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Isolation, characterization and growth assessment of biodegrading chlorpyrifos-methyl Bacillus species isolated from Algerian soil

Slimani Hanane, Abdi Akila, Branes Zidane

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2022

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Vol. 31, No. 2

135--146

EN

Chlorpyrifos-methyl (CM) is a broad-spectrum organophosphate insecticide, which is widely used in pest control. In this research, the isolation, and biochemical and molecular identification of bacterial strains obtained from three soils located in northeastern Algeria were carried out, as well as the evaluation of their ability to grow in the presence of CM. Out of 48 bacterial isolates between Gram-negative and Gram-positive identified, several were able to grow on mineral agar with at least 25 mg·l–1 of CM. Four bacteria showed the best growth capacity, were identified as Bacillus sp. H1-80, Brevibacterium frigoritolerans strain WJB99 and two Bacillus sp. strains GL5. The strains were tested for their ability to grow on liquid media with CM as the sole energy and carbon source. In general, these strains showed slow but significant growth visualized by the 600 nm turbidity control, suggesting that they could be used for bioremediation applications of CM polluted soils.

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Detecting food limitation of bacterial growth during dilution experiments

Rychert Krzysztof

Oceanologia

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2022

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No. 64 (3)

405--416

EN

The dilution method is typically applied to estimate the growth and mortality rates of phytoplankton, but it is also used to study bacterioplankton. The method comprises creating a gradient of dilutions to reduce the encounter rates between bacterivores and bacteria, thus allowing for estimations of bacterial growth and grazing pressure exerted on the bacteria. However, the manipulations involved in the method can lead to biased results. In this study, 12 dilution experiments performed in the coastal zone of the Baltic Sea were accompanied by additional measurements capable of detecting possible artefacts. Only six measurements performed during spring and summer (March–August) produced results that were free of artefacts and were statistically significant. During fall and winter (October–February) measurements were unsuccessful because of food limitation of bacterial growth during experimental incubation. Twice (in September and October) bacterial growth and grazing mortality rates were underestimated because grazing pressure was not successfully removed. The study demonstrated that 24-hour and five-day oxygen consumption measurements incorporated into dilution experiments permitted estimating the fraction of biodegradable organic matter used during incubation, and, thus, detecting the food limitation of bacterial growth.

3

Wpływ niklu na wzrost szczepu stenotrophomonas maltolphilia KB2 w obecności fenolu

Szczyrba Elżbieta, Gąszczak Agnieszka, Szczotka Anna, Kolarczyk Hanna, Janus Bożena

Prace Naukowe Instytutu Inżynierii Chemicznej Polskiej Akademii Nauk

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2020

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nr 24

95--105

PL

Wykonano eksperymenty mające na celu zbadanie wzrostu komórek szczepu KB2 w obecności niklu, przy zastosowaniu fenolu jako źródła węgla i energii. Przeprowadzane badania potwierdziły hamujący wpływ niklu na wzrost badanego szczepu nawet dla niskich stężeń tego metalu.

EN

The influence of nickel on the growth of KB2 strain was tested for different concentrations of metal in the presence of phenol as the sole carbon and energy source. The inhibition effect of nickel on bacterial growth was confirmed even for low concentration of tested metal.

4

Przyczyny i zapobieganie zmianom jakości wody w systemach wodociągowych

Kowal A. L.

Ochrona Środowiska

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2003

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R. 25, nr 4

3-6

PL

W pracy omówiono czynniki wpływające na zmiany jakości wody w systemach jej dystrybucji. Do głównych czynników wpływających na pogorszenie jakości wody wodociągowej zaliczono korozję i gromadzenie osadów, występowanie procesów biochemicznych w sieci, a także raptowne zmiany ciśnienia oraz remonty prowadzone na sieci. Podkreślono szczególną rolę procesów biochemicznych przebiegających w sieci wodociągowej na jakość wody dostarczanej odbiorcom. Rozwojowi bakterii w sieci wodociągowej sprzyja obecność przyswajalnego węgla organicznego w wodzie poddanej w procesie uzdatniania działaniu utleniaczy chemicznych (ozon, dwutlenek chloru, chlor). Do warunków ograniczających rozwój życia biologicznego w wodzie wodociągowej zaliczono m.in. utrzymanie wysokiego stopnia oczyszczania wody (z optymalnym usunięciem zarówno bakterii, jak i węgla organicznego oraz związków azotowych) celem zapewnienia jej biostabilności, utrzymanie w należytej czystości urządzeń technicznych do oczyszczania i gromadzenia wody, płukanie sieci wodociągowej oraz właściwe postępowanie podczas usuwania awarii sieci i urządzeń sieciowych. Przedsiębiorstwa wodociągowe ujmujące wody powierzchniowe powinny wprowadzić do praktyki analitycznej oznaczanie zawartości ogólnego węgla organicznego (OWO), rozpuszczonego węgla organicznego (RWO) oraz przyswajalnego węgla organicznego (PWO) w wodzie tłoczonej do układu dystrybucji.

EN

Of the various contributors to the deterioration of tap water quality, major importance is attached to the corrosive power of the water, the accumulation of suspended solids, the occurrence of biochemical processes in the pipes, as well as rapid pressure variations and frequent damage repairs. In this paper, consideration has been focused on the contribution of the biochemical processes that occur in the water during distribution through the pipe network to the quality of the water supplied to the users. Bacterial growth in the water-pipe network is supported by the presence of assimilable organic carbon (AOC), which persists in the water after treatment with chemical oxidants (ozone, chlorine dioxide, chlorine). But there are also factors limiting microorganism growth in tap water, e.g. a continuingly high treatment efficiency (and this includes an optimal removal of bacteria, organic carbon and nitrogen compounds), biostability assurance, appropriate cleanup of the technical equipment for water treatment and storage, rinsing of the water-pipe network, as well as well-planned and well-organized procedures adopted for damage repair or failure removal. Waterworks with surface-water intakes are supposed to extend the range of analyses by including determinations of total organic carbon (TOC), dissolved organic carbon (DOC) and AOC in the water pumped into the distribution system.