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Antagonistic properties of Streptomyces isolated from forest soils against fungal pathogens of pine seedlings

100%

Golinska P., Dahm H.

Dendrobiology

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2013

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tom 69

Biological control of plant diseases has received worldwide attention in recent years mainly as a response to use of hazardous chemicals in the environment. Soil actinomycetes particularly Streptomyces spp. enhance soil fertility and have antagonistic activity against wide range of soil-borne plant pathogens. In study of antifungal activity of streptomycetes against plant fungal-pathogens Fusarium oxysporum (Schlecht.), F. culmorum (Wm. G. Sm.) Sacc. and Rhizoctonia solani (Kühn) causing damping-off of pine seedlings, in vitro and in vivo tests were carried out. Two types of in vitro tests in mixed cultures of actinomycetes and fungi were performed. In majority of the cases, an inhibitory effect of actinomycetes on fungi was noticed. Three isolates (SG9, SR2, SR4) were highly active against pathogenic fungi and were chosen for exopolysaccharides extraction and in vivo tests. The sensitivity to exopolysaccharide action was noted in fungi from the genus Fusarium. Fusarium oxysporum showed a higher sensitivity to the analyzed exopolysaccharides than F. culmorum. Biocontrol interactions both in sterile and non-sterile soil were found for the actinomycete Streptomyces cyaneus (strain SG9) isolated from root free soil of the pine. The latest experiment confirmed the strong pathogenicity of the fungus Rhizoctonia solani. Antifungal properties of Streptomyces cyaneus (strain SG9) need further comprehensive studies.

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Occurrence of actinomycetes in forest soil

100%

Golinska P., Dahm H.

Dendrobiology

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2011

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tom 66

Actinomycetes from the genus Streptomyces are Gram-positive bacteria commonly and in large numbers isolated from the soil, which is their natural habitat. Due to their metabolic activity and high adaptative capabilities they are an important link in the circulation of matter and energy. They play an important role in the formation of bioactive metabolites, mainly antibiotic compounds. In contrast to numerous elaborations concerning actinomycetes of cultivated soils, little is known about their occurrence in forest soils. The main factor limiting actinomycete development in forest soils is believed to be the low pH, as the development of most actinomycetes is facilitated by a neutral or alkaline soil reaction. However, these microorganisms have also been isolated from strongly acidic soils, which was confirmed in our studies. The pH value of analysed soils was in the range 4.0–4.3 (4.0 for bulk soil of alder; 4.1 for bulk soil of Scots pine; 4.3 for bulk soil of birch). Root soil of the analyzed trees contained more microorganisms than soil outside the range of the roots. This also concerned actinomycetes, eubacteria as well as saprophytic fungi. In our investigations the greatest number of eubacteria were connected with the alder (bulk soil, rhizosphere and rhizoplane), and the smallest number with the pine, whereas actinomycetes were the most numerous in the birch rhizosphere. The analyzed actinomycete strains were identified to 18 taxa, with a dominant species Streptomyces exfoliatus.

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Enzymatic activity of actinomycetes from the genus Streptomyces isolated from the bulk soil and rhizosphere of the Pinus sylvestris

100%

Golinska P., Dahm H.

Dendrobiology

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2011

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tom 65

The enzymatic activity (chitinolytic, proteolytic, pectolytic andcellulolytic) of twenty strains of Streptomyces isolated from soil and rhizosphere of Scots pine was analyzed. Most strains produced chitinases, catalyzing the degradation of chitin, the main component of fungal cell walls including fungi pathogenic for plants. This activity was about 4 times higher in the presence of Fusariumoxysporum than Rhizoctonia solani mycelium or chitin flakes. The number of the proteolytic strains was also significant. In general, rhizosphere and soil organisms synthesizedcomparable amounts of these enzymes. Over half of the analyzed Streptomyces strains produced pectolytic enzymes (polygalacturonase, pectin lyase and pectate lyase). This property was more common among rhizosphere than among soil strains. The Streptomyces strains also showedcellulolytic activity (endocellulases, exocellulases) – enzymes decomposing basic components of cell walls of plant and lower fungi (cellulose). The cellulolytic activity was differentiated and depended on the Streptomyces strain. Conclusion of our studies is that Streptomyces are the microorganisms more chitinolytic andproteolytic than pectolytic and cellulolytic.

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Intensywność mineralizacji igieł w borze sosnowym w odniesieniu do warunków siedliskowych i mikrobiologicznych stoków wydm o kontrastowej ekspozycji

81%

Sewerniak P., Jasinska J., Golinska P., Skladanowski M.

Sylwan

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2015

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tom 159

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nr 10

The aim of the study was to determine the rate of mineralization of needles in a pine stand in relation to site and to microbiological conditions occurring on dune slopes of contrasting aspects. The research was conducted in the old−growth pine forest overgrowing a latitudinally located dune in the Bydgoska Forest (N Poland). On contrasting dune slopes (northern and southern) rate of mineralization of pine needles was investigated in the 2−years experiment (2012−2014) with the litterbag method. Besides, following investigations were conducted in the middle part of both slopes: 1. dynamics of soil moisture and soil temperature were measured at a depth of 3 cm for 18 days during the 2013 growing season (interval of 2 weeks was applied) and 2. populations of bacteria and fungi were determined for all subhorizons of organic soil horizon (Ol, Of, Oh) as well as for a mineral horizon (AEs) of both soils. Weight loss of needles was found to be higher on northern than on a southern slope what was consequently stated for all 4 terms of taking measurements (6, 12, 18 and 24 months after placement of litterbags). The discrepancy has increased with time and after 2 years it equaled 14.7% when the loss was 61.1% for northern and 46.4% for a southern slope. It could be surprising that such differences were found in spite a sunny slope was characterized by stated in a study higher soil temperature. It should have a stimulating effect on mineralization of organic material; however a soil located on a southern slope was also found as much drier. Thus, the periodic deficiency of soil moisture was indicated as a limiting factor for occurrence of both bacteria and fungi on a southern slope due to the numbers of both groups of microorganisms were much lower on the slope than on a northern aspect. Conditioned by more favourable site parameters, higher number of microbial population occurring on a shadow slope could explain higher rate of mineralization of needles stated for the slope aspect. The moisture factor can be of especially high significance for microbial occurrence and activity and thus for litter decomposition just in dry inland dune ecosystems. It was concluded that in relatively monotonous pine forests overgrowing dry and poor in nutrients soils of inland dunes the slope aspect is an agent significantly differentiating both site and soil microbial conditions.

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Myxobacteria as a potential biocontrol agent effective against pathogenic fungi of economically important forest trees

61%

Dahm M., Brzezinska A. J., Wrotniak-Drzewiecka W., Golinska P., Rozycki H., Rai M.

Dendrobiology

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2015

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tom 74

The broad biocontrol properties of myxobacteria (mainly members of the genera Corallococcus and Myxococcus) isolated from forest soils against main fungal pathogens of pine seedlings were estimated. Among the myxobacterial strains studied (in vivo tests), the strongest antagonism towards fungi was noticed for the strains of the species Myxococcus virescens Thaxter and Corallococcus exiguus Reichenbach. They inhibited the fungal growth within the range 38–63%. The strongest inhibitory reaction towards Cylindrocarpon destructans (Zinssm.) Scholten was observed. A predominating part of myxobacteria (22 from among 30) inhibited the growth of Rhizoctonia solani Kühn. Myxobacteria suppressed any pathogenic action of Rhizoctonia solani (strain 411) towards Scots pine seedlings (in vitro tests). They produced extracellular (but not intracellular) acidic and neutral proteinases. None of the myxobacterial strain under examination produced chitinases. The 57% of the myxobacterial strains studied produced siderophores. The numbers of myxobacterial strains, obtained from under forest trees were in the following order: Betula pendula Roth. > Pinus sylvestris L. > Alnus glutinosa Gaertn. = Quercus robur L. The results gained in present work have proved potential use of myxobacteria as biocontrol agents against Rhizoctonia solani, common fungal pathogen of pine seedlings.

Ograniczanie wyników

4 Dendrobiology

1 Sylwan

5 Golinska P.

3 Dahm H.

1 Brzezinska A. J.

1 Dahm M.

1 Jasinska J.

1 Rai M.

1 Rozycki H.

1 Sewerniak P.

1 Skladanowski M.

1 Wrotniak-Drzewiecka W.

2 2015

1 2013

2 2011

Antagonistic properties of Streptomyces isolated from forest soils against fungal pathogens of pine seedlings

Occurrence of actinomycetes in forest soil

Enzymatic activity of actinomycetes from the genus Streptomyces isolated from the bulk soil and rhizosphere of the Pinus sylvestris

Intensywność mineralizacji igieł w borze sosnowym w odniesieniu do warunków siedliskowych i mikrobiologicznych stoków wydm o kontrastowej ekspozycji

Myxobacteria as a potential biocontrol agent effective against pathogenic fungi of economically important forest trees