Many alternatives for the proper disposal of horticultural plant wastes have been studied, and composting is one of the most attractive due to its insignificant environmental impact and low cost. The ...quality of compost for agronomical use is related to the degree of organic matter maturation and stabilization. Traditional parameters as well as temperature, ratio C/N, cationic exchange capacity, extractable carbon, or evolution of humificated substances have been successfully used to assess compost maturity and stability. However, microorganisms frequently isolated during composting release a wide range of hydrolytic enzymes, whose activity could apparently give interesting information on the rate of decomposition of organic matter and, therefore, on the product stability. The aim of this work was to study the evolution of some important enzymatic activities during composting of agricultural wastes and their comparison with other chemical parameters commonly employed as quality and maturity indexes, to establish a relationship between the degradation intensity of specific organic carbon fractions throughout the process. In this work, the chemical and biochemical parameters of plant wastes were studied along a composting process of 189 days to evaluate their importance as tools for compost characterization. Results showed an intense enzymatic activity during the first 2–3 weeks of composting (bio-oxidative phase), because of the availability of easily decomposable organic compounds. From a biological point of view, a less intense phase was observed between second and third month of composting (mesophilic or cooling phase). Finally, chemical humification parameters were more closely associated with the period between 119 and 189 days (maturation phase). Significant correlations between the enzymatic activities as well as between enzyme activities and other more traditional parameters were also highlighted, indicating that both kind of indexes can be a reliable tool to determine the degree of stability and maturation of horticultural plant wastes based-compost.
•Enzymatic and temperature patterns registered inside the pile are directly related.•Enzymatic activity reaches its peak during the first days of the composting process.•When piles begin to cool, the enzymatic activity decreases noticeably.•The intensity of the enzymatic activity indirectly affects the humification process.
Olive mill wastewater (OMW) resulting from the olive oil extraction process is usually disposed of in evaporation ponds where it concentrates generating a sludge that pollutes the ponds nearby area. ...In this study, four bio-treatments were applied for the in-situ bioremediation and valorization of OMW sludge: Landfarming, phytoremediation, composting and vermicomposting. In all cases, the OMW sludge was added with organic residues (mushroom compost, rabbit manure, and chicken manure). The bio-treatments were carried out in duplicate, inoculated and non-inoculated, to determine the effect of a specialized fungal consortium (Aspergillus ochraceus H2 and Scedosporium apiospermum H16) on the efficacy of the bio-treatments. The evaluation of chemical parameters, toxicity, and functional microbial biodiversity revealed that the four techniques depleted the toxicity and favored the stimulation of functional microbiota. Landfarming and phytoremediation allowed the decontamination and improvement of soils. Composting and vermicomposting also offered high-quality products of agronomic interest. Inoculation improved the bioremediation effectiveness. Biological treatments are effective for the safe recovery of contaminated OMW sludge into high-quality services and products.
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•Composting transforms Olive Mill Wastewater (OMW) sludge into high-quality product.•Landfarming and phytoremediation allow the decontamination of OMW sludge.•Vermicomposting promotes microbial functional biodiversity in OMW sludge.•Fungal consortium accelerates degradation processes inherent to the bio-treatments.•Organic residues added to OMW sludge stimulate microbial activity.
Microalgae and cyanobacteria could play an important role in crop protection, since they produce bioactive substances that promote plant growth and/or trigger the plant resistance mechanisms. The ...present study focuses on the control of bacterial canker caused by
Clavibacter michiganensis
subsp.
michiganensis
on tomato plants by using sonicated extracts from cyanobacteria and microalgae of the genera
Leptolyngbya
,
Nostoc
,
Chlorella
, and
Scenedesmus
. For the development of this study, 8 strains were firstly tested for their capacity to inhibit the growth of
C. michiganensis
subsp.
michiganensis
in vitro, as well as to produce cytokinins and salicylic acid. In order to discard those more phytotoxic strains, the germination index was also estimated in watercress seeds.
Scenedesmus
-677 and
Leptolyngbya
-1267 strains were selected in this first phase based on their pesticide and phytostimulant capacity in vitro. Subsequent bioassays on tomato seedlings showed that root application of
Scenedesmus
-677 could be more aimed at controlling the disease caused by
C. michiganensis
subsp.
michiganensis
, while foliar and root application of
Leptolyngbya-
1267 seems to be more related to the strengthening of the plant through the salicylic acid route. These preliminary results could serve as the basis for a deeper characterization of the biopesticidal and biostimulant effect of both strains, as well as to reveal the benefits derived from the combination of both capacities.
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•Cyanobacteria distinguished as biological control agents in seeds and seedlings.•SAB-M465 stood out as a muting agent for damping-off in seedbeds.•SAB-B912 stimulated plant growth in ...pre and post emergence phases.•Seed biopriming was successful as a preventive treatment against damping-off.•Seed biopriming was positioned as an eco-friendly strategy to promote plant growth.
This work highlights the ability of various cyanobacterial extracts from Anabaena spp., Tolypothrix spp., Nostoc or Trichormus, among others genera, to control the incidence of damping-off caused by Pythium ultimum in cucumber seedlings. Protocols applied aimed at the preliminary characterization of the cyanobacterial collection were very useful for predicting their phytotoxic, phytostimulating and biopesticidal capacity. First, the phytostimulatory or phytotoxic potential of a collection of 31 sonicated cyanobacterial extracts was analyzed by calculating the germination index in watercress seeds and the increase or loss of seedling weight. Likewise, the collection was characterized according to its ability to inhibit the growth of P. ultimum by dual culture bioassays and detached-leaf test. Finally, after selecting the most effective extracts, a preventive damping-off bioassay was performed based on cucumber seed biopriming. The strain SAB-M465 showed to be the most efficient strain against the in vitro growth of P. ultimum, while SAB-B912 was more discreet in this regard, but proved to be the most effective as a germination stimulator. Seed biopriming strategy with sonicated extracts of cyanobacteria revealed a remarkable promoter effect in the early stages of plant development, although only SAB-M465 was positioned as an effective control agent against damping-off caused by P. ultimum in cucumber seedbeds.
Little is known on the characteristics of patients diagnosed with idiopathic pulmonary fibrosis (IPF) in Spain. We aimed to characterize the demographic and clinical profile of IPF patients included ...in the IPF National Registry of the Spanish Respiratory Society (SEPAR).
This is a prospective, observational, multicentre and nationwide study that involved 608 IPF patients included in the SEPAR IPF Registry up to June 27th, 2017, and who received any treatment for their disease. IPF patients were predominantly males, ex-smokers, and aged in their 70s, similar to other registries.
Upon inclusion, mean ± SD predicted forced vital capacity was 77.6% ± 19.4, diffusing capacity for carbon monoxide was 48.5% ± 17.7, and the 6-min walk distance was 423.5 m ± 110.4. The diagnosis was mainly established on results from the high-resolution computed tomography in the proper clinical context (55.0% of patients), while 21.2% of patients required invasive procedures (surgical lung biopsy) for definitive diagnosis. Anti-fibrotic treatment was prescribed in 69.4% of cases, 51.5% pirfenidone and 17.9% nintedanib, overall with a good safety profile.
The SEPAR IPF Registry should help to further characterize current characteristics and future trends of IPF patients in Spain and compare/pool them with other registries and cohorts.
• Using cyanobacteria extracts at low doses reduces the toxicity risk in cucumber seeds.• Optimal doses of cytokinins and salicylic acid benefit the early plant growth stages.• Cyanobacterial ...siderophores favor plant growth during the seedling phase.• Strain Nostoc SAB-M612 stood out for their stimulant ability in cucumber seedlings.
This work clarifies some of the substances involved with the biostimulant effect shown by 28 cyanobacteria isolated from different aquatic environments. The production of salicylic acid, cytokinins, siderophores and phosphate solubilization were analyzed in vitro, as well as the phytostimulant/phytotoxic effect on watercress seeds at two different extract concentrations (0.5 and 0.2 mg mL−1). The most prominent plant growth promoting cyanobacteria were verified in vivo at two different doses (0.5 and 0.1 mg mL−1). 21.4 % and 7.1 % of the tested strains produced siderophores or phosphate solubilization, respectively. The production of salicylic acid was stood out for the strains Calothrix SAB-B797, Nostoc SAB-B1300 and Nostoc SAB-M612, while Nostoc SAB-M251 and Trichormus SAB-M304 were noticeable regard to cytokinin production. The highest values of germination occurred when the extracts were applied in low dose (0.5 mg mL−1). Nostoc SAB-M612 provoked the stimulation of aerial and radicular growth in cucumber seedlings.
Invasive aspergillosis (IA) is a life-threatening infection that affects an increasing number of patients undergoing chemotherapy or allo-transplantation, and recent studies have shown that genetic ...factors contribute to disease susceptibility. In this two-stage, population-based, case-control study, we evaluated whether 7 potentially functional single nucleotide polymorphisms (SNPs) within the
and
genes influence the risk of IA in high-risk hematological patients. We genotyped selected SNPs in a cohort of 500 hematological patients (103 of those had been diagnosed with proven or probable IA), and we evaluated their association with the risk of developing IA. The association of the most interesting markers of IA risk was then validated in a replication population, including 474 subjects (94 IA and 380 non-IA patients). Functional experiments were also performed to confirm the biological relevance of the most interesting markers. The meta-analysis of both populations showed that carriers of the
,
, and
alleles (where the RefSeq identifier appears as a subscript) had a significantly increased risk of developing IA according to a log-additive model (
value from the meta-analysis
= 9.8 · 10
,
= 1.5 · 10
, and
=7.9 · 10
, respectively). Haplotype analysis also confirmed the association of the
haplotype with
CGG with an increased risk of IA (
= 4.0 · 10
). Mechanistically, we observed that monocyte-derived macrophages (MDM) from subjects carrying the
allele or the GG genotype showed a significantly impaired fungicidal activity but that MDM from carriers of the
and
or
alleles had deregulated immune responses to
conidia. These results, together with those from expression quantitative trait locus (eQTL) data browsers showing a strong correlation of the
allele with lower levels of
mRNA in whole peripheral blood (
= 2.46 · 10
) and primary monocytes (
= 4.31 · 10
), highlight the role of the
and
loci in modulating and predicting IA risk and provide new insights into the host immune mechanisms involved in IA development.
•Microbial inoculation modified the initial biodiversity of the compost piles.•Bio-inoculation favored a quicker degradation of the easily biodegradable fractions.•Microbial augmentation activated ...the nitrification process.•Biodegradation process was continuous and accelerated during the first 2 weeks.•Inoculation was found useful to enhance the lignocellulosic waste-based composting.
Intensive agriculture produces more than one million tons of organic waste mainly composed of lignocellulosic compounds. Though some management strategies have been lately adopted, many problems related to time and surface required for a proper treatment and final product quality remain unsolved. In this work, a staggered bioaugmentation process is proposed for the improvement of horticultural waste composting. Inocula were composed of 30 microbial strains previously isolated from identical composting piles, operated under the same conditions used in this work. The high levels of biomass carbon at the beginning of the bio-oxidative phase and the parallel evolution of reducing sugars reflected a quick adaptation of microbial inocula to the high temperatures reached during the process. Reducing sugar content during the process in the uninoculated pile was below 200μgg−1, while a higher content was detected in the inoculated pile (2500μgg−1). Hemicellulose degraded at the end of the process in the inoculated pile was near to 85% whereas in the control pile was below 70%. Lignin degradation ratio was also higher in the inoculated pile (41% in comparison to 23% in the control pile). Moreover, several stabilization and humification indices supported that the bio-inoculation procedure here reported yields better quality products, earlier stabilized, from processes in which lignocellulosic carbon is more efficiently biotransformed.
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•Deactivation of harmful agents occurs by a blend of biotic and abiotic factors in composting.•A relationship exists between phosphate solubilizing and Rhizoctonia solani ...suppression.•A link-up is proved between the microbial production of siderophores and salicylic acid.•Geobacillus thermodenitrificans suppresses damping-off caused by Phytophthora capsici.•Geobacillus thermodenitrificans stimulates root development in pepper seedlings.
Along with the high temperatures generated during the composting process, the microbial community of a compost pile collaborates actively in the control of damping-off producing agents. Such collaboration could be justified on the basis of the ability of the microbiota to produce fungicide substances that are involved in the control of damping-off or other bioactive compounds that affect the growth promotion of plants. Thanks to ex situ experiments, a remarkable suppressive effect was corroborated against different agents producing damping-off. The microbial strains involved in this effect were detected mainly in the bio-oxidative and maturation phases of the composting process. However, only 3% of the total collection of strains proved to have a multipotential character with respect to its spectrum of action against the damping-off producing agents, as well as in relation to its capacity to produce substances of agronomic interest. It is worth mentioning the presence of two thermophilic isolates identified as Geobacillus thermodenitrificans and Bacillus aerius that showed the ability to inhibit the symptoms caused by Phytophthora capsici in vivo. Both strains were able to produce siderophores, salicylic acid and chitinase enzymes in vitro, but only G. thermodenitrificans was able to stimulate the development of the root in pepper seedlings. In this sense, it is suspected that the production of cyanide by this thermophilic bacteria could be related to this latter effect.
•Composting as bioprospecting source.•Collection of actinobacteria with potential as biocontrol agents isolated from composted lignocellulosic material.•Bioactive substances produced by ...microorganisms against damping-off.•Family Microbacteriaceae stood out for its biopesticidal and biostimulant capacity.
Strains isolated during composting processes of plant waste, and identified as Actinobacteria, proved to be significant producers of compounds that actively participate in the control of phytopathogens, such as those that cause Damping-off disease. Although most of the actinomycetes analyzed showed to be antagonistic strains against common phytopathogens, only some 30% proved to be capable of producing bioactive substances, such as siderophores, salicylic acid, chitinase enzymes or cyanide, so that antibiosis could be considered the most probable antagonistic mechanism for a high proportion of the strains investigated. 6% of the microorganisms identified in this work, were selected as potential strains to be investigated in depth, since they further stimulated plant growth (germination index tests greater than 100%). Microbacteriaceae was one of the most prominent families.
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