Nadjette DJEMOUAI, Atika MEKLAT, Rabéa GACEB-TERRAK, Khadidja OULAD HADJ YOUCEF, Asma NACER, Salim MOKRANE, Noureddine BOURAS, Carol VERHEECKE-VAESSEN
Abstract. Actinobacteria isolated from the rhizosphere of plants are of interest as they produce a diverse range of molecules, such as antibiotics and enzymes. This study investigates the antibacterial activity, plant growth-promoting (PGP) abilities as well as the production of extracellular enzymes by the actinobacterial strain BTS40. This strain was isolated from the rhizospheric soil of the medicinal plant Artemisia herba-alba Asso that was naturally grown in a semi-arid environment. Morphological characteristics showed that the strain BTS40 belongs to the genus Streptomyces. Analysis of BTS40’s 16S rRNA gene sequence showed 99.45% similarity to Streptomyces alboniger NRRL B-1832T, in the EzTaxon database. This actinobacterium showed only antibacterial activity against Gram-positive bacteria. The strain also showed potential multiple traits for plant growth promotion and hydrolysis of enzymes. Hence, this study reveals that strain BTS40 has multiple PGP traits and produces many extracellular hydrolytic enzymes.
Key words: Artemisia herba-alba; rhizosphere; Streptomyces; taxonomy; PGP; enzymes; semi-arid area; Algeria.
Abderrezak CHEBOUTI, Fadila BESSEDIK, Nassila MEZIANI, Soraya AMRANI
Abstract. The aims of the present research were to study the nodulation in local populations of Medicago truncatula collected from different steppe regions of Djelfa (Algeria), isolate rhizobial strains nodulating M. truncatula to evaluate their tolerance to some environmental stress. Five M. truncatula populations were evaluated for their nodulation and growth. Nodules collected were used for the isolation of the rhizobia strains. Twelve strains were isolated and purified in YEM medium containing Congo red. Strains were tested for their tolerance to high temperature (30, 32, 35, 40 and 44 °C), to different concentraions of NaCl (200, 400, 600 and 800 mM) and to different levels of pH (5.5, 6.5, 7.5, 8.5 and 9.5). Results of variance analysis showed significant differences, nodules number and nodules and root biomass between M. truncatula populations, but aerial biomass did not exhibit significant diferences. For physiological characterization of rhizobia, the assessment of the tolerance of all strains to salinity, pH and high temperatures showed some strains with high tolerance to NaCl (600 mM) and high temperatures (>40 °C). The strains were also able to grow over a fairly wide pH range from 4.5 to 9.5.
Key words: Medicago truncatula; nodulation; rhizobia; temperature; salinity; pH.
Assia BOUCHEMAL, Halima SLIMANI, Réda DJEBBAR
Abstract. Coastal dunes are a globally distributed ecosystem characterized by strong internal gradients in disturbance and abiotic stress. When plants are subjected to these environmental stresses, the balance between the production of reactive oxygen species (ROS) and the quenching activity of antioxidants is upset, often resulting in oxidative damage to lipids, protein, and nucleic acids. Plants possess several antioxidant systems that protect them from these cytotoxic effects. In the present work we reported for the first time the results of the study of the antioxidant systems in leaves of ten plant species characteristic of coastal dunes by the measurement of the antioxidant activity of superoxide dismutase (SOD), guaiacol peroxidase (GPOX) and catalase (CAT), as well as total non-enzymatic antioxidant capacity and proline content. Our study results showed a varied response in studied species to abiotic stress in coastal dune. This variation in the response of the studied species with respect to oxidative stress is an intrinsic character. Thus, the following species Pancratium maritimum, Diotis maritima, Ononis variegata, Cakile maritima and Orlaya pumila were more adapted under stress. The tolerance of these species to abiotic stress firmly linked to higher capacity of CAT, SOD activity and/or GPOX therefore a low MDA content and efficient non enzymatic activity (Total non-enzymatic antioxidant capacity and proline). However other species (Ammophila arenaria, Agropyrum junceum, Lotus creticus and Salsola kali) were characterized by a low effective antioxidant defense, with high MDA. We can also conclude that Eryngium maritimum is the less affected species with oxidative stress with low MDA and antioxidant activity.
Key words: coastal vegetation; antioxydant enzymes; non-enzymatic antioxidant; proline; malondialdehyde.
Maria DUCA, Ion BURCOVSCHI, Ion GÎSCĂ
Abstract: Quantitative traits (plant height, number of leaves, head diameter, number of achenes per head, achene weight per head thousand seed weight, hectolitre mass of seed and seed yield) of 25 sunflower hybrids, created within AMG-Agroselect Comert LLC were analyzed. Homogeneity of individuals, relative contributions of genotype, environment and genotype environment interaction in determining the variance of the respective traits in different climatic conditions of two growing season (2019, 2020), were assessed. Some traits such as the head diameter and the number of leaves has practically not changed, and the hectolitre mass even registered a slight increase in 2020 compared to 2019. The parameters achene weight per head and number of achene per head, followed by seed yield have the highest degree of variation related to growing season. The drought conditions in 2020 also caused a decrease in the phenotypic uniformity of sunflower populations according to various traits. Coefficient of variation (CV) of the individuals of a population according to the achene weight per head, registers an increase of almost 6 times, in 2020 compared to 2019. The analysis of variance showed that the achene weight per head, number of achenes per head, seed yield and plant height traits is determined to a greater extent by environmental conditions (E) than by genotype (G). A higher stability of most traits was established for 2019 compared to 2020, which is explained by the unfavorable climatic conditions manifested in 2020.
Keywords: Helianthus annuus L.; quantitative traits; genotype-environment interaction; climatic conditions.
Cristina STANCĂ-MOISE
Abstract. The study of museum collections is a permanent concern for us, and the publication for the first time of the data from these collections have scientific, systematic and faunistic importance, providing information about the evolution in time of different species of lepidopterans. This paper aimed to present the collection data for two species belonging to the Genus Vanessa, Vanessa atalanta and Vanessa cardui. The collections of Lepidopterans studied and where these species have been identified are made by: Daniel Czekelius, Eugen Worell, Viktor Weindel, Heinrich Hann von Hannenheim, Rolf Weirauch and Eckbert Schneider. Following the analysis, a total of 101 specimens were concentrated, 52 of the Vanessa atalanta species and 49 specimens of Vanessa cardui. Most of the specimens collected during the time interval between 1904-1984, come from Sibiu and the surroundings of Sibiu or other places in Transylvania. Within the collections, there are also some specimens coming from Dobrogea and Banat but also from other countries such as Republic of Moldova and Spain.
Key words: Vanessa atalanta; Vanessa cardui; Lepidoptera; Nymphalidae.
Nadejda EFREMOVA, Alina BEȘLIU, Agafia USATÎI, Bîrsa MAXIM
Abstract: At the moment, technologies based on the use of nanomaterials in various fields of medicine and industry are developing. The study of the influence of metal nanoparticles on microorganisms is an important area of modern biotechnology and microbiology. Of particular interest in this regard, is the use of microbiological methods for assessing the effects of metal nanoparticles on living organisms. Among other nanoparticles, zinc oxide nanoparticles are probably the most widely used nanomaterials. The cell viability is one of the important parameters for the determination of nanotoxicity. The present research paper contains information related to the validation of the method for microbial counting for pigmented yeasts cultivated in the presence of ZnO nanoparticles. The validation of this method was performed according to the USP 30-NF25 and method validation by U.S. Environmental Protection Agency. Pigmented yeasts were selected for this research. The microbial counting method was validated to ensure precision, accuracy, linearity and robustness and can be applicated safely for the study of the effect of nanoparticles on microorganisms cell viability.
Key words: validation; microbial count; yeasts; ZnO nanoparticles
Tassadit AZOUAOUI-AIT KETTOUT, Rabéa GACEB-TERRAK, Baya BOUCENNA-MOUZALI, Fatma RAHMANIA
Abstract. Fusarium oxysporum f. sp. albedinis (Foa) is one of the major soil-borne pathogens that induces vascular wilt on date palm (Phoenix dactylifera L.), known as Bayoud. Although extensive studies have been carried out on the biology of Foa, little is known about the compounds that stimulate or inhibit this fungus. In this study, the effect of flavonic aglycones isolated from date palm leaves on fungal growth, sporulation and fusaric acid (FA) production of Foa was investigated. The flavonic aglycones extract was obtained by acid hydrolysis of the leaves of two date palm cultivars: Takerboucht (TK, a bayoud-resistant cultivar) and Deglet Nour (DN, a susceptible cultivar). The results indicate that the leaflets of TK contain a low amount of flavonic aglycones, estimated at 0.02 mg.g-1 equivalent of quercetin, while the leaflets of DN contain a high amount with approximately 0.21 mg.g-1 equivalent of quercetin. TLC analysis shows the presence of three flavonols: quercetin, isorhamnetin, kaempferol, and three flavones: luteolin, tricine, chrysoeriol. It is well known that Flavonoids are essential in the resistance of plants against pathogenic fungi. Activities of flavonic aglycone from date palm leaves against Foa were evaluated using agar dilution methods. The experimental results demonstrate that TK flavonic aglycone to Foa culture medium stimulated mycelial growth and inhibited conidiogenesis and FA production. The rate of inhibition of these two last processes on the 4th day of incubation was 91.66% and 87.14%, respectively. In addition, DN flavonic aglycones only affect FA production, the reduction rate being 88.17%. Furthermore, activity of flavonic aglycones in date palm leaves depends on incubation time and cultivar type. In addition, it is very interesting to note that leaf extracts could be applied to control fusariosis vascular (Bayoud) in date palm.
Key words: Fusarium oxysporum f. sp. albedinis; date palm, bayoud; flavonoïdes; antifungal activity
Kumkum VERMA, Neelam GARG
Abstract. Extracellular chitinase was produced by a chitinolytic bacterium, Bacillus licheniformis NK-7, under submerged fermentation. Maximum chitinase production (398.36 U/mL) was obtained when fermentation was carried out at 30°C for 72 h using 1500 µL of 24 h old bacterial culture in a 50 mL minimal salt medium (pH-7) amended with chitin (0.5% w/v; pH-6) under 150 rpm agitation rate. Supplementation of additional carbon, nitrogen and metal ion sources such as lactose, yeast extract and manganese (Mn2+) respectively increased the chitinase production. Further, B. licheniformis NK-7 chitinase demonstrated antifungal activity against Fusarium sp., Curvularia sp. and Aspergillus niger. Protoplasts were also isolated from Aspergillus niger by the action of chitinase produced from B. licheniformis NK-7.
Key words: Chitin; chitinase; submerged; enzyme; fermentation; antifungal; protoplasts.
Aida BOUSBIA BRAHIM, Abdelmalek ZAATER, Bachir KHEZZANI, Fatma ALIA, Atef CHOUIKH
Abstract: This work aims to carry out a quantitative and qualitative assessment of the effect of type of soil on the physicochemical and biological properties of the Portulaca oleracea L. growing in two different regions of the southeast of Algeria. For this purpose, sampling tests on saline and sandy soils were considered and values of electrical conductivity, ash percentage, the polyphenol content and its fractions were measured for both types of soil. It was shown that the plant cultivated in sandy soil showed better physicochemical and biological properties, except the anthocyanin content, which has the tendency to increase in some saline soil. According to High-Performance Liquid Chromatography (HPLC) results, it was observed that the chlorogenic acid and naringin are present in all the subtracts issued from the Portulaca oleracea L. However, higher quercetin concentration compared to the other phenolic compounds was observed. The Inhibition Concentration (IC50) values obtained by the (DPPH.) test show fluctuation in the antioxidant activity of extracts that varies between 18.62 to 399.60 μg/mL. This indicates that the reducing capacity of the extracts is medium in saline soil and highly variance in sandy soil. In addition, the extracts of aerial part showed a better total antioxidant capacity compared to the extracts roots. Regarding the values of the Sun Protection Factor (SPF), we could say that all samples of the plant have given average protection values, highlighing that the roots showed better values compared to aerial parts of the extracts. Statistically, the type of soil shows significant differences in the pH, also an influence on the total polyphenols content (p≤0.01), and in flavonoids content (p≤0.05). On the other hand, the parts of the plant have exhibited significant differences in the amount of ashes and in the total antioxidant capacity (p≤0.01), and in the SPF values (p≤0.05).
Key words: Portulaca oleracea L.; soil type; physicochemical characteristics; bioactive compounds; biological properties; Antioxidant activity; HPLC.
Paul-Marian SZATMARI
Abstract. With the exception of the oligotrophic marshes (peat bogs), the Romanian literature makes too little distinction between fens and the rest of the eutrophic wetlands in the country. Therefore, this article aims to contribute in understanding the formation, the ecological and the floristic peculiarities of the alkaline and transitional eutrophic mires, known as rich fens, respectively poor fens. At the same time, like the peat bogs, the fens have become an important refugia for many glacial relicts, found today only in the boreal and arctic-alpine regions. The paper offer some new contributions through the research of these fens regarding the postglacial refugia in the South-Eastern Carpathians and reports of new species for some areas. Eight major regions comprising rich fens and poor fens have been identified that still retain somehow their archaic character by conserving many species considered to be glacial relicts. At the same time, these regions thus became true postglacial refugia of relict species, which have managed to maintain a local microclimate favorable to the perpetuation of these plants. Fens are among the most endangered wetland ecosystems in the country. They require strict protection and reassessment of their surface, flora and vegetation, as the vast majority of them have been severely affected by human activity in recent decades.
Key words: rich fens; poor fens; postglacial refugia; South-Eastern Carpathian region; Romania.
Aissa BAKELLI, Saïd AMRANI, Asma NACER, Meriam BOURI, Fikrettin SAHIN
Abstract. Phragmites communis L. is a halophytic plant that can withstand harsh environmental conditions such as salinity. In the present study, we isolated a bacterium associated with the rhizosphere of Phragmites communis L. Based on morphological and biochemical as well as MALDI-TOF and 16S rRNA sequencing results, the strain S6 was identified as Klebsiella aerogenes with a score of 2.34 for MALDI-TOF and a similarity of 99.86% with type strain Klebsiella aerogenes KCTC 2190T. Furthermore, we demonstrated that strain S6 tolerated up to 2.5 M of NaCl and exhibited resistance to only three antibiotics that are frequently used for Enterobacteriaceae. Plant growth-promoting (PGP) results showed that the strain S6 had multiple traits, it was able to fix atmospheric nitrogen, solubilized inorganic phosphate (Ca3(PO4)2 and potassium in addition to the production of siderophores, ammonia, cellulase, protease and amylase. Indole acetic acid (IAA) production was also detected, and the strain S6 showed a positive ACC deaminase activity. Moreover, when the strain S6 was used as an inoculum for pepper seeds, increases in different parameters including shoot and root lengths and fresh and dry weights were shown under normal and saline conditions. We reported in this study, that the inoculation of pepper (Capsicum annuum L.) seeds with the Klebsiella sp. strain S6 was efficient for pepper growth in normal and salt stress conditions. The results of this study thus indicate that natural plants from saline habitats present a good source for isolating beneficial PGPR to grow crops like pepper under saline conditions.
Key words: Phragmites communis L.; Klebsiella aerogenes; rhizosphere; arid environments; PGPR; MALDI-TOF; phylogeny.
Eliyanti ELIYANTI, Zulkarnain ZULKARNAIN, Budiyati ICHWAN, Adriani ADRIANI
Abstract. The present study was aimed to evaluate the effects of six different technology packages to improve tolerance of three chili cultivars for drought stress conditions. Six technology packages namely trichocompost and Local Microorganism (LMo) spray every 7 days, trichocompost and LMo spray every 14 days, trichocompost only, LMo spray every 7 days only, LMo spray every 14 days only, and a control (no trichocompost nor LMo spray) were applied on three chili cultivars (Lado, Laris and Vitra). The trial was arranged in a randomized block design with three replicates consisting of four individual plants. Results indicated that the enrichment of growing media with trichocompost along with spraying of LMo improved the growth and yield of Lado, Laris and Vitra cultivars in drought conditions. Trichocompost in combination with LMo spray at 7-day interval increased the number of productive branches, as well as fruit number and fruit weight up to 28%, 58.84% and 64.28% in the cultivar Vitra, which was higher than the Laris and Lado. The application of Trichoderma-based compost plus spraying LMo every 7 days was able to increase tolerant properties of the three chili cultivars for drought stress. Within cultivars, Vitra was proven to be more adaptive and more tolerant against drought stress in comparison with Laris and Lado cultivars.
Key words: Capsicum annuum; biofertilizer; abiotic stress; Pomacea canaliculata.
Yasser KADRI, Abdelhafid NANI
Abstract. The use of medicinal plants is well developed in the wilaya of Adrar, and this modest work is only a small attempt to better understand these medicinal plants used traditionally. In this study, we are interested in evaluating the antibacterial activity of the medicinal plant Cynomorium coccineum, characterized by being a medicinal plant, and a spontaneous species. The antibacterial study was carried out against six bacterial strains (Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis). In fact, the extract of Cynomorium coccineum exerted a good inhibitory effect against four strains out of the six strains studied (Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Escherichia coli). and For the Staphylococcus aureus, Bacillus cereus and Escherichia coli strains, the MIC obtained is equal to 25 mg/mL. For this study, the minimum inhibitory concentration (MIC= 25 mg/mL) values obtained enabled us to confirm the results of the diffusion tests on disks initially carried out.
Key words: medicinal plants; Cynomorium coccineum; antibacterial; the minimum inhibitory concentration.