Barbara Breza-Boruta

Hygienic aspects of cattle slurry storage as tHe most popular and cHeapest metHod of Handling liquid animal excrements

Abstract Slurry is a very valuable natural fertilizer, but its improper use in agriculture poses a serious sanitary threat. Therefore its treatment before use for fertilization is advisable. One of such methods, which is still the most popular, is storage of liquid excrements. The aim of this study was to estimate the sanitization effectiveness of storage at 4ºC and 20ºC based on parameters describing the kinetics of changes in the population of some indicator bacteria in cattle slurry with different dry matter content. The material for the study was fresh cattle slurry. The liquid excrements used in the experiment had a dry matter content of 2, 6 and 14%. Slurry was stored at 4ºC and 20ºC. Bacilli of Salmonella Dublin, E. coli and enterococci were used as indicator bacteria. Number of microorganisms was determined based on MPN method in a 3-tube design. Basic parameters of the bacteria inactivation kinetics were calculated and statistical analysis was made using the program SAS 9.2 PL. In stored slurry a gradual elimination of all the studied microorganisms was observed. Hygienization effect of storage was smaller at 4ºC than at 20ºC and in excrements with a high dry matter content. Depending on storage temperature and dry matter proportion, the theoretical times of survival ranged from 81.85 to 220.80 days for bacilli of Salmonella Dublin, from 74.93 to 199.36 days for E. coli, and from 118.67 to 335.84 days for enterococci. The study showed explicitly that statutory time of slurry storage is insufficient to ensure its complete hygienization. Streszczenie Gnojowica stanowi bardzo wartościowy nawóz naturalny, jednak jej niewłaściwe zastosowanie w rolnictwie stwarza poważne zagrożenie sanitarno-higieniczne. W związku z powyższym celowa jest jej obróbka przed nawozowym wykorzystaniem. Jedną z metod, cieszącą się wciąż największą popularnością, jest składowanie płynnych odchodów. Celem badań była ocena skuteczności higienizacyjnej składowania w temperaturze 4 i 20ºC w oparciu o parametry opisujące kinetykę zmian populacji wybranych bakterii wskaźnikowych w gnojowicy bydlęcej o różnym udziale suchej masy. Materiał do badań stanowiła świeża gnojowica bydlęca. W badaniach wykorzystano płynne odchody o zawartości suchej masy: 2, 6 i 14%. Gnojowicę składowano w temperaturze 4 i 20ºC. Jako bakterie wskaźnikowe wykorzystano pałeczki Salmonella Dublin, E. coli oraz enterokoki. Liczbę drobnoustrojów ustalono w oparciu o metodę NPL w układzie 3-probówkowym. Obliczono podstawowe parametry kinetyki inaktywacji bakterii oraz przeprowadzono analizę statystyczną w programie SAS 9.2 PL. W składowanej gnojowicy obserwowano stopniową eliminację wszystkich badanych drobnoustrojów. Efekt higienizacyjny składowania był słabszy w temperaturze 4 niż 20ºC oraz w odchodach o wysokim udziale suchej masy. W zależności od temperatury składowania i udziału suchej masy teoretyczne czasy przeżycia wahały się dla pałeczek Salmonella Dublin od 81,85 do 220,80 dnia, dla E. coli - od 74,93 do 199,36 dnia, a dla enterokoków - od 118,67 do 335,84 dnia. Badania jednoznacznie wykazały, że ustawowo przewidziany czas składowania gnojowicy jest niewystarczający dla zapewnienia jej pełnej higienizacji.

Occurrence of amylolytic microorganisms in soil depending on the type of cultivation

Abstract The count and growth dynamics of amylolytic microorganisms in soil beyond rhizosphere and within rhizosphere as well as in potato rhizoplane was compared in ecological (organic) and conventional farming systems. Potatoes in the ecological system were fertilized only with organic fertilizers and in the conventional system NPK fertilizers + manure were used. The results showed that the count of bacteria showing amylolytic activity was generally higher in ecological farming than in conventional one. Vegetation stage had a significant effect on the growth dynamics of microorganisms tested. The highest level of their count was achieved at the end of the vegetation during tuber harvest maturity. A remarkable smaller count of microorganisms secreting amylases was recorded in the soil beyond rhizosphere in comparison with the rhizosphere area and rhizoplane. Selected physico-chemical properties of soils (humidity and pH) were more favourable in the soil cultivated under organic farming system in comparison to the conventional one.

THE ANTAGONISTIC ACTIVITY OF ACTINOMYCETES OF STREPTOMYCES GENUS IN RELATION TO TRICHODERMA KONINGII

The aim of the study was to estimate the effect of actinomycetes of genus Streptomyces on the growth of the antagonistic fungus Trichoderma koningii. 150 strains of Streptomyces spp. isolated from two potato cropping systems were used to the tests. Analyses were conducted experimentally in vitro on PDA medium with pH 6 and 7. The results obtained clearly indicate the inhibitory effect of actinomycetes on the fungus T. koningii. Of the tested population of actinomycetes only two strains did not inhibit the growth of the tested fungus. The strains from the rhizosphere of potato cultivated under the ecological system were predominant in the group of actinomycetes with a very strong effect. pH value appeared to be a crucial factor influencing the inhibition zone. High antagonistic activity in relation to the useful fungus T. koningii noted with numerous strains of Streptomyces spp. is unfavorable in respect of biological control.

Assessment of the content of heavy metals and potential pathogenic microorganisms in soil under illegal dumping sites

The aim of the study was the assessment of the environmental contamination of soil by heavy metals and microorganisms within the uncontrolled landfill dumps and the impact of anthropogenic sources on the activity of selected soil surface horizons. Some physicochemical properties were determined according to commonly used procedures in soil science laboratories. The total of heavy metals concentration was assessed according to Crock and Severson and forms available according to Lindsay and Norvell. The total contents and mobile forms were determined by atomic absorption spectrophotometry. As part of the microbiological tests, potentially pathogenic evidence of bacteria was found indicating fecal contamination of the soil (E. coli and other coliform bacilli, Salmonella spp., and Enterococcus spp.). Quantitative analyses were carried out based on the calculation of the most probable number of microorganisms (MPN method). The activity of selected redox and hydrolases enzymes: the activity of dehydrogenases with the Thalmann method, catalase with the Johnson and Temple method, alkaline and acid phosphatase with the method of Tabatabai and Bremner. It was concluded that depending on the composition of the dump, the physicochemical properties of the soil were changed, too. Uncontrolled landfills significantly affected the increase or decrease in the pH of the tested soil and the organic content of the tested soil. The waste stored at the site affected the contamination of the soil by heavy metals to varying degrees. The results show that the most dangerous bacteria exist in the soil under the C landfill and this is where the greatest risk of soil contamination exists. The highest amount of selected enzymes activity was observed in soils under illegal C dumping sites. In the soil sourced from A and B landfills, the enzyme inhibition occurred which was linked to the lowering of the organic carbon. The results of the principal component analysis demonstrated that the content of heavy metals and the activity of enzymes are the indicators of anthropogenic pollution, whereas granulometric composition (sand and silt) is mainly associated with the natural environment.

Maize Voc Induction after Infection by the Bacterial Pathogen, Pantoea ananatis, Alters Neighbouring Plant Voc Emissions

Plants induce volatile organic compounds (VOCs) after pathogen infection and exposure to a neighbouring infected plant. In a greenhouse, we measured VOCs from maize cv. ‘Prosna’ 3 or 7 d following foliar, or 42 d following soil, inoculation of Panteoa ananatis, a bacterial pathogen, as well as from uninfected neighbouring maize located 1 or 3 m from each infected plant treatment. We predicted the degree of VOC induction to be greatest 7 d post-foliar > 3 d post-foliar > 42 d post-soil inoculation; also, infected plant VOC induction > 1 m uninfected neighbour > 3 m uninfected neighbour. Maize infected by P. ananatis induced six common green leaf volatiles (GLVs), four common terpenes, and one common skikimic acid pathway derivative. Our results in general confirmed these two predictions, but there was an interaction. While 3 d post-foliar inoculated plants had greater VOC induction than an uninfected neighbour exposed 1 m from a 7 d post-foliar inoculated plant, 42 d post-soil inoculated plants had lower VOC induction than an uninfected neighbour exposed 1 m from a 3 d post-foliar inoculated plant. Thus, infected maize did not always emit higher VOC concentrations than uninfected maize exposed to an infected plant; it depended on the route of infection (foliar vs. soil inoculation) for the infected plant and which infected plant treatment was exposed to an uninfected plant. The VOC blend of maize cv. ‘Prosna’ after P. ananatis infection appears to be quantitatively different when compared to infection by a Fusarium spp. blend. The relevance of these maize VOC blend differences after infection by different pathogens needs to be studied, but our results suggest that maize responds with quantitatively different VOC blends depending on the infecting pathogen.

Występowanie potencjalnie antagonistycznych bakterii w stosunku do patogenicznych grzybów na powierzchni korzeni ziemniaka (Solanum tuberosum) [Occurrence of potentially antagonistic bacteria on surface of potato (Solanum tuberosum) roots]

The research was carried out on farms in Kielpin in Bory Tucholskie Landscape Park in vicinity of Tuchola over 1997-1999. The purpose was to determine of quantitative composition of Pseudomonas and Artrobacter genera, coryneform group and total count of bacteria on roots of potato. Aster cultivar of potato was cultivated in two systems: conventional and ecological. The microbiological analysis showed that the coryneform group dominated over other investigated groups of bacteria. The greatest number of bacteria was isolated from rhizoplane of potatoes cultivated in ecological system. The results obtained during three years of the experiment show that the nmnber of potentially antagonistic bacteria increased along with plant vegetation. The maximum number of these bacteria inhabited roots of older plants.