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Plant growth biostimulators originated from marine environment intended for agricultural application

dc.contributor.advisorDimitrijević-Branković, Suzana
dc.contributor.otherRajilić-Stojanović, Mirjana
dc.contributor.otherLazić, Vesna
dc.contributor.otherDavidović, Slađana Z.
dc.creatorRadovanović, Neda
dc.date.accessioned2022-09-06T14:02:50Z
dc.date.available2022-09-06T14:02:50Z
dc.date.issued2021-06-23
dc.identifier.urihttps://eteze.bg.ac.rs/application/showtheses?thesesId=8689
dc.identifier.urihttps://uvidok.rcub.bg.ac.rs/bitstream/handle/123456789/4271/Referat.pdf
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:26229/bdef:Content/download
dc.identifier.urihttps://plus.cobiss.net/cobiss/sr/sr/bib/70923529
dc.identifier.urihttps://nardus.mpn.gov.rs/handle/123456789/20619
dc.description.abstractPredmet istraživanja ove doktorske disertacije je izolacija mikroorganizama iz morskog sedimenta, kao i sinteza hidrogel prevlaka, odnosno filmova na bazi polisaharida poreklom iz morskih algi i ispitivanje njihovog biostimulatornog dejstva na rast biljaka, sa ciljem utvrđivanja mogućnosti njihove primene u agroindustriji. Iz uzorka morskog sedimenta Crvenog mora, izolovano je ukupno 32 bakterijske kulture. Utvrđivanjem prisustva osnovnih direktnih i indirektnih mehanizama stimulacije biljnog rasta, izvršen je odabir najpotentnijeg soja za potencijalnu primenu u agroindustriji. Za dalji rad odabran je izolat PPM3, kod koga je utvrđeno prisustvo svih ispitivanih mehanizama: sposobnost fiksiranja atmosferskog azota i rastvaranja fosfata, antagonističko dejstvo prema četiri biljne patogene plesni (Aspergillus flavus, Fusarium graminearum, Alternaria sp. i Mucor sp.), kao i sposobnost proizvodnje hidrolitičkih enzima (proteaza, celulaza, hitinaza i amilaza). Standardnim morfološkim, biohemijskim i molekularnim metodama, novi morski izolat PPM3 je identifikovan kao pripadnik roda Bacillus, a odlikovali su ga sposobnost rasta na raznovrsnim supstratima u širokom opsegu temperature (4-55 °C) i pH uslova sredine (5-10), kao i sposobnost tolerancije visokih koncentracija soli (do 10 %). Detaljniji uvid u mehanizme delovanja, kao i mogućnost primene potencijalnih formulacija na bazi odabranog izolata Bacillus sp. PPM3 u agroindustriji, dobijen je ispitivanjem antagonističkog dejstva njegovog ekstraćelijskog filtrata (EF) utvrđivanjem sposobnosti sprečavanja rasta patogenih plesni: A. flavus, F. graminearum, Alternaria sp. i Mucor sp. Antagonističko svojstvo EF Bacillus sp. PPM3 posledica je proizvodnje termostabilnih antifungalnih jedinjenja, koja direktno sprečavaju rast i germinaciju spora svih ispitivanih plesni. Molekularnom analizom, kod morskog soja Bacillus sp. PPM3 utvrđeno je prisustvo gena odgovornih za sintezu antifungalnih jedinjenja, lipopeptida: iturina, bacilomicina D, mikosubtilina i surfaktina, a njihova uloga u antagonizmu, potvrđena je u in vitro testu, ispitivanjem antifungalnog dejstva lipopeptidnog ekstrakta. Radi utvrđivanja mogućnosti i načina primene Bacillus sp. PPM3 na polju, najpre je ispitana njegova potencijalna fitotoksičnost u testu klijavosti semena, a zatim i uticaj na parametre rasta biljke in vivo. Na osnovu indeksa klijavosti semena, utvrđeno je da ćelije i EF Bacillus sp. PPM3 ne ispoljavaju fitotoksični efekat i bezbedne su za upotrebu, a mogu se okarakterisati kao fitonutrijenti. U in vivo testu sa biljkom kukuruza utvrđeno je pozitivno dejstvo soja Bacillus sp. PPM3 na rast biljke, kako u uslovima infekcije, uzrokovane patogenom F.graminearum, tako i u odsustvu patogena. Svi primenjeni tretmani doveli su do povećanja visine biljke, ukupne dužine korena i biomase, kao i značajnog smanjenja pojave obolelih biljaka. Na osnovu ispoljavanja velikog broja korisnih dejstava na rast biljke, putem raznovrsnih mehanizama, utvrđeno je da postoji veliki potencijal za praktičnu i jednostavnu primenu novog morskog soja Bacillus sp. PPM3 kao biostimulatora biljnog rasta u održivoj poljoprivredi. Funkcionalizovani filmovi na bazi polisaharida iz morskih algi (agara, alginata i njihovih mešavina) uspešno su sintetisani jednostavnom metodom izlivanja polimernog rastvora uz otparavanje rastvarača. Direktnim umešavanjem EF soja Bacillus sp. PPM3 u formulacije filmova, izvršena je njihova funkcionalizacija za primenu u agroindustriji kao filmova za malčiranje i stimulaciju rasta biljaka. Dodatna funkcionalizacija filmova, sa ciljem poboljšanja njihovih optičkih, mehaničkih i barijernih svojstava, izvršena je umrežavanjem polimera posredstvom soli bakra. Svojstva agarnih filmova modifikovana su metodom in situ mineralizacije, odnosno istovremenom sintezom bakarnih mineralnih faza i polimerne mreže, dok su svojstva alginatnih i kopolimernih agarno-alginatnih filmova modifikovana eksternim umrežavanjem već formiranih filmova jonima bakra. FT-IR analiza je pokazala da upotrebljenim metodama sinteze i funkcionalizacije filmova ne dolazi do narušavanja hemijske strukture polimera, iako dolazi do određenih interakcija između dodatih bioaktivnih komponenti (EF Bacillus sp. PPM3 i umreživača) i polimera...sr
dc.description.abstractThe scope of this doctoral dissertation was the isolation of microorganisms from marine sediment, as well as the synthesis of hydrogel coatings and films based on marine algae polysaccharides, and determination of their potential application in agriculture as plant growth stimulators. Thirty-two new bacterial cultures were isolated from the coastal sediment of the Red sea. The selection of strains for potential application in agriculture was done based on the presence of direct and indirect plant growth promoting (PGP) mechanisms. Strain designated as PPM3 exhibited all tested PGP mechanisms: nitrogen fixation, phosphate solubilization, antagonism towards four plant pathogenic fungi (Aspergillus flavus, Fusarium graminearum, Alternaria sp. i Mucor sp.), as well as the ability to produce hydrolythic enzymes (proteases, cellulases, chitinases and amylases), therefore it was selected for further tests. By employing standard phenotypic, biochemical and molecular approaches, the new marine strain PPM3 was identified as the member of the genus Bacillus. Bacillus sp. PPM3 was able to grow on various substrates, in a wide range of temperatures (4-55 °C) and pH (5-10) and tolerate high concentrations of salt (up to 10%). More detailed insight into Bacillus sp. PPM3 modes of action, as well as the possibility of utilizing formulations based on this strain in agriculture, was obtained by testing antagonistic activity of its’ extracellular filtrate (EF) in an in vitro test with pathogenic fungi: A. flavus, F. graminearum, Alternaria sp. i Mucor sp. The antifungal effect of the EF from Bacillus sp. PPM3 was due to production of highly stable secondary metabolites, that directly suppressed the growth and spore germination of all tested fungi. Molecular analysis confirmed the presence of genes involved in the synthesis of antifungal compounds, lipopeptides: iturin, bacillomycin D, mycosubtilin and surfactin. The role of these compounds in the antagonism of Bacillus sp. PPM3 was confirmed in vitro, by determining the antifungal activity of the lipopeptide extract. In order to test the possibility of applying Bacillus sp. PPM3 in the field, the phytotoxic effect of its’ cells and EF on seed germination was evaluated, as well as their effect on plant growth in vivo. Based on the obtained values of germination index, it was determined that cells and EF of Bacillus sp. PPM3 do not display a phytotoxic effect on seed germination, and therefore are safe for application in the field, as phytonutrients. In a green house experiment, Bacillus sp. PPM3 displayed a positive effect on plant growth in the presence, as well as in the absence of the pathogenic fungi F. graminearum. All employed treatments led to a significant increase of the root length, stem height and total biomass of the plant. Due to the multiple beneficial effects of novel marine strain Bacillus sp. PPM3 on plant growth, exerted through various PGP mechanisms, there is an ample scope for practical application of this strain as a plant growth stimulator in sustainable agriculture. Functionalized films based on polysaccharides from marine algae (agar, alginate and their blend) were successfully produced by a solvent casting method. The functionalization of the films for potential application in agriculture as mulching films and plant growth stimulators, was obtained by directly mixing the EF of Bacillus sp. PPM3 into the polymer solution. In order to obtain films with improved optical, mechanical and water vapor barrier properties, additional functionalization was employed by copper sulfate mediated cross-linking of the polymer chains. Properties of agar films were modified by in situ mineralization by simultaneous formation of copper minerals and polymer network, while properties of alginate and agar-alginate films were modified by external crosslinking with Cu2+ ions. FT-IR analysis showed that the employed methods of functionalization did not alter the chemical structure of the polymers, although interactions between additives (EF of Bacillus sp. PPM3 and cross-linker) and the polymer were detected. SEM analysis showed that the cross-linking method and the presence of the additives in the polymeric network affect the microstructure of all obtained films. Agar films mineralized with copper-carbonate phase had more homogenous structure than the copper-phosphate mineralized films...en
dc.formatapplication/pdf
dc.languagesr
dc.publisherУниверзитет у Београду, Технолошко-металуршки факултетsr
dc.rightsopenAccessen
dc.rights.urihttps://creativecommons.org/licenses/by-nc-nd/4.0/
dc.sourceУниверзитет у Београдуsr
dc.subjectmorski sediment, Bacillus sp. PPM3, morske alge, stimulacija biljnog rasta, biološka kontrola, biljne plesni, polisaharidni filmovi, bakar, malčiranje zemljištasr
dc.subjectmarine sediment, Bacillus sp. PPM3, marine algae, stimulation of plant growth, biological control, phytopathogenic fungi, polysaccharide films, copper, soil mulchingen
dc.titleBiostimulatori biljnog rasta poreklom iz morske sredine za primenu u agroindustrijisr
dc.title.alternativePlant growth biostimulators originated from marine environment intended for agricultural applicationen
dc.typedoctoralThesis
dc.rights.licenseBY-NC-ND
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/145446/Disertacija_12398.pdf
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/145447/Izvestaj_Komisije_12398.pdf
dc.identifier.rcubhttps://hdl.handle.net/21.15107/rcub_nardus_20619


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