This study investigated the effect of plants inoculation with Azospirillum spp. and Pseudomonas stutzeri in soils freshly contaminated with PAH's on enzymatic activities. During the 30-days experiment a relatively higher dehydrogenase, acid and alcaline phosphatases activities were detected in chernozem and rendzina after grown of maize and meadow feascue inoculated with Azospirillum spp. and Pseudomonas stutzeri. Statistically important decrease of enzymatic activities in soil after grown of plants non-inoculated and inoculated were confirmed after pollution of soils with diesel fuel at the dose of 1%.
The biological activity of the medium alluvial soil amended with the wheat straw (series with mineral nitrogen and without nitrogen) was investigated. In the field experiments, the authors determined: the total number of bacteria, actinomycetes, fungi, activity of dehydrogenase. The total content of organic matter and organic nitrogen in the soil were determined also. The investigated changes of the ratio of the total number of bacteria and total number of fungi in the soil may be proposed as one of the indices of soil fertility. It was found that the soil amended with wheat straw (with mineral nitrogen and without nitrogen) showed higher biological activity, than uninoculated one.
The effect of the celulolitic bacteria Azospirillum spp. and Pseudomonas stutzeri on the biological activity of the medium alluvial soil amended with the wheat straw (series with mineral nitrogen and without nitrogen) was investigated. In the pot experiments, the authors determined: the total number of bacteria, actinomycetes, fungi, activity of dehydrogenase. The total content of organic matter and organic nitrogen in the soil were determined also. The investigated changes of the ratio of the total number of bacteria and total number of fungi in the soil may be proposed as one of the indices of soil fertility. It was found that the soil amended with wheat straw (with mineral nitrogen and without nitrogen) and inoculated with celulolitic bacteria Azospirillum spp. showed higher biological activity, than uninoculated one.
Contamination of soils artificially polluted with PAHs and aged polluted with crude oil in the phytoremediation process were compared. The plant used in the tests was maize (Zea mays L.). In chamber tests with soils artificially polluted (chernozem, calcareous rendzina, and lessives), selected three PAHs (anthracene, phenanthrene, and pyrene) were used at the doses of 100, 500, and 1000 mg·kg⁻¹ d.m. of soil and diesel fuel at the doses of 0.1%, 0.5%, and 1% (v/v). Brown soil from crude oil refinery was chosen as the soil naturally, aged polluted with crude oil. Additionally, plant inoculation with the mixture of bacteria strains Azospirillum and Pseudomonas stutzeri was applied in the bioremediation process in the amount of 1 ml·500 g⁻¹ of soil. Chamber pot-tests were carried out in controlled conditions (temperature, humidity) during a four-week-long plant growth period. Physical properties of soils and the dry mass of above- and underground parts of plants were analyzed in the work. The obtained results showed a statistically significant increase in the dry mass of the above- and underground parts of plants (both artificially and aged polluted) inoculated with Azospirillum and Pseudomonas stutzeri after maize growth.
In this study the effects of meadow fescue (Festuca pratensis) inoculated (I+) and non-inoculated (I-) by diazothrophic species of bacteria (Azospirillum spp. and Pseudomonas stutzeri) on the degradation of polycyclic aromatic hydrocarbons in soils freshly contaminated with a mixture of PAHs and diesel fuel was investigated. Plants were grown in three different soils (chernozem, rendzina, lessives) for 4 weeks and unplanted soils considered as control. At the end of the experiment, physical properties of soils, dry masses of plants, and Σ 15PAH contents were measured in the soils. The results demonstrated that I (+) plants contained more root and shoot biomass than I (-) plants. Planting stimulated the bioremediation process in contaminated soils. The differences in concentration between the inoculated or non-inoculated soils indicate that the presence of plant roots, in addition to the passage of time, contributes, to reduction in the bioavailability of a mixture of PAHs and diesel fuel. The choice of soils, contamination, and inoculation has a significant effect of PAH degradation (mixture 1: in chernozem 24.8-59.7%, in rendzina 15.4-41.4%, in lessives 48.4-71,4%). It was revealed that they were more degraded in the rhizosphere of (I+) plants compared to I (-) ones. Obtained results suggests that inoculation of plants with Azospirillum spp. and P. stutzeri looks promising as a low-cost treatment method for PAH-contaminated soil.
Badano wpływ skażenia gleb (czarnoziemu, rędziny wapiennej i gleby płowej) wielopierścieniowymi węglowodorami aromatycznymi (WWA) w dawkach 100, 500, 1000 mg∙kg-1 s.m. gleby i olejem napędowym (ON) w dawkach 0,1%, 0,5%, 1% w stosunku do s.m. gleby na zmiany aktywności biologicznej gleb w ryzosferze kukurydzy po 30-dniowym okresie wegetacji roślin w doświadczeniach doniczkowych w fitotronie. Oznaczono: ogólną liczebność: bakterii, promieniowców, grzybów, drobnoustrojów zdolnych do degradacji WWA i ON, a także aktywności enzymatyczne (aktywność dehydrogenaz, fosfataz zasadowej i kwaśnej). Silne korelacje wystąpiły pomiędzy właściwościami fizyko-chemicznymi skażonych gleb a ogólną liczebnością drobnoustrojów zdolnych do degradacji WWA oraz aktywnością dehydrogenaz. Stwierdzono statystycznie istotne zmniejszenie ogólnej liczebności bakterii i promieniowców oraz istotny wzrost ogólnej liczebności grzybów i drobnoustrojów degradujących WWA i ON we wszystkich glebach wraz ze wzrostem dawki skażenia. Aktywności dehydrogenaz oraz fosfatazy zasadowej były istotnie wyższe w glebach przy skażeniu olejem napędowym w dawce 1% w stosunku do s.m. gleby.
Contamination of soils artificially polluted with polycyclic aromatic hydrocarbons (PAHs) and soils aged polluted with crude oil in the phytoremediation process were compared. The plant used in the tests was maize (Zea mays L.). In chamber tests with soils artificially polluted (chernozem, calcareous rendzina, and lessives), selected three PAHs (anthracene, phenanthrene, and pyrene) were used at the doses of 100, 500, and 1000 mg·kg-1 d.m. of soil and diesel fuel at the doses of 0.1%, 0.5%, and 1% (v/v). The soil naturally, aged polluted with crude oil chosen for the experiment was brown soil from crude oil refinery. Additionally, in the bioremediation process, the inoculation of plants with the mixture of bacteria strains Azospirillum and Pseudomonas stutzeri was used in the amount of 1 ml·500 g-1 of soil. Chamber pot-tests were carried out in controlled conditions (temperature, humidity) during four weeks of plant growth period. Physical properties of soils polluted with PAHs, diesel fuel, and crude oil and the degree of PAHs degradation were analyzed in the study. The amounts of anthracene, phenanthrene, and pyrene were determined in soils artificially polluted and Σ15 PAHs in soils artificially polluted with diesel fuel, as well as in brown soil aged polluted with crude oil. The obtained results showed a statistically important increase in the physical properties of soils polluted with PAHs, diesel fuel, and crude oil compared with the control and also an important decrease in the content of PAHs in soils (both artificially and aged polluted) inoculated with Azospirillum and Pseudomonas stutzeri after maize growth. The bioremediation processes were especially intensive in calcareous rendzina artificially polluted with PAHs and in brown soil aged polluted with crude oil.
This study investigated the effect of plants inoculation with Azospirillum spp. and Pseudomonas stutzeri in soils freshly contaminated with PAH's on number of microorganisms. During the 30-days experiment a relatively higher number of bacteria, actinomycetes, ammonifying and proteolitic bacteria and microorganisms able to use PAH's and disel fuel as a only source of carbon and energy were detected in chernozem and rendzina after grown of maize and meadow feascue inoculated with Azospirillum spp. and Pseudomonas stutzeri. Statistically important decrease number of microorganisms (except for fungi) in soil after grown of plants non- inoculated and inoculated were confirmed after pollution of soils with diesel fuel at 1% dose.
Obecność odpowiednio wyselekcjonowanych szczepów bakterii w ryzosferze ma pozytywny wpływ na kiełkowanie, wzrost i rozwój roślin. Szczepy bakterii z rodzaju Azospirillum są zdolne do wiązania azotu przy wykorzystaniu jako jedynego źródła węgla kwasów organicznych i ich soli, jak również węglowodorów i cukrów. Celem pracy była ocena wykorzystania kwasu ferulowego i kumarowego jako jedynych źródeł węgla w procesie wiązania wolnego azotu przez 12 szczepów bakterii z rodzaju Azospirillum. Szczepy te wyizolowano z endoryzosfery jęczmienia jarego (Hordeum sativum L.): 12/6, 1/7 i 15/7, kukurydzy (Zea mays L.): 4B, 23B, 35Bb, 48B, 77Bb1, 83B1 i trawy nadmorskiej z okolic Sobieszewa (Elymus arenarius L.): 29S, 36S, 42S. Szczepy te należały do gatunków: A. amasoense i A. brasilense. Wszystkie szczepy bakterii z rodzaju Azospirillum wiązały azot przy wykorzystaniu kwasu ferulowego i kumarowego jako jedynego źródła węgla. Wyniki badań przedstawiono jako aktywność nitrogenazy po 168 h hodowli “głodzonych” szczepów bakterii Azospirillum przy wykorzystaniu powyższych kwasów. Aktywność nitrogenazy szczepów Azospirillum była bardzo zróżnicowana i zależała zarówno od gatunku szczepu, jak i czasu hodowli. Największą aktywność nitrogenazy stwierdzono u szczepów wyizolowanych z ryzosfery jęczmienia jarego przy wykorzystaniu kwasu ferulowego jako jedynego źródła węgla i energii (szczep 1/7 – 824,32 nM C2H4•24 h-1 • cm-3 fazy gazowej, po 24 h inkubacji). W przypadku szczepów wyizolowanych z endoryzosfery kukurydzy najwyższą aktywnością nitrogenazy charakteryzował się szczep 4B (715,14 nM C2H4•24 h-1•cm-3 fazy gazowej, po 24 h inkubacji. Szczepy z najniższą aktywnością nitrogenazy pochodziły z endoryzosfery trawy Elymus arenarius, gdzie najwyższą aktywnością nitrogenazy charakteryzował się szczep 29S przy wykorzystaniu kwasu ferulowego jako jedynego źródła węgla (274,56 nM C2H4•24 h-1•cm-3 fazy gazowej). Badania in vitro wpływu różnych źródeł węgla na aktywność nitrogenazy szczepów bakterii z rodzaju Azospirillum pozwolą lepiej zrozumieć ich rolę i znaczenie w ryzosferze roślin.
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