Comparative Study on Two Commercial Strains of Saccharomyces cerevisiae for Optimum Ethanol Production on Industrial Scale

Two commercial strains of Saccharomyces cerevisiae, Saf-Instant (Baker's yeast) and Ethanol red (Mutant) were compared for ethanol production during hot summer season, using molasses diluted up to 6-7° Brix containing 4%-5% sugars. The yeasts were propagated in fermentation vessels to study the effects of yeast cell count and varying concentrations of Urea, DAP, inoculum size and Lactrol (Antibiotic). Continuous circulation of mash was maintained for 24 hours and after this fermenter was allowed to stay for a period of 16 hours to give time for maximum conversion of sugars into ethanol. Saccharomyces cerevisiae strain (Saf-instant) with cell concentration of 400 millions/mL at molasses sugar level of 13%–15% (pH 4.6 ± 0.2, Temp. 32°C ± 1), inoculum size of 25% (v/v), urea concentration, 150 ppm, DAP, 53.4 ppm and Lactrol,150 ppm supported maximum ethanol production (8.8%) with YP/S = 250 L ethanol per tone molasses (96.5% yield), and had significantly lower concentrations of byproducts. By selecting higher ethanol yielding yeast strain and optimizing the fermentation parameters both yield and economics of the fermentation process can be improved

Ethylene signaling under stressful environments: analyzing collaborative knowledge

Ethylene is a gaseous plant growth hormone that regulates various plant developmental processes, ranging from seed germination to senescence. The mechanisms underlying ethylene biosynthesis and signaling involve multistep mechanisms representing different control levels to regulate its production and response. Ethylene is an established phytohormone that displays various signaling processes under environmental stress in plants. Such environmental stresses trigger ethylene biosynthesis/action, which influences the growth and development of plants and opens new windows for future crop improvement. This review summarizes the current understanding of how environmental stress influences plants’ ethylene biosynthesis, signaling, and response. The review focuses on (a) ethylene biosynthesis and signaling in plants, (b) the influence of environmental stress on ethylene biosynthesis, (c) regulation of ethylene signaling for stress acclimation, (d) potential mechanisms underlying the ethylene-mediated stress tolerance in plants, and (e) summarizing ethylene formation under stress and its mechanism of action

In silico-designed lignin peroxidase from Phanerochaete chrysosporium shows enhanced acid stability for depolymerization of lignin

Background: The lignin peroxidase isozyme H8 from the white-rot fungus Phanerochaete chrysosporium (LiPH8) demonstrates a high redox potential and can efficiently catalyze the oxidation of veratryl alcohol, as well as the degradation of recalcitrant lignin. However, native LiPH8 is unstable under acidic pH conditions. This characteristic is a barrier to lignin depolymerization, as repolymerization of phenolic products occurs simultaneously at neutral pH. Because repolymerization of phenolics is repressed at acidic pH, a highly acid-stable LiPH8 could accelerate the selective depolymerization of recalcitrant lignin. Results: The engineered LiPH8 was in silico designed through the structural superimposition of surface-active site-harboring LiPH8 from Phanerochaete chrysosporium and acid-stable manganese peroxidase isozyme 6 (MnP6) from Ceriporiopsis subvermispora. Effective salt bridges were probed by molecular dynamics simulation and changes to Gibbs free energy following mutagenesis were predicted, suggesting promising variants with higher stability under extremely acidic conditions. The rationally designed variant, A55R/N156E-H239E, demonstrated a 12.5-fold increased half-life under extremely acidic conditions, 9.9-fold increased catalytic efficiency toward veratryl alcohol, and a 7.8-fold enhanced lignin model dimer conversion efficiency compared to those of native LiPH8. Furthermore, the two constructed salt bridges in the variant A55R/N156E-H239E were experimentally confirmed to be identical to the intentionally designed LiPH8 variant using X-ray crystallography (PDB ID: 6A6Q). Conclusion: Introduction of strong ionic salt bridges based on computational design resulted in a LiPH8 variant with markedly improved stability, as well as higher activity under acidic pH conditions. Thus, LiPH8, showing high acid stability, will be a crucial player in biomass valorization using selective depolymerization of lignin

Continuous fungal treatment of non-sterile veterinary hospital effluent: pharmaceuticals removal and microbial community assessment

Source point treatment of effluents with a high load of pharmaceutical active compounds (PhACs), such as hospital wastewater, is a matter of discussion among the scientific community. Fungal treatments have been reported to be successful in degrading this type of pollutants and, therefore, the white-rot fungus Trametes versicolor was applied for the removal of PhACs from veterinary hospital wastewater. Sixty-six percent removal was achieved in a non-sterile batch bioreactor inoculated with T. versicolor pellets. On the other hand, the study of microbial communities by means of DGGE and phylogenetic analyses led us to identify some microbial interactions and helped us moving to a continuous process. PhAC removal efficiency achieved in the fungal treatment operated in non-sterile continuous mode was 44 % after adjusting the C/N ratio with respect to the previously calculated one for sterile treatments. Fungal and bacterial communities in the continuous bioreactors were monitored as well.Authors want to acknowledge the UAB veterinary hospital staff for their kind permission and help for the samplings. This work has been funded by the Spanish Ministry of Economy and Competitiveness and FEDER (projects CTM2013-48545-C2 and AIB2010PT-00169) and supported by the Generalitat de Catalunya (Consolidated Research Groups 2014-SGR-476 and 2014-SGR-291). The Department of Chemical Engineering of the Universitat Autonoma de Barcelona (UAB) is a member of the Xarxa de Referencia en Biotecnologia de la Generalitat de Catalunya. M. Badia-Fabregat and D. Lucas acknowledge the predoctoral grants from UAB and from the Spanish Ministry of Education, Culture and Sports (AP-2010-4926), respectively. The authors also thank the Portuguese Foundation for Science and Technology (FCT) Strategic Project PEst-OE/EQB/LA0023/2013, Project FCOMP-01-0124-FEDER-027462 co-funded by Operational Competitiveness Programme, FEDER, and Project "BioEnv-Biotechnology and Bioengineering for a sustainable world," REF. NORTE-07-0124-FEDER-000048, co-funded by Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER

Stability Analysis of Charged Rotating Black Ring

We study the electromagnetic field equation along with the WKB approximation. The boson tunneling phenomenon from charged rotating black ring(CRBR) is analyzed. It is examined that reserve radiation consistent with CRBR can be computed in general by neglecting back reaction and self-gravitational of the radiated boson particle. The calculated temperature depends upon quantum gravity and CRBR geometry. We also examine the corrected tunneling rate/probability of boson particles by assuming charge as well as energy conservation laws and the quantum gravity. Furthermore, we study the graphical behavior of the temperature and check the stability and instability of CRBR.Comment: 7 pages, 2 figures, version accepted for publication in Symmetr

Harnessing the potential of ligninolytic enzymes for lignocellulosic biomass pretreatment

Abundant lignocellulosic biomass from various industries provides a great potential feedstock for the production of value-added products such as biofuel, animal feed, and paper pulping. However, low yield of sugar obtained from lignocellulosic hydrolysate is usually due to the presence of lignin that acts as a protective barrier for cellulose and thus restricts the accessibility of the enzyme to work on the cellulosic component. This review focuses on the significance of biological pretreatment specifically using ligninolytic enzymes as an alternative method apart from the conventional physical and chemical pretreatment. Different modes of biological pretreatment are discussed in this paper which is based on (i) fungal pretreatment where fungi mycelia colonise and directly attack the substrate by releasing ligninolytic enzymes and (ii) enzymatic pretreatment using ligninolytic enzymes to counter the drawbacks of fungal pretreatment. This review also discusses the important factors of biological pretreatment using ligninolytic enzymes such as nature of the lignocellulosic biomass, pH, temperature, presence of mediator, oxygen, and surfactant during the biodelignification process

Copyright in Academia

A presentation by Tim Bowen and Karen Melanson of the Copyright Clearance Center

Gender and contemporary risk of adverse events in atrial fibrillation

Background and Aims: The role of gender in decision-making for oral anticoagulation in patients with atrial fibrillation (AF) remains controversial.Methods: Population cohort study using electronic healthcare records of 16,587,749 patients from UK primary care (2005-2020). Primary (composite of all-cause mortality, ischaemic stroke or arterial thromboembolism) and secondary outcomes were analysed using Cox hazard ratios (HR), adjusted for age, socioeconomic status and comorbidities.Results: 78,852 patients were included with AF, age 40-75 years, no prior stroke and no prescription of oral anticoagulants. 28,590 (36.3%) were women and 50,262 (63.7%) men. Median age was 65.7 years (interquartile range 58.5-70.9) with women being older and other differences in comorbidities. During total follow-up of 431,086 patient-years, women had a lower adjusted primary outcome rate with HR 0.89 vs men (95% CI 0.87-0.92; p&lt;0.001), and HR 0.87 after censoring for oral anticoagulation (95% CI 0.83-0.91; p&lt;0.001). This was driven by lower mortality in women (HR 0.86, 0.83-0.89; p&lt;0.001). No difference was identified between women and men for the secondary outcomes of ischaemic stroke or arterial thromboembolism (adjusted HR 1.00, 0.94-1.07; p=0.87), any stroke or any thromboembolism (1.02, 0.96-1.07; p=0.58), and incident vascular dementia (1.13, 0.97-1.32; p=0.11). Clinical risk scores were only modest predictors of outcomes, with CHA2DS2-VA (ignoring gender) superior to CHA2DS2-VASc for primary outcomes in this population (receiver operator curve area 0.651 vs 0.639; p&lt;0.001), and no interaction with gender (p=0.45).Conclusions: Removal of gender from clinical risk scoring could simplify the approach to which patients with AF should be offered oral anticoagulation.  <br/