Comparing carriers as a support media of white-rot fungi in natural tannins removal

In the last decades, White-rot Fungi bioremediation potential has been widely investigated, providing remarkable results toward several recalcitrant molecules. However, full-scale applications based on fungi are not employed yet and little is known about their optimal operating conditions, such as (i) their ability to grow without sterile conditions, (ii) co-substrate requirements and (iii) the accurate carrier design for fungal growth. In this study, several batch tests were performed as preliminary steps to evaluate the possible design of a pilot-scale reactor based on fungal biomass to be operated under not-sterile conditions in the removal of Quebracho natural tannin. The tests were performed to verify fungal affinity, including Basidiomycetes and Ascomycetes for innovative cellulose-containing carriers compared to commonly employed PolyUrethane Foam Cubes. In particular, four fungi, including three Basidiomycetes White-rot Fungi, Bjerkandera adusta, Phanerochaete chrysosporium and Tyromyces chioneus and the Ascomycota strain Aspergillus tubingensis, were employed. As a first step, fungi were tested to evaluate their ability to attach and grow onto 12 types of innovative carriers made by High-Density PolyEthylene and containing cellulose in different percentages. Other tests were performed without sterile conditions. In particular, fungal abilities (i) to attach and grow onto two different types of support, including cellulose-containing carrier and polyurethane foam cubes and (ii) to biotransform recalcitrant molecules (Quebracho natural tannin) (iii) to grow and operate synergistically in a consortium of two fungi, were evaluated. The main parameters evaluated were soluble Chemical Oxygen Demand (sCOD) reduction and dry weight increase. Basidiomycetes showed high affinity for cellulose-containing carrierswith the highest cellulose percentage (7%) achieving full colonization and 60% coverage, in sterile conditions and not- sterile conditions, respectively. These results were associated with a Quebracho sCOD removal of 25 ± 4%, without sterility. When combined, the two selected strains, Bjerkandera adusta and Aspergillus tubingensis were able to grow on carriers and to remove up to 15 ± 4% of tannins recalcitrant sCOD. This study provides evidence of (i) Basidiomycetes high affinity for cellulose-containing carriers that could favour fungi attachment in sterile and not-sterile conditions and (ii) the feasibility of a combined use of Ascomycetes and Basidiomycetes in bioremediation

Migration through physical constraints is enabled by MAPK-induced cell softening via actin cytoskeleton re-organization

Cancer cells are softer than the normal cells, and metastatic cells are even softer. These changes in biomechanical properties contribute to cancer progression by facilitating cell movement through physically constraining environments. To identify properties that enabled passage through physical constraints, cells that were more efficient at moving through narrow membrane micropores were selected from established cell lines. By examining micropore-selected human MDA MB 231 breast cancer and MDA MB 435 melanoma cancer cells, membrane fluidity and nuclear elasticity were excluded as primary contributors. Instead, reduced actin cytoskeleton anisotropy, focal adhesion density and cell stiffness were characteristics associated with efficient passage through constraints. By comparing transcriptomic profiles between the parental and selected populations, increased Ras/MAPK signalling was linked with cytoskeleton rearrangements and cell softening. MEK inhibitor treatment reversed the transcriptional, cytoskeleton, focal adhesion and elasticity changes. Conversely, expression of oncogenic KRas in parental MDA MB 231 cells, or oncogenic BRaf in parental MDA MB 435 cells, significantly reduced cell stiffness. These results reveal that MAPK signalling, in addition to tumour cell proliferation, has a significant role in regulating cell biomechanics

Migration through physical constraints is enabled by MAPK-induced cell softening via actin cytoskeleton re-organization

Cancer cells are softer than the normal cells, and metastatic cells are even softer. These changes in biomechanical properties contribute to cancer progression by facilitating cell movement through physically constraining environments. To identify properties that enabled passage through physical constraints, cells that were more efficient at moving through narrow membrane micropores were selected from established cell lines. By examining micropore-selected human MDA MB 231 breast cancer and MDA MB 435 melanoma cancer cells, membrane fluidity and nuclear elasticity were excluded as primary contributors. Instead, reduced actin cytoskeleton anisotropy, focal adhesion density and cell stiffness were characteristics associated with efficient passage through constraints. By comparing transcriptomic profiles between the parental and selected populations, increased Ras/MAPK signalling was linked with cytoskeleton rearrangements and cell softening. MEK inhibitor treatment reversed the transcriptional, cytoskeleton, focal adhesion and elasticity changes. Conversely, expression of oncogenic KRas in parental MDA MB 231 cells, or oncogenic BRaf in parental MDA MB 435 cells, significantly reduced cell stiffness. These results reveal that MAPK signalling, in addition to tumour cell proliferation, has a significant role in regulating cell biomechanics. This article has an associated First Person interview with the first author of the paper

Winery wastewater treatment by microalgae to produce low-cost biomass for energy production purposes

Even though biofuel production from microalgae has become more and more attractive in recent years, it is limited especially by the high cost of microalgae cultivation. However, microalgae can be grown in wastewater in order to reduce their production cost and, at the same time, the polluting impact of wastewaters. Winery wastewaters, which are abundantly released from the wine making process, have a large pollution impact related to their high loads of total solids, chemical oxygen demand (COD) and polyphenol concentration. In this research work a co-culture of Chlorella vulgaris and Arthrospira platensis was used to treat three different winery wastewaters from different steps of the wine production process, in order to produce low-cost biomass intended for biofuel production. Growth of the co-culture and reduction of wastewater pollutant impact were followed by daily determinations of biomass concentration, COD and polyphenol content. The highest productivities of biomass (0.66 gDry Weight/L\ub7day) and lipids (7.10 \ub1 0.22 gLipid/100 L\ub7day) were obtained using 20% of second washing winery wastewater after 4 days of treatment. Moreover, COD and polyphenol content of the three different wastewaters were reduced by the co-culture by more than 92% and 50%, respectively. These results suggest that winery wastewaters can be used successfully for the growth of A. platensis and C. vulgaris co-culture in order to obtain inexpensive biomass for energy production purposes