The secretome of Agaricus bisporus: Temporal dynamics of plant polysaccharides and lignin degradation

Despite substantial lignocellulose conversion during mycelial growth, previous transcriptome and proteome studies have not yet revealed how secretomes from the edible mushroom Agaricus bisporus develop and whether they modify lignin models in vitro. To clarify these aspects, A. bisporus secretomes collected throughout a 15-day industrial substrate production and from axenic lab-cultures were subjected to proteomics, and tested on polysaccharides and lignin models. Secretomes (day 6-15) comprised A. bisporus endo-acting and substituent-removing glycoside hydrolases, whereas β-xylosidase and glucosidase activities gradually decreased. Laccases appeared from day 6 onwards. From day 10 onwards, many oxidoreductases were found, with numerous multicopper oxidases (MCO), aryl alcohol oxidases (AAO), glyoxal oxidases (GLOX), a manganese peroxidase (MnP), and unspecific peroxygenases (UPO). Secretomes modified dimeric lignin models, thereby catalyzing syringylglycerol-β-guaiacyl ether (SBG) cleavage, guaiacylglycerol-β-guaiacyl ether (GBG) polymerization, and non-phenolic veratrylglycerol-β-guaiacyl ether (VBG) oxidation. We explored A. bisporus secretomes and insights obtained can help to better understand biomass valorization

Fruit and vegetable consumption and its contribution to inequalities in life expectancy and disability-free life expectancy in ten European countries

ObjectivesTo assess to what extent educational differences in total life expectancy (TLE) and disability-free life expectancy (DFLE) could be reduced by improving fruit and vegetable consumption in ten European countries.MethodsData from national census or registries with mortality follow-up, EU-SILC, and ESS were used in two scenarios to calculate the impact: the upward levelling scenario (exposure in low educated equals exposure in high educated) and the elimination scenario (no exposure in both groups). Results are estimated for men and women between ages 35 and 79years.ResultsVarying by country, upward levelling reduced inequalities in DFLE by 0.1-1.1years (1-10%) in males, and by 0.0-1.3years (0-18%) in females. Eliminating exposure reduced inequalities in DFLE between 0.6 and 1.7years for males (6-15%), and between 0.1years and 1.8years for females (3-20%).ConclusionsUpward levelling of fruit and vegetable consumption would have a small, positive effect on both TLE and DFLE, and could potentially reduce inequalities in TLE and DFLE.Peer reviewe

Data from: The scope for nuclear selection within Termitomyces fungi associated with fungus-growing termites is limited

Background: We investigate the scope for selection at the level of nuclei within fungal individuals (mycelia) of the mutualistic Termitomyces cultivated by fungus-growing termites. Whereas in most basidiomycete fungi the number and kind of nuclei is strictly regulated to be two per cell, in Termitomyces mycelia the number of nuclei per cell is highly variable. We hypothesised that natural selection on these fungi not only occurs between mycelia, but also at the level of nuclei within the mycelium. We test this hypothesis using in vitro tests with five nuclear haplotypes of a Termitomyces species. Results: First, we studied the transition from a mixture of five homokaryons (mycelia with identical nuclei) each with a different nuclear haplotype to heterokaryons (mycelia with genetically different nuclei). In vitro cultivation of this mixture for multiple asexual transfers led to the formation of multiple heterokaryotic mycelia, and a reduction of mycelial diversity over time. All heterokaryotic mycelia contained exactly two types of nucleus. The success of a heterokaryon during in vitro cultivation was mainly determined by spore production and to a lesser extent mycelial growth rate. Second, heterokaryons invariably produced more spores than homokaryons implying that homokaryons will be outcompeted. Third, no homokaryotic ‘escapes’ from a heterokaryon via the formation of homokaryotic spores were found, despite extensive spore genotyping. Fourth, in contrast to most studied basidiomycete fungi, in Termitomyces sp. no nuclear migration occurs during mating, limiting the scope for nuclear competition within the mycelium. Conclusions: Our experiments demonstrate that in this species of Termitomyces the scope for selection at the level of the nucleus within an established mycelium is limited. Although ‘mate choice’ of a particular nuclear haplotype is possible during mating, we infer that selection primarily occurs between mycelia with two types of nucleus (heterokaryons)

Genetic variation and combining ability analysis of bruising sensitivity in Agaricus bisporus.

Advanced button mushroom cultivars that are less sensitive to mechanical bruising are required by the mushroom industry, where automated harvesting still cannot be used for the fresh mushroom market. The genetic variation in bruising sensitivity (BS) of Agaricus bisporus was studied through an incomplete set of diallel crosses to get insight in the heritability of BS and the combining ability of the parental lines used and, in this way, to estimate their breeding value. To this end nineteen homokaryotic lines recovered from wild strains and cultivars were inter-crossed in a diallel scheme. Fifty-one successful hybrids were grown under controlled conditions, and the BS of these hybrids was assessed. BS was shown to be a trait with a very high heritability. The results also showed that brown hybrids were generally less sensitive to bruising than white hybrids. The diallel scheme allowed to estimate the general combining ability (GCA) for each homokaryotic parental line and to estimate the specific combining ability (SCA) of each hybrid. The line with the lowest GCA is seen as the most attractive donor for improving resistance to bruising. The line gave rise to hybrids sensitive to bruising having the highest GCA value. The highest negative SCA possibly indicates heterosis effects for resistance to bruising. This study provides a foundation for estimating breeding value of parental lines to further study the genetic factors underlying bruising sensitivity and other quality-related traits, and to select potential parental lines for further heterosis breeding. The approach of studying combining ability in a diallel scheme was used for the first time in button mushroom breeding

data on mycelial growth, nodulation and genotyping

The file contains data on Termitomyces mycelial growth rate and asexual spore yield, and on genotyping data from the mixing experiment

a. Boxplots describing variation in cap whiteness for each hybrid classified as white (flush 1).

<p>he box spans the interquartile range of the values of cap whiteness of each hybrid, so that the middle 50% of the data lie within the box, with a line indicating the median. Whiskers extend beyond the ends of the box as far as the minimum and maximum values. The crosses indicate outliers. The cap whiteness of these hybrids were measured based on 20 individual mushrooms of flush 1 per hybrid. Long boxes indicate large variation of cap whiteness, and short boxes indicate small variation of cap color. By comparing <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076826#pone-0076826-g008" target="_blank">Figure 8a and Figure 8b</a> individual mushrooms of non-white hybrids show larger difference of cap color than that of white hybrids. b. Boxplots describing variation in cap whiteness for each hybrid classified as non-white (flush 1).</p