Midiia KIROIANTS, Mykola PATYKA
Abstract. Microbial biome of soil biocenosis determine the main functional role in the circulation of substances and energy and represent key components of the transformation of organic residues, both their mineralization and immobilization of nutrients. Therefore, the studying of the biome of soil microorganisms (especially dominant strains) is the scientific basis for the development of measures aimed at enhanced reproduction of chernozem fertility. Two dominant endophytic bacterial isolates were recovered from native Hordeum vulgare rhizosphere varieties at central Ukraine area. New isolates were evaluated for their morphological and biochemical characteristics. So, the aim of the work was to investigate and identify these important dominant strains of bacteria with help of the innovative colorimetric identification system for carbohydrate utilization – KB009 TM HiCarbo Kit. The results of researches based on the study of morphological, biochemical and physiological state of bacteria in regard to sources of carbon and metabolic similarity with standard strain Azospirillum brasilense. Methods of research - physiological features were studied by one of the most accurate methodological approaches in determining the physiological diversity of the association of soil microorganisms - the testing system KB009 TM HiCarbo Kit for carbon sources. Thanks to previous investigation, it was learned number of dominant groups of microorganisms, microbiological processes orientation and ecological indexes of biodiversity. And in result of the researches, it was possible to classify allocated dominant strains to the genus Phyllobacterium and Bacillus.
Key words: carbohydrate utilization; soil microorganisms; KB009 TM HiCarbo Kit; Phyllobacterium; Bacillus.
Chikezie Franklin AMBROSE, Onyebuchi Ephraim NWANKWO, Eberechukwu Stella OBASI, Blessing Ngozi OGAH, Kelechi NWANCHOR
Abstract. The study was carried out to determine the effect of fungal rot disease on nutritional value of banana fruits. Standard methods were used to carry out the study. Results of this study show the presence of Colletotrichum musae, Aspergillus niger, Aspergillus flavus and Rhizopus stolonifer on the rotten banana fruits and result of proximate analysis of the diseased banana fruits shows higher moisture content (75.85%) than the apparently healthy banana fruits (74.34%). There was decrease in the crude protein (2.63%), carbohydrate (19.54%), lipid extract (0.20%), ash (0.91%) and crude fibre (0.88%) contents of the rotten fruits relative to the apparently healthy ones. Vitamin B2 (riboflavin), vitamin B9 (folic acid) and vitamin C values are significantly low in infected banana fruits relative to the values of apparently healthy ones. The results are clear evidence that C. musae, A. niger, A. flavus and R. stolonifer bring about reduction in the nutritional value of banana fruits, therefore, banana should be carefully handled to preserve their nutrient composition. This study has shown that banana fruits contain high level of vitamin B9 with low lipid and fibre; this will help the general public especially, fruitarians and dietitians to make proper combination of their foods.
Key words: Banana; effect; fruits; fungi; infection; nutritional value.
Ludmila RUDI, Ecaterina PLÎNGĂU, Ana VALUȚA, Vera MISCU
Abstract. The study aimed to assess the effect of some Co(II) compounds on the production of biomass, β-carotene and astaxanthin by green microalga Haematococcus pluvialis at different stages of its life cycle. Cobalt compounds (Co(OAc)2 and CoCl2) were added to the nutrient medium of Haematococcus pluvialis on the first day of the cultivation cycle. The biomass of H. pluvialis was collected according to some conventional stages of the life cycle: day 3 - green cell stage; day 10 - brown cell stage, and day 14 - aplanospore stage. Changes in the amount of microalgae biomass were determined depending on the stage of the life cycle, as well as the content of β-carotene and astaxanthin pigments. Analysis of the data obtained in the course of a series of experiments indicates that the studied Co(II) compounds did not inhibit cell proliferation within the limits of applied concentrations. Co(II) acetate, depending on the concentration, was involved in the processes of cell multiplication and the synthesis of β-carotene. In concentrations of 1.5 and 2.0 mg/L, Co(OAc)2 stimulated biomass and astaxanthin production. CoCl2 was involved in the proliferation of microalgae cells, the green cell stage being the most sensitive to the action of the compound.
Key words: Haematococcus pluvialis; stages of growth; cobalt compounds; biomass; β-carotene; astaxanthin.
Antony KINGSLIN, Ammasaikutty VANITHA, Devaraj SATHIYA SHEELA, Kandasamy KALIMUTHU
Abstract: The aim of the present study was to evaluate seed germination, embryonic axis length, toxicity, and antioxidant efficacy of silver nanoparticles synthesized (SNPs) from seaweed extract of Sargassum prismaticum V.D. Chauhan. The seaweed S. prismaticum extract was mixed with silver nitrate, change in colour from yellow to dark brown. The formation of SNPs is confirmed by the appearance signatory brown colour of the solution and a characteristic peak at 411 nm in the UV-Vis spectrum. FTIR spectrum shows 11 peaks. The S. prismaticum extract was subjected to XRD analysis for further confirmation of its crystalline nature. FESEM images were found that the SNPs were uniformly distributed and size ranging between 69.99 - 99.15 nm with spherical and cuboidal morphology. The obtained zeta potential value of SNPs through DLS method was had an average size of 94.73 nm. The seedling growth was positively affected by certain concentration of SNPs. For DWt (Dry Weight) of embryonic axis, All the SNPs concentration (25, 50 and 100%) significantly increases EAL (Embriyonic Axis Length) and DWt in all the three plant seeds. The highest percentage inhibition was 79.8% observed in algal extract at the concentration of 500 µg/mL. The IC50 value of algal SNP was 238.21 µg/mL and algal extract was 110.63 µg/mL. S. prismaticum extract SNPs react with earthworm Lampitomauritii in the mortality rate of 25% and 100% for 3 minutes. Overall, the biotransformation of silver nanoparticles utilizing S. prismaticum bioreagent is a low-cost, environmentally friendly approach with enormous biotechnological potential.
Key words: Sargassum prismaticum; algae; biosynthesis; aqueous; embryonic axis length; earthworm
Eliyanti ELIYANTI, Zulkarnain ZULKARNAIN, Elis KARTIKA, Budiyati ICHWAN
Abstract. Acclimatization of in vitro-regenerated plantlets often requires modifications to growing media because the root architecture of regenerated plantlets have not yet well-developed. Therefore, the objective of our study was to find the effective dose of Trichoderma-based compost and arbuscular mycorrhizae isolates in growing media at plantlet acclimatization. The trial was conducted for approximately 4 months at the Plant Biotechnology Laboratory, Faculty of Agriculture, University of Jambi, Indonesia. Plant materials were in vitro-regenerated plantlets of Banana cv. Barangan Kuning, transplanted on acclimatization media consisted of soil and Trichoderma-based compost (1:1, 1:2 and 2:1) and arbuscular mycorrhizae fungi (0, 10, and 20 g per plantlet). The trial used a factorial randomized block design with 3 replications. Each experimental unit consisted of 10 polyethylene bags with one individual plant in it. Data were recorded on survival rate, plantlet height, pseudostem diameter, leaf number, as well as length and width of fully developed leaves. Analysis of Variance and Least Significant Difference tests were employed to see the effect of the Trichoderma-based compost and mycorrhizae applications on plantlet growth. Results showed that all plantlets succeeded acclimatization (100% survival rate). Statistical analysis indicated that the combination of Trichoderma-based compost + mycorrhizae or the application of mycorrhizae alone did not show significant effect on all variables. Trichoderma-based compost, however, was found to significantly affect plantlet height, leaf number, and leaf length, but not pseudostem diameter and leaf width. Though there was no significant effect of mycorrhizae, microscopic study proved that mycorrhizal infection on plantlet roots had been occurred. Our investigation confirmed the benefit of Trichoderma-based compost in growing media during acclimatization, in which the ratio of 2:1 of soil and Trichoderma-based compost resulted in the best plantlet growth.
Key words: in vitro propagation; plant tissue culture; plantain; Musa spp.
Tamara SIRBU, Cristina MOLDOVAN, Olga TURCAN
Abstract. From the large number of methods used for the long-term preservation of microorganisms, the most effective are cryopreservation and lyophilization. Lyophilization is a method of preserving microorganisms, which consists of the freeze-drying process based on the removal of water from the frozen cellular material, by sublimation in a vacuum. Freezing plays an important role in the lyophilization process, as well as the lyoprotectors used. In this study, the lyoprotective medium used for lyophilization of micromycetes was supplemented with nanoparticles of Fe2O3, Fe2ZnO4, and ZnO. As a result of the evaluation of the viability of micromycetes of the genus Aspergillus, Trichoderma, and Penicillium after lyophilization and 1 year of storage in a lyophilized state, a stimulation of viability was obtained in the variants with Fe2O3 and Fe2ZnO4 nanoparticles in a concentration of 5.0 mg/L, and in the variants with ZnO nanoparticles after lyophilization.
Key words: micromycetes; nanoparticles; lyophilization; lyoprotective medium; viability.
Khaoula AOUAICHIA, Nedjoud GRARA, Aissam BOUSBIA
Abstract. The present study was conducted to assess the potential hazards of potassium nitrate (NK) fertilizer on the adult earthworm Aporrectodea trapezoides (Dugès, 1828) as a bioindicator animal test of soil pollution. The research was based mainly on two complementary toxicity tests in order to point out the 50 LC values then the adverse effect on growth rate and morphohistological alterations in worms. Four increasing concentrations for the lethality test ranged from 2500 to 5500 mg/kg of dry soil weight (d.w.) of potassium nitrate fertilizer. Therefore, the sub-lethal’s concentrations were determined based on 10%, 30%, 40%, and 50% of 14 days’ median lethal concentration (LC50), with a control set for both tests. The 50 LC values of NK fertilizer were recorded relatively higher at 7 days than at 14 days of exposure, with 5530.43 and 4955.70 mg/kg d.w., respectively. Significant inhibitory effects on the growth rate of earthworms were found under exposure to various concentrations and time exposures. Morphological deformations were also accentuated with high concentrations, namely: clitellar swelling, bloody lesions, yellowish fluid, body strangulation, and fragmentation, as major morpho-pathological changes in worms. While the histopathological manifestations included epidermal layer injuries, vacuolated body walls, and circular and longitudinal muscles were disintegrated completely with increasing concentrations of fertilizer. The bioindicator A. trapezoides earthworm displayed a worthwhile biological control agent against the toxic salinity of potassium nitrate fertilizer with a strong concentration and exposure timeresponse relationship. The present work is noteworthy for being used in the biological control of environmental risk assessment of chemical fertilizers and then as biomarkers to evaluate soil toxicity.
Key words: earthworm; biomonitoring; potassium nitrate; chemical fertilizer, Aporrectodea trapezoides, ecotoxicology
Amina OUAHAB, Nedjoud GRARA, Ali DEBBI
Abstract. Fungal resistance is a growing problem in protecting human and plant health. Natural bee products, including propolis, are efficient antifungal agents. As the biological activities of the propolis from the northeast regions of Algeria are poorly investigated, the present study aimed to determine the antifungal activity of ethanolic propolis (EPE) and acetone propolis (APE) extracts from two regions (sample N°1 and sample N° 2) in the province of Souk Ahras (northeast Algeria). Herein, four propolis extracts (two extracts ( EPE1,APE1) of the Sample N°1 and two extracts (EPE2, APE2) of Samle N° 2) were tested for their antifungal activity against two phytopathogenic fungi species (Botrytis cinerea and Fusarium oxysporum) based on the determination of the radial growth of the fungus. Results showed that both propolis extracts (EPE and APE) generally exhibit very good antifungal effects against the studied phytopathogenic microorganisms. However, they do not have the same effect on phytopathogenic fungi. The extract of sample No. 2 (EPE2, APE2) had the best antifungal activity, which were 73% and 71%, respectively. In conclusion, the study suggests Algerian propolis collected from the province of Souk Ahras as a potent natural antifungal agent against Botrytis cinerea and Fusarium oxysporum.
Keywords: propolis; antifungal activity; Fusarium oxysporum f. sp lycopersici (FOL); Botrytis cinerea; Souk Ahras.
Anjali SHARMA, Daljeet KAUR, Prabhjot KAUR, Sunita DALAL, Amarjit SINGH, Kajal CHAUHAN, Jitender SHARMA
Abstract. Rice crop has great affinity to silica and can accumulate approximately 10% of the element to its dry mass. The absorption of silica by paddy roots was possible just due to the conversion of silica into soluble forms with the services of soil micro-fauna. The conversion of silicates into silicic acid by producing enzyme (silicase) is the most appropriate route carried by microbes to dissolve silicates. The paddy soils are potentially rich in silica solubilising bacteria which can be isolated, screened and utilized for silicase production. Silicase enzyme vividly crucial for many industrial application and exploration of natural paddy sites for its production is an eco-friendly and sustainable approach. This present work aimed at isolating, screening and identifying the silicase producing bacteria from paddy soil that solubilize silicate into uptake form. To enhance the microbial population, the soil was artificially enriched with different materials and found that soil enriched with rice straw produced enormous microbial colonies. The screening of isolated colonies was performed on different media which depicted that the Glucose silicate assay plate media was perfect for the screening of silicase producing bacteria (SPB). The production of silicase was carried out and resulted in highest activity (1.45U/mL/min) of SPB with production media comprising bagasse as siliceous material. The physiological and biochemical testing of SPB was performed which indicated that the bacteria might be Klebsiella. The molecular identification report confirmed that the isolated SPB culture highly resembled with Klebsiella quasipneumoniae.
Key words: enzyme; microbiota; paddy soil; silicase producing bacteria; siliceous material.
Iglicea BOJINESCU ROSTESCU
Abstract. In the present study, we conduct a phytosociological analysis of the Pulmonario rubrae-Fagetum association, identified in the northern part of the Semenic Mountains in southwestern Romania. The aim of the research is to perform a floristic, phytocenological, ecological, ecoprotective and bioeconomic study of the beech forests in the Banat region, formed by Fagus sylvatica, Abies alba, Pulmonaria rubra and Symphytum cordatum, identified in the northern part of the Semenic Mountains. The phytocoenoses of these forests have been analyzed in terms of physiognomy, floristic composition, spectrum of life forms, floristic elements and the influence of ecological factors. The discussions summarize the main differences in biodiversity research between the Semenic Mountains and the results of research in the Orăștie River Basin (Șureanu Mountains).
Key words: Pulmonaria rubra; association; phytocoenoses; relevés; life forms; floristic elements; ecological indicators