scholarly journals Removal of heavy oil from contaminated surfaces with a detergent formulation containing biosurfactants produced by Pseudomonas spp.

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12518
Author(s):  
Charles Bronzo B. Farias ◽  
Rita de Cássia F. Soares da Silva ◽  
Fabíola Carolina G. Almeida ◽  
Valdemir A. Santos ◽  
Leonie A. Sarubbo

Industrial plants powered by heavy oil routinely experience problems with leaks in different parts of the system, such as during oil transport, the lubrication of equipment and mechanical failures. The surfactants, degreasing agents and solvents that make up detergents commonly used for cleaning grease-covered surfaces are synthetic, non-biodegradable and toxic, posing risks to the environment as well as the health of workers involved in the cleaning process. To address this problem, surfactant agents of a biodegradable nature and low toxicity, such as microbial surfactants, have been widely studied as an attractive, efficient solution to replace chemical surfactants in decontamination processes. In this work, the bacterial strains Pseudomonas cepacia CCT 6659, Pseudomonas aeruginosa UCP 0992, Pseudomonas aeruginosa ATCC 9027 and Pseudomonas aeruginosa ATCC 10145 were evaluated as biosurfactant producers in media containing different combinations and types of substrates and under different culture conditions. The biosurfactant produced by P. aeruginosa ATCC 10145 cultivated in a mineral medium composed of 5.0% glycerol and 2.0% glucose for 96 h was selected to formulate a biodetergent capable of removing heavy oil. The biosurfactant was able to reduce the surface tension of the medium to 26.40 mN/m, with a yield of approximately 12.00 g/L and a critical micelle concentration of 60.00 mg/L. The biosurfactant emulsified 97.40% and dispersed 98.00% of the motor oil. The detergent formulated with the biosurfactant also exhibited low toxicity in tests involving the microcrustacean Artemia salina and seeds of the vegetable Brassica oleracea. The detergent was compared to commercial formulations and removed 100% of the Special B1 Fuel Oil (OCB1) from different contaminated surfaces, demonstrating potential as a novel green remover with industrial applications.

Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 638
Author(s):  
Diana I. S. P. Resende ◽  
Joana R. Almeida ◽  
Sandra Pereira ◽  
Alexandre Campos ◽  
Agostinho Lemos ◽  
...  

Biofouling, which occurs when certain marine species attach and accumulate in artificial submerged structures, represents a serious economic and environmental issue worldwide. The discovery of new non-toxic and eco-friendly antifouling systems to control or prevent biofouling is, therefore, a practical and urgent need. In this work, the antifouling activity of a series of 24 xanthones, with chemical similarities to natural products, was exploited. Nine (1, 2, 4, 6, 8, 16, 19, 21, and 23) of the tested xanthones presented highly significant anti-settlement responses at 50 μM against the settlement of mussel Mytilus galloprovincialis larvae and low toxicity to this macrofouling species. Xanthones 21 and 23 emerged as the most effective larval settlement inhibitors (EC50 = 7.28 and 3.57 µM, respectively). Additionally, xanthone 23 exhibited a therapeutic ratio (LC50/EC50) > 15, as required by the US Navy program attesting its suitability as natural antifouling agents. From the nine tested xanthones, none of the compounds were found to significantly inhibit the growth of the marine biofilm-forming bacterial strains tested. Xanthones 4, 6, 8, 16, 19, 21, and 23 were found to be non-toxic to the marine non-target species Artemia salina (<10% mortality at 50 μM). Insights on the antifouling mode of action of the hit xanthones 21 and 23 suggest that these two compounds affected similar molecular targets and cellular processes in mussel larvae, including that related to mussel adhesion capacity. This work exposes for the first time the relevance of C-1 aminated xanthones with a 3,4-dioxygenated pattern of substitution as new non-toxic products to prevent marine biofouling.


Marine Drugs ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 5
Author(s):  
Daniela Pereira ◽  
Catarina Gonçalves ◽  
Beatriz T. Martins ◽  
Andreia Palmeira ◽  
Vitor Vasconcelos ◽  
...  

Over the last decades, antifouling coatings containing biocidal compounds as active ingredients were used to prevent biofouling, and eco-friendly alternatives are needed. Previous research from our group showed that polymethoxylated chalcones and glycosylated flavones obtained by synthesis displayed antifouling activity with low toxicity. In this work, ten new polymethoxylated flavones and chalcones were synthesized for the first time, including eight with a triazole moiety. Eight known flavones and chalcones were also synthesized and tested in order to construct a quantitative structure-activity relationship (QSAR) model for these compounds. Three different antifouling profiles were found: three compounds (1b, 11a and 11b) exhibited anti-settlement activity against a macrofouling species (Mytilus galloprovincialis), two compounds (6a and 6b) exhibited inhibitory activity against the biofilm-forming marine bacteria Roseobacter litoralis and one compound (7b) exhibited activity against both mussel larvae and microalgae Navicula sp. Hydrogen bonding acceptor ability of the molecule was the most significant descriptor contributing positively to the mussel larvae anti-settlement activity and, in fact, the triazolyl glycosylated chalcone 7b was the most potent compound against this species. The most promising compounds were not toxic to Artemia salina, highlighting the importance of pursuing the development of new synthetic antifouling agents as an ecofriendly and sustainable alternative for the marine industry.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 745
Author(s):  
Melaine González-García ◽  
Fidel Morales-Vicente ◽  
Erbio Díaz Pico ◽  
Hilda Garay ◽  
Daniel G. Rivera ◽  
...  

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.


Microbiology ◽  
2003 ◽  
Vol 149 (11) ◽  
pp. 3073-3081 ◽  
Author(s):  
Gerardo Medina ◽  
Katy Juárez ◽  
Rafael Díaz ◽  
Gloria Soberón-Chávez

The Pseudomonas aeruginosa rhlR gene encodes the transcriptional regulator RhlR which has a central role in the quorum-sensing response. Different gene products involved in bacterial pathogenesis are regulated at the transcriptional level by two quorum-sensing response systems, Las and Rhl. The expression of rhlR has been reported to be under the control of the Las system, but its transcriptional regulation has not been studied in detail. Here, the rhlR promoter region has been characterized and shown to present four different transcription start sites, two of which are included in the upstream gene (rhlB) coding region. It was found that rhlR expression is not only dependent on LasR but also on different regulatory proteins such as Vfr and RhlR itself, and also on the alternative sigma factor σ 54. It is reported that rhlR expression is partially LasR-independent under certain culture conditions and is strongly influenced by environmental factors.


2016 ◽  
Vol 24 (4) ◽  
pp. 460-470 ◽  
Author(s):  
Xiaomeng Wang

Water-soluble polymers have been used in many applications in the oil sand and heavy oil industries, including drilling, enhanced oil recovery, tailings treatment, and water treatment. Because they are water soluble, residual polymer can remain with the aqueous phase, potentially leading to environmental impacts. Investigating the environmental fate of these water-soluble polymers is particularly important as they may be toxic to aquatic biota or terrestrial animal life. However, since polymers are somewhat complex because of their high molecular weight, there are many challenges in their measurement, especially in complex matrices. In this paper, polymers used in oilfield applications, particularly in the oil sand or heavy oil industries, are reviewed and various analytical methods for polymer characterization are compared.


Author(s):  
Guojie Zhang ◽  
Xiaojie Guo ◽  
Yongfa Zhang ◽  
Yaling Sun ◽  
Bo Tian
Keyword(s):  
Coal Tar ◽  

2021 ◽  
Vol 104 ◽  
pp. 103-112
Author(s):  
Andrea Gilang Fauzi ◽  
Cut Nanda Sari ◽  
Andre Fahriz Perdana Harahap ◽  
Muhammad Yusuf Arya Ramadhan ◽  
Misri Gozan

Surfactants are amphiphilic molecules that have been used in widely used as emulsifier and cleaning agent in various industries. These broad industrial applications made the global surfactant production increased annually. In 2020, the amount of global surfactant production estimated would reach more than 24 million per year. However, the currently used surfactants are synthetically produced from chemical or petroleum-derived products, so it is often toxic and non-biodegradable. Rhamnolipids are “surfactant like” molecules produced by Pseudomonas aeruginosa, which could be alternatives for more environmentally friendly surfactants. The use of rhamnolipids is quite limited due to its expensive production cost. The production cost of rhamnolipid could be reduced using by agro-industrial by-product as a substrate. One of the abundant agro-industrial by-products in Indonesia that can be used as a substrate for rhamnolipid production is Oil Palm Empty Fruit Bunch (OPEFB). This study employed SuperPro Designer v9.5 to performed process simulation and economic assessment of rhamnolipid production using OPEFB as a substrate through two different purification methods, which are solvent extraction and chromatography adsorption. Based on the process simulation that has been done, the process that used adsorption chromatography purification methods more efficient in terms of the usage of the feedstock and energy. The economic assessment also showed that these methods were more profitable and economically attractive, with the value of NPV 11.400.000 USD, IRR 11,64%, and Payback Period 6,21 years.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Agata Cieślik-Bielecka ◽  
Tadeusz Bold ◽  
Grzegorz Ziółkowski ◽  
Marcin Pierchała ◽  
Aleksandra Królikowska ◽  
...  

The aim of the study was to investigate the leukocyte- and platelet-rich plasma (L-PRP) antimicrobial activity. The studied sample comprised 20 healthy males. The L-PRP gel, liquid L-PRP, and thrombin samples were testedin vitrofor their antibacterial properties against selected bacterial strains using the Kirby-Bauer disc diffusion method. Two types of thrombin were used (autologous and bovine). Zones of inhibition produced by L-PRP ranged between 6 and 18 mm in diameter. L-PRP inhibited the growth ofStaphylococcus aureus(MRSA and MSSA strains) and was also active againstEnterococcus faecalisandPseudomonas aeruginosa. There was no activity againstEscherichia coliandKlebsiella pneumoniae. The statistically significant increase of L-PRP antimicrobial effect was noted with the use of major volume of thrombin as an activator. Additionally, in groups where a bovine thrombin mixture was added to L-PRP the zones of inhibition concerning MRSA,Enterococcus faecalis, andPseudomonas aeruginosawere larger than in the groups with autologous thrombin. Based on the conducted studies, it can be determined that L-PRP can evokein vitroantimicrobial effects and might be used to treat selected infections in the clinical field. The major volume of thrombin as an activator increases the strength of the L-PRP antimicrobial effect.


Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1227
Author(s):  
Robert H. Hicks ◽  
Mauro Moreno-Beltrán ◽  
Deborah Gore-Lloyd ◽  
Christopher J. Chuck ◽  
Daniel A. Henk

Metschnikowia pulcherrima is a non-conventional yeast with potential to be used in biotechnological processes, especially those involving low-cost feedstock exploitation and biocontrol applications. The combination of traits that supports these industrial applications in M. pulcherrima also makes it an attractive option to study in the context of livestock health. In this study, we examined the specific interactions between M. pulcherrima and multiple avian pathogenic bacteria. We tested individual bacteria–yeast interactions and bacterial combinations in both solid and liquid media and in variable nutrient environments. Across multiple isolates of M. pulcherrima, we observed different levels of antimicrobial activity, varying from supporting the growth of competing bacteria through suppression and bacterial killing, and we found that these responses varied depending on the bacterial strains and media. We identified multiple molecular routes, including proteins produced by M. pulcherrima strains, that acted to control these microbial interactions. Furthermore, protein screening revealed that M. pulcherrima strains were induced to produce proteins specifically when exposed to bacterial strains, suggesting that fine-tuned mechanisms allow M. pulcherrima to function as a potential lynchpin in a microbial community.


2020 ◽  
Vol 9 (8) ◽  
Author(s):  
Everton Holanda Sales ◽  
Gustavo Oliveira Everton ◽  
Paulo Victor Serra Rosa ◽  
Carlos Eduardo Pereira Conceição ◽  
Feliciana Santos Pinheiro ◽  
...  

Este estudo teve por objetivo realizar a secagem dos rizomas de Curcuma longa L. aplicando modelagem matemática, determinou a atividade antimicrobiana e a toxicidade do óleo essencial (OE) obtido após o processo de secagem aplicado. O material vegetal coletado foi submetido a estufa convectiva de secagem a temperatura 45 °C. Modelos matemáticos foram aplicados para representar o processo de secagem e análise estatística realizada utilizando o software statistica 10. Os OE's foram obtidos através da técnica de hidrodestilação e a atividade antimicrobiana pelo Método de Difusão de Disco e Diluição em Caldo frente a Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa e Salmonella sp. Para o teste de toxicidade, foi aplicado o bioensaio de Artemia salina. Através dos resultados obtidos foi possível determinar que o modelo matemático de Logarithm foi o que melhor se encaixava nos dados experimentais. O OE apresentou atividade bactericida frente a todos os microrganismos testados. O ensaio de toxicidade comprovou a toxicidade do OE com uma CL50 superior a 250 mg/L. Os resultados obtidos comprovam o potencial necessário para a aplicação do OE dos rizomas de C. longa como antimicrobiano, sendo ainda não tóxico frente a organismos não-alvo.


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