Biosolubilization of Polish Chemically Oxidated Brown Coal

Optimization of weathered coal biodegradation by Penicillium aculeatum 13-2-1 and UV-visible spectral characteristics of active degraded products

“…In particular, the appearance of chief peaks in the range 220 to 330 nm indicated the presence of aromatic and humic materials released from coals under the fungal attack (Sabar et al 2019), while the absorbance strength of the released organics in the coal-containing control (HWP) was only detectable at about 240 nm. For the combination of A1B3C3, A2B2C3, and A3B1C3, absorbance at about 240 and 300 nm indicated that alkyl substituted unsaturated aldehyde and ketone compounds and probable hydrophilic humic contents were present in the biosolubilisation products of weathered coal, which might be attributed to the coal bioconversion by phenol-oxidases of fungus (Tao et al 2009) and the solubility of waterbased media (Haider et al 2015) or alkaline compounds produced by fungus (Miszkiewicz et al 2016), respectively. For those of A1B1C1, A2B3C1, and A3B2C1, absorbance at about 230 and 250 nm implied that most probably low-molecular-weight phenolic compounds (Yakimenko et al 2018) and unconjugated phenolic lignin (Gärtner and Gellerstedt 1999) appeared in the biosolubilisation products, which might be ascribed to the coal lignin decomposition through microbial extracellular enzymes-lignin peroxidase, manganese peroxidase, laccase, or others (Reid 1995;Kamimura et al 2019).…”