure drivers on ecosystem management. For this purpose, macroinvertebrates sampling was performed from four study stations during four seasons in 2018-2019, physical and chemical parameters also were measured. In this study, Of the Ephemeroptera, the total number of Caenidae and Baetidae families had the highest abundance (66 / 60 %). The results showed that the Index of Biotic Integrity varied from 3 to 1.1 and based on this biodiversity indicator, Kardeh River water quality was classified into three relatively good, poor and very poor quality classes. The Stream Invertebrate Grade Number Average Level index was classified into two categories: moderate pollution and severe pollution. Canonical Corrspondence Analysis also showed that nitrate, biochemical oxygen demand and chemical oxygen demand had the most effect on the distribution of macroinvertebrates at the study stations. In general, the Kardeh River water quality was poorly evaluated and among the study stations the station conditions were relatively better than the other stations. Therefore, among the available indices, multimetric indices are more reliable. However, these index should be calibrated according to the conditions of Iranian rivers.

In order to assess zebrafish swimming behaviour and colour preferences, 16 adult zebrafish were used individually using a T-maze model. Behavioural indices such as habituation time in the start box, approaching time to the decision area, the number of crossings and the time spent in each combination of coloured arms (green-red and blue-yellow) were calculated. Habituation time in the start box and approaching time to the decision area were 300 and 120 s, respectively. The results indicated that zebrafish have more crossings to the red arm and preferred red colour rather than green colour. (p < 0.05). But, there was no significant difference for the number of crossings in the blue-yellow combination (P>0.05). Also, the time spent in each combination of coloured arms was not significant (P>0.05). Based on the current results, zebrafish have the ability to discriminate between colours and the T-maze is a valid tool for assessing colour preferences in zebrafish.

Mesoporous iron oxide nanoparticles (MIONPs) have various applications in the medical and pharmaceutical industries. Therefore, investigating their effects on cancer cells could be of great essence. Accordingly, the aim of this study was to synthesize MIONPs and to compare their effect between lymphocytes and chronic myeloid leukemia cells (K562). MIONPs were made by the hydrothermal method and examined by scanning and transmission electron microscopy. The effects of different concentrations of MIONPs on lymphocytes and chronic myeloid leukemia cells (K562) were then investigated using MTT and flow cytometry (FCM) approaches. X-ray diffraction, transmission electron microscope, and dynamic light scattering (DLS) analysis verified the synthesis of MIONPs. The results showed that the nanoparticles were spherical in shape with an average diameter of about 100 nanometres. The results of the MTT test showed that the MIONPs reduced the life of the cells in a dose-dependent manner, although this toxicity was higher for the chronic myeloid leukemia cells (K562) compared to the lymphocytes. After the determination of IC50 concentration for MIONPs, flow cytometry was performed to investigate the programmed cell death (apoptosis) on chronic myeloid leukemia and lymphocytes cells.The rate of programmed death and necrosis in chronic myeloid leukemia cells treated with MIONPs was much higher than in lymphocytes. As a result, it can be concluded that porous iron oxide nanoparticles can be used as a possible anti-cancer agents.

The aim of this study was to evaluate the ability of treated Azolla filiculoides to uranium biosorption as a new biosorbent. In this study, uranium biosorption experiments were performed by untreated biomass and [Fe(CN)6]4--treated biomass and H2O2/MgCl2-treated biomass. Studies showed that the maximum uranium uptake capacity by various treated sorbents is pH 5. Freundlich isotherm was examined to evaluate the experimental data. The results showed that the treated sorbent with H2O2/MgCl2 is more efficient than other sorbents and its uranium adsorption is relatively rapid, reaching to the maximum in 60 minutes. Maximum uranium adsorption was obtained using the large adsorbent particles (2-4 mm). The maximum adsorption capacity of uranium ions by H2O2/MgCl2-treated sorbent under optimal conditions is about 42.2 mg /g dry biomass. The results showed that pretreatment can be a good way to increase the adsorption capacity of biosorbents.