In the last decade, numerous studies have evaluated the benefits of biochar for improving soil quality. The purposes of the current study were to use Fourier transform infrared-photoacoustic ...spectroscopy (FTIR-PAS) to analyse P species in biochar and to determine the effect of pyrolysis temperature on P speciation. The photoacoustic detector has a range of advantages for the very dark biochar samples in comparison to more traditional reflectance or transmission FTIR detectors. The spectra turned out to be more informative in the regions with P vibrations for biochar produced at temperatures above 400°C, where most of the remaining organic compounds were aromatic and therefore not overlapping with the P vibrations. For biochars produced from the solid fraction of digestate from biogas production, an increase in the pyrolysis temperature led to the formation of a large variety of P species. Hydroxylapatite and tricalcium phosphate were the most dominant P species in the mid to high temperature range (600–900°C), while at 1050°C apatite, iron phosphates, variscite and calcium phosphates were identified. However, the changes in P speciation in biochars produced from bone meal at different temperatures were smaller than in the biochars from digestate. Hydroxylapatite and calcium phosphates were identified in biochar produced at all temperatures, while there was some indication of struvite formation.
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•FTIR photoacoustic spectroscopy was capable of identifying P species.•Pyrolysis temperature affected more the P speciation in digestate solids biochars.•Hydroxylapatite and calcium phosphates were the abundant species in bone meal biochars.
Previous studies have demonstrated the feasibility of employing by-products of the olive and wine sectors for the production of
mushrooms with enhanced functionalities. In this work we investigated ...the influence of endogenous and exogenous factors on free amino acids (FAAs) profile of
,
and
mushrooms produced on wheat straw (WS), alone or mixed with grape marc (GM), and on by-products of the olive industry (OL). Overall, 22 FAAs were determined in substrates and mushrooms, including all the essential amino acids, the neurotransmitter γ-aminobutyric acid (GABA) and ornithine. On a dry weight (dw) basis, total FAAs ranged from 17.37 mg/g in
to 130.12 mg/g in
samples, with alanine, leucine, glutamine, valine and serine predominating. Similar distribution patterns were followed by the monosodium glutamate (MSG)-like, sweet and bitter FAAs. Significant differences in FAAs level were observed among the species examined and among the cultivation substrates used. Principal Component Analysis (PCA) performed on the entire FAAs profile of six
strains, clearly separated
from
and
, in accordance to their phylogenetic affinity. This is the first report of FAAs in
Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was used to monitor the infrared absorption spectra of 79 mushroom samples from 29
,
and
strains cultivated on wheat ...straw, grape marc and/or by-products of the olive industry. The spectroscopic analysis provided a chemical insight into the mushrooms examined, while qualitative and quantitative differences in regions related to proteins, phenolic compounds and polysaccharides were revealed among the species and substrates studied. Moreover, by using advanced chemometrics, correlations of the recorded mushrooms' spectra versus their content in glucans and ergosterol, commonly determined through traditional analytical techniques, allowed the development of models predicting such contents with a good predictive power (
: 0.80-0.84) and accuracy (low root mean square error, low relative error and representative to the predicted compounds spectral regions used for the calibrations). Findings indicate that FTIR spectroscopy could be exploited as a potential process analytical technology tool in the mushroom industry to characterize mushrooms and to assess their content in bioactive compounds.
Alterations of gut microbiota are evident during the aging process. Prebiotics may restore the gut microbial balance, with β-glucans emerging as prebiotic candidates. This study aimed to investigate ...the impact of edible mushrooms rich in β-glucans on the gut microbiota composition and metabolites by using in vitro static batch culture fermentations and fecal inocula from elderly donors (n = 8).
,
,
and
mushrooms derived from various substrates were examined. Gut microbiota composition (quantitative PCR (qPCR)) and short-chain fatty acids (SCFAs; gas chromatography (GC)) were determined during the 24-h fermentation.
induced a strong lactogenic effect, while
and
induced a significant bifidogenic effect (
for all <0.05). Furthermore,
produced on wheat straw and the prebiotic inulin had comparable Prebiotic Indexes, while
produced on wheat straw/grape marc significantly increased the levels of tested butyrate producers.
,
and
had similar trends in SCFA profile;
mushrooms were more diverse, especially in the production of propionate, butyrate and branched SCFAs. In conclusion, mushrooms rich in β-glucans may exert beneficial in vitro effects in gut microbiota and/or SCFAs production in elderly subjects.
Globally, more than 30% of soils are poor in phosphorus (P) and the productivity of these soils is severely restricted without the addition of P fertiliser. With future P supplies becoming limited, ...it is becoming increasingly important to identify ways of optimising the use of waste materials as P fertilisers. One technology that has been promoted extensively in recent years to improve quality of degraded soils is the application of biochar. In this context, char produced from recycled animal bone is of special interest because of its high P content (∼15%). This study investigated how production temperature affects chemical P forms in bone char and the impact on soil P availability in different P-deficient soils.
The major P form in dried bone meal was poorly crystalline hydroxyapatite. As the pyrolysis temperature increased to 1050 °C, the hydroxyapatite structure measured with X-ray absorption near edge structure (XANES) spectroscopy persisted. Furthermore, crystallinity increased at temperatures above 750 °C, as revealed by X-ray powder diffraction (XRD). Plant availability was highest for bone char produced between 300 °C and 500 °C in three acidic soils from three continents, and declined rapidly above 750 °C. This strongly indicated that crystallinity of hydroxyapatite limits plant availability at high pyrolysis temperatures. In a high pH soil, all materials resulted in low P availability. As pyrolysis increased the P availability in comparison with dried bone, it was concluded that bone char produced at temperatures between 300 °C and 500 °C has the potential to improve fertility of P-poor, low pH soils.
•The major P form in bone char was hydroxyapatite.•Crystallinity of hydroxyapatite increased with increasing pyrolysis temperature.•Plant P availability was highest for bone char produced between 300 °C and 500 °C.•Hydroxyapatite crystallinity in bone char at high temperatures limits availability.
Solid-state fermentation of various lignocellulosic residues through the use of mushroom fungi leads to the production of edible/medicinal biomass. However, several aspects of this process remain ...obscure, while the potential exploitation of a wide range of agro-industrial wastes as mushroom substrates is of questionable usefulness. This study attempts to develop a fast and inexpensive method based on Fourier transform infrared (FTIR) spectroscopy for (a) determining compositional changes in lignocellulosic wastes used for the cultivation of
Cyclocybe cylindracea
mushrooms, (b) identifying compounds in substrates which are related to enhanced productivity and (c) developing a chemometric model through the use of multivariate analysis to predict biological efficiency in mushroom production process. High prediction scores were obtained (
R
2
CAL
: 0.95,
R
2
CV
: 0.70, RMSE
CV
: 24%), while interpretation of regression coefficients was congruent to results of principal component analysis demonstrating a positive correlation of
C. cylindracea
biological efficiency values to the initial materials content in lignocellulosic compounds, and a negative correlation to their protein and phenolics content. The combined use of FTIR data and chemometrics provides valuable information on structural modifications of major substrate components during
C. cylindracea
growth and fructification, and could be exploited for evaluating substrates’ suitability prior to their use for mushroom cultivation.
A variety of bioactive compounds, constituents of edible mushrooms, in particular β-glucans, i.e., a group of β-d-glucose polysaccharides abundant in the fungal cell walls, have been linked to ...immunomodulating, anticancer and prebiotic activities. The aim of the study was the investigation of the genoprotective effects of edible mushrooms produced by
,
and
(Basidiomycota). Mushrooms from selected strains of the species mentioned above were fermented in vitro using faecal inocula from healthy volunteers. The cytotoxic and anti-genotoxic properties of the fermentation supernatants (FSs) were investigated in Caco-2 human colon adenocarcinoma cells. The FSs were cytotoxic in a dose-dependent manner. Non-cytotoxic concentrations were used for the genotoxicity studies, which revealed that mushrooms' FSs have the ability to protect Caco-2 cells against tert-butyl hydroperoxide (
-BOOH), a known genotoxic agent. Their global metabolic profiling was assessed by
H-NMR spectroscopy. A total of 37 metabolites were identified with the use of two-dimensional (2D) homo- and hetero-nuclear NMR experiments. Multivariate data analysis monitored the metabolic variability of gut microbiota and probed to biomarkers potentially associated with the health-promoting effects of edible mushrooms.
In this letter we study the mean sizes of H clumps in turbulent disk galaxies relative to kinematics, gas fractions, and Toomre Q. We use ∼100 pc resolution HST images, IFU kinematics, and gas ...fractions of a sample of rare, nearby turbulent disks with properties closely matched to main-sequence galaxies (the DYNAMO sample). We find linear correlations of normalized mean clump sizes with both the gas fraction and the velocity dispersion-to-rotation velocity ratio of the host galaxy. We show that these correlations are consistent with predictions derived from a model of instabilities in a self-gravitating disk (the so-called "violent disk instability model"). We also observe, using a two-fluid model for Q, a correlation between the size of clumps and self-gravity-driven unstable regions. These results are most consistent with the hypothesis that massive star-forming clumps in turbulent disks are the result of instabilities in self-gravitating gas-rich disks, and therefore provide a direct connection between resolved clump sizes and this in situ mechanism.
The influence of genetic (species, strain) and environmental (substrate) factors on the volatile profiles of eight strains of Pleurotus eryngii and P. ostreatus mushrooms cultivated on wheat straw or ...substrates enriched with winery or olive oil by products was investigated by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). Selected samples were additionally roasted. More than 50 compounds were determined in fresh mushroom samples, with P. ostreatus presenting higher concentrations but a lower number of volatile compounds compared to P. eryngii. Roasting resulted in partial elimination of volatiles and the formation of pyrazines, Strecker aldehydes and sulfur compounds. Principal component analysis on the data obtained succeeded to discriminate among raw and cooked mushrooms as well as among Pleurotus species and strains, but not among different cultivation substrates. Ketones, alcohols and toluene were mainly responsible for discriminating among P. ostreatus strains while aldehydes and fatty acid methyl esters contributed more at separating P. eryngii strains.
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