Strain Improvement of Native Saccharomyces cerevisiae LN ITCC 8246 Strain Through Protoplast Fusion To Enhance Its Xylose Uptake

Abstract

Co-utilization of xylose and glucose and subsequent fermentation using Saccharomyces cerevisiae could enhance ethanol productivity. Directed engineering approaches have met with limited success due to interconnectivity of xylose metabolism with other intrinsic, hidden pathways. Therefore, random approaches like protoplast fusion were used to reprogram unidentified mechanisms.Saccharomyces cerevisiae LN, the best hexose fermenter, was fused with xylose fermenting Pichia stipitis NCIM 3498. Protoplasts prepared using glucanex were fused under electric impulse and fusants were selected using 10% ethanol and cycloheximide (50 ppm) markers. Two fusants, 1a.23 and 1a.30 showing fast growth on xylose and tolerance to 10% ethanol, were selected. Higher extracellular protein expression observed in fusants as compared to parents was corroborated by higher number of bands resolved by twodimensional analysis.Overexpression of XYL1, XYL2, XKS and XUT4 in fusants as compared to S. cerevisiae LN as observed by RT-PCR analysis was substantiated by higher specific activities of XR, XDH and XKS enzymes in fusants. During lignocellulosic hydrolysate fermentation, fusants could utilize glucose faster than the parent P. stipitis NCIM 3498 and xylose consumption in fusants was higher than S. cerevisiae LN.

Detannification of Ananas comosus Rinds Juice with Tnnase Immobilized on the Beads of Chrysophyllum albidum Seeds

“…Optimum numbers of beads were used in a repeated batch cycle to study the effect of reusability on Ananas comosus rinds juice, tannase activity was assayed as describe by Sharmal et al, 9 . At the end of each batch, the beads were washed in phosphate buffer (pH 7.0), dried, and used for the next batch.…”

Use of Plant Regulators for Activation of Antioxidant Enzymes in Basil Plants under Water Deficit Conditions

“…The increase in CAT enzyme activity in the basil plants with a water deficit and that were subjected to the application of the mixture of plant regulators shows that these help in the elimination of H2O2, which consequently becomes effective for water stress resistance [36]. CAT then acts in conjunction with other antioxidant enzymes to prevent the oxidative stress produced at the site of infection [37]. In the second evaluation, carried out at 35 DAT (Figure 2B), CAT activity in the plants with a water deficit was inverse, showing lower enzymatic activity when plant regulator doses were applied.…”

Variability of Functional Groups of Rhizosphere Fungi of Norway Spruce (Picea abies (L.) H.Karst.) in the Boreal Range: The Wigry National Park, Poland

“…The rhizosphere microbiome changes and adapts to current environmental conditions, i.e., biotic and abiotic stress [ 21 , 22 , 23 ]. In the early stages of plant growth, when there is a poor root density, the fungal community is dominated by species with relatively long hyphae and fast growth (e.g., the genera Cenococcum , Cortinarius , Inocybe , Laccaria , Scleroderma , Sebacina , Thelephora i Tomentella , and the order Pezizales) [ 24 ].…”