Complementary substrate‐selectivity of metabolic adaptive convergence in the lignocellulolytic performance by Dichomitus squalens

Abstract

The lignocellulolytic platform of the wood-decaying organism Dichomitus squalens is important for production of biodegradable elements; however, the system has not yet been fully characterized. In this study, using statistical target optimization, we analysed substrate selectivity based on a variety of D. squalens metabolic pathways using combined omics tools. As compared with the alkali-lignin (AL) programme, the rice straw (RS) programme has the advantage of multilayered signalling to regulate cellulolytic-related genes or to connect their pathways. The spontaneous instability of the AL programme was accelerated by harsh starvation as compared with that of the RS programme. Therefore, the AL programme converged on cellular maintenance much easier and more rapidly. However, regardless of external substrate/concentration type, the compensatory pattern of the major targets (especially peroxidases and growth regulators) was similar, functioning to maintain cellular homeostasis. Interestingly, ligninolytic-mediated targets under non-kaleidoscopic conditions were induced by a substrate-input-control, and especially this mechanism had an important effect on the early stages of the biodegradation process. This optimized target analysis could be used to understand lignocellulolytic network and to improve downstream efficiency.

Electron beam irradiation enhances the digestibility and fermentation yield of water-soaked lignocellulosic biomass

“…2 ). Furthermore, 9.8 g (62.0% of maximum) of ethanol in a statistical-based optimal biosystem was finally obtained after 144 h of SSF [3] , which was not more than the WEBI-level (10.6 g; 67.1% of maximum; Fig. 2 ).…”

Process evaluation of electron beam irradiation-based biodegradation relevant to lignocellulose bioconversion

“…Under drastic starvation (or the presence of recalcitrant substrates), it means that fungal cells should not make any more a needless waste of metabolic pathways, probably due to the homeostasis to fulfill the heavy energy expenditure. Furthermore, self-regulated fungal biodegradation may maintain their stability and effectiveness as a complementary manner (Bak, 2014 a). In addition, the demand of cellular equilibrium and defense against the external stresses may not keep any more lignocellulolytic convergence, and thus can be predicted in the limited improvement of % theoretical yield (Figure 1 and Table 1 ).…”

Effective inactivation of Saccharomyces cerevisiae in minimally processed Makgeolli using low-pressure homogenization-based pasteurization

“…Based on a previously reported protocol (i.e., extracellular metabolic profiling; Bak 2014 ), downstream odor-active chemicals, as classified by the National Institute of Standards and Technology database ( http://webbook.nist.gov/chemistry/ ), in Makgeolli suspensions were analyzed using a quadrupole 5975/7890 mass analyzer (Agilent Technologies, Waldbronn, Germany) with DB-5MS column (J&W Scientific, Folsom, CA). After preprocessing for mass spectrometry (Additional file 1 ), based on a previously confirmed procedure with minor modifications (Bak 2014 ; Park et al 2013 ), the GC-MS profiles were as follows: 40°C for 5 min, 5°C/min to 130°C, 15°C/min to 220°C with holding for 1 min, 2.5°C/min to 265°C with holding for 1 min, 10°C/min to 280°C with holding for 1 min, 1°C/min to 290°C, and 10°C/min to 300°C. Further details are provided in Additional file 1 .…”