Comparative Study on Multiway Enhanced Bio- and Phytoremediation of Aged Petroleum-Contaminated Soil

Bioremediation and phytoremediation of soil polluted with petroleum hydrocarbons (PHs) are an e ective and eco-friendly alternative to physicochemical methods of soil decontamination. These techniques can be supported by the addition of e ective strains and/or surface-active compounds. However, to obtain maximum e cacy of bioremediation, the interactions that occur between the microorganisms, enhancement factors and plants need to be studied. Our study aimed to investigate the removal of petroleum hydrocarbons from an aged and highly polluted soil (hydrocarbon content about 2.5%) using multiway enhanced bio- and phytoremediation. For this purpose, 10 enhanced experimental groups were compared to two untreated controls. Among the enhanced experimental groups, the bio- and phytoremediation processes were supported by the endophytic strain Rhodococcus erythropolis CDEL254. This bacterial strain has several plant growth-promoting traits and can degrade petroleum hydrocarbons and produce biosurfactants. Additionally, a rhamnolipid solution produced by Pseudomonas aeruginosa was used to support the total petroleum hydrocarbon loss from soil. After 112 days of incubation, the highest PH removal (31.1%) was observed in soil planted with ryegrass (Lolium perenne L. cv. Pearlgreen) treated with living cells of the CDEL254 strain and rhamnolipid solution. For non-planted experimental groups, the highest PH loss (26.1%) was detected for soil treated with heat-inactivated CDEL254 cells and a rhamnolipid solution. In general, the di erences in the e cacy of the 10 experimental groups supported by plants, live/dead cells of the strain tested and rhamnolipid were not statistically significant. However, each of these groups was significantly more e ective than the appropriate control groups. The PH loss in untreated (natural attenuation) and soils that underwent phytoremediation reached a value of 14.2% and 17.4%, respectively. Even though the CDEL254 strain colonized plant tissues and showed high survival in soil, its introduction did not significantly increase PH loss compared to systems treated with dead biomass. These results indicate that the development of e ective biological techniques requires a customized approach to the polluted site and e ective optimization of the methods used

Characterization of hydrocarbon-degrading and biosurfactant-producing "Pseudomonas" sp. P-1strain as a potential tool for bioremediation of petroleum contaminated soil

The Pseudomonas sp. P-1 strain, isolated from heavily petroleum hydrocarbon-contaminated soil, was investigated for its capability to degrade hydrocarbons and produce a biosurfactant. The strain degraded crude oil, fractions A5 and P3 of crude oil, and hexadecane (27, 39, 27 and 13 % of hydrocarbons added to culture medium were degraded, respectively) but had no ability to degrade phenanthrene. Additionally, the presence of gene-encoding enzymes responsible for the degradation of alkanes and naphthalene in the genome of the P-1 strain was reported. Positive results of blood agar and methylene blue agar tests, as well as the presence of gene rhl, involved in the biosynthesis of rhamnolipid, confirmed the ability of P-1 for synthesis of glycolipid biosurfactant. 1H and 13C nuclear magnetic resonance, Fourier transform infrared spectrum and mass spectrum analyses indicated that the extracted biosurfactant was affiliated with rhamnolipid. The results of this study indicate that the P-1 and/or biosurfactant produced by this strain have the potential to be used in bioremediation of hydrocarbon-contaminated soils

Analysis of the Genome of the Heavy Metal Resistant and Hydrocarbon-Degrading Rhizospheric Pseudomonas qingdaonensis ZCR6 Strain and Assessment of Its Plant-Growth- Promoting Traits

The Pseudomonas qingdaonensis ZCR6 strain, isolated from the rhizosphere of Zea mays growing in soil co-contaminated with hydrocarbons and heavy metals, was investigated for its plant growth promotion, hydrocarbon degradation, and heavy metal resistance. In vitro bioassays confirmed all of the abovementioned properties. ZCR6 was able to produce indole acetic acid (IAA), siderophores, and ammonia, solubilized Ca3(PO4)2, and showed surface active properties and activity of cellulase and very high activity of 1-aminocyclopropane-1-carboxylic acid deaminase (297 nmol α-ketobutyrate mg−1 h−1). The strain degraded petroleum hydrocarbons (76.52% of the initial hydrocarbon content was degraded) and was resistant to Cd, Zn, and Cu (minimal inhibitory concentrations reached 5, 15, and 10 mM metal, respectively). The genome of the ZCR6 strain consisted of 5,507,067 bp, and a total of 5055 genes were annotated, of which 4943 were protein-coding sequences. Annotation revealed the presence of genes associated with nitrogen fixation, phosphate solubilization, sulfur metabolism, siderophore biosynthesis and uptake, synthesis of IAA, ethylene modulation, heavy metal resistance, exopolysaccharide biosynthesis, and organic compound degradation. Complete characteristics of the ZCR6 strain showed its potential multiway properties for enhancing the phytoremediation of co-contaminated soils. To our knowledge, this is the first analysis of the biotechnological potential of the species P. qingdaonensis

Environmental Applications of Biosurfactants: Recent Advances

Increasing public awareness of environmental pollution influences the search and development of technologies that help in clean up of organic and inorganic contaminants such as hydrocarbons and metals. An alternative and eco-friendly method of remediation technology of environments contaminated with these pollutants is the use of biosurfactants and biosurfactant-producing microorganisms. The diversity of biosurfactants makes them an attractive group of compounds for potential use in a wide variety of industrial and biotechnological applications. The purpose of this review is to provide a comprehensive overview of advances in the applications of biosurfactants and biosurfactant-producing microorganisms in hydrocarbon and metal remediation technologies

Metagenomic Functional Profiling Reveals Differences in Bacterial Composition and Function During Bioaugmentation of Aged Petroleum-Contaminated Soil

Our objective was to study the bacterial community changes that determine enhanced removal of petroleum hydrocarbons from soils subjected to bioaugmentation with the hydrocarbon-degrading strains Rhodococcus erythropolis CD 130, CD 167, and their combination. To achieve this, a high-throughput sequencing of the 16S rRNA gene was performed. The changes in the bacterial community composition were most apparent the day after bacterial inoculation. These changes represented an increase in the percentage abundance of Rhodococcus and Pseudomonas genera. Surprisingly, members of the Rhodococcus genus were not present after day 91. At the end of the experiment, the bacterial communities from the CD 130, CD 167, and control soils had a similar structure. Nevertheless, the composition of the bacteria in the CD 130 C CD 167 soil was still distinct from the control. Metagenomic predictions from the 16S rRNA gene sequences showed that the introduction of bacteria had a significant influence on the predicted pathways (metabolism of xenobiotics, lipids, terpenoids, polyketides, and amino acids) on day one. On day 182, differences in the abundance of functional pathways were also detected in the CD 130 and CD 130 C CD 167 soils. Additionally, we observed that on day one, in all bioaugmented soils, the alkH gene was mainly contributed by the Rhodococcus and Mycobacterium genera, whereas in non-treated soil, this gene was contributed only by the Mycobacterium genus. Interestingly, from day 91, the Mycobacterium genus was the main contributor for the tested genes in all studied soils. Our results showed that hydrocarbon depletion from the analyzed soils resulted from the activity of the autochthonous bacteria. However, these changes in the composition and function of the indigenous bacterial community occurred under the influence of the introduced bacteria

Do nanoparticles pose a threat to microbes? Response of soil microbial communities to Cu-nanoparticles

tekst w j. pol. i ang.Obecny stan wiedzy nie pozwala przewidzieć losu nanocząstek w środowisku, a w konsekwencji ich wpływu na organizmy nie będące celem ich działania. Celem doświadczenia była ocena wpływu zsyntetyzowanych nanocząstek miedzi związanych z matrycą krzemową (Cu/SiO2) na mikroorganizmy glebowe i ocena potencjalnego ryzyka środowiskowego. W ramach prac określono toksyczność nanocząstek miedzi względem mikroorganizmów referencyjnych wykorzystując metodę spot test. Przeprowadzono doświadczenie typu microcosm, w którym badano odpowiedź mikroflory glebowej na skażenie gleby nanocząstkami w stężeniu 10 mg·kg-1 (NP) i dawką 50-razy większą (50NP). Zmiany porównywano do układów skażonych jonami miedzi (10 mg Cu2+·kg-1) i 50Cu oraz odnosząc do nieskażonego układu kontrolnego (K). Pomiary prowadzono w dniu 1 i 28. Metoda Biolog oraz płytki Eco-Plates i FF zostały wykorzystane do określenia bioróżnorodności funkcjonalnej zespołu bakterii i grzybów. Całkowitą liczebność bakterii określono z wykorzystaniem metody reakcji PCR w czasie rzeczywistym (real-time quantitative PCR)

Mycoremediation of petroleum contaminated soils: progress, prospects and perspectives

Mycoremediation, an aspect of bioremediation, has been investigated for some decades. However, there seems to be little progress on its commercial application to petroleum-contaminated soils despite some promising outcomes. In this review, mycoremediation is examined to identify development, limitations and perspectives for its optimal utilization on petroleum-contaminated soils. Mycoremediation agents and substrates that have been used for the treatment of petroleum contaminated soils have been identified, application methods discussed, recent advances highlighted and limitations for its applications accentuated. Possible solutions to the challenges in applying mycoremediation to petroleum-contaminated soils have also been discussed. From this review, we conclude that for optimal utilization of mycoremediation of petroleum-contaminated soils, ideal environmental, edaphic and climatic factors of a typical contaminated site must be incorporated into the approach from first principles. Development of application procedures that can easily translate laboratory results to field applications is also required

Wstępne badania właściwości przeciwgrzybowych bakterii z rodzaju Bacillus rosnących na odpadach z przemysłu rolno-spożywczego

The three Bacillus species isolated from petroleum refinery waste were examined for antifungal activity on brewery effluents and molasses for biotechnological applications. Bacillus strains were identified by three different methods: 16S rRNA gene sequences, BIOLOG system and fatty acid analysis (FAME). The results demonstrated the ability of all three Bacillus strains cultured on brewery effluents and molasses to inhibit mycelial growth of the 10 tested fungi to varying degrees measured by agar plate inhibition assays. Fungi inhibited to the greatest degree as measured by the zones of inhibition were Botrytis cinerea A 258, Phomopsis viticola W 977, Septoria carvi K 2082, Colletotrichum gloeosporioides A 259, Phoma complanata A 233 and Phoma exigua var. exigua A 175. It was also observed that the fungal mycelial growth was inhibited by the cell-free supernatants, indicating lipoprotein-like activity of antifungal agents (mainly biosurfactants). Tested fungi were most sensitive to the Bacilli supernatants obtained from the molasses cultures including: B. cinerea A 258, R. solani W 70, S. sclerotiorum K 2291, Phomopsis diachenii K 657, C. dematium K 425, P. complanata A 233, P. exigua var. exigua A 175. In the previous study it was shown that Bacillus species produced biosurfactants. Application of natural products such as these Bacillus species or their byproducts may be a new approach to phytopathogen control therefore reducing the need for fungicides.Właściwości przeciwgrzybowe gatunków Bacillus hodowanych na ściekach browarnianych i melasie były oceniane. Bakterie wyizolowano z odpadów zanieczyszczonych związkami ropopochodnymi, a do ich identyfikacji wykorzystano następujące metody: amplifikację i sekwencjonowanie genu 16S rRNA, system Biolog oraz analizę kwasów tłuszczowych (FAME). W pracy stwierdzono, że bakterie Bacillus rosnące na ściekach browarnianych i melasie powodują zahamowanie wzrostu 10 badanych gatunków fitopatogenów, przy czym stopień zahamowania wzrostu był różny dla różnych gatunków grzybów. Najbardziej wrażliwe na badane bakterie były następujące gatunki grzybów: Botrytis cinerea A 258, Phomopsis viticola W 977, Septoria carvi K 2082, Colletotrichum gloeosporioides A 259, Phoma complanata A 233 and Phoma exigua var. exigua A 175. Jednocześnie stwierdzono również, że czyste supernatanty otrzymane z hodowli Bacillus na ściekach browarnianych i melasie powodują zahamowanie wzrostu grzybów na płytkach. Największą aktywność inhibicyjną wykazywały supernatanty otrzymane z hodowli bakterii Bacillus na melasie. Najbardziej wrażliwe na te supernatanty były następujące gatunki grzybów: B. cinerea A 258, R. solani W 70, S. sclerotiorum K 2291, Phomopsis diachenii K 657, C. dematium K 425, P. complanata A 233, P. exigua var. exigua A 175. We wcześniejszych pracach badano właściwości powierzchniowe supernatantów jako pośrednia metoda oceny obecności w nich biosurfakatntów. Szczepy Bacillus lub produkty przez nie syntetyzowane stanowią potencjalne Ĩródło biopestycydów i mogą być wykorzystane w kontroli fitopatogenów, przyczyniając się do redukcji zastosowania chemicznych fungicydów