Les bactéries qui promeuvent la croissance de plantes (PGPR) font une partie indispensable du biote dans la rhizosphère. Plusieurs espèces de Bacillus appartiennent aux PGPR et ont la capacité de produire des peptides non ribosomiques différents, tels que les lipopeptides cycliques. La surfactine, fengycine et iturine sont des lipopeptides cycliques produits par B. subtilis and B. amyloliquefaciens. Dans cette étude, nous avons mis en avant l’étude de deux facteurs. Premièrement, la croissance bactérienne et la production de surfactine dans la rhizosphère pendant 21 jours. On outre, les effets des exsudats racinaires et des certaines sources de carbone. Finalement, le rôle de la formation de biofilm a été élaboré par la construction d’un mutant qui a perdu la capacité de la formation de biofilm. Deux souches ont été choisies pour cette étude : B. amyloliquefaciens FZB42 est une souche sauvage et B. subtilis BBG131 qui est un micro-organisme génétiquement modifié. La biomasse de B. amyloliquefaciens FZB42 était 25 fois plus élevée qu’avec B. subtilis BBG131, tandis que la production de surfactine était 5 fois plus faible que celle de B. subtilis BBG131. Les deux souches ont la capacité de croitre dans des exsudats racinaires et produire de la surfactine. B. amyloliquefaciens FZB42 a montré la capacité intense un biofilm alors que B. subtilis BBG131 a montré le contraire. Un mutant de B. amyloliquefaciens FZB42 EPS- a été comparé à d’autres souches. Un comportement similaire de B. amyloliquefaciens FZB42 EPS- et B. subtilis BBG131 a été observé dans la formation de biofilm qui se reflète dans leur colonisation dans la rhizosphère. / Plant growth promoting bacteria (PGPR) are an indispensable part of rhizosphere biota. Many of Bacillus species belong to PGPR and have the ability to produce different non-ribosomal peptides such as cyclic lipopeptides. Surfactin, Fengycin and Iturin are cyclic lipopeptides produced by B. subtilis, and B. amyloliquefaciens. In this work, we shed light to study these factors. Firstly, bacterial growth and surfactin production in the rhizosphere during 21 days. Additionally, the effects of root exudates and certain carbon sources. Finally, the role of biofilm formation was elaborated by the construction of a mutant that lost the ability to form a biofilm. Two strains were chosen: Bacillus amyloliquefaciens FZB42 which is a natural wild-type strain and Bacillus subtilis BBG131 which is a genetically engineered microorganism. The biomass of B. amyloliquefaciens FZB42 was 25 times higher than with B. subtilis BBG131, whereas surfactin production was 5 times less than this produced by B. subtilis BBG131. The two strains have the ability to grow in the root exudates and produce surfactin. B. amyloliquefaciens FZB42 and B. subtilis BBG131. B. amyloliquefaciens FZB42 showed intense ability to form a biofilm whereas B. subtilis BBG131 showed contrarily. A mutant of B. amyloliquefaciens FZB42 EPS- was compared to other strains. A similar behavior of B. amyloliquefaciens FZB42 EPS- and B. subtilis BBG131 was observed in the biofilm formation which is reflected to their colonisation in the rhizosphere.

La PGPR Burkholderia phytofirmans PsJN (Bp) stimule la croissance de diverses plantes et les protège également contre certains stress environnementaux. L’objectif des travaux a été d’approfondir les connaissances sur l’interaction Bp-plante, en se focalisant sur l’aspect physiologique et métabolique des feuilles d’Arabidopsis thaliana. Nous avons également déterminé les mécanismes impliqués dans la réponse des feuilles suite à l’inoculation de cette bactérie lors d’un stress abiotique (froid) ou biotique (Pseudomonas syringae pv. tomato DC3000, Pst).Nos résultats montrent que l’induction de la promotion de croissance d’A. thaliana par Bp pourrait être liée à l’accumulation des teneurs en métabolites primaires (acides aminés, glucides solubles et vitamines) et la variation du niveau des hormones dans les feuilles. La physiologie et le métabolisme des feuilles sont modifiés localement et de façon distale par la colonisation épi- et endophytique de Bp. De plus, les modifications des taux de métabolites sont plus marquées après une interaction plante-bactéries relativement longue. Par ailleurs, l’inoculation de Bp peut réduire les dommages sur l’activité photosynthétique dus au froid par une limitation non-stomatique de la photosynthèse et l’accumulation de pigments photosynthétiques. Enfin, la présence de Bp entraîne localement un retard dans le développement initial de Pst. Cependant, l’inoculation par Bp ne protège pas l’appareil photosynthétique lors d’une attaque par Pst. Ces travaux soulignent donc que le temps de présence et la localisation d’une PGPR dans une plante influencent la physiologie, le métabolisme et la tolérance aux stress de cette même plante. / Endophytic PGPR Burkholderia phytofirmans PsJN (Bp) promotes growth of various plants and triggers protection against several environmental stresses. To get more insights into the interaction between plant and Bp, we focused on leaf physiological and metabolic aspects of Arabidopsis thaliana. We also determined the mechanisms involved in the defense of leaves after inoculation of the bacteria followed by an abiotic (cold) or a biotic (Pseudomonas syringae pv. tomato DC3000, Pst) stress. Our results show that the induction of growth promotion of A. thaliana by Bp could be related to the accumulation of primary metabolite levels (amino acids, soluble carbohydrates and vitamins) and to the variation of hormone levels in the leaves. Leaf physiology and metabolism are changed locally and distally by Bp epi- and endophytic colonization. In addition, changes in metabolite levels are more pronounced after a relatively long interaction between plant and bacteria.Moreover, Bp inoculation can also reduce cold injury on the photosynthetic activity by a non-stomatal limitation of photosynthesis and accumulation of photosynthetic pigments. Finally, the local presence of Bp causes a delay in the development of Pst, but only in the early stages of the infection. However, the inoculation with Bp does not protect the photosynthetic apparatus during Pst attack.Thus, our results emphasize that the time of presence of a PGPR and his location in the plant could influence the plant physiology and stress tolerance.

The diploma thesis „The Effect of Application of Bacterial Preparations on Fruit Trees“ compares quantitative and qualitative properties of apricots treated and nontreated with bacterial praparations. The theoretical part of the thesis is divided into three parts; the first is focused on description of the species apricot (Prunus armeniaca L.), the next part deals with nutrition of fruit trees. The last part focuses on importance of soil microorganisms, especially PGPR bacteria, for plants. PGPR bacteria is group of plant growth promoting bacteria. At the end of the theoretical part there is a description of the most important genera of plant growth promoting bacteria. The practical part focuses on application of bacterial preparations in an apricot orchard. Variants with bacterial applications were compared to control variants in yield, size and weight of apricot, analytical evaluation of fruits (content of elements, vitamin C, flavonoids and antioxidant capacities) and monitoring of storage parametres, such as weight loss, content of refractometric dry matter, total titratable acidity and fruit firmness.

Two strains of plant growth-promoting rhizobacteria, Pseudomonas chlororaphis (PA23) and Bacillus amyloliquefaciens (BS6), can control some fungal diseases of canola through production of bacterial metabolites and through induced systemic resistance, which is initiated by the signalling molecule jasmonic acid. Direct application of jasmonic acid activates defence-related compounds and influences insect herbivory in canola. Field and laboratory studies investigated the effects of the two bacteria and of jasmonic acid on insects of canola. In the field there were no consistently significant effects of treatment on insects sampled by beat cloth or sweep net, level of flea beetle injury, canola yield or quality. In the laboratory, jasmonic acid significantly increased oviposition and decreased larval feeding in diamondback moth (Plutella xylostella) and slowed development and reduced reproduction in turnip aphid (Lipaphis erysimi). The effects of jasmonic acid on canola were systemic. Analysis of leaf tissue showed significant effects of treatment on defence-related compounds. / October 2008

Two strains of plant growth-promoting rhizobacteria, Pseudomonas chlororaphis (PA23) and Bacillus amyloliquefaciens (BS6), can control some fungal diseases of canola through production of bacterial metabolites and through induced systemic resistance, which is initiated by the signalling molecule jasmonic acid. Direct application of jasmonic acid activates defence-related compounds and influences insect herbivory in canola. Field and laboratory studies investigated the effects of the two bacteria and of jasmonic acid on insects of canola. In the field there were no consistently significant effects of treatment on insects sampled by beat cloth or sweep net, level of flea beetle injury, canola yield or quality. In the laboratory, jasmonic acid significantly increased oviposition and decreased larval feeding in diamondback moth (Plutella xylostella) and slowed development and reduced reproduction in turnip aphid (Lipaphis erysimi). The effects of jasmonic acid on canola were systemic. Analysis of leaf tissue showed significant effects of treatment on defence-related compounds.

Two strains of plant growth-promoting rhizobacteria, Pseudomonas chlororaphis (PA23) and Bacillus amyloliquefaciens (BS6), can control some fungal diseases of canola through production of bacterial metabolites and through induced systemic resistance, which is initiated by the signalling molecule jasmonic acid. Direct application of jasmonic acid activates defence-related compounds and influences insect herbivory in canola. Field and laboratory studies investigated the effects of the two bacteria and of jasmonic acid on insects of canola. In the field there were no consistently significant effects of treatment on insects sampled by beat cloth or sweep net, level of flea beetle injury, canola yield or quality. In the laboratory, jasmonic acid significantly increased oviposition and decreased larval feeding in diamondback moth (Plutella xylostella) and slowed development and reduced reproduction in turnip aphid (Lipaphis erysimi). The effects of jasmonic acid on canola were systemic. Analysis of leaf tissue showed significant effects of treatment on defence-related compounds.

This diploma work is focused on the use of bioadditives (products based on algae and bacteria) in the production of basil (Ocimum basilicum). In the literar rewiew, this bioadditives are described generally in terms of their material composition, effect and use in practise. The experimental part deals with a field experiment with basil, which took place in Lednice in the land of the Faculty of Horticulture, Mendel University in Brno in 2013. Basil was divided into 5 variants (4 + control). Individual variants were treated by Amalgerol Premium, EM -- farming Super aktiviert, Pro Milieu Terra and product from Rawat without trade name. The effect of these bioadditives on yield and nutritional parameters of basil were observed. Nutritional parameters were determined from fresh basil matter and from the dried matter. It was the total antioxidant capacity, content of phenols, flavonoids and dry matter. The results show that the application of these products has both positive and negative impact on the monitored parameters in basil. Yield parameters of these preparations were not significantly affected. The greatest effect has Amalgerol Premium and EM -- farming Super aktiviert on increase of total antioxidant capacity. EM -- farming variant was also found to increase total phenols and flavonoids.

Upstream oil and gas production has caused soil salinity problems across western Canada. In this work we investigated the use of ACC (1-aminocyclopropane-1-carboxylate) deaminase-producing plant growth-promoting rhizobacteria (PGPR) and the arbuscular mycorrhizal fungus (AMF) Glomus intraradices to enhance the efficiency and feasibility of phytoremediation of saline soils. This work involved laboratory and field research for three sites in south east Saskatchewan, Canada. The three research sites were Cannington Manor South (CMS), Cannington Manor North (CMN) and Alameda (AL). CMS and AL were highly saline, while the CMN site had moderate salinity. Indigenous PGPR were isolated from these sites and tested in greenhouse experiments using authentic salt-contaminated soils taken from the research sites. Increased plant biomass by PGPR and/or AMF was observed. This growth promotion effect varied with plant species, soil salinity and soil fertility. The combination treatment of two previously isolated PGPR Pseudomonas putida UW3 and UW4 (noted as UW3+4) from farm soil in Ontario consistently promoted shoot growth of both barley and oats grown in saline soils by approximately 100%. The indigenous PGPR Pseudomonas corrugata (CMH3) and Acinetobacter haemolyticus (CMH2) also promoted plant growth on par with UW3+4. In addition, in one experiment where alfalfa was tested, UW3+4, CMH2 and CMH3 treatments not only enhanced shoot biomass but also increased root nodulation. For AMF effects, G. intraradices enhanced biomass of oats and barley. Furthermore, the AMF+CMH3 was effective in promoting growth of Topgun ryegrass, while AMF+CMH2 was beneficial for Inferno tall fescue growth in salt impacted soils. The concentration of NaCl in the plants grown in salt-impacted soils ranged from 24 – 83 g/kg. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR and/or AMF treatments. In addition, to determine the importance of nutrient addition to research sites, liquid fertilizer was applied to 2-week old plants. Results demonstrated that fertilizer effectively increased biomass, and more importantly the biomass of PGPR treated plants supplied with fertilizer was approximately 20% higher than that of plants treated with fertilizer alone. Therefore, research sites were then amended with compost before planting of the 2007 field trial. Plant growth promotion by UW3+4 and CMH3 was tested in the summer of 2007 in the field. Prior to planting, soils were sampled from each site for soil salinity analysis. Barley, oats, tall fescue and ryegrass treated with and without PGPR were sown in plots. The plant coverage condition, NaCl concentrations and biomass of plant shoots were assessed to evaluate the PGPR effect. The results showed that PGPR promoted shoot dry weight by 30% - 175%. The NaCl concentrations of barley, oats and tall fescue averaged 53 g/kg, 66 g/kg and 35 g/kg, respectively. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR in the field. The salt removal of the CMN site was the highest among three sites due to the large amount of shoot biomass produced. The amount of salt accumulated in the shoots on the CMN site is estimated to be 1580 kg per hectare per year when both barley and ryegrass are planted together as a mix and treated with PGPR. Based on the field data, the estimated time required to remove 50% salt in the top 50 cm soil is seven years with PGPR treatments, while it takes fifteen years to do so without PGPR. In conclusion, PGPR-promoted phytoremediation was proven to be a feasible and effective remediation technique for soils with moderate salinity.

Although the pesticide DDT has been banned from use in Canada for more than three decades, DDT still persists in Canadian farmlands at detectable levels. Much effort, such as incineration, thermal desorption, and bioremediation, has been used to remediate DDT contaminated soils, but so far it is either too expensive or impractically slow. In this study, a three-year period of field trials was performed to investigate phytoremediation of DDT contaminated soil. In the field trials, millet, fall rye, sugar beet, potato, and pumpkin, treated with plant growth-promoting rhizobacteria (PGPR) were planted on two sites. As well, untreated plants were planted as a control. Plant growth, and 4,4’-DDT plus 4,4’-DDE concentrations in plant tissues and soil were monitored regularly. Comparing the plant growth between PGPR treated and untreated, PGPR significantly promoted the plant growth. On site 1, the root length and root weight of fall rye treated with PGPR were 16% and 44% greater, respectively, compared to the untreated plants. The root and shoot dry weights of millet treated with PGPR were 38% and 47% greater than those untreated plants. Root dry weight of sugar beet treated with PGPR was increased by 74% compared to untreated sugar beet. A significant effect of growth promotion was also observed in pumpkin and potato treated with PGPR. Following plant growth, DDT detection in plants was performed. 4,4’-DDT and 4,4’-DDE were found in plant tissues of fall rye, millet, sugar beet, and pumpkin. The concentrations of 4,4’-DDT and 4,4’-DDE in fall rye roots were 0.61 and 0.59 μg/g, respectively. In pumpkin tissues at harvest, 4,4’-DDT and 4,4’-DDE concentrations were 0.67 and 1.64 μg/g in roots, 1.06 and 2.05 μg/g in the lower stems, and 0.2 and 0.32 μg/g in the upper stems. The data indicated that it is feasible to phytoremediate DDT from contaminated soil. In addition, 4,4’-DDT concentrations in soils with different plant species were determined. In millet plot on site 1, 4,4’-DDT concentration in rhizosphere soil dropped by 41% in 2006 compared to 4,4’-DDT concentration at t0. In sugar beet plot on site 1, 28% of 4,4’-DDT dropped in rhizosphere soil in 2007. In pumpkin plot on site 1, 4,4’-DDT in rhizosphere soil was decreased by 22% in 2007. The results show that 4,4’-DDT concentration in rhizosphere soil was significantly lower than the initial level of DDT. Based on the data of 4,4’-DDT in soils and plant tissues, a mass balance was constructed and calculated. The preliminary mass balance shows that the total amount that DDT decreased in rhizopshere soil approximately equals to the total amount of DDT accumulated in plant tissues. This indicates that phytoextraction is the mechanism of DDT phytoremediation. In addition, PGPR promoted plant growth and then enhanced the phytoremediation efficiency of DDT. Therefore, the research indicates that PGPR assisted phytoremediation has a great potential for remediation of DDT and other chlorinated aromatics from impacted soil.

Upstream oil and gas production has caused soil salinity problems across western Canada. In this work we investigated the use of ACC (1-aminocyclopropane-1-carboxylate) deaminase-producing plant growth-promoting rhizobacteria (PGPR) and the arbuscular mycorrhizal fungus (AMF) Glomus intraradices to enhance the efficiency and feasibility of phytoremediation of saline soils. This work involved laboratory and field research for three sites in south east Saskatchewan, Canada. The three research sites were Cannington Manor South (CMS), Cannington Manor North (CMN) and Alameda (AL). CMS and AL were highly saline, while the CMN site had moderate salinity. Indigenous PGPR were isolated from these sites and tested in greenhouse experiments using authentic salt-contaminated soils taken from the research sites. Increased plant biomass by PGPR and/or AMF was observed. This growth promotion effect varied with plant species, soil salinity and soil fertility. The combination treatment of two previously isolated PGPR Pseudomonas putida UW3 and UW4 (noted as UW3+4) from farm soil in Ontario consistently promoted shoot growth of both barley and oats grown in saline soils by approximately 100%. The indigenous PGPR Pseudomonas corrugata (CMH3) and Acinetobacter haemolyticus (CMH2) also promoted plant growth on par with UW3+4. In addition, in one experiment where alfalfa was tested, UW3+4, CMH2 and CMH3 treatments not only enhanced shoot biomass but also increased root nodulation. For AMF effects, G. intraradices enhanced biomass of oats and barley. Furthermore, the AMF+CMH3 was effective in promoting growth of Topgun ryegrass, while AMF+CMH2 was beneficial for Inferno tall fescue growth in salt impacted soils. The concentration of NaCl in the plants grown in salt-impacted soils ranged from 24 – 83 g/kg. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR and/or AMF treatments. In addition, to determine the importance of nutrient addition to research sites, liquid fertilizer was applied to 2-week old plants. Results demonstrated that fertilizer effectively increased biomass, and more importantly the biomass of PGPR treated plants supplied with fertilizer was approximately 20% higher than that of plants treated with fertilizer alone. Therefore, research sites were then amended with compost before planting of the 2007 field trial. Plant growth promotion by UW3+4 and CMH3 was tested in the summer of 2007 in the field. Prior to planting, soils were sampled from each site for soil salinity analysis. Barley, oats, tall fescue and ryegrass treated with and without PGPR were sown in plots. The plant coverage condition, NaCl concentrations and biomass of plant shoots were assessed to evaluate the PGPR effect. The results showed that PGPR promoted shoot dry weight by 30% - 175%. The NaCl concentrations of barley, oats and tall fescue averaged 53 g/kg, 66 g/kg and 35 g/kg, respectively. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR in the field. The salt removal of the CMN site was the highest among three sites due to the large amount of shoot biomass produced. The amount of salt accumulated in the shoots on the CMN site is estimated to be 1580 kg per hectare per year when both barley and ryegrass are planted together as a mix and treated with PGPR. Based on the field data, the estimated time required to remove 50% salt in the top 50 cm soil is seven years with PGPR treatments, while it takes fifteen years to do so without PGPR. In conclusion, PGPR-promoted phytoremediation was proven to be a feasible and effective remediation technique for soils with moderate salinity.