scholarly journals Biocleaning to Remove Graffiti: A Real Possibility? Advances towards a Complete Protocol of Action

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 104 ◽  
Author(s):  
Patricia Sanmartín ◽  
Pilar Bosch-Roig

The first academic studies on the use of microorganisms in cleaning procedures appeared in the late 1980s/early 1990s. In the past thirty years, most of such studies have addressed the removal of nitrate and sulphate salts and organic matter from surfaces by using non-pathogenic anaerobic microorganisms, mainly sulphate-reducing bacteria. The successful use of microbes in the removal of graffiti paint remains, however, a work in progress. Biocleaning surfaces to remove graffiti is not a simple task, because of the complex chemical composition of graffiti paints. This study looks at ways of improving the bioremoval of graffiti and presents the latest findings regarding different methodological aspects of cleaning natural and man-made stone. Granite and concrete substrates were coated with silver and black graffiti spray paints for comparison of the efficacy of the biocleaning method on these different materials. Visual and microscopic examination along with colour and infrared measurements made after application of the bacterial strains tested (previously shown to be suitable candidates for bioremoval of graffiti) revealed remarkably successful results. The findings presented thus represent progress in the development of a biocleaning protocol applicable to the in-situ removal of graffiti. Important improvements have been made regarding the time of treatment, which has been reduced by up to 20 days, and the use of a culture medium enriched with powdered graffiti, which facilitates and accelerates the adaptation of the microorganisms to the target surface.

2014 ◽  
Vol 2014 ◽  
pp. 1-21 ◽  
Author(s):  
Fayyaz Ali Shah ◽  
Qaisar Mahmood ◽  
Mohammad Maroof Shah ◽  
Arshid Pervez ◽  
Saeed Ahmad Asad

Anaerobic digestion is the method of wastes treatment aimed at a reduction of their hazardous effects on the biosphere. The mutualistic behavior of various anaerobic microorganisms results in the decomposition of complex organic substances into simple, chemically stabilized compounds, mainly methane andCO2. The conversions of complex organic compounds toCH4andCO2are possible due to the cooperation of four different groups of microorganisms, that is, fermentative, syntrophic, acetogenic, and methanogenic bacteria. Microbes adopt various pathways to evade from the unfavorable conditions in the anaerobic digester like competition between sulfate reducing bacteria (SRB) and methane forming bacteria for the same substrate.Methanosarcinaare able to use both acetoclastic and hydrogenotrophic pathways for methane production. This review highlights the cellulosic microorganisms, structure of cellulose, inoculum to substrate ratio, and source of inoculum and its effect on methanogenesis. The molecular techniques such as DGGE (denaturing gradient gel electrophoresis) utilized for dynamic changes in microbial communities and FISH (fluorescentin situhybridization) that deal with taxonomy and interaction and distribution of tropic groups used are also discussed.


2021 ◽  
Vol 11 (2) ◽  
pp. 620
Author(s):  
Magdalena Dyda ◽  
Agnieszka Laudy ◽  
Przemyslaw Decewicz ◽  
Krzysztof Romaniuk ◽  
Martyna Ciezkowska ◽  
...  

The aim of the presented investigation was to describe seasonal changes of microbial community composition in situ in different biocenoses on historical sandstone of the Northern Pergola in the Museum of King John III’s Palace at Wilanow (Poland). The microbial biodiversity was analyzed by the application of Illumina-based next-generation sequencing methods. The metabarcoding analysis allowed for detecting lichenized fungi taxa with the clear domination of two genera: Lecania and Rhinocladiella. It was also observed that, during winter, the richness of fungal communities increased in the biocenoses dominated by lichens and mosses. The metabarcoding analysis showed 34 bacterial genera, with a clear domination of Sphingomonas spp. across almost all biocenoses. Acidophilic bacteria from Acidobacteriaceae and Acetobacteraceae families were also identified, and the results showed that a significant number of bacterial strains isolated during the summer displayed the ability to acidification in contrast to strains isolated in winter, when a large number of isolates displayed alkalizing activity. Other bacteria capable of nitrogen fixation and hydrocarbon utilization (including aromatic hydrocarbons) as well as halophilic microorganisms were also found. The diversity of organisms in the biofilm ensures its stability throughout the year despite the differences recorded between winter and summer.


2012 ◽  
Vol 9 (3) ◽  
pp. 1033-1040 ◽  
Author(s):  
M. Barlett ◽  
K. Zhuang ◽  
R. Mahadevan ◽  
D. Lovley

Abstract. Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III) was depleted whereas the SRB grow more slowly and reached dominance after 30–40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III) would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III) availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.


2015 ◽  
Vol 1130 ◽  
pp. 19-22
Author(s):  
M.P. Belykh ◽  
S.V. Petrov ◽  
V.F. Petrov ◽  
A.Yu. Chikin ◽  
N.L. Belkova

The methods of biodegradation are of special interest because they help solving environmental problems of wastes detoxification from gold-mining operations. The use of bacterial strains is a promising approach in the field of biotechnology to destruct cyanide-bearing compounds. The diversity of microbial communities both in heap in situ and in the enriched cultures was studied with molecular genetic methods. The differences in representation of bacteria, cultivated in unexploitable and operating heaps, are territory, site and heap specific. The strains of Pseudomonas sp. and Methylobacterium sp. possess the biotechnological potential and might be used in biodegradation of heap leaching wastes in extreme continental climate.


Author(s):  
Xiao Wang ◽  
Yuetao Zhang ◽  
Huaying Li ◽  
Ming-yu Huang

Type 316 steels have been heavily utilized as the structural material in many construction equipment and infrastructures. This paper reports the characterization of degradation in 316 austenitic stainless steel during the plastic deformation. The in-situ EBSD results revealed that, with the increase of plastic strain, the band contrast (BC) value progressively decreased in both grain and grain boundaries, and the target surface becomes uneven after the plastic tensile, which indicates that the increase of surface roughness. Meanwhile, the KAM and ρGND values are low in the origin specimen but increased significantly after the in-situ tensile. The results indicated that the KAM and ρGND are closely related to the deformation degree of the materials, which can be used as the indicator for assessing the degradation of 316 steel. Besides, the re-orientation of grain occurred after the tensile deformation, which can be recognized from the lattice orientation and local orientation maps.


1999 ◽  
Vol 39 (7) ◽  
pp. 41-47 ◽  
Author(s):  
Satoshi Okabe ◽  
Hisashi Satoh ◽  
Tsukasa Itoh ◽  
Yoshimasa Watanabe

The vertical distribution of sulfate-reducing bacteria (SRB) in microaerophilic wastewater biofilms grown on fully submerged rotating disk reactors (RDR) was determined by the conventional culture-dependent MPN method and in situ hybridization of fluorescently-labelled 16S rRNA-targeted oligonucleotide probes for SRB in parallel. Chemical concentration profiles within the biofilm were also measured using microelectrodes for O2, S2-, NO3- and pH. In situ hybridization revealed that the SRB probe-stained cells were distributed throughout the biofilm even in the oxic surface zone in all states from single scattered cells to clustered cells. The higher fluorescence intensity and abundance of SRB probe-stained cells were found in the middle part of the biofilm. This result corresponded well with O2 and H2S concentration profiles measured by microelectrodes, showing sulfate reduction was restricted to a narrow anaerobic zone located about 500 μm below the biofilm surface. Results of the MPN and potential sulfate reducing activity (culture-dependent approaches) indicated a similar distribution of cultivable SRB in the biofilm. The majority of the general SRB probe-stained cells were hybridized with SRB 660 probe, suggesting that one important member of the SRB in the wastewater biofilm could be the genus Desulfobulbus. An addition of nitrate forced the sulfate reduction zone deeper in the biofilm and reduced the specific sulfate reduction rate as well. The sulfate reduction zone was consequently separated from O2 and NO3- respiration zones. Anaerobic H2S oxidation with NO3- was also induced by addition of nitrate to the medium.


2018 ◽  
Vol 64 (11) ◽  
pp. 876-886 ◽  
Author(s):  
Daniela Maizel ◽  
Pilar Balverdi ◽  
Barry Rosen ◽  
Adriana M. Sales ◽  
Marcela A. Ferrero

Arsenic-hypertolerant bacteria were isolated from arsenic-contaminated well water from the village of Los Pereyra in Tucumán province, Argentina. Microorganisms that biotransform arsenic are a major factor in arsenic mobilization in contaminated aquifers. Groundwater analyses showed a level of arsenic contamination (mean concentration of 978 μg·L−1) that exceeds the safe drinking water limit of 10 μg·L−1recommended by the World Health Organization and the Argentine Food Code. There was considerable spatial variability in the concentration of arsenic in each of the wells analyzed and in the distribution of the major anions HCO3–, SO42–, and Cl–. Eighteen bacterial strains were characterized. Six strains belonging to the Actinobacteria phylum were able to grow in media with 20 mmol·L–1As(III) or 200 mmol·L–1As(V) and were also highly resistant to Cr, Cd, and Cu. Their ability to biotransform arsenic was examined by speciation of the products by high-performance liquid chromatography inductively coupled plasma mass spectrometry. In addition, two strains, Brevibacterium sp. strain AE038-4 and Microbacterium sp. strain AE038-20, were capable of aerobic arsenate reduction, which suggests that these strains could increase the mobility of arsenic by formation of more mobile As(III).


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2867
Author(s):  
Zeng-Yei Hseu

Soils, sediments, and water require careful stewardship for the planet’s security to achieve the Sustainable Development Goals (SGDs) set from the United Nations. However, the contamination of these natural resources can damage ecological and human health, and thus we need a comprehensive approach to provide a remediation reference for the SDGs. The aim of this Special Issue (SI) was to gather the papers emphasizing different aspects and findings of the contamination processes, remediation techniques, and risk assessment of soils, sediments, and water. The Guest-Editor of this SI collected seven papers dealing with biochar application for the reduction in soil nutrient leaching by Kuo et al. and for the immobilization of soil cadmium by Chen et al. Their works contributed to not only sustain soil functions but also to prevent sediments and water from contamination. Moreover, in situ stabilization by environmentally compatible approach is a green remediation of sediments such as thin-layer capping for freshwater and estuary sediments by Ou et al. and Ch’ng et al., respectively. Bioassays including microbiological response and enzyme activities were used to test water quality by Martín et al. and Aljahdali et al., in addition to the finding of antibiotic-degrading bacterial strains reported by Yang et al. in sewage sludge. These papers may aid to update and incorporate new views and discussion for the SDGs.


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