Facultatea de Biologie și Geoştiinţe / Faculty of Biology and Geosciences

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Author: search.filters.author.Dobrojan, Sergiu

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    Valorificarea lichidului cultural al cianobacteriei spirulina platensis pentru germinarea seminţelor de Galega orientalis lam. menţinute în colecţii
    (CEP USM, 2024) Dobrojan, Sergiu; Melnic, Victor; Ţiţei, Victor; Dobrojan, Galina; Melnic, Angela
    Following quantitative research, it was found that treating Galega orientalis L. seeds with a biostimulant derived from the cultural liquid of the cyanobacterium Spirulina platensis over 3 years significantly improved germination capacity and germination index, while the relative root elongation had a lesser impact. The optimal concentration of 4% and exposure for 4 hours resulted in the highest germination rates (50,00%) and germination index (10,0) compared to the control group (FG – 33,00% and IG – 6,6). These findings suggest that cyanobacterial biostimulants could effectively enhance seed germination and conserve species in seed collections, potentially benefiting agricultural practices.
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    FUNCȚIILE SANO-ECOLOGICE ALE FRACȚIUNII LABILE A SUBSTANȚELOR ORGANICE DIN SOL: O ABORDARE CONCEPTUAL-TEORETICĂ
    (CEP USM, 2024) Jigău, Gheorghe; Dobrojan, Sergiu; Dobrojan, Galina; Plăcintă, Nina; Moşoi, Iurie; Turchin, Boris; Turchin, Boris; Gaberi, Valentin
    Through the concept of ,,soil resources,” the ,,system of soil organic substances” was defined as the entirety of discrete particles of organic residues of biogenic origin, non-humic biomolecules, humic substances adsorbed and integrated into the mineral conglomerate (matrix) of the soil. The driving force of the functionality of the organic substances system is the labile fraction of organic substances, which represents a complex heterogeneous bioenergetic system consisting of organic dead matter and the living phase, exclusively determined by landscape conditions. The primary function of the labile fraction of organic substances within the organic substances system involves the continuous provision of bioorganic-mineral resources for its functioning within the soil ecosystem.
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    STUDIEREA EFECTULUI BIOSTIMULATOR AL LICHIDULUI CULTURAL DE LA CULTIVAREA CIANOBACTERIEI SPIRULINA PLATENSIS ASUPRA GERMINĂRII SEMINȚELOR DE GALEGA ORIENTALIS LAM. MENȚINUTE ÎN COLECȚII
    (CEP USM, 2024) Dobrojan, Sergiu; Melnic, Victor; Ţiţei, Victor; Dobrojan, Galina; Melnic, Angela; Trofim, Alina; Merciucari, Tamara
    In this study, the potential of biostimulants obtained from the culture medium of the cyanobacterium Spirulina platensis to improve the germination of Galega orientalis L. seeds maintained in collection conditions for 4 years was investigated. Throughout the experiments, the germination rate (GR) and germination index (GI) of seeds treated with different concentrations (1%, 2%, 4%) of the biostimulant were evaluated, compared to the control group. The results indicate a significant improvement in the germination of seeds treated with cyanobacterial biostimulants. The concentration of 2% biostimulant with a 2-hour exposure presented the highest germination rate over the analyzed period. These findings suggest that cyanobacterial biostimulants have potential in enhancing the germination efficiency of Galega orientalis L. seeds maintained in collection conditions for 4 years, offering promising applications in the efficient conservation of the species’ gene pool in seed collections and for agricultural practices aimed at improving crop performance.
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    EFECTUL BIOSTIMULATORILOR ALGALI ASUPRA GERMINĂRII SEMINȚELOR DE ECHINACEA PURPUREA L.
    (CEP USM, 2024) Dobrojan, Sergiu; Jigău, Gheorghe; Dobrojan, Galina; Melnic, Cristin; Ciolacu, Tatiana; Ciobanu, Eugeniu
    Articolul prezintă rezultatele obținute ale experimentelor privind utilizarea biostimulatorilor algali pentru stimularea germinării semințelor de Echinacea purpurea L., evidențiind efectele obținute. Biostimulatorii algali au fost obținuți prin combinarea biomasei algelor Nostoc gelatinosum, Nostoc punctiforme și Nostoc linckia în diverse concentrații. Rezultatele au arătat o creștere semnificativă a facultății germinative și a indicelui de germinare a semințelor de Echinacea purpurea L. tratate cu biostimulatori algali comparativ cu variantele de control. Cele mai bune rezultate s-au obținut în variantele cu biostimulatori algali în concentrația de 1%, timpul de tratare a semințelor 1 oră, și 3% cu expunerea la tratare de 3 ore. Se recomandă utilizarea biostimulatorilor algali pentru tratarea seminţelor de Echinacea purpurea L. în vederea stimulări germinării acestora.
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    PERSPECTIVA UTILIZĂRII ALGELOR ÎN CALITATE DE BIOFERTILIZANT LA CULTIVAREA PLANTELOR AROMATICE ŞI MEDICINALE
    (CEP USM, 2024) Dobrojan, Sergiu
    Algele prezintă o sursă naturală de biofertilizanţi, eficienţi, siguri şi relativ ieftini, care pot fi utilizaţi la cultivarea plantelor aromatice şi medicinale. Aplicarea biofertilizanţilor şi a fertilizanţilor foliari algali la cultivarea plantelor aromatice şi medicinale contribuie la îmbunătățirea calității solurilor, după caz fitoremedierea acestora, îmbunătățirea stării fiziologice a platelor, creşterea rezistenţei acestora la factorii de mediu şi de stres, majorarea şi îmbunătățirea calității biomasei, precum şi sporirea conţinutului de substanţe biologic active din plante. În lucrare sunt indicate aspectele pozitive ale utilizării algelor în calitate de biofertilizant. Propunem ca la utilizarea biofertilizanţilor algali pentru cultivarea plantelor să se realizeze evaluarea stării structural-funcționale a algoflorei edafice a terenurilor cultivate, astfel încât speciile selectate ca biofertilizant să facă parte din biocenoza algală activă autohtonă, să se dezvolte intens pe sol şi să contribuie la îmbunătățirea sau după caz menținerea stării biodiversității algelor edafice.
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    CULTIVAREA ALGEI NOSTOC FLAGELLIFORME (BERK ET. CURT) ELENK. DUPĂ METODA SEMICONTINUĂ
    (CEP USM, 2014) Stratulat, Irina; Dobrojan, Sergiu; Şalaru, Victor
    The semicontinuous method for cultivation the alga Nostoc flagelliforme leads to a higher quantity of biomass in a short period of time. The high algal productivity is obtained at elimination and substitution of 25% of the nutritive medium Z-8 (12,44 g/l) and elimination and substitution of 50% of medium Drew (5,78 g/l). The pH of the nutritive media for cultivation the alga Nostoc flagelliforme by semicontinuous method have increasing trends followed by decreasing and does not differ substantially depending on the concentrations of elimination and substitution of nutritive medium.
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    UTILIZAREA ALGEI CYLINDROSPERMUM LICHENIFORME ÎN PROCESUL DE EPURARE A APELOR REZIDUALE ORĂŞENEŞTI
    (CEP USM, 2014) Popescu, Tudor; Şalaru, Vasile; Şalaru, Victor; Dobrojan, Sergiu; Ouddane, Boghdad; Nelea, Andruh; Rabodonorina, Suzanah
    Les eaux de sortie des stations de traitement des eaux (eaux de STEP) peuvent être utilisées pour cultiver l’algue Cylindrospermum licheniforme. On obtient une biomasse algale moins chère et on réduit considérablement le flux de matière inorganique dans l’eau. On peut obtenir plus de quantité de biomasse en cultivant l’algue Cylindrospermum licheniforme dans un milieu fait avec 100% d’eau de STEP (680,96104 mg/l) et la quantité de biomasse obtenue diminue en milieu constitué avec 50% d’eau de STEP (538,3942mg/l).
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    SELECTAREA MEDIULUI OPTIMAL PENTRU CULTIVAREA SPECIEI NOSTOC GELATINOSUM (SCHOUSB.) ELENK.
    (CEP USM, 2014) Donţu, Natalia; Şalaru, Vasile; Şalaru, Victor; Stratulat, Irina; Trofim, Alina; Dobrojan, Sergiu
    The choice of culture medium for algae growing is an important milestone because it can affect the economic aspects of the production process. For cultivation of Nostoc gelatinosum algae the most optimal medium are Drew and Z8. The highest values of algal productivity may be obtained according the semicontinuous method. With the increase of algal productivity pH values change to basic direction.
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    EFFECT OF LIGHT ON THE PROCESS OF BIOLOGICAL NITROGEN FIXATION IN BLUE-GREEN ALGAE NOSTOC GELATINOSUM (SCHOUSB) ELENK.AND CYLINDROSPERMUM LICHENIFORME (BORY) KÜTZ. (CYANOPHYTA)
    (CEP USM, 2014) Dobrojan, Sergiu; Stratulat, Irina; Şalaru, Victor; Dobrojan, Galina
    Lighting regime directly influences the process of biological nitrogen fixation carried out by algae Nostoc gelatinosum (Schousb) Elenk. and Cylindrospermum licheniforme (Bory) Kutz. The natural light contributes to the intensification of biological fixation of atmospheric nitrogen in these algae, and the dark regime leads to inhibition the biological nitrogen fixation. Biological nitrogen fixation by blue-green algae achieved by Cylindrospermum licheniforme and Nostoc gelatinosum is a reversible self-regulating process.
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    THE INFLUENCE OF LIGHT ON MORPHOLOGICAL CHANGES OF BLUE-GREEN ALGAE NOSTOC GELATINOSUM (SCHOUSB) ELENKAND CYLINDROSPERMUM LICHENIFORME (BORY) KÜTZ. (CYANOPHYTA)
    (CEP USM, 2014) Dobrojan, Sergiu; Stratulat, Irina; Şalaru, Vasile; Trofim, Alina; Dobrojan, Galina
    The light influences the morphological aspects of algae Nostoc gelatinosum (Schousb) Elenk. and Cylindrospermum licheniforme (Bory) Kutz.. The dark regime generates the dimensional reducing of vegetative cells and heterocysts leading to the alteration of biomass, but spores do not suffer significant changes. Cultivating these algae to favorable conditions of natural and artificial light (continuous), results with launching the process of self-regulating dimensional of cells. The most beneficial sources of ilumination are natural and artificial light.