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Searching of Phenol-Degrading Bacteria in Raw Wastewater from Underground Coal Gasification Process as Suitable Candidates in Bioaugmentation Approach

Jałowiecki Łukasz, Borgulat Jacek, Strugała-Wilczek Aleksandra, Glaser Mikołaj, Płaza Grażyna

Journal of Ecological Engineering

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2024

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Vol. 25, nr 2

62--71

EN

The aim of the conducted study was to isolate, identify and characterize suitable bacterial strains from UCG wastewater as potential candidates for the bioaugmentation approach. For this purpose, the straightforward cultivation procedure and unique biochemical selection were employed to gain insights into the specific properties of bacteria. From the 100 strains isolated from UCG wastewater, three (Paenibacillus pasadensis SAFN-007, Peanibacillus humicus Au34, and Staphylococcus warneri DK131) demonstrated the capacity to degrade phenol and specific biochemical properties. Phenol degradation reached more than 90% for the above-mentioned strains, while the average phenol removal rate for other selected strains was 82.9%, ranging from 66.1% to 90%. The bacterial strains belong to multi-enzyme producers and constitute a possible source of potential technologically important enzymes. Phenotypic microarray plates were used to characterise the metabolic properties of the strains. It was found that 74%, 67.4% and 94.2% of the carbon metabolites tested were utilised by Paenibacillus pasadensis SAFN-007, Peanibacillus humicus Au34 and Staphylococcus warneri DK131, respectively. Among C sources, the strains have the capability to metabolize some substrates appearing in phenol pathways, such as: N-acetyl-D-glucosamine, succinic acid, α-hydroxy-glutaric acid-γ-lactone, bromosuccinic acid, mono-methyl succinate, methyl-pyruvate, p-hydroxy-phenyl acetic acid, m-hydroxyphenylacetic acid, L-galactonic acid-γ-lactone, D-galactonic acid-γ- lactone, phenylethylamine. Bacteria show different levels of tolerance to pH and osmolality, and they can thrive in different habitats. Another characteristic of these strains is their high resistance to many antibiotics (multi-resistant bacteria). These properties allow the use of the isolated bacterial strains as good candidates for bioremediation of phenol-contaminated environments. The wastewater from the underground coal gasification process is an example of a good extreme environment for the isolation of unique bacteria with specific metabolic properties.

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Bioeffects of silver nanoparticles (AgNPs) synthesized by producer of biosurfactant Bacillus subtilis strain : in vitro cytotoxicity, antioxidant properties and metabolic activities of mammalian cells

Chojniak-Gronek Joanna Małgorzata, Jałowiecki Łukasz, Płaza Grażyna Anna

Archives of Environmental Protection

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2022

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Vol. 48, no. 4

45--52

EN

The present study is focused on the evaluation of bioeffects of silver nanoparticles (AgNPs) synthesized by Bacillus subtilis strain I’-1a, the producer of iturin A lipopeptide biosurfactant. The following properties of biologically synthesized silver nanoparticles (bio-AgNPs) were evaluated: in vitro cytotoxicity, antioxidant properties, and metabolic activities of mammalian cells. As a control, chemically synthesized silver nanoparticles (chem-AgNPs) were used. In vitro, antioxidant activity of bio-AgNPs showed a significant effect on the scavenging of free radicals. Bio-AgNPs can be potent natural antioxidants and can be essential for health preservation against oxidative stress-related degenerative diseases, such as cancer. The cell viability of human skin fibroblasts NHDF was remarkably inhibited in the presence of both AgNPs. However, bio-AgNPs were more active than chem-AgNPs. In our experiment, microarrays PM-M1–PM-M4 were used to evaluate the growth of NHDF fibroblast cells in the presence of bio-AgNPs and chem-AgNPs. The NHDF fibroblast cells were more active in the presence of bio-AgNPs than in chem-AgNPs. Probably, the presence of biosurfactant produced by Bacillus subtilis I’-1a significantly increased the stability of biogenic AgNPs and enhanced their biological activities and specific interaction with human DNA. Furthermore, the evaluated biological activities were enhanced for the biosurfactant-based AgNPs.

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Aerobic biodegradation of norfloxacin and ofloxacin by a microbial consortium

Jałowiecki Łukasz, Płaza Grażyna, Ejhed Helena, Nawrotek Monika

Archives of Environmental Protection

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2019

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Vol. 45, no. 4

40--47

EN

Since fluoroquinolone (FQ) antibiotics are extensively used both in human and veterinary medicine their accumulation in the environment is causing increasing concern. The aim of the study was to isolate a microbial consortium resistant to ofloxacin and norfloxacin and able to biodegrade both antibiotics. Green compost was used as a source of microorganisms. The biodegradation efficiency was monitored by changes of antibiotics concentrations and toxicity. The microbial consortium was composed of two bacterial isolates: Klebsiella pneumoniae (K2) and Achromobacter sp. (K3) and two fungi Candida manassasensis (K1) and Trichosporon asahii (K4). All the isolates were characterized as highly resistant to both antibiotics – ofloxacin and norfloxacin. FQs were supplied individually into the culture medium in the presence of an easily degradable carbon source – glucose. Biodegradation of norfloxacin was much faster than ofloxacin biodegradation. During 20 days of the experiment, the norfloxacin level decreased by more than 80%. Ofloxacin was generally biodegraded thereafter at relatively slow biodegradation rate. After 28 days the ofloxacin level decreased by 60%. Similarly, the toxicity of biodegraded antibiotics decreased 4-fold and 3.5-fold for norfloxacin and ofloxacin, respectively. The ability of the bacterial-fungal consortium to degrade antibiotics and reduce toxicity could help to reduce environmental pollution with these pharmaceutical.

PL

Antybiotyki to zróżnicowana grupa związków, która nie ma konkretnych uregulowań prawnych, dotyczących ich występowania w środowisku, zarówno wodnym jak i glebowym. Farmaceutyki przedostają się do środowiska m.in. wraz ze ściekami oczyszczonymi z oczyszczalni ścieków i jako substancje czynne biologicznie stanowią poważne zagrożenie dla organizmów żywych. Ich akumulacja w środowisku prowadzi do nieodwracalnych zmian w ekosystemach oraz szerzenia się zjawiska oporności wśród mikroorganizmów. Fluorochinolony (FQ) to syntetyczne substancje antybakteryjne o zwiększonym potencjale farmakokinetycznym i szerokim spektrum działania. FQ to jedna z najszybciej rozwijających się klas antybiotyków coraz częściej stosowanych zarówno w szpitalach, jak i w społecznościach lokalnych w leczeniu różnego typu zakażeń. Norfloksacyna i ofloksacyna to FQ II generacji o podobnej budowie strukturalnej wykazujące aktywność głównie wobec bakterii Gram-ujemnych. Ze względu na swoja budowę antybiotyki te w niewielkim stopniu są rozkładane w środowisku, przez długi czas kumulują się w wodzie i w glebie, oddziałując w na organizmy żywe. Celem pracy była ocena toksyczności ofloksacyny i norfloksacyny po biodegradacji przez zespół mikroorganizmów wyizolowany z kompostu. Proces biodegradacji przeprowadzono w bioreaktorach New Brunswick™ BioFlo® 415 o pojemności 5,5 l. Stopień degradacji określono za pomocą chromatografi i cieczowej w odwróconym układzie faz. Do oceny toksyczności wykorzystano test Microtox® oparty na pomiarach aktywności bakterii luminescencyjnych Vibrio fischeri.