Biochemical, functional and antioxidant potential of higher fungi cultivated on agro-industrial residues. Part Ⅱ: Cultures on mixtures of spent mushroom substrates and mushroom cropping by-products

Novel substrates consisted of different fresh agro-industrial residues,their corresponding and commercial spent mushroom substrates(i.e.SMS deriving from laboratory-scale experiments and SMS deriving from industrial-scale experiments by Green Zin S.A.-SMS GZ)and Pleurotus waste(PW;stipes/mishappen mushrooms)were used in blends for a new cultivation cycle of Pleurotus ostreatus and P.eryngii mushrooms in bags.Their impact on the biochemical properties(intra-cellular polysaccharides-IPSs,protein,lipid,total phenolic compounds-TPCs,individual carbohydrates composition of the IPSs)in the first-and second-flush whole mushrooms,pilei and stipes,as well as the fatty acids composition,the antioxidant activity(in the first-flush mushroom parts)and glucan content of stipes were examined.Both species produced satisfactory IPSs quantities in all substrates(28.69-46.38%,w/w)and significant protein amounts(18.37-26.80%,w/w).The further SMS addition(80%,w/w instead of 40%,w/w)in the cultivation substrates affected positively the mushroom IPSs values,whereas the highest protein content was detected in mushroom’s parts cultivated on substrates consisted of fresh agro-industrial residues.Mushroom’s lipid content was affected differently by the various substrate combinations,with SMS presence resulting in mushrooms with a lower fat content than those produced in substrates with PW addition.Fresh substrates with PW and those with coffee residue were the most favorable for TPCs production.Regarding production flushes,the nutritional value of mushrooms was comparable between them,only a slight increase in TPCs of second-flush carposomes was detected.Glucose was the predominant monosaccharide of the produced IPSs,combined with a significant production of total and β-glucans.SMSs and PW addition had a positive impact on antioxidant activity,too.A higher quantity of lipids,TPCs and significant antioxidant activity were detected in all Pleurotus pilei than stipes,whereas the latter were richer in IPSs.Both pilei and stipes had a significant protein amount.Hence,the data obtained by this study support the positive effect of different types of SMS and mushroom waste on P.ostreatus and P.eryngii nutritional value.

Comparative proteomics analysis reveals the domesticated Lepista sordida primordium differentiation regulation mechanism and the subsequent different development patterns in the pileus and stipe

The wild Lepista sordida is a kind of precious and rare edible fungus.An excellent strain of it by artificial domestication was obtained,which was high-yield and high in iron content.In this study,high-throughput comparative proteomics was used to reveal the regulatory mechanism of its primordium differentiation in the early fruiting body formation.The mycelium before the primordium differentiation mainly expressed high levels of mitochondrial functional proteins and carbon dioxide concentration regulatory proteins.In young mushrooms,the highly expressed proteins were mainly involved in cell component generation,cell proliferation,nitrogen compound metabolism,nucleotide metabolism,glutathione metabolism,and purine metabolism.The differential regulation patterns of pileus and stipe growth to maturity were also revealed.The highly expressed proteins related to transcription,RNA splicing,the production of various organelles,DNA conformational change,nucleosome organization,protein processing,maturation and transport,and cell detoxification regulated the pileus development and maturity.The proteins related to carbohydrate and energy metabolism,large amounts of obsolete cytoplasmic parts,nutrient deprivation,and external stimuli regulated the stipe development and maturity.Multiple CAZymes regulated nutrient absorption,morphogenesis,spore production,stress response,and other life activities at different growth and development stages.

Utilization of spent substrates and waste products of mushroom cultivation to produce new crops of Pleurotus ostreatus,Pleurotus eryngii and Agaricus bisporus

Five agro-industrial residues,their corresponding spent mushroom substrates(SMS),commercial fresh and spent mushroom compost of Agaricus(SMC)and Pleurotus ostreatus(SMS GZ)cultivation,Pleurotus and Agaricus waste(stipes/mishappen mushrooms)were combined and re-utilized as novel substrates for the cultivation of P.ostreatus,P.eryngii and A.bisporus mushrooms.SMSs/SMC were used up to 40%(treatment 1 and 2),while 20%of mushroom waste were added in fresh and spent substrates(treatment 3 and 4).The impact of different substrates on mycelial growth rate and biomass production was examined.Then,Pleurotus spp.were cultivated on the most promising substrates and essential cultivation aspects(earliness,total mushroom yield,biological efficiency-BE)and carposomes’quality parameters(weight,morphological characteristics)were evaluated.Laccase and endoglucanase production by Pleurotus species were also determined at 50 and 100%of colonization stages.All species showed their fastest mycelial growth rate(up to 5 mm/day)on substrates consisted of SMC,whereas many combinations of species/substrate enhanced biomass production.The SMS GZ supplementation positively affected laccase activity;in the cultures of P.ostreatus and P.eryngii the highest values were 62,539 and 17,584 U/g d.w.,respectively.On the contrary,small amounts of endoglucanase were produced(0.007 to 0.322 U/g d.w.);the greatest production was recorded for P.ostreatus at full colonization.Regarding fermentation in bags,significant amount of total mushroom yield was produced in all substrates and those with SMS GZ supported the fastest earliness period and the highest BE for both Pleurotus species.BE values ranged from 54 to 133%for P.ostreatus and from 53 to 121%for P.eryngii.Concerning morphological characteristics,mushroom waste addition seemed to affect them positively.The data included in this paper support the effective re-utilization of different types of SMS and mushroom waste for fungal mass and enzymes’production and for new high quality Pleurotus spp.carposomes.

Cultivating Pleurotus ostreatus and Pleurotus eryngii mushroom strains onagro-industrial residues in solid-state fermentation. Part II: Effect onproductivity and quality of carposomes

The potential of selected Pleurotus ostreatus and P. eryngii wild-type and commercial strains to colonize andproduce carposomes after solid-state fermentation of five substrates constituted of agro-residues namely wheatstraw (WS), beech wood shavings (BWS), coffee residue (CR), barley and oats straw (BOS), rice bark (RB),supplemented with wheat bran was investigated. The effect of substrate composition on bioprocess feasibilitywas assessed for the different strains by quantitative (i.e., mushroom yield and Biological Efficiency-BE %) andcarposome qualitative parameters (i.e., weight, size, colour, firmness). P. ostreatus strains produced carposomesearlier than P. eryngii ones. Early fruiting formation was promoted in WS for P. ostreatus strains, whereas forP. eryngii the lowest values of earliness were observed on BOS substrate. As for crop productivity, P. ostreatusstrain AMRL 150 provided the highest BE (>70%) in all substrates except for RB, while P. ostreatus strain AMRL144 achieved the highest yield and BE in BOS and BWS (75.30 and 64.26%, respectively). P. eryngii stainsproduced less number but heavier carposomes. The highest values of BE% for these strains were recorded on WSand BOS substrates. The BE was further correlated to growth parameters of fungal vegetative phase. As formushroom colour, P. ostreatus were lighter than P. eryngii and BOS substrate promoted lightness in both strains.Firmer P. ostreatus mushrooms were produced at CR. No differences in the whiteness and firmness were detectedamong P. eryngii mushrooms and at any substrate used. The data included in this paper showed that Pleurotusmushrooms can be cultivated on low- or zero-value agro-industrial residues of great financial and environmentalimportance towards the production of value-added food products.