Fig 1.
Schematic representation of sampling.
Table 1.
Mass balance of dry matter and organic matter and structural components (carbohydrates, nitrogen, lignin and ash) in the compost during composting and mycelium growth.
BM: basic mixture; PI: compost after Phase I; PII: compost after Phase II; PIII–16: compost after 16 days of mycelium growth for batch A.
Fig 2.
Identities of lignin-derived phenolic S (syringyl-like) and G (guaiacyl-like) compounds identified with Py-GC/MS and relative molar area higher than 1% in wheat straw (out of total S+G molar area).
aInterpretation based on pure compounds. bInterpretation based on Ralph and Hatfield (1991), reverse search of compound in compost or WUS versus compound in wheat straw: 34S>99%, 42S>97%, 49S>99%. RS = reverse search
Table 2.
Carbohydrate, ash, nitrogen, Klason lignin and dry matter content (based on dry matter) for compost after PI, PII and PIII–16. BM: basic mixture; PI: compost after Phase I; PII: compost after Phase II; PIII–16: compost after 16 days of mycelium growth; A, B, C different batches.
Fig 3.
Mass balance of constituent monosaccharides during composting and mycelium growth for batch A and B (BM, PI, PII, PIII–16). BM = basic mixture, PI = compost after Phase I, PII = compost after Phase II, PIII–16 = compost after 16 days of mycelium growth; Rha = ramnosyl, Ara = arabinosyl, Xyl = xylosyl, Man = mannosyl, Gal = galactosyl, Glc = glucosyl, UA = uronyl.
aCalculation was performed based on 1000 kg of DM using values presented in Tables 1 and 4.
Table 3.
Carbohydrate composition (mol%) and degree of substitution of xylan in different compost phases, based on dry matter.
BM: basic mixture; PI: compost after Phase I; PII: compost after Phase II; PIII–16: compost after 16 days of mycelium growth.
Table 4.
Relative pyrogram area (%) and Py-GC/MS pyrogram based lignin for wheat straw and different compost phases for batch A.
BM: basic mixture; PI: compost after Phase I; PII: compost after Phase II; PIII–16: compost after 16 days of mycelium growth.
Fig 4.
Py-GC/MS pyrograms of wheat straw, basic compost mix (BM) and compost after 16 days of mycelium growth (PIII–16) (A) and water un-extractable solids (WUS) of Phase I and PIII–16 (B) for batch A.
The identities and structures of main syringyl and guaiacyl (and p-hydroxyphenyl) compounds are listed in Fig 2, S1 Table and S2 Table. PI: compost after Phase I: PII: compost after Phase II.
Fig 5.
S:G ratio (A) and distribution of syringyl (S) and guaiacyl (G) units (B), based on molar area, of wheat straw (WS) and total compost samples during composting BM, PI, PII and mycelium growth PIII–16 and in water insoluble compost PIwus, PIII-16wus.
Rest S* and Rest G* S2 Table, BM: basic mixture; PI: compost after Phase I: PII: compost after Phase II; PIII–16: compost after 16 days of mycelium growth, A and B are biological duplicates and each sample measurement was performed in quadruplicates.