European Journal of Biological Research <p><strong>ISSN: 2449-8955</strong><br><strong><a title="MNiSW points: 11" href="" target="_blank" rel="noopener">MNiSW points 2016: 11<br></a></strong><a title="ICV: 93.39" href=",p24783440,3.html" target="_blank" rel="noopener"><strong>ICV 2016: 95.65</strong><br></a><strong>Acceptance rate: 2016 - 64%, 2017 - 56%</strong><br><strong>Google-based IF (2017): 0.586&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; h-index: 11</strong><a title="ICV: 93.39" href=",p24783440,3.html" target="_blank" rel="noopener"><br></a></p> TMKarpinski Publisher en-US European Journal of Biological Research 2449-8955 Plant Growth Promoting Rhizobacteria (PGPR) and their various mechanisms for plant growth enhancement in stressful conditions: a review <p>The population has been rising in a rapid state and so is the demand of basic necessities like food requirements. Today agriculture demands increase in yield with a substantial decrease in chemical fertilizer and pesticides that are responsible for huge environmental degradation. Today a huge part of yield has been lost due to various stresses plant are subjected too. It could be broadly divided into biotic and abiotic stress. Meanwhile, plant growth promoting rhizobacteria has promised us a substantial agriculture development platform. These are generally a group of microorganism that is found either in the plane of the rhizosphere or above root impacting some positive benefits to plants. These stresses include but in no sense limited to ion toxicity, pathogen susceptibility, physiological disorder, salinity, temperature, flooding, pH etc. In response to the above-mentioned stresses plant with PGPR exhibits various sorts of response to handle these unfavorable conditions. They could be further divided into direct and indirect mechanics. PGPR has shown both synergistic as well as antagonist interaction with microorganism inhabiting in near surrounding to boost plant favorably. This review has tried to undertake all possible mechanism of PGPR along with reported studies for various possibilities through which sustainable agriculture development could take place. This review has tried to understand the mechanism to take PGPR at a commercial level under bio-fertilizer.</p> <p><strong>DOI</strong>: <a href=""></a></p> Indranil Singh ##submission.copyrightStatement## 2018-10-10 2018-10-10 8 4 191 213 Capability of Plant Growth-Promoting Rhizobacteria (PGPR) for producing indole acetic acid (IAA) under extreme conditions <p>Plant Growth-Promoting Rhizobacteria (PGPR) inhabiting the area around the plant roots or in plant tissues and stimulate plant growth directly or indirectly. Synthesis of the phytohormone auxin indole-3-acetic acid (IAA) is one of the direct effects of PGPR on plant growth. This study aimed to isolate and screen IAA producing bacteria from soil and study the impacts of the alkalinity and salinity on IAA production and total antioxidant activity of the highly IAA producing strain. From the fifteen isolates tested, six were selected as efficient IAA producer, from which one isolate was highly IAA producer. The highly producing isolate was identified based on molecular characteristics using 16S rRNA. The sequence analysis showed 99% similarity with <em>Bacillus subtilis</em> from GenBank data base. The strain yielded IAA in a wide range of pH (5-9), giving its maximum IAA production at pH 8. High IAA concentration was also observed in the presence of 0.5% and 1% NaCl in comparison with control (with no NaCl). Furthermore, the results indicated that, total antioxidant was increased in acidic (pH 5 and pH 6) and alkaline (pH 8) media, as well as in salinity up to 2%. This study could be stated as the prospective of IAA producing bacterial isolate in the field, as a result, using it as alternative valuable biofertilizer.</p> <p><strong>DOI</strong>: <a href=""></a></p> Naeima M. H. Yousef ##submission.copyrightStatement## 2018-09-10 2018-09-10 8 4 174 182 Dynamics of oxygen consumption during the formation of the anoxic zone in aquatic environment <p>Anoxic environments and communities of anaerobic organisms are encountered in aquatic environments and biotechnological reactors. Because of their importance, they are continuously studied. In this study, the dynamics of oxygen removal were observed during experiments reproducing the formation of the anoxic zone. Seven experiments were performed in an aquarium (volume: 60 l) with bottom sediments and water collected from different aquatic environments (river, pond, eutrophic lake, sea). To exclude reaeration, the water was isolated from the air by a layer of liquid paraffin. Below the paraffin layer the water was periodically mixed with a stirrer and sampled for oxygen concentration. Initially, a high rate of oxygen consumption was observed. Later, at low oxygen concentrations, the oxygen removal rate switched to a much lower one. Anoxic conditions were observed after 4-20 days of incubation, depending on the experiment. The point at which the microbial community converted from aerobic respiration to anaerobic metabolism was distinct and was observed at an oxygen concentration of 0.26-1.41 mg/l, depending on the experiment. The experiments were accompanied by bacterial counts and analyses of ciliate communities. The study indicates how the disappearance of oxygen during anoxic zone formation should be modeled, and provides data on the oxygen removal rates associated with aerobic and anaerobic communities of microorganisms.</p> <p><strong>DOI</strong>: <a href=""></a></p> Krzysztof Rychert Beata Mendrzejewska Anna Kiestrzyń ##submission.copyrightStatement## 2018-10-03 2018-10-03 8 4 183 190 Heavy metal composition in the Plantago major L. from center of the Murmansk City, Kola Peninsula, Russia <p><em>Plantago major</em> is an indicator of environmental pollution in the city. The plant grows along the traversed paths, close to the sidewalks. Contaminating substances accumulate on the leaves of the plantain. In the summer of 2016, samples of plants were collected in the central Murmansk region for analysis using a scanning electron microscope to identify dust particles on their surface, and to study leaves using the ICP-MS method to determination of heavy metals content. A relatively serious concentration of lead, zinc, copper, nickel as well as high arsenic and chromium content has been demonstrated in the city center, along with ties with human activities (vehicular traffic). High iron content is associated with peat soils used in the city for fertilization. The remaining metal content is relatively low.</p> <p><strong>DOI</strong>: <a href=""></a></p> Miłosz Andrzej Huber M. Y. Menshakova S. Chmiel G. V. Zhigunova R. Dębicki О. А. Iakovleva ##submission.copyrightStatement## 2018-10-12 2018-10-12 8 4 214 223 Anti-oxidant effect of Flemingia stricta Roxb. leaves methanolic extract <p>Aim of the study was to evaluate the possible anti-oxidant activity of <em>Flemingia stricta </em>leaf extract. In antioxidant study, plant crude methanol extract was evaluated for 1,1-diphenyl,2-picrylhydrazyl (DPPH) and reducing power capacity. Moreover, total phenolic and total flavonoid content of plant extracts were determined and expressed in mg of gallic acid equivalent per gram of dry sample (mg GAE/g dry weight). In the DPPH free radical scavenging assay, methanol extract showed concentration dependent inhibition of the free radicals. IC<sub>50</sub> of ascorbic acid and <em>F. stricta</em> leaves were 4.25 µg/ml and 320.47 µg/ml respectively. In case of reducing capacity, the methanol extract at concentrations of 25, 50, 100, 200, 400 µg/ml, the absorbances were 0.56, 0.92, 1.41, 1.76, 2.23, respectively. Total phenolic content was estimated by gallic acid and expressed as milligrams of gallic acid equivalent (GAE). The methanol extracts contained a considerable amount of phenolic contents of 482±8.72 of GAE/g of extract and the total flavonoid content of the <em>F. stricta</em> leaf was estimated by using aluminium chloride colorimetric technique and found that the extract contained flavonoid content 340.625±4.50 of GAE/g of extract. These results suggested that the methanol extract of <em>F. stricta </em>Roxb. possess anti-oxidant activity.</p> <p><strong>DOI</strong>: <a href=""></a></p> Md. Shahrear Biozid Mohammad Nazmul Alam Md. Jainul Abeden Ahmad Ibtehaz Chowdhury Md. Faruk Khandoker Usran Ferdous Iffat Ara Nitul Md. Masudur Rahman ##submission.copyrightStatement## 2018-10-23 2018-10-23 8 4 224 231 Biochemical composition and antioxidant properties of some seaweeds from Red Sea coast, Egypt <p>The current study investigated the biochemical composition and antioxidant properties of four seaweeds: <em>Laurencia</em> sp. (Rhodophyta), <em>Cystoseira myrica</em>, <em>Hydroclathrus clathratus</em> and <em>Padina pavonica </em>(Ochrophyta). The highest amount of carbohydrates was (215.78 mg/g dry wt.) in <em>Laurencia</em> sp. and proteins content was maximum (50 mg/g dry wt.) in <em>Laurencia</em> sp. and <em>Cystoseira myrica</em>. The highest values of free amino acid content were recorded in the brown seaweed species <em>Cystoseira myrica</em> (4.01 mg/g dry wt.). The pressurized hot water extract of <em>Cystoseira myrica</em> has the highest total phenolic content (1.61 mg GAE/g dry wt.). Cy<em>stoseira myrica</em> contained the highest amounts of flavonoids (3.35 mg/g dry wt.), ascorbic acid (9.07 mg/g dry wt.) and α-tocopherol (27.25±0.00 abs. at 520 nm/g dry wt.). Furthermore, the ethyl alcohol extract of <em>Cystoseira myrica </em>showed high antioxidant capacities (541.6 mg/g dry wt.) and achieved the most powerful reducing ability among all of the different extracts of algal species. Statistical evaluation by Spearman correlation between the TAC assay and the total phenolic contents was found to be significant, but the correlation was nonsignificant between FRAP assay and the total phenolic contents. The composition of elements of the studied seaweed species was also analyzed. The most significant macro-elements present in the studied seaweeds were K, Na and Ca, representing that the seaweeds are good sources of these elements. Since, these seaweeds are widespread in the Egyptian waters, their biochemical composition and antioxidant capacities made them promising candidates for industrial, nutritional and pharmaceutical applications.</p> <p><strong>DOI</strong>: <a href=""></a></p> Rasha M. El-Shazoly Mustafa A. Fawzy ##submission.copyrightStatement## 2018-11-06 2018-11-06 8 4 232 242