A REVIEW ON DISSOCIATIVE PERSPECTIVE OF ATTENTION AND CONSCIOUSNESS

Purpose of the study: To answer the two existing controversies regarding attention and consciousness as brain processes. 1) Can one be aware of objects or events without attending to it? 2) Can one attend to objects or events without being aware of it? And also how top-down attention and awareness have opposing functions. Methodology: This article is a systematic review of the relationship between visual attention and awareness. An extensive elaborate study on concepts relating to attention and consciousness dissociation has been done. In this article we also narrow it down to experimental design that requires independent manipulation of each. Which include top-down attention and awareness aspect of consciousness? Main Findings: Many researches have been put forward supporting the independent nature of attention from awareness using sophisticated experimental and physiological shreds of evidence. On the other hand, some researches still stick to the contemporary common-sense notion of no awareness no attention. Our evaluation suggests an independent nature of attention and awareness. Application: This article intends to give a clear perspective of the ongoing debate on the relationship between attention and consciousness. Simplification of both umbrella terms will give basis for building more empirical evidence. Novelty: Further, this article put forward studies on both sides of debate aiming to bridge the gap to get a conclusive outlook in the future

Augmenting Pentose Utilization and Ethanol Production of Native Saccharomyces cerevisiae LN Using Medium Engineering and Response Surface Methodology

Economics of ethanol production from lignocellulosic biomass depends on complete utilization of constituent carbohydrates and efficient fermentation of mixed sugars present in biomass hydrolysates. Saccharomyces cerevisiae, the commercial strain for ethanol production uses only glucose while pentoses remain unused. Recombinant strains capable of utilizing pentoses have been engineered but with limited success. Recently, presence of endogenous pentose assimilation pathway in S. cerevisiae was reported. On the contrary, evolutionary engineering of native xylose assimilating strains is promising approach. In this study, a native strain S. cerevisiae LN, isolated from fruit juice, was found to be capable of xylose assimilation and mixed sugar fermentation. Upon supplementation with yeast extract and peptone, glucose (10%) fermentation efficiency was 78% with ~90% sugar consumption. Medium engineering augmented mixed sugars (5% glucose + 5% xylose) fermentation efficiency to ~50 and 1.6% ethanol yield was obtained with concomitant sugar consumption ~60%. Statistical optimization of input variables Glucose (5.36%), Xylose (3.30%), YE (0.36%), and peptone (0.25%) with Response surface methodology led to improved sugar consumption (74.33%) and 2.36% ethanol within 84 h. Specific activities of Xylose Reductase and Xylitol Dehydrogenase exhibited by S. cerevisiae LN were relatively low. Their ratio indicated metabolism diverted toward ethanol than xylitol and other byproducts. Strain was tolerant to concentrations of HMF, furfural and acetic acid commonly encountered in biomass hydrolysates. Thus, genetic setup for xylose assimilation in S. cerevisiae LN is not merely artifact of xylose metabolizing pathway and can be augmented by adaptive evolution. This strain showed potential for commercial exploitation

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Not AvailableLignocellulosic biomass is currently the most promising alternative energy source for realizing sustainable demands of agrarian economies. Its natural recalcitrance to degradation necessitates a detailed study on the complex biochemistry involved in bioconversion of this lignin–carbohydrate complex. A comprehension of the enzymology and role of principal and accessory glycosyl hydrolases involved in biomass degradation are, hence, noteworthy in this context and the xyloglucan-active hydrolases warrant special mention. These are enzymes which carry out hydrolysis and transglucosylation of xyloglucan, the major hemicellulosic polysaccharide in plant biomass. The structurally complex xyloglucans cover and cross-link the cellulosic microfibrils in plant cell walls and make cellulose inaccessible to saccharification by cellulases. Solubilisation of biomass polysaccharides and release of sugars are central to the biomass-to-bioethanol process. Complete conversion of biomass carbohydrates requires a suite of hydrolytic enzymes, which may be designed specifically to accommodate the predominant and subsidiary biomass-cleaving enzymes. Xyloglucan hydrolases which are known to act synergistically with cellulases and xylanases in loosening the plant cell wall are vital enzymes to be deployed for successful bioconversion processes. This chapter is an insight into the capacity of these accessory, but indispensable, hydrolytic enzymes in unlocking the inaccessible biomass polysaccharides for increased sugar recovery and thereby, in drafting the fuels of future.Not Availabl

Glycoside hydrolase production by Aspergillus terreus CM20 using mixture design approach for enhanced enzymatic saccharification of alkali pretreated paddy straw

518-524A successful lignocellulosic ethanol production process needs to address the technological impediments such as cost-competitiveness and sustainability of the process. Effective biomass utilization requires a repertoire of enzymes including various accessory enzymes. Developing an enzyme preparation with defined hydrolytic activities can circumvent the need for supplementing cellulases with accessory enzymes for enhanced hydrolysis. With this objective, mixture design approach was used in the present study to enhance glycoside hydrolase production of a fungal isolate, Aspergillus terreus CM20, by determining the proportion of different lignocellulosic components as enzyme inducers in the culture medium. A mixture of paddy straw and wheat straw (1.42:1.58) resulted in improved cellulolytic activities. The precipitated crude enzyme showed higher CMCase (365.03 18 IU g-1), FPase (161.48 IU g-1), avicelase (15.46 IU g-1), β-glucosidase (920.92 IU g-1) and xylanase (9627.79 IU g-1) activities. The potential of the crude enzyme for saccharification of alkali pretreated paddy straw was also tested. Under optimum conditions, saccharification released 25.0 g L-1 of fermentable sugars. This indicates the superiority of the crude enzyme produced with respect to its hydrolytic enzyme components

MOESM1 of Notable mixed substrate fermentation by native Kodamaea ohmeri strains isolated from Lagenaria siceraria flowers and ethanol production on paddy straw hydrolysates

Additional file 1. Table S1. Sugar utilization by K. ohmeri strain 5 and strain 6. Table S2. Ethanol production, sugar consumption and fermentation efficiency of K. ohmeri strain 5 and strain 6 during xylose fermentation. Figure S1. Growth of K. ohmeri strain 5 and strain 6 on minimal medium with xylose as sole C source. Figure S2. K. ohmeri strain 5 (A) and strain 6 (B) as observed under phase contrast microscope. Figure S3. Effect of furfural on K. ohmeri strain 5 (A) and strain 6 (B)