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•Ultrasound is a fast method for phenolic compounds recovery from C. chinense leaves.•Solvent polarity has a strong effect on the recovery of phenolic compounds.•Dielectric constant ...was propose to predict the most appropriate solvent for phenolic extraction.•Antioxidant activity correlates with total phenolic content of C. chinense leaves extracts.•Identification of phenolic compounds was performed by UPLC-PDA-ESI-MS/MS.
Phenolic compounds are secondary metabolites involved in plant adaptation processes. The development of extraction procedures, quantification, and identification of this compounds in habanero pepper (Capsicum chinense) leaves can provide information about their accumulation and possible biological function. The main objective of this work was to study the effect of the UAE method and the polarity of different extraction solvents on the recovery of phenolic compounds from C. chinense leaves. Quantification of the total phenolic content (TPC), antioxidant activity (AA) by ABTS+ and DPPH radical inhibition methods, and the relation between the dielectric constant (ε) as polarity parameter of the solvents and TPC using Weibull and Gaussian distribution models was analyzed. The major phenolic compounds in C. chinense leaves extracts were identified and quantified by UPLC-PDA-ESI-MS/MS. The highest recovery of TPC (24.39 ± 2.41 mg GAE g−1 dry wt) was obtained using MeOH (50%) by UAE method. Correlations between TPC and AA of 0.89 and 0.91 were found for both radical inhibition methods (ABTS+ and DPPH). The Weibull and Gaussian models showed high regression values (0.93 to 0.95) suggesting that the highest phenolic compounds recovery is obtained using solvents with “ε” values between 35 and 52 by UAE. The major compounds were identified as N-caffeoyl putrescine, apigenin, luteolin and diosmetin derivatives. The models presented are proposed as a useful tool to predict the appropriate solvent composition for the extraction of phenolic compounds from C. chinense leaves by UAE based on the “ε” of the solvents for future metabolomic studies.
Plastic and hydrocarbon pollution in aquatic ecosystems is a worldwide reality and serious concern today. Plastic debris presents a threat to ecosystems and organisms. Hydrocarbons are also ...considered priority pollutants. The hydrophobicity of the polymer in combination with the high surface area causes plastics to act as a vector for organic contaminants such as hydrocarbons. The first aim of this work was to evaluate the presence of plastic and hydrocarbon pollution in water from two reefs and two rivers and to identify plastic in six sediment beaches in Veracruz State, Mexico. In addition, the second aim was to analyse the ability of a bacterial consortium to biodegrade hydrocarbons in an airlift bioreactor and to identify degrading bacterial strains of polyethylene terephthalate (PET). Microplastics (100 nm–5 mm) were found in four water samples. Fragments of plastic collected from the reefs ranged in size from 0.716 to 32 μm and in rivers from 0.833 to 784 μm. On the sediment beaches, macroplastics of sizes 2–10 cm were detected. A number of hydrocarbons were also detected in the water samples of both reefs and one river, including n-octane, n-nonane, phenanthrene, n-eicosane, n-dotriacontane, n-hexatriacontane, n-triacontane, and n-tetratriacontane. As a biotechnological alternative for remediation of hydrocarbons and plastics, we attempted to produce a collection of native microorganisms able to degrade them. This work shows results from the bioprospection of a bacterial consortium (
Xanthomonas
,
Acinetobacter bouvetii
,
Shewanella
, and
Aquamicrobium lusatiense
) for hydrocarbon biodegradation in an airlift bioreactor. The tested consortium was able to successfully degrade the maximum diesel concentration (20 g L
−1
) tested for 10 days. Also, the first visual evidence of PET degradation by an isolated forest-native bacterial strain showed that
Bacillus muralis
is the most efficient degrader.
•Mass transfer rates of hexadecane and oxygen were close to the stoichiometric.•Damköhler numbers suggested an enhancement of hexadecane mass transport.•Production of an oil-degrading consortium was ...enhanced with mass transfer.
The production of oil-degrading bacteria in multiphase airlift reactors (ALBs) could be limited by the mass transport of both the gaseous and oil phases. In our study, the mass transfer rates of hexadecane and oxygen (HTR/OTR) were evaluated during the production of oil-degrading bacteria in a 3-L airlift reactor. To improve the HTR/OTR ratios during kinetics, a high initial concentration of hexadecane (77 g L−1) and constant superficial gas velocity (UG) in the range of 1.5–3.5 cm s−1 were used. Under these conditions, all initial HTR/OTR were close to the stoichiometric consumption ratio (SCR, ∼0.28), which in turn decreased at the end of the culture until 0.173 ± 0.013, 0.108 ± 0.006 and 0.123 ± 0.006 (g HXD) (g O2)−1 for UG of 1.5, 2.5, 3.5 cm s−1, respectively. The evaluation of the Damköhler numbers suggested an enhancement of HXD mass transport that allowed for obtaining a maximum suspended solids (SS) production of 4.9–6.0 g SS (L h)−1. Since the operation of the ALB at high superficial gas velocities may lead to high power inputs, the variable UG technique was used for energy saving, finding similar maximum SS production (6.09 g SS (L h)−1) to that obtained at a constant UG of 2.5 cm s−1 and an energy saving of 33.4%. The improvement in the HTR/OTR ratio during ALB performance allowed us to enhance the production of an oil-degrading microbial consortium.
The objective of this article is to review the environmental problems in Mexican state of San Luis Potosí (mining region) and the state of compliance with the right to a healthy environment. Our ...study helps to demonstrate complexity of the environmental impact in a broader context, if it is repeated in other mining regions of the non-developing world. The findings include heavy metals as lead and arsenic, in soil, with neurotoxic and carcinogenic properties. Impact on the biota as a whole, decrease of the biological activity and enzymatic inhibition. Heavy metals, including arsenic, mercury, cadmium and lead, as a product of the metallurgical and foundry industry were detected in children of the city of San Luis Potosí. Water contaminated with fluorine and arsenic, product of the extensive drilling of water wells and the transfer of contaminants from the mining and metallurgical industry. Air contaminated with heavy metals product of mining and metallurgy and hydrocarbons in urban and rural areas. Plastics as a global problem, but with the absence of local diagnosis, despite having one of the main pollution factors: industrial development. Hydrocarbons as pollution with very little diagnosis, beyond environmental emergencies. There is no evidence that the right to a healthy environment is fulfilled in the State of San Luis Potosí.
The objectives of this research are: identify the hydrocarbons in water from the Bitzal River, Tabasco; select a carbon source that serves as a representative substrate of the determined compounds; ...and finally, design an experimental proposal for bioreactors that are capable of consuming compounds formed by complex mixtures and, therefore be effective in the elimination of specific hydrocarbons. We identified 16 compounds that belong to different hydrocarbon fractions. Pentacene (24.3 ± 0.09 mg L−1), n-nonane (2.11 ± 0.96 mg L−1) and benzo a pyrene (1.39 ± 0.57 mg L−1) were the compounds with the highest concentrations in water. Two culture media, mineral medium and seawater were used. Diesel and Mayan crude oil were used for each culture medium, with a total of four bioreactors. Diesel represented light- and medium-fraction hydrocarbons, while Mayan crude oil represented the heavy fraction as well as the recalcitrant and polycyclic aromatic hydrocarbons (PAH). The maximum growth of suspended solids for diesel in mineral medium reached 2.95 g L−1, and diesel was completely consumed in 8 days. In seawater, suspended solids for diesel reached 2.70 g L−1, and diesel was consumed in 12 days. For Mayan crude oil in mineral medium, suspended solids increased from 0.8 to 2.41 g L−1, and Mayan crude oil was completely consumed in 12 days. Using seawater, Mayan crude oil also degraded in 12 days, and suspended solids growth reached 2.11 g L−1. Compounds that simulate complex mixtures of hydrocarbons from light to heavy fractions could be degraded, and the use of bioreactors is an alternative method of hydrocarbon pollution remediation in the Bitzal River.
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•We identified 16 compounds belonging to different hydrocarbon fractions.•Pentacene, nonane and benzo a shows the highest concentrations.•Diésel was completely consumed in 8 days.•Mayan crude oil was completely consumed in 12 days.•Complex mixtures of hydrocarbons from light to heavy fractions were degraded.
Capsule: Pentacene, n-nonane and benzo a pyrene showed the highest concentrations, complex mixtures of hydrocarbons from light to heavy fractions were degraded.
The biotechnological approach used for pollutants remotion has presented good yields at relatively low cost, nevertheless it still presents a wide margin for improvement to become the principal ...response to environmental contingencies. As immobilization of microorganisms has demonstrated the decrease of most of the disadvantages of biodegradation, this work aims to briefly review the microorganism’s immobilization for environmental purposes, focusing on encapsulation and exploring its different techniques and carrier materials. The principal reasons to encapsulate microorganisms for bioremediation, the types of capsules and their main characteristics, the physical, chemical, or physicochemical encapsulation methods that have been applied for environmental purposes, and those that have potential in the field, are also revised and explained. The principal biopolymers used to encapsulate and the characteristics they can confer to the capsules. Finally, recent cases of encapsulated microorganisms for bioremediation applications are discussed, highlighting the tendency in the works of the last decade for its application in contaminated waters and the need to explore more carrier materials and encapsulation techniques are also explored.
The Yucatan Peninsula is the most important beekeeping region. However, the presence of hydrocarbons and pesticides violates the human right to a healthy environment twice over; it can affect human ...beings directly due to its toxicological characteristics, but it also constitutes a risk, not very well dimensioned, regarding the loss of biodiversity of the ecosystem via the impact on pollination. On the other hand, the precautionary principle obliges the authorities to prevent damage to the ecosystem that may be caused by the productive activity of individuals. Although there are studies that separately warn about the decrease of bees in the Yucatan due to industrial activity, this work has the novelty of presenting an intersectoral analysis of the risk that includes the soy industry, the swine industry and the tourist industry. The latter incorporates a new risk not considered until now, which is the presence of hydrocarbons in the ecosystem. Additionally, we can demonstrate that hydrocarbons, such as diesel and gasoline, should be avoided when using no genetically modified organisms (GMOs) in bioreactors. The objective of this work was to propose the precautionary principle around the risks in a beekeeping area and to propose biotechnology without using GMOs.
Chromium Cr(VI) is a highly toxic environmental contaminant for any organism, its presence in the environment is mainly due to anthropogenic activities. The use of biotechnology has been implemented ...for the treatment of effluents contaminated with Cr(VI).Our working group has isolated several fungi and bacteria capable of removing Cr(VI) from the culture medium.
var
Ed8 is a strain that can produce metabolites which reduce Cr (VI) to Cr (III). The objective of this work was to determine the effect of sodium salicylate on the growth of this strain and on the Cr(VI) reduction system, as well as to identify the metabolites that are produced from sodium salicylate. Our results show that the Culture medium containing sodium salicylate (20 mM) inhibits strain growth compared to the control condition (0 mM). However, it increases the specific reduction capacity of Cr (VI) red/mg Biomass in order of magnitude. Analysis of the culture medium corresponding to 48 h of incubation shows the presence of catechol and salicylate diminution. In addition, as a product of the enzymatic activity of a cell-free cellular extract, after 24 h of incubation, the consumption of salicylate is detected, as well as the presence of peaks corresponding to resorcinol and catechol. Our results show that it is possible to increase the Cr(VI) reducing capacity of the Ed8 strain, depending on the composition of the culture medium.
Sinkholes, also called cenotes, are a common feature in the karst aquifers found along the state Quintana Roo in México. Certain aliphatic and aromatic hydrocarbons have been found in the surface ...water of these sinkholes resulting in health and environmental hazards. In this study, a mathematical model is evaluated based on its predictive capacity on the biodegradation of oil in an airlift bioreactor (ALB). The model describes the oil uptake at the water-oil interface, whereas the previous modeling approaches focused on oil uptake in emulsified form. Biodegradation of 20 g L−1 diesel in an ALB is achieved by using an oil-degrading microbial consortium isolated from a sinkhole located in the urban zone of Playa del Carmen in Quintana Roo. The diesel degraded 83.6% confirming an effective use of ALB for the bioremediation of oil in water. The model is capable of predicting biomass growth and biodegradation by either integrating Monod or Teissier kinetics depending on the inhibitory effect of high concentration of oil on the microbial growth rate. The model is validated against three experimental campaigns performed in ALBs which indicated that it can serve as a valuable tool in the design and scale-up of bioreactors for the biodegradation of oil.
•Karst aquifers are susceptible to pollution that might be caused due to human activity.•Surface water of sinkholes along Yucatan Peninsula is contaminated with hydrocarbons.•ALB is a useful tool for the biodegradation of hydrocarbon using microbial consortium.•83.6% degradation of 20 g L-1 diesel is obtained in a 7 L Airlift Bioreactor (ALB).•A direct interfacial uptake model of macroscopic oil droplets was used for experimental validation.
Our work shows that in multiphase systems, it is more important to take into account the mass transfer of oil rather than that of just oxygen. The oxygen volumetric transfer coefficient is important ...in aerobic bioreactor design. However, in multiphase systems with non-soluble substrates, oil transfer can impose larger restrictions but is usually not considered. Emulsification and surface tension could play an important role due to effects on oil droplet size and interfacial transfer area. Petroleum oil and is derivates such as diesel can negatively affect living organisms. This study evaluated the effects of the volumetric transfer coefficients (k
L
a) of hydrocarbons and oxygen on the production of an oil-degrading consortium in an airlift bioreactor relative to emulsifying activity and surface tension, which play important roles in the biodegradation of non-soluble substrates such as diesel due to a combined mass transfer constraint. Our results showed a clear difference in k
L
a values, which ranged from 15 to 91 h
−1
for oxygen and from 0 to 0.0014 h
−1
for diesel. Most aerobic biodegradation studies focus on the oxygen volumetric transfer coefficient (k
L
a
oxygen
), but our results indicated that non-soluble constraints, such as the volumetric transfer coefficient of diesel (k
L
a
diesel
), could be more important. Additionally, d
32diesel
decreased as superficial gas velocity (Ug) increased. Lower Ug rates (0.15 cm s
−1
) resulted in higher values of d
32diesel
(0.38 cm
−1
), whereas higher Ug rates (2.7 cm s
−1
) resulted in lower values of d
32diesel
(0.21 cm
−1
) at the beginning of the cultivation.
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