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•Biosurfactants possess diversity in structural and functional properties.•Screening methodologies play important role to obtain desired biosurfactant producer.•Biosynthesis of ...rhamnolipid (RL) by Pseudomonas aeruginosa is discussed.•Rhamnolipids have potential application in microbial enhanced oil recovery.•Research should be focused on utilization of renewable substrates for RL production.
Surfactants are one of the most versatile group of chemicals used in various industrial processes. Their market is competitive, and manufacturers will have to expand surfactant production in ecofriendly and cost effective manner. Increasing interest in biosurfactants led to an intense research for environment friendly and cost-efficient production of biosurfactant. Structural diversity and functional properties of biosurfactants make them an attractive group of compounds for potential use in wide variety of industrial, environmental and biotechnological applications. Screening methods make task easier to obtain potential biosurfactant producing microorganisms. Variety of purification and analytical methods are available for biosurfactant structural characterization. This review aims to compile information on types and properties of biosurfactant, microbial screening methods as well as biosynthesis, extraction, purification and structural characterization of biosurfactant using rhamnolipid as a model biosurfactant. It also describes factors affecting rhamnolipid production. It gives an overview of oil recovery using biosurfactant from Pseudomonas aeruginosa.
Contamination of agricultural land(s) is a major problem worldwide which is associated with activities of petroleum industry. Due to these exploration activities remedial techniques for clean-up of ...contaminated agricultural soil(s) has become an alarming research topic. Hydrocarbon utilizing bacterial consortium (HUBC), isolated from petroleum crude (petroleum industry waste water and soil) contaminated sites, India has been used for soil microcosm study. The aim of present study was to compare potency of five different techniques to remediate petroleum hydrocarbons contaminated agricultural soil by employing soil microcosm study. To the best of our knowledge this is the first report for comparison of five different techniques (abiotic control, natural attenuation, biostimulation, bioaugmentation and simultaneous bioaugmentation & biostimulation) for bioremediation of agricultural soil using consortium of hydrocarbon utilizers by employing soil microcosms. Concurrent application of bioaugmentation (with HUBC) and biostimulation (with nutrient amendments) in the soil microcosm resulted in 93.67 ± 1.80% hydrocarbons degradation in 45 days of experiment and hydrocarbon utilizing bacterial count was recorded 4.11 ± 0.11 × 108 CFU/g. In the bioaugmented and biostimulated soil microcosm organic carbon was reduced from 3.49 ± 0.08% to 0.62 ± 0.11% with simultaneous decrease of other nutrients. The consortium could survive in artificially crude oil contaminated and nutrients amended agricultural soil microcosm and could degrade petroleum hydrocarbons effectively in soil microcosm conditions. This suggests its application as a potential bioremediation agent for farmland restoration i.e. management of soil environment.
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•First report for microcosm experiments with five treatments using petroleum crude contaminated agricultural soil.•HUBC along with nutrient amendments finds utility as bioremediation agent.•BA + BS treatment showed faster and highest degradation of petroleum hydrocarbons.•Gross and molecular compositions of crude oil have been studied by gas chromatography.•Reported study as soil microcosms would be a promising option in restoration of agricultural soil.
In recent years, there has been increasing concern over public health threat presented by introduction of petroleum hydrocarbon pollutants in environment due to anthropogenic activities to a greater ...extent and natural processes to some extent. Many countries all over the world are currently facing severe problem due to these pollutants as they are one of the persistent organic pollutants (POPs). Remediation of polluted sites by biodegradation is a viable option as conventional physico-chemical methods for remediation seems technically as well as economically challenging. Biodegradation is non-invasive and could be cost-effective in removal of petroleum hydrocarbon pollutants. It is considered as ultimate mechanism for pollutants removal. Immobilized microbial cells give advantage over free microbial cells to improve the survival and retention of the bioremediation agents in polluted sites. However, current biodegradation approaches suffer from a number of limitations, which include pollutant characteristics, poor capabilities of microbial communities in the field, lesser bioavailability of pollutants, growth conditions, etc. Understanding the factors affecting microbial degradation is of great research interest in present scenario. This review selectively examines and provides a critical view on bioavailability of the substrates, microorganisms in petroleum hydrocarbon pollutants degradation and the molecular techniques for their characterization, degradation mechanisms under aerobic and anaerobic conditions, commercially available bioremediation agents and factors affecting biodegradation of these pollutants. Role of genetically modified organisms and biodegradation of petroleum hydrocarbon pollutants by immobilized will also be discussed.
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•Bioremediation is cost effective and eco-friendly method for cleanup of pollutants.•Electron acceptors play vital role in biodegradation of petroleum hydrocarbon pollutants.•Molecular techniques are effective tool to characterize microbial assemblages.•Commercial bioremediation agents are available to combat hydrocarbon pollutants.•Immobilization increases pollutant biodegradation rate with less environmental impact.
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•P. aeruginosa NCIM 5514 completely decolorized 2,6-dichlorophenol indophenol.•Oil droplets in the vicinity of the colonies showed oleophilic nature.•This isolate degraded C8–C36+ ...(60.63%) of crude oil based on GC analysis.•First report on the use of 3%v/v crude oil as sole carbon source by an individual strain.•Paraffin(s) degradation ability demonstrates its potential for removal of well clogging.
The aim of this work was to study the potential of an indigenous strain of Pseudomonas aeruginosa NCIM 5514, isolated from petroleum-polluted soil, for the biodegradation of crude petroleum oil. The isolate completely decolorized 2,6-dichlorophenol indophenol in 120h when grown at (37±1°C), indicating its hydrocarbon utilizing nature. Ex situ biodegradation study was performed to find out quantitative utilization and biodegradation of paraffin(s) present in crude oil. When the culture was grown in Bushnell-Hass medium containing crude oil (3%,v/v) at 37°C, 180rpm for 60days, the viscosity of the oil was reduced from 1883cp to 1002cp. Gravimetric and gas chromatographic analysis showed 61.03% and 60.63% of biodegradation of C8–C36+ hydrocarbons, respectively. These results indicated that the isolate has potential to be used for ex-situ and in-situ bioremediation of hydrocarbon pollutants and could have promising applications in petrochemical industry.
Agricultural land pollution is key a problem globally, which is linked with growth of industries. Petroleum industrial sector is one of the major industrial sectors and the activities of petroleum ...industry lead to the agricultural land pollution. Oily sludge is a type of solid and hazardous waste generated from petroleum industrial activities. Hence, there is an urgent need to find remediation methods of the oily sludge contaminated agricultural land. Thus, the aim of this work was to study bioremediation of oily sludge polluted soil employing a novel strain of Pseudomonas aeruginosa and evaluation of phytotoxicity on germination of Vigna radiata seed in pots. Five different approaches were adopted for the bioremediation studies, which included Bioaugmentation + Biostimulation, bioaugmentation, biostimulation, natural attenuation and abiotic factors. Simultaneous application of P. aeruginosa NCIM 5514 and nutrients in microcosm showed 92.97 ± 0.92% decrease in oily sludge with good hydrocarbon utilizing bacterial count and decreased nutrient level in 56 days. Pot experiments on seed germination of mung beans (Vigna radiata) seeds was performed by pot experiments. 80.95% germination in five days in treated soil. From the results it was concluded that simultaneous use of oily sludge degraders and nutrient supplement could revive seed germination ability of oily sludge polluted soil effectively. This is first report of comparing five techniques to bioremediate oily sludge polluted soil using Pseudomonas aeruginosa, followed by pot study using V. radiata seeds, showing that P. aeruginosa can be an efficient bioremediation agent and can be effectively used for remediation of oily sludge contaminated soil.
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•Microcosm experiments with five bioremediation approaches using oily sludge polluted agricultural soil have been performed.•Nutrient supplementation is a vital parameter to promote biodegradation of petroleum hydrocarbons.•Highest degradation of oily sludge was obtained when combined treatment of bioaugmentation and biostimulation was given.•P. aeruginosa proved to be a potential bioremediator and can be used for soil remediation.•The study presented here has potential of agricultural and social benefits.
•P. aeruginosaNCIM 5514 finds utility as bioremediation agent.•P. aeruginosa NCIM 5514 showed 76.14 ± 0.85% oily waste degradation in 56 days.•This study would have noteworthy applicability for ...environmental sustainability.
This study was aimed at remediation ofoily waste contaminated area by utilizing a newly obtained bacterium. For experimental setup three different approachessuch as bioaugmentation, natural attenuation and abiotic factors were employed. In bioaugmented experimental set up (treatment withP. aeruginosaNCIM 5514),76.14 ± 0.85% loss in oily waste with notable hydrocarbon utilizers was noted in 56 days. From the results, it was concluded that bioaugmentation with novel P. aeruginosasp. (oily waste degrader) could remediate oily waste pollution effectively. Results of this study demonstrate applicability of P. aeruginosa NCIM 5514 for environmental sustainability.
Petroleum sludge has been reported as noteworthy hazardous solid waste generated from industrial activities of petroleum sector. Environment friendly and economically sound treatment of petroleum ...sludge has attracted global attention worldwide and has become a thrust area of research. Petroleum sludge bioremediation is gaining interest of researchers globally to clean pollutants from soil ecosystems. To date of submission of the work there is no literature available reporting comparing five approaches for remediation of agricultural soil polluted with petroleum sludge employing hydrocarbon utilizing bacterial consortium (HUBC). Further studies on toxicity were performed through pot experiments using Vigna radiata. The aim of this research work was to compare capability of five approaches for remediating petroleum sludge polluted agricultural soil by employing soil microcosms. Best results were obtained when simultaneous application of HUBC and nutrients was performed in microcosm. Highest decrease (93.14 ± 1.75%) of petroleum sludge with sufficient count of hydrocarbon utilizers and decreased nutrients in 42 days was reported. Quality improvement of petroleum sludge contaminated agricultural soil after its bioremediation was performed by pot experiments by checking germination of V. radiata seeds. 85.71% germination of seeds in 5 days was noted for treated soil. Thus, HUBC can be applied as a bioremediating consortium to reclaim petroleum sludge polluted soil.
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•Hydrocarbon degrading bacterial consortium degraded 93.14 ± 1.75% petroleum sludge in 42 days.•85.71% germination of mung beans was noted for HUBC treated soil.•Petroleum sludge polluted agricultural soil has been restored (confirmed by seed germination).•This study imparts a notable approach for farming application(s).
Many marine invertebrates have larval stages covered in linear arrays of beating cilia, which propel the animal while simultaneously entraining planktonic prey1. These bands are strongly conserved ...across taxa spanning four major superphyla2, 3, and they are responsible for the unusual morphologies of many invertebrate larvae4, 5. However, few studies have investigated their underlying hydrodynamics6, 7. Here, we study the ciliary bands of starfish larvae, and discover a beautiful pattern of slowly evolving vortices that surrounds the swimming animals. Closer inspection of the bands reveals unusual ciliary 'tangles' analogous to topological defects that break up and re-form as the animal adjusts its swimming stroke. Quantitative experiments and modelling demonstrate that these vortices create a physical trade-off between feeding and swimming in heterogeneous environments, which manifests as distinct flow patterns or 'eigenstrokes' representing each behaviour--potentially implicating neuronal control of cilia. This quantitative interplay between larval form and hydrodynamic function may generalize to other invertebrates with ciliary bands, and illustrates the potential effects of active boundary conditions in other biological and synthetic systems.
Introduction
Among surgeons worldwide, a concern with the use of minimally invasive techniques has been raised due to a proposed risk of viral transmission of the coronavirus disease of 2019 ...(COVID-19) with the creation of pneumoperitoneum. Due to this proposed concern, we sought to collect the available data and evaluate the use of laparoscopy and the risk of COVID-19 transmission.
Methods
A literature review of viral transmission in surgery and of the available literature regarding the transmission of the COVID-19 virus was performed. We additionally reviewed surgical society guidelines and recommendations regarding surgery during this pandemic.
Results
Few studies have been performed on viral transmission during surgery, but to date there is no study that demonstrates or can suggest the ability for a virus to be transmitted during surgical treatment whether open or laparoscopic. There is no societal consensus on limiting or restricting laparoscopic or robotic surgery; however, there is expert consensus on the modification of standard practices to minimize any risk of transmission.
Conclusions
Despite very little evidence to support viral transmission through laparoscopic or open approaches, we recommend making modifications to surgical practice such as the use of smoke evacuation and minimizing energy device use among other measures to minimize operative staff exposure to aerosolized particles.
Oily sludge is a hazardous waste generated through petroleum producing and processing industrial units. Due to its harmful environmental impacts, it needs to be treated in sustainable manner. The ...present study aimed to evaluate influence of bioaugmentation on oily sludge biodegradation efficiency of a novel hydrocarbon utilizing bacterial consortium (HUBC) using microcosms. Three approaches (bioaugmentation, natural attenuation and abiotic factors) were used for microcosm studies. Bioaugmentation treatment showed best results for oily sludge degradation than natural attenuation and abiotic factors, resulting 82.13 ± 1.21% oily sludge degradation in 56 days. In bioaugmented microcosm on 56th day 0.30 ± 0.07 × 108 CFU/g hydrocarbon utilizing bacteria were noted. Results showed that HUBC could be used to remediate soil polluted with oily sludge. This study imparts a notable approach for farming application(s).
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•Bioaugmentation with exogenous bacterial consortium increased degradation of oily waste•HUBC used in the study is suitable for bioremediation of oily waste polluted agri-field.•Soil: an important resource can be recovered through bioremediation•Substantial biodegradation of oily waste by HUBC through microcosms was noted.
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