Improvement of lignocellulosic biomass conversion by optimization of fungal ligninolytic enzyme activity and molasses stillage supplementation

Fungal treatment of lignocellulose is an ecologically and economically acceptable method. However, it needs improvement to increase the hydrolysis rate. A novel combination of multiple response optimization of ligninolytic activity ofTrametes hirsutaF13 and supplementation of the lignocellulosic substrate (beechwood sawdust) with sugar beet molasses stillage was employed to improve and manage the desired type of fungal ligninolytic activity leading to a significant enhancement of biomass saccharification. Obtained optimal cultivation conditions (molasses stillage concentration, 13%; substrate moisture, 63%; and temperature, 25 degrees C) provided the desired combination of laccase and manganese-dependent peroxidase activity, and maintained the activities longer and at higher values (51.5 +/- 3.5 U/L and 91 +/- 4.24 U/L, respectively) than the conditions without molasses stillage (21.5 +/- 2.12 U/L and 31.5 +/- 4.9 U/L, respectively). Enzyme hydrolysis of the substrate treated for 7 days in the presence of molasses stillage released 20.54 +/- 0.80 mg/mL fermentable sugars, and 63.58 +/- 1.47 mg/mL from 18-days treated substrate, while sugar concentrations released from the substrates pretreated without the supplementation were 16.84 +/- 0.30 mg/mL and 53.63 +/- 2.16 mg/mL, respectively. The proposed new approach of the lignocellulose supplementation with sugar beet molasses stillage and manipulation and improvement of fungal ligninolytic activity proved to be a promising solution for the enhancement of lignocellulose bioconversion

Rab11 activity and PtdIns(3)P turnover removes recycling cargo from endosomes

Directional transport of recycling cargo from early endosomes (EE) to the endocytic recycling compartment (ERC) relies on phosphatidylinositol 3-phosphate (PtdIns(3)P) hydrolysis and activation of the small GTPase Rab11. However, how these events are coordinated is yet unclear. By using a novel genetically-encoded FRET biosensor for Rab11, we report that generation of endosomal PtdIns(3)P by the clathrin-binding phosphoinositide 3-kinase class 2 alpha (PI3K-C2 alpha) controls the activation of Rab11. Active Rab11, in turn, prompts the recruitment of the phosphatidylinositol 3-phosphatase myotubularin 1 (MTM1), eventually enabling the release of recycling cargo from the EE and its delivery toward the ERC. Our findings thus define that delivery of recycling cargo toward the ERC requires spatial and sequential coupling of Rab11 activity with PtdIns(3)P turnover

Examining the Effects of the Destroying Ammunition, Mines and Explosive Devices on the Presence of Heavy Metals in Soil of Open Detonation Pit; Part 2: Determination of Heavy Metal Fractions

As a result of the destruction of ammunition, mines, and explosive devices by the method of open detonation, the increased concentration of heavy metals is often recorded in the soil of military polygons, which is a serious ecological problem. However, in order to determine the potential risk of such locations to the environment, it is necessary to determine, in addition to the total content, the forms in which the metals are present. In this paper, a sequential extraction method was used to analyze the six fractions of five heavy metals (cadmium, lead, nickel, copper, and zinc) in the soil of the polygon for destruction of ammunition, mines, and explosive devices. Samples were collected from the place of direct detonation (so-called pits) and from the edge of the pit. The aim of this research is determination of metal speciation in order to obtain a better insight in their mobility and risk arising from this. The results showed that heavy metals are predominantly present in the residual, oxide, and organic fractions. Cd and Cu were also significantly present in the mobile fractions due to conducted activities on the polygon. To assess the potential environmental risk of soil, the risk assessment code (RAC) and individual (ICF) and global (GCF) contamination factors were used. According to the RAC, the mobility and bioavailability of the analyzed heavy metals decreases in the following order: Cd gt Cu gt Zn gt Pb gt Ni. ICF results show low to moderate risk, while GCF results show low risk in terms of heavy metal contamination in the examined area