120 research outputs found
The alleviation of reforestation challenges by beneficial soil microorganisms
Surface mining causes major destruction of natural landscapes and ecosystems. The most fertile, surface soil layer is lost permanently, together with vegetation, wildlife, and micro flora. Post-mining areas are characterized with diverse edaphic, topographic, hydrographic conditions, which complicate land restoration. Successful establishment of forest ecosystems on such land depends mostly on selection of tree species. The chosen plants must be capable of tolerating a wide range of acidity, fertility, moisture, and have potential to ameliorate such substrates for more demanding species. But, reforestation of heavily damaged ecosystems, such as post-mining areas, demands a new approach in seedlings production. This new approach takes into account specific requirements of habitat and integrates them into “targeted production of planting materialâ€. A good strategy for successful reforestation of post-mining areas is the input of organic matter (compost, mulch). Also, current knowledge and experiences emphasize the potential of beneficial microorganisms such as, mycorrhizal fungi (MF) and plant growth promoting rhizobacteria (PGPR). The majority of studies that deal with beneficial interactions between trees and microorganisms are focused on the mycorrhiza, while plant growth promoting rhizobacteria are less present in silviculture. In this study, the focus is on the reforestation challenges of two mining basins, Majdanpek and Kolubara and suggests beneficial microorganisms as potential solution. The study presents results of several years’ researches on plant response to the presence of mycorrhizal fungi and PGPR. The substrates used for plant growth were Majdanpek and Kolubara mine deposals. Mycorrhizal seedlings were grown in Majdanpek mine deposal, and at the end of the experiment they had 30% higher biomass in comparison to control (seedlings without mycorrhiza). Seedlings linked with fungi had a higher survival rate. Deposals from Kolubara Mining Basin were used as a substrate for seedlings inoculated with PGPR. In the first experiment, Scots pine and Norway spruce were inoculated with Azotobacter chroococcum, Bacillus megaterium, B. circulans, B. licheniformis, B. pumilus, B. amyloliquefaciens. Inoculation resulted with higher biomass production (Scots pine 43%, Norway spruce 34%). Similar results were obtained in the second experiment where Scots pine and black locust were inoculated with Bacillus licheniformis, Aeromonas hydrophila, Pseudomonas putida and Burkholderia cepacia. Both species had higher biomass (around 20%) in comparison to un-inoculated control. The results confirmed the fact that early establishment and successful growth of vegetation on devastated areas depends on the presence and activity of soil microbes. Microorganisms as a “nature’s solution†pose the potential to alleviate reforestation challenges of anthropogenic devastated landscapes. Their presence and activity is crucial for ecosystem stability. In areas with compromised balance, their introduction is justified action for achieving the goal of long term ecosystem sustainability
Bakterijska inokulacija - postupak za stimulaciju rasta crvene deteline gajene u zagađenom zemljištu
Red clover (Trifolium pratense L.) seeds were inoculated with several plant growth-promoting bacteria (PGPB) and sown in the substrate contaminated with polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organometallic derivatives of tin (OT). The aim was to determine if selected PGPB strains can promote the growth of red clover in the substrate contaminated with several organic pollutants. The influence of bacteria on red clover growth (height, root length and biomass) was monitored during the three-month experimental period. The most significant improvements of seedling height were noted in the treatment with Bacillus amyloliquefaciens D5 ARV and Pseudomonas putida P1 ARV. Root growth was positively affected by Serratia liquefaciens Z-I ARV. The same isolates significantly affected biomass production. Those isolates caused total biomass increases of 70%, 48% and 33% compared to control. Bacterial strains used in this study were already confirmed as PGPB by biochemical testing, as well as by an in vivo test of mixed inoculums on several woody plants grown in the coal-mine overburden site. This work is the first-time record on their individual effects on one plant species. Obtained results confirmed that inoculation with several PGPB strains can enhance red clover growth in polluted soil.Seme crvene deteline (Trifolium pratense L.), inokulisno sa nekoliko bakterija stimulatora biljnog rasta (PGPB), posejano je u supstrat kontaminiran policikličnim aromatičnim ugljovodonicima (PAHs), polihlorovanim bifenilima (PCBs) i organometalnim derivatima kalaja (OT). Cilj je bio da se utvrdi da li selektovane PGPB mogu promovisati rast crvene deteline u supstratu kontaminiranom sa nekoliko organskih zagađujućih materija. Uticaj bakterija na rast crvene deteline (visina, dužina korena i biomasa) praćen je tri meseca. Najveća visina je zabeležena kod biljaka inokulisanih sa Bacillus amyloliquefaciens D5 ARV i Pseudomonas putida P1 ARV. Rast korena je stimulisan od strane Serratia liquefaciens Z-I ARV. Ovi izolati su značajno uticali i na produkciju biomase. Ukupna biomasa dobijena tokom celog ogleda je za 70%, 48% i 33% veća u odnosu na kontrolu. Bakterijski sojevi korišćeni u ovoj studiji su prethodno potvrđeni kao PGPB kroz biohemijske i in vivo testove mešanog inokuluma na nekoliko drvenastih vrsta gajenih u jalovini. Ovaj rad prvi put beleži njihove pojedinačne efekte na jednu biljnu vrstu. Dobijeni rezultati potvrđuju da inokulacija sa nekoliko PGPB sojeva može ubrzati rast crvene deteline u zagađenom zemljištu
Pseudomonas SP. in tomato rhizosphere (Lycopersicon esculentum Mill)
The aim of research is determining the presence and number of Pseudomonas sp in tomato rhizosphere. The tests were conducted on a tomato hybrid Big Beef grown on the soil type pseudoclay-hard. Bacteria isolation was conducted in the root zone 20-40 cm. Rhizosphere was separated mechanically on rhizospheral soil, root (unsterilized) and root (sterilized). Tripofan Medium was used for isolation of Pseudomonas sp. from the soil. In the obtained results biochemical and morphological characteristics were conducted. Results analysis was conducted with suitable statistical methods. Based on the results, we can conclude that the number of bacteria in different variants is statistically extremely significantly different on Tripofan Medium and statistically significantly different on Nutritious agar
Application of 1-methylcyclopropene in fruit of five apple cultivars grown in Serbia
Fruits of five apple cultivars were treated using 1-methylcyclopropene (1-MCP or SmartFresh (TM)) after cropping and were stored at normal atmosphere 2 +/- 0.5 degrees C, 90 +/- 5% relative humidity (RH) and 20.9 kPa O-2 + lt 0.5 kPa CO2. Fruit firmness was assessed at three periods: 7 d after storing, 120 d after storing and 30 d after the second assessment and storing at room temperature. Contents of K in all of the cultivars and in all years of study varied within the average values between 1390.5 and 2028.0 mg kg(-1), while the Ca content varied between 21.7 and 59.5 mg kg(-1). The K:Ca ratio was the lowest in cultivar 'Granny Smith' (24.0) and the highest in 'Redchief ' (99.1). Application of 1-MCP made the strongest impact on fruit firmness of the cultivars 'Granny Smith' and 'Idared' in all measuring periods. Cultivars 'Redchier', 'Cadel' and 'Morrens Ionagored' responded well to the application of 1-MCP in the storage conditions, whereas the effect of its application influenced conservability of the fruits stored at room temperature except in fruits of the cultivar 'Morens Jonagored'. Application of 1-MCP made an important effect on the preservation of fruit firmness, all in accordance with the degree of ripeness of the fruits subjected to the treatment and the contents of K, Ca and K:Ca ratio. This study indicates that the use of 1-MCP treatment in post harvest handling of apples is promising for maintaining the freshness and quality of fruits
Uticaj zemljišnih bakterija na klijanje semena korovske vrste Ambrosia artemisiifolia L.
Soil bacteria are able either to stimulate or inhibit seed germination. If seed germination is stimulated, the seedlings of weed species emerge more uniformly, so that they could be killed in the next step of weed control. This investigation focused on testing the germination of Ambrosia artemisiifolia L. on several media: Pseudomonas fluorescens (B1), Azotobacter chroococcum (B2), Bacillus licheniformis (B3), B. pumilus (B4), B. amyloliquefaciens (B5). In control, seeds germinated in water. Seed germination varied depending on bacterial media. Germination was inhibited by bacterial treatments B1 and B3, treatments B2 and B4 stimulated germination, while germination in treatment B5 was similar to control.Zemljišne bakterije mogu imati stimulativno ili inhibitorno delovanje na klijanje semena mnogih biljaka. Ukoliko je klijanje semena stimulisano, ponici korova se javljaju znatno uniformnije, što pruža realnu mogućnost da se u nekoj od narednih operacija nege useva korovi eliminišu. U ovim istraživanjima ispitivan je uticaj nekoliko zemljišnih bakterija (Pseudomonas fluorescens (B1), Azotobacter chroococcum (B2), Bacillus licheniformis (B3), B. pumilus (B4), B. amyloliquefaciens (B5) na klijanje semena alohtone invazivne korovske vrste Ambrosia artemisiifolia L. U kontrolnu varijantu je dodata česmenska voda. Na osnovu dobijenih rezultata može se konstatovati da je klijanje semena A. artemisiifolia variralo u zavisnosti od toga na kojoj bakterijskoj podlozi je vršeno naklijavanje. Naime, utvrđen je manji procenat klijavosti semena na podlozi B1 i B3, odnosno veća klijavost je postignuta na podlogama B2 i B4 u odnosu na čistu vodu. Osim toga, klijanje semena A. artermisiifolia na podlozi B5 je bilo gotovo istovetno kao i u čistoj vodi (kontroli)
Microbiological activity of barley rhizosphere grown on deposol
The aim of this paper was to investigate microbiological activity in barley rhizosphere, after the experiment with 17 recultivation treatments of deposols with different organo-mineral materials. The most important agrochemical properties of deposols have been examined. The presence of the microorganisms was determined by the usual microbiological mediums. Dehydrogenase activity was determined by the Cassida et al. method. The deposols were poor in organic matter, nitrogen, phosphorus and potassium. The number of bacteria ranged from 9.3 to 413.3 × 106g-1. The addition of organo-mineral materials into deposols has caused an increase of microbial biomass and dehydrogenase activity, comparing with control
Stimulacija zemljišne mikrobiološke aktivnosti sa klinoptilolitom - uticaj na rast biljke
Zeolites can mitigate ammonium losses to the environment by taking up the ions from sources such as farmyard manure and ammonium-bearing fertilizers. This ability can improve nitrogen fertilizing practice given that ammonium ions loaded onto zeolite are available for plant uptake. The main goal of this study was to assess the influence of zeolite (clinoptilolite) and ammonia-loaded clinoptilolite on growth and yield of red clover (Trifolium pratense L.), as well as their influence on the microbial dynamics in soil. Plants sown in pots were cut four times, and dry matter yield (DM) of each harvest was weighed. The number of culturable bacteria, moulds, ammonifiers, Azotobacter sp. and actinomycetes was determined at the beginning of the experiment, and after each harvest. Two control treatments (soil without fertilizer and soil supplemented with mineral fertilizer - CAN) were included in the study. The application of ammonia-loaded clinoptilolite positively and significantly affected the microbial activity and provided higher yields (from 4.9 g/pot in ammonia-loaded clinoptilolite treatment to 4.3 g/pot in soil with zeolite treatment). Our results suggest that the addition of clinoptilolite to organic fertilizers (manure, composts) could be recommended. The increase of microbial communities’ abundances and their activity represented the key benefit from clinoptilolite application.Zeoliti mogu ublažiti otpuštanje amonijaka u prirodu preko uzimanja jona iz izvora kao što su stajnjak i đubriva bogata amonijakom. Ova sposobnost može unaprediti đubrenje azotom preko zeolitom usvojenih amonijum jona koji bi tako postali dostupni za usvajanje biljkama. Cilj ovih ispitivanja je bio procena uticaja zeolita (klinoptilolita) i zeolita obogaćenog amonijakom na rast i prinos crvene deteline (Trifolium pratense L.), kao i na njihovu ulogu u mikrobiološkoj dinamici zemljišta. Biljke sejane u sudovima su košene četiri puta i meren je prinos suve materije (SM) svakog otkosa. Broj bakterija, plesni, amonifikatora, Azotobacter sp. i aktinomiceta je utvrđen na početku ogleda i nakon svakog košenja. U istraživanja su uključena dva kontrolna tretmana (zemljište bez đubriva i zemljište sa dodatim mineralnim đubrivom - KAN). Primena klinoptilolita obogaćenog sa amonijakom je pozitivno i značajno uticala na mikrobiološku aktivnost i povećala je prinos (od 4,9 g po sudu kod tretmana sa klinoptilolitom obogaćenim amonijakom do 4,3 g po sudu u zemljištu sa zemljištem i zeolitom zajedno). Naša istraživanja sugerišu da se može preporučiti dodavanje klinoptilolita organskim đubrivima (stajnjaku, kompostu). Ključna dobit od primene klinoptilolita bi se ogledala u povećanju zastupljenosti mikrobioloških zajednica i njihove aktivnosti
Primena mikrobioloških đubriva u vinogradarstvu - prinos grožđa i kvalitet vina u sorte Rizling rajnski
The recommended cultivars for top quality wines Riesling in the vineyards of Grocka is in full crop. It was grafted on Kober 5 BB stock and planted on the soil type cambysoil. The content of total nitrogen is 0.1-0.15%. Supply of easily available potassium varies between 12.3-15 mg/100g a.d.s.2, i.e. phosphorus 0.4-3.6 mg/100g a.d.s. in layer up to 40 cm. Microbiological fertilizer was used in the study - biological preparation prepared with mixed natural populations Azotobacter chroococcum, Bacillus megaterium and Bacillus circulons. The space in row is idle land and the space between rows was sown each year (March-April) with a mixture of field pea and barley and ploughed in the inflorescence phase of legumes. Grape yield varied between 8772-6804 kg/ha. Microbiological fertilizer with Azotobacter had the highest yield and the control treatment had the lowest yield, where only grass mixture was sown. Extremely dry climatic conditions in the trial period caused the grape yield in cv. Riesling to be extremely low. In combination of fertilizers Bacillus megaterium + Bacillus circulons wine with the most ethanol, extracts and polyphenols was obtained. The wine obtained from the control treatment had a typical taste.Ispitivanja su obavljena na sorti Rizling rajnski - klon 239 okalemljen na podlozi Kober 5 BB na Oglednom dobru "Radmilovac" Poljoprivrednog fakulteta u Zemunu. U prostoru između redova svake godine u rano proleće zasejavana je smeša legumonoze: stočnog graška i jarog ječma (2:1). U fazi cvetanja leguminoze zelena masa je zaoravana. Zemljište u redu u vinogradu je ručno obrađivano 2-3 puta и toku vegetacije. U radu je korišteno mikrobiološko đubrivo-biopreparat pripremljen od mešanih populacija Azotobacter chroococcum, Bacillus megaterium i Bacillus circulons. Sojevi mikroorganizama koji su korišteni za ova istraživanja su iz kolekcije mikroorganizama Katedre za mikrobiologiju Poljoprivrednog fakulteta u Zemunu. Mikroorganizmi su umnoženi u odgovarajućim hranljivim medijumima i naneti na sterilan treset. Mikrobiološko đubrivo je neposredno pre upotrebe rastvoreno u vodi, unešeno u zemljište na dubini do 20 cm, na početku vegetacije. Ogled je postavljen po blok sistemu a korišćen je soj Azotobacter chroococcum - varijanta A, smeša populacija Azotobacter chroococcum i Bacillus megaterium - varijanta AB, smeša populacija Azotobacter chroococcum, Bacillus megaterium i Bacillus circulons varijanta ABC i kontrola K. Prostor u redu je jalovi ugar, a prostor između redova zasejavan je svake godine (mart-april) smešom semena stočnog graška i ječma i u fazi cvetanja leguminoze zaoravan. Berba grožđa obavljena je u fazi pune zrelosti, utvrđen je prinos grožđa, broj i masa grozda, sadržaj šećera i ukupnih kiselina za period 2000 do 2002. godine. Mikrovinifïkacija po varijantama obavljena je u 2000. i 2001. godini. Obuhvata sadržaj etanola, ekstrakta, polifenola, pepela, slobodnog i vezanog sumpordioksida isparljive i ukupne kiseline u vinu. Ispitivanom periodu visina i raspored padavina и toku vegetacije bili su niski i neujednačeni, a temperaturni uslovi ekstremno visoki. Gročansko vinogorje, u kome se nalazi Ogledno dobro "Radmilovac", odlikuje se umereno kontinentalnom klimom, međutim u navedenom periodu poprimilo je odlike aridne klime. Posebno se ističe 2000. godina sa visinom padavina u toku vegetacije 137,9 mm i najtoplijim mesecom avgustom tprosek=24.5°C. Prinos grožđa po jedinici površine u proseku iznosio je 7580.25 kg/ha. Upoređujući primenjena mikrobiološka đubriva i visinu prinosa grožđa, aktivnost Azotobacter chroococcum - tretman A uz zaoravanje zelene mase stočnog graška i raži, pozitivno je uticala na količinu grožđa 8772 kg/ha. Vegetativni potencijal uz primenu mikrobiološkog đubriva Azotobacter chroococcum - A približava se kategoriji slabe bujnosti, što nije odlika Rizlinga rajnskog u normalnim uslovima. Nedostatak vlage tokom celog perioda vegetacije uslovio je slabiji porast lastara. Visok sadržaj šećera i nešto niži sadržaj kiselina ostvaren je uz primenu mikrobiološkog đubriva Azotobacter chroococcum+Bacillus megaterium - AB. Između tretmana A i kontrole razlike u pogledu ova dva pokazatelja su bile najmanje
Izolacija i karakterizacija bakterija i kvasaca iz kontaminiranog zemljišta
Plant growth promoting (PGP) bacteria and yeasts play an important role in bioremediation processes. Thirty bacterial and ten yeast isolates were obtained from PAH and PCB contaminated soil with an aim of determining the presence of PGP mechanisms (production of ammonia, indoleacetic acid, siderophores and solubilization of inorganic phosphate). As a result, three bacterial (Serratia liquefaciens, Micrococcus sp. and Serratia sp.) and two yeast isolates (Candida utilis and Candida tropicalis) were recognized as PGP strains. Among them, Serratia sp. showed the highest indole production (25.5 μg/ml). Analyses of metal tolerance (Cu+2, Cr+6 and Ni+2) revealed that Serratia liquefaciens, Micrococcus sp., Serratia sp. and Candida tropicalis were capable to tolerate significant concentration of metals. As a result of this study several bacterial and yeast strains were attributed as potential plant growth promoters which can be applied in future remediation activities and environmental quality improvements.Zemljište predstavlja dinamičan ekosistem naseljen brojnim mikroorganizmima među kojima su bakterije najbrojnije. Najveći broj je skoncentrisan u uskoj zoni zemljišta koja okružuje koren i koja se naziva rizosfera. Procenjuje se da 1-2% bakterija koje naseljavaju ovu zonu imaju sposobnost da promovišu rast biljaka (engl. plant growth promoting bacteria - PGPB). Pored bakterija, sve više je podataka da i zemljišni kvasci poseduju ove sposobnosti. Mikroorganizmi koji stimulišu rast biljaka koriste različite mehanizme kojima povećavaju dostupnost nutrijenata biljkama, regulišu njihov hormonski status kao i odnos prema biljnim patogenima. Bakterije i kvasci koji stimulišu rast biljaka igraju važnu ulogu i u procesima bioremedijacije. Trideset bakterijskih i deset izolata kvasaca je izolovano iz kontaminiranog zemljišta (PAH i PCB) i testirano na prisustvo mehanizama kojima se pospešuje rast biljaka. Cilj je bio doći do sojeva koji su prilagođeni na život u zagađenom zemljištu, a istovremeno imaju i potencijalno stimulativno dejstvo. Nakon izvršenih biohemijskih analiza (produkcija amonijaka, indol-sirćetne kiseline, siderofora, rastvaranje neorganskog fosfora) u stimulatore biljnog rasta svrstana su tri bakterijska (Serratia liquefaciens, Micrococcus sp. i Serratia sp.) i dva izolata kvasaca (Candida utilis i Candida tropicalis). Među njima najveću sposobnost produkcije indol-sirćetne kiseline je pokazao izolat Serratia sp. (25,5 μg/ml). Analize tolerancije na prisustvo teških metala (Cu+2, Cr+6 i Ni+2) pokazale su da su izolati Serratia liquefaciens, Micrococcus sp., Serratia sp. i Candida tropicalis sposobni da podnesu više koncentracije. Rezultati ovih istraživanja mogu imati praktičnu primenu u budućim remedijacionim aktivnostima i unapređenju kvaliteta životne sredine
Pripremanje aktivnih kultura za biološke mliječne fermentativne procese
Pripremanje kultura bakterija mliječne kiseline sa jako izraženim stupnjem biokemijske aktivnosti za biološke fermentativne procese mliječnih proizvoda predstavlja interesantnu problematiku ispitivanja, koja još uvijek nije dovoljno proučena
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