Hydrophilic compounds in liquids of enzymatic hydrolyzed spruce and pine biomass.

This study was focused on organic acids and metals in biofluids of wood. Without seasoning, fresh woods from spruce and bark, phloem, and heartwood from pine were used as materials, which were degraded with either microbes of oyster mushroom, baker's yeast, or lactic acid bacteria. Due to neutral pH of the fluids, ambient temperature, atmospheric pressure, and short reaction time, native wood microbe populations were supposed to be present. The water content of the fresh woods was 4 to 20%. The study showed that process methodology and experimental conditions affected the generation of lactic, citric, succinic, and adipic acids, which are considered as source chemicals in the biopolymer industry. In addition to the organic acids and metals, the process produced monosaccharides, polysaccharides, and phenolic acids such as benzoic, salicylic, cinnamic, vanillic, tannic, and conifer (ferulic) acids. Concentrations of total acids and acetic and succinic acids in pine fluids from bark, phloem, and heartwood were 58.4 g/kg and 3.5 to 6.9 g/kg, respectively. In spruce, the most dominant acids were l-lactic and l-malic acids. As for metals, Ag and Cr were detected at 0.01-g/kg quantities in pine bark. Alkali metals K, Mg, Sr, and Ca were detected at 10, 8, 1.3, and 4 g/kg, respectively.