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Tunicate maize (Zea mays var. tunicata A. St. Hil) is a landrace that constitutes a fundamental aspect of the socio-cultural identity of Ixtenco, Tlaxcala (Mexico) and represents an exotic phenotype whose kernels are enclosed in leaflike glumes. Despite multiple studies conducted worldwide on plant growth-promoting-rhizobacteria (PGPR) in commercial maize varieties grown under monoculture systems, very little is known about bacteria inhabiting native maize landraces in agroecosystems, but for tunicate maize such knowledge is non-existent. This research described and profiled functional groups of culturable rhizobacteria from tunicate maize at two phenological stages (tasseling and maturity/senescence) in a polyculture system, highlighting potential PGPR for biotechnological purposes. Ninety-five rhizobacteria were isolated and molecularly identified, and their physiological activities such as plant growth promotion, production of exogenous lytic enzymes, and antagonism against fungal pathogens were determined. The culturable rhizobacterial community associated to tunicate maize comprised 42 genera, dominated by Bacillaceae, Comamonadaceae, Microbacteriaceae, Micrococcaceae, Oxalobacteraceae, Pseudomonadaceae, and Rhizobaceae families. At tasseling stage, the identified bacteria corresponded to Arthrobacter, Priestia, Herbaspirillum, Pseudomonas, and Rhizobium, and exhibited redundant capabilities for stimulating plant growth and nutrition, and inhibiting fungal phytopathogens. At maturity/senescence stage, the main genera Arthrobacter and Microbacterium displayed lytic capabilities to support mineralization process. We recorded potential novel rhizosphere functional bacteria such as Rhizobium, Sphingobium, and Arthrobacter which are not previously described associated to maize landraces, as well as their bioprospection as PGPR detected at plant phenological stages poorly explored (like maturity/senescence). This taxonomic and functional diversity was attributed to the application of agricultural practices as well as the rhizosphere effect during specific phenological stages. Results described the diversity and functionality of culturable rhizosphere bacteria from tunicate maize in polyculture systems that allowed us the detection of potential rhizobacteria for further developing of biofertilizers and biocontrollers directed as biotechnology for sustainable agriculture, and for generating strategies for conservation of native plants and their microbial genetic resources. [ABSTRACT FROM AUTHOR]

Tunicate maize (Zea mays var. tunicata A. St. Hil) is a landrace that constitutes a fundamental aspect of the socio-cultural identity of Ixtenco, Tlaxcala (Mexico) and represents an exotic phenotype whose kernels are enclosed in leaflike glumes. Despite multiple studies conducted worldwide on plant growth-promoting-rhizobacteria (PGPR) in commercial maize varieties grown under monoculture systems, very little is known about bacteria inhabiting native maize landraces in agroecosystems, but for tunicate maize such knowledge is non-existent. This research described and profiled functional groups of culturable rhizobacteria from tunicate maize at two phenological stages (tasseling and maturity/senescence) in a polyculture system, highlighting potential PGPR for biotechnological purposes. Ninety-five rhizobacteria were isolated and molecularly identified, and their physiological activities such as plant growth promotion, production of exogenous lytic enzymes, and antagonism against fungal pathogens were determined. The culturable rhizobacterial community associated to tunicate maize comprised 42 genera, dominated by Bacillaceae, Comamonadaceae, Microbacteriaceae, Micrococcaceae, Oxalobacteraceae, Pseudomonadaceae, and Rhizobaceae families. At tasseling stage, the identified bacteria corresponded to Arthrobacter, Priestia, Herbaspirillum, Pseudomonas, and Rhizobium, and exhibited redundant capabilities for stimulating plant growth and nutrition, and inhibiting fungal phytopathogens. At maturity/senescence stage, the main genera Arthrobacter and Microbacterium displayed lytic capabilities to support mineralization process. We recorded potential novel rhizosphere functional bacteria such as Rhizobium, Sphingobium, and Arthrobacter which are not previously described associated to maize landraces, as well as their bioprospection as PGPR detected at plant phenological stages poorly explored (like maturity/senescence). This taxonomic and functional diversity was attributed to the application of agricultural practices as well as the rhizosphere effect during specific phenological stages. Results described the diversity and functionality of culturable rhizosphere bacteria from tunicate maize in polyculture systems that allowed us the detection of potential rhizobacteria for further developing of biofertilizers and biocontrollers directed as biotechnology for sustainable agriculture, and for generating strategies for conservation of native plants and their microbial genetic resources.

Pollution caused by spent engine oil has become a major global ecological concern as it constitutes a big threat to plants, animals, microorganisms and the soil ecosystem. This study was undertaken to examine the remediation of spent engine oil-contaminated soil through biostimulation and bioaugmentation with sodium dodecyl sulphate and indigenous hydrocarbonoclastic bacterial isolates. Twelve mesocosms were organized into four groups designated G1, G2, G3 and G4 and each filled with 2.5 kg of soil samples. Each group was composed of three mesocosms to produce a triplicate setup. G1 contained pristine soil which served as a positive control. G2 contained a total petroleum hydrocarbon (TPH) of 913.333 mg/kg in the untreated oil-polluted soil which served as a negative control. G3 contained a TPH of 913.333 mg/kg in the polluted soil inoculated with indigenous hydrocarbonoclastic bacterial isolates. G4 contained a TPH of 913.333 mg/kg in the polluted soil mixed with bacterial consortium and sodium dodecyl sulphate. The level of pollution was 36.5% in the triplicate setup G2, G3 and G4. Fourier Transform Infrared spectroscopy was used to determine the degree of hydrocarbon degradation. The initial TPH value of 913.33 mg/kg was reduced by 84.44% (142 mg/kg) in soil inoculated with indigenous hydrocarbonoclastic bacterial isolates and by 88.28% (106.66 mg/kg) in biostimulated soil. Result of this study show that soil stimulation involving bacterial consortium and sodium dodecyl sulphate was more efficient than bioaugmentation strategy alone used in the remediation of spent engine oil-polluted soil. [ABSTRACT FROM AUTHOR]

The presence of heavy metals (HMs) in the environment represents a serious environmental problem. In this regard, this work was conceived with the aim of finding, among indigenous microorganisms, the species and their combinations with the best biosorption activity for the following HMs: zinc, lead, cadmium, copper, and nickel. The experiment was carried out in several steps: (1) isolation and identification of microbial strains from the Central Effluent Treatment Plant's wastewater; (2) studying the interaction of microorganisms and the ability to form biofilms in 96-well plates; (3) testing the resistance of biofilms to HMs; (4) testing the growth of biofilms on AMB media carriers in the presence of HMS; and (5) biosorption assay. The selected strains used in this study were: Enterobacter cloacae, Klebsiella oxytoca, Serratia odorifera, and Saccharomyces cerevisiae. The best biofilm producers in control medium were K. oxytoca/S. odorifera (KS), followed by K. oxytoca/S. odorifera/S. cerevisiae (KSC), and E. cloacae/K. oxytoca/S. odorifera (EKS) after 10 days of incubation. Mixed cultures composed of three species showed the highest resistance to the presence of all tested metals. The best biosorption capacity was shown by KSC for Cu2+ (99.18%), followed by EKS for Pb2+ (99.14%) and Cd2+ (99.03%), K. oxytoca for Ni2+ (98.47%), and E. cloacae for Zn2+ (98.06%). This research offers a novel approach to using mixed biofilms for heavy metal removal processes as well as its potential application in the bioremediation of wastewater. [ABSTRACT FROM AUTHOR]

The presence of heavy metals (HMs) in the environment represents a serious environmental problem. In this regard, this work was conceived with the aim of finding, among indigenous microorganisms, the species and their combinations with the best biosorption activity for the following HMs: zinc, lead, cadmium, copper, and nickel. The experiment was carried out in several steps: (1) isolation and identification of microbial strains from the Central Effluent Treatment Plant’s wastewater; (2) studying the interaction of microorganisms and the ability to form biofilms in 96-well plates; (3) testing the resistance of biofilms to HMs; (4) testing the growth of biofilms on AMB media carriers in the presence of HMS; and (5) biosorption assay. The selected strains used in this study were: Enterobacter cloacae, Klebsiella oxytoca, Serratia odorifera, and Saccharomyces cerevisiae. The best biofilm producers in control medium were K. oxytoca/S. odorifera (KS), followed by K. oxytoca/S. odorifera/S. cerevisiae (KSC), and E. cloacae/K. oxytoca/S. odorifera (EKS) after 10 days of incubation. Mixed cultures composed of three species showed the highest resistance to the presence of all tested metals. The best biosorption capacity was shown by KSC for Cu2+ (99.18%), followed by EKS for Pb2+ (99.14%) and Cd2+ (99.03%), K. oxytoca for Ni2+ (98.47%), and E. cloacae for Zn2+ (98.06%). This research offers a novel approach to using mixed biofilms for heavy metal removal processes as well as its potential application in the bioremediation of wastewater.

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Quinoa sourdough can safely be produced if the hygienic threshold of miss-fermentation during the start-up period is overcome. The aims of the present study are to map the microbiota of spontaneously formed quinoa sourdough without backslopping and select Lactiplantibacillus-strains. Viable count from grains and sourdough were performed and picked isolates were identified by gene sequencing. Lactiplantibacillus interspecies differentiation was evaluated by specific primers targeting the recA region, fermentation capacity and enzymatic abilities applying colorimetric assays, respectively. High initial levels of Enterobacteriaceae and other opportunistic pathogens decreased gradually, and the pH dropped below 4. The results indicate that spontaneous fermentation involves a variety of quinoa autochthonous microorganisms, with low presence of lactobacilli due to the delay lactic acid fermentation. Lactobacilli strains able to ferment xylose and glycerol and metabolize phenolic compounds were identified holding great prospects as suitable starter cultures for production of fermented quinoa products.

With the purpose of correcting variables indicating organic contamination in waters for human consumption from the localities Severino, Julián and Balsa en Medio located in the microbasin of the Carrizal River (Manabí, Ecuador), depuration strategies based on zeolite filters and efficient microorganisms (EM) were evaluated. Three water sources were sampled: springs, tanks and faucets of regular consumption. Five treatments were tested: a) incubated with EM•1® at 5 mL/L and filtered in Cuban zeolite; b) incubated with EM • 1® at 5 mL/L and filtered in Ecuadorian zeolite; c) incubated with 5 mL/L; d) 10 mL/L and e) 15 mL/L of autochthonous microorganisms, respectively. A randomized block experimental design was used, with four repetitions. The comparison of treatments was performed by orthogonal contrasts. The variables evaluated were pH, biological oxygen demand, nitrites and phosphates. It was determined that, regardless of the location and source of treated water, the application of doses of 15 mL/L of autochthonous microorganisms and the filtration with zeolite + efficient microorganisms (EM•1®), induced significant corrections in the variables biological oxygen demand (BOD5), nitrites and pH. With the exception of the BOD5, the purification treatments reduced the levels of organic components of the waters of the localities Severino, Julian and Balsa en Medio to values acceptable for the quality regulations of drinking water and freshwater bodies in force in Ecuador. The application of autochthonous microorganisms represents a viable alternative for the reduction of organic pollutants in rural areas of the Carrizal River micro-basin. [ABSTRACT FROM AUTHOR]

This study monitors the influence of basic automotive paints on plankton and biofilms of selected microorganisms isolated from the wastewater of an automotive factory. Minimum Biofilm Eradication Concentration-High Throughput Plates system was used for the simultaneous tolerance testing. Minimal inhibitory concentration and minimal lethal concentration of the tested substances were determined for both planktonic cells and their biofilms. The resistance level of biofilms was also tested in standard 96 microtiter plates, whereby the results for bacteria and yeasts were confirmed by the fluorescence microscopy. The results were mutually compared for both plankton and biofilms, as well as for plankton and biofilm of the same microorganisms. In no case, the resistance of the planktonic form was higher than the biofilm for the same microorganism. Saccharomyces cerevisiae PMFKG-F7 in the presence of basic color, as well as Rhodotorula mucilaginosa PMFKG-F8 in the presence of the thinner for rinsing paint, shows high sensitivity in planktonic form, whereby the same species are the most resistant in the form of biofilm for the same substances. The highest resistance to all test substances was shown by the biofilm of R. mucilaginosa PMFKG-F8, as well as Candida utilis PMFKG-F9 which was significantly resistant in both tested forms. The obtained results suggest that autochthonous microorganisms that form biofilms can significantly improve the process of removing car paints from the wastewater and being thus new grounds for the development of new biotechnologies. [ABSTRACT FROM AUTHOR]

Abstract The present work aimed to explore the potential of autochthonous microorganisms from an urban estuary and from activated sludge of an associated wastewater treatment plant (WWTP), for biodegradation of an antidepressant drug, paroxetine, and on a cholesterol-lowering agent, bezafibrate. These compounds were chosen as representatives of extensively used pharmaceuticals. Autochthonous microorganisms from the indicated sources were exposed to the target pharmaceuticals (1 mg/L) in co-metabolism with sodium acetate (500 mg/L) along a two-weeks period, for a total of 7 two-weeks periods (here referred as cycles). Exposures were carried out in batch mode, under different incubation conditions (agitation vs. static). Removal of pharmaceuticals was monitored at the end of each cycle, by analysing the culture medium. For paroxetine, fluoride ion release was also followed as an indicator of defluorination of the molecule. The structure of the bacterial communities was analysed by ARISA (Automated rRNA Intergenic Spacer Analysis), at the beginning of the experiment and at the end of the first and the last cycles to identify substantial changes associated with the time of exposure, the incubation conditions and the presence and type of pharmaceuticals. Incubation conditions affected not only the bacterial community structure, but also the biodegradation efficiency. At the beginning of the experiment, removal of target pharmaceuticals was found to be lower under agitation than under static conditions, but at the end of the experiment, results showed high removal of the pharmaceuticals from the culture medium (>97%) under both conditions, mainly by microbiological processes. For paroxetine, adsorption and abiotic processes also had an important influence on its removal, but defluorination only occurred in the presence of microorganisms. These results highlight that autochthonous microorganisms from estuarine sediments and WWTP sludge have high ability to remove the selected pharmaceuticals with relevant implications for the development of new bioremediation tools for environmental restoration. Graphical abstract Unlabelled Image Highlights • Potential of autochthonous microorganisms for bioremediation of pharmaceuticals tested • Microorganisms from a sediment and an activated sludge degraded paroxetine and bezafibrate • Microbial community structure changed to adapt to pharmaceuticals presence • Results are relevant for development of new bioremediation tools for environmental restoration. [ABSTRACT FROM AUTHOR]

Fermentation has recently been rediscovered as an attractive technique to process legumes, as it can improve the nutritional quality and value of the end product. This study investigated the dynamics and stability of the microbial communities in spontaneously fermented sourdoughs made from flours of two cultivars of faba beans and two cultivars of peas. Sourdoughs were established by the backslopping technique, and the microbial development at 22 °C and 30 °C was followed by culture dependent and culture independent methods. The utilization of substrates and formation of metabolites were also determined by high-performance liquid chromatography. A stable pH was reached in all the sourdoughs after 11–15 days of daily backslopping. Lactic acid bacteria and yeast from pH stable sourdoughs were isolated, characterized and identified. The fermentation temperature influenced the development of the microbial community and the substrate utilization during spontaneous fermentation. In the 30 °C fermentations, one species dominated (Lactiplantibacillus plantarum/pentosus), a lower pH was achieved, and the available substrates were more extensively converted. The 22 °C fermentation resulted in a more diverse microbial community (Lactiplantibacillus , Leuconostoc , Pediococcus), a higher pH, and more residual substrates were available after fermentation. Yeasts were only detected in one of the pea sourdoughs fermented at 30 °C, with Saccharomyces cerevisiae being the dominant species. Nearly all sourdoughs were depleted of maltose after 24 h fermentation cycles, and higher levels of lactic and acetic acid were detected in 30 °C fermen-tations. This research adds to our understanding of the autochthonous microbial community present in faba beans and peas as well as their natural capacity to establish themselves and ferment legume flours. These findings enhance the possibilities of utilizing and improving plant based protein sources. • Lactic acid bacteria and yeast were isolated from spontaneous legume fermentations. • Temperature was a selective factor for the bacterial composition in mature sourdoughs. • The bacterial composition and pH remained stable throughout the weekly propagation. [ABSTRACT FROM AUTHOR]

This document presents results of research in which an autochthonous consortium of cyanide-degrading microorganisms was developed for use in the biological treatment of hazardous cyanide waste. These autochthonous microorganisms were lyophilized (freeze dried) in different protective media, such as gelatin and lactose broth, at different temperatures (-35,-45,-55 and -65 oC). The preliminary treatment of cyanide wastes involved pretreatment of sludge for 3-5 days to leach the waste, and a subsequent treatment in aerated lagoons, where the consortium of lyophilized microorganisms was applied. Eight different lyophilized samples were obtained at different temperatures using two protective media for lyophilization, which produced excellent results six months after lyophilization. The consortium of lyophilized microorganisms showed 70% to 80% viability, with cyanide extraction percentages higher than 95%, and can be kept active for long periods of time (for years). Lyophilized microorganisms can be used for biodegradation of cyanide wastes from gold mines or from any other cyanide waste such as that from metallic electroplating baths, or from the jewelry manufacturing industry.

One of the possible ways of recovering the environmental quality of contaminated soils is the bioremediation process, in which soil pollutants are degraded using microorganisms. In this context, the evaluation of the bioremediation process efficiency was evaluated by preparing a consortium of autochthonous microorganisms of the soil from an area contaminated by wood preservatives. Subsequently, biodegradation experiments were performed on microcosm scale, applying bioaugmentation, enrichment and biostimulation techniques in two inoculums. The experiments were monitored by CO production and the presence of total polycyclic aromatic hydrocarbons (PAHs). Organic extracts of this soil were prepared before and after being submitted to bioremediation, in which the 16 PAHs considered priority pollutants by USEPA were analyzed, and compared to the responses found for microbial respiration. The initial concentration of the PAHs was 34 mg/Kg. All the treatments achieved a removal rate above 60 %, and the mean degradation was 88 %. Statistical analyses of the results of CO production showed a significant difference between all treatments for the control soil, except inoculum 1 (bioaugmented). However, inoculums 1 and 2 present a more efficient performance than the contaminated soil itself. When inoculums 1 and 2 (bioaugmented, biostimulated, and enriched) were compared, inoculum 2 presented a greater evolution of CO and a better performance in PAHs degradation. Therefore, it was more efficient in the experiment. Hence, as the best results were obtained with the inoculum whose mixed culture had been enriched, this technique definitely has a greater potential for biodegradation in bioremediation processes with these contaminants. [ABSTRACT FROM AUTHOR]

Oil-containing wastewaters are regarded as main industrial pollutants of soil and water environments. They can occur as free-floating oil, unstable or stable oil-in-water (O/W) emulsions, and in the case of extreme organic load, as water-in-oil (W/O) emulsions. In this study two types of oily effluents, a typical O/W emulsion marked as E1 and a W/O emulsion E2, both discharged by local metal processing plants were examined to test their toxicity to microbial communities and the ability to serve as nutrient sources for bacterial growth. The organic contaminant load of the samples was evaluated on the basis of chemical oxygen demand (COD) parameter values and was equal to 48 200 mg O2·dm-3 and >300 000 mg O2·dm-3 for E1 and E2, respectively. Both emulsions proved to be non toxic to bacterial communities and were shown to contain biodiverse autochthonous microflora consisting of several bacterial strains adapted to the presence of xenobiotics (the total of 1.36 · 106 CFU·cm-3 and 1.72 · 105 CFU·cm-3 was determined for E1 and E2, respectively). These indigenous bacteria as well as exogenously inoculated specialized allochthonous microorganisms were biostimulated so as to proliferate within the wastewater environment whose organic content served as the only source of carbon. The most favorable cultivation conditions were determined as fully aerobic growth at the temperature of 25 °C. In 9 to 18 day-tests, autochthonous as well as bioaugmented allochthonous bacterial population dynamics were monitored. For both emulsions tested there was a dramatic increase (up to three orders of magnitude) in bacterial frequency, as compared to the respective initial values. The resultant high biomass densities suggest that the effluents are susceptible to bioremediation. A preliminary xenobiotic biodegradation test confirmed that mixed auto- and allochthonous bacterial consortia obtained upon inoculation of the samples with microbiocenoses preselected for efficient hydrocarbon biodegradation led to a decrease in the organic pollution level. [ABSTRACT FROM AUTHOR]

Highlights: [•] P. corethrurus was tested for its capacity to remove benzo(a)pyrene (BaP). [•] The autochthonous microorganisms removed BaP from soil. [•] Addition of P. corethrurus further increased the removal of BaP 4-fold. [•] B. humidicola increased removal of BaP from sterilized and unsterilized soil. [•] P. corethrurus could be used in the remediation of hydrocarbon-contaminated soils. [Copyright &y& Elsevier]

Abstract: The aim of this study was to select autochthonous microorganisms that are able to biosorb heavy metals in aqueous systems. Forty-eight strains, included fungi, yeasts and bacteria, were isolated from water and sludge samples from urban and industrial wastewater treatment plants in the province of Jaén, southern Spain. Purified isolates were screened on the basis of their resistance to Pb(II), Zn(II) and Ag(I). Ten strains were selected and identified by molecular techniques. Tolerance index and minimum inhibitory concentration (MIC) for the three metals were also determined. It can be noted that tolerance of the strains appears to be associated with the sites of their isolation. The best results were obtained for the yeast Trichosporon sp. 4S3 which showed the following MICs: 32–35mM for lead, 16–18mM for zinc and 3–5mM for silver. The use of native strains can be an interesting alternative for bioremediation processes of heavy metals. This study increases the number of microbial strains that have the ability to resist relatively higher concentrations of metals, which may make them recommendable as potentially low-cost biosorbents. The nucleotide sequences of all the selected isolates were deposited in GenBank, which could be of great interest for other investigators as reference strains in bioremediation processes of heavy metals. [Copyright &y& Elsevier]

Petroleum substances are the main source of pollutants stored in old waste pits. They cause degradation of biological life in the area of storage. The aim of this article is to present laboratory research on petroleum pollutant biodegradation. The hydrocarbon contaminants in old drilling wastes came from the Graby-19 waste pit. The tests included basic bioremediation and inoculation with a biopreparation based on non-pathogenic species of bacteria and fungi, which were identified in molecular research. Multicriteria effectiveness estimation of petroleum pollutant biodegradation in the tested wastes enabled determination of a role of fungi in this process. Biopreparation enrichment was done in the final phase with non-pathogenic fungi isolated from the waste during purification. As a result, an increase in long-chain n-alkanes and aromatic hydrocarbon (BTEX and PAH) biodegradation was observed. Biodegradation rate constants for petroleum hydrocarbons, calculated on the basis of a mathematical model, can serve as proof of fungi usage in the bioremediation process. [ABSTRACT FROM AUTHOR]

Various deep, compact, sedimentary formations have been studied in recent years as potential host rock for a repository for high-level, long-lived radioactive waste. Considering that microbial activities may influence radionuclide chemistry and migration in such environments, we investigated the potential presence of microorganisms in the Opalinus Clay formation, from unperturbed sediment samples (i.e., not affected by gallery excavation and borehole drilling) recovered under aseptic conditions in the Mont Terri Underground Rock Laboratory (Switzerland). A combination of molecular biology techniques and a cultivation-based approach suggested the presence of a few sparse autochthonous microbial cells in the Opalinus Clay. For the first time, ribosomal RNA (rRNA) genes were sequenced from enrichment cultures from such samples. The results suggested that at least two of the bacterial strains isolated were likely unknown species of the Sphingomonas and Alicyclobacillus genera, as their fully-sequenced 16S-rRNA genes shared less than 97% similarity with validly published sequences. Early genetic divergence occurring after physical isolation of bacterial ancestors in the geosphere by the sedimentation process or following later geological events may have resulted in the generation of particular taxa in the subsurface. [ABSTRACT FROM AUTHOR]

Abstract: Virus adsorption and inactivation in soil matrix are crucial processes controlling the potential of viruses to contaminate water resources. These two processes behave interactively and are controlled by various factors. In this study, batch and incubation experiments were conducted at 4°C to compare the adsorption of bacteriophage MS2 in different soils, and to examine its inactivation behavior at different soil water content. Soils with presence/absence of autochthonous microorganisms were used. The interactive effects of sterilization and soil water content on virus inactivation were also evaluated. The Ustisandic Primosols showed no virus adsorption and minimal differences in activation regardless of the presence or absence of soil autochthonous microorganisms. For the Ferriudic Cambosols, however, sterilization increased adsorption and enhanced inactivation, and inactivation was accentuated by decreasing soil water content. The results indicate that soil water content and sterilization had additive effects on virus inactivation, and reveal that the enhanced “adsorption” by sterilization was mainly due to greater die-off in the Ferriudic Cambosols. The greater inactivation observed in the Ferriudic Cambosols, which has relative high contents of Fe- and Al-oxides and low pH, resulting from the additive effect of sterilization and decreasing soil water content was mainly due to increased reactions at the solid–water interface. We conclude that the effect of sterilization and soil water content on virus inactivation depends on soil type, and the extent of inactivation is likely controlled by the content of metal oxides. [Copyright &y& Elsevier]

• Pathogenic bacteria were present before and during fermentation of quinoa grains. • Fermentation of quinoa grains is linked to a hygiene risk due to the native microbiota composition. • Novel L. plantarum strains possessing xylose degradation enzymes were isolated. • Isolated L. plantarum strains were capable of metabolizing phenolic compounds. Quinoa sourdough can safely be produced if the hygienic threshold of miss-fermentation during the start-up period is overcome. The aims of the present study are to map the microbiota of spontaneously formed quinoa sourdough without backslopping and select Lactiplantibacillus -strains. Viable count from grains and sourdough were performed and picked isolates were identified by gene sequencing. Lactiplantibacillus interspecies differentiation was evaluated by specific primers targeting the recA region, fermentation capacity and enzymatic abilities applying colorimetric assays, respectively. High initial levels of Enterobacteriaceae and other opportunistic pathogens decreased gradually, and the pH dropped below 4. The results indicate that spontaneous fermentation involves a variety of quinoa autochthonous microorganisms, with low presence of lactobacilli due to the delay lactic acid fermentation. Lactobacilli strains able to ferment xylose and glycerol and metabolize phenolic compounds were identified holding great prospects as suitable starter cultures for production of fermented quinoa products. [ABSTRACT FROM AUTHOR]

In July 2013, a fatal train derailment led to an explosion and fire in the town of Lac-Mégantic (LM), Quebec, and the crude oil contamination of regional surface water, soil, and sediment in the adjacent Lake Mégantic. This study investigated the degradation potential of the spilled crude oil by using the sediments from the incident site as the source of microorganisms. Two light crude oils (LM source oil and Alberta Sweet Mixed Blend (ASMB)) were tested at 22 °C for 4 weeks and 4 °C for 8 weeks, respectively. The post-incubation biological and chemical information of the samples were analysed. There was no marked difference in degradation efficacy and biological activities for both the LM and ASMB oils, although the biodegradation potential differed between the two incubations. Higher temperature favoured the growth of microorganisms, thus for the degradation of all petroleum hydrocarbons, except for some conservative biomarkers. The degradation of both oils followed the order of resolved components > total saturated hydrocarbons (TSH) > unresolved complex mixture (UCM) >total aromatic hydrocarbons (TAH). Normal alkanes were generally degraded more significantly than branched ones, and polycyclic aromatic hydrocarbons (PAHs). Degradation of polycyclic aromatic hydrocarbons (PAHs) and their alkylated congeners (APAHs) for both incubations generally decreased as the number of aromatic rings, and the degree of alkylation increased. This study showed that the LM sediments can biodegrade the petroleum hydrocarbons efficaciously if appropriate ambient temperatures are generated to favour the growth of autochthonous microorganisms., (Copyright © 2019 Elsevier Ltd. All rights reserved.)