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101.
102.
Abhijit R. Chavan Anuradha Raghunathan K. V. Venkatesh 《Journal of industrial microbiology & biotechnology》2009,36(4):509-519
Simultaneous saccharification and fermentation (SSF) is a combined process of saccharification of a renewable bioresource
and fermentation process to produce products, such as lactic acid and ethanol. Recently, SSF has been extensively used to
convert various sources of cellulose and starch into fermentative products. Here, we present a study on production of buttery
flavors, namely diacetyl and acetoin, by growing Lactobacillus rhamnosus on a starch medium containing the enzyme glucoamylase. We further develop a structured kinetics for the SSF process, which
includes enzyme and growth kinetics. The model was used to simulate the effect of pH and temperature on the SSF process so
as to obtain optimum operating conditions. The model was experimentally verified by conducting SSF using an initial starch
concentration of 100 g/L. The study demonstrated that the developed kinetic was able to suggest strategies for improved productivities.
The developed model was able to accurately predict the enhanced productivity of flavors in a three stage process with intermittent
addition of starch. Experimental and simulations demonstrated that citrate addition can also lead to enhanced productivity
of flavors. The developed optimal model for SSF was able to capture the dynamics of SSF in batch mode as well as in a three
stage process. The structured kinetics was also able to quantify the effect of multiple substrates present in the medium.
The study demonstrated that structured kinetic models can be used in the future for design and optimization of SSF as a batch
or a fed-batch process.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
103.
104.
Das T Banerjee S Samuel G Bapat K Subramanian S Pillai MR Venkatesh M 《Bioorganic & medicinal chemistry letters》2006,16(22):5788-5792
With an insight that ligands possessing a N2S2 tetradentate array of donor atoms serve as ideal bifunctional chelating agents (BFCA) in the radiolabeling of target-specific agents, 5-hydroxy-3,7-diazanonan-1,9-dithiol (DAHPES) with a derivatizable substituent in the form of a hydroxyl group in the backbone was synthesized. The preparation of a steroid conjugate via coupling of this BFCA with testosterone-3-(O-carboxymethyl) oxime and the subsequent radiolabeling of the conjugate under optimized conditions with 99mTc, the ideal diagnostic radionuclide in nuclear medicine procedures, are reported. The immunoreactivity of the radiolabeled conjugate was demonstrated in a study using anti-testosterone antibodies, wherein the radiolabeled conjugate exhibited significant binding with antiserum to testosterone. Cell-uptake studies in DU145 prostate carcinoma cell line bearing androgen receptors (ARs) and comparison with AR non-bearing breast carcinoma cell line revealed the specific binding of the steroidal moiety with the testosterone receptor. 相似文献
105.
Genetic interplay between human longevity and metabolic pathways — a large‐scale eQTL study
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106.
Joyneel Misra Srinivas Govinda Surampudi Manasij Venkatesh Chirag Limbachia Joseph Jaja Luiz Pessoa 《PLoS computational biology》2021,17(9)
Insights from functional Magnetic Resonance Imaging (fMRI), as well as recordings of large numbers of neurons, reveal that many cognitive, emotional, and motor functions depend on the multivariate interactions of brain signals. To decode brain dynamics, we propose an architecture based on recurrent neural networks to uncover distributed spatiotemporal signatures. We demonstrate the potential of the approach using human fMRI data during movie-watching data and a continuous experimental paradigm. The model was able to learn spatiotemporal patterns that supported 15-way movie-clip classification (∼90%) at the level of brain regions, and binary classification of experimental conditions (∼60%) at the level of voxels. The model was also able to learn individual differences in measures of fluid intelligence and verbal IQ at levels comparable to that of existing techniques. We propose a dimensionality reduction approach that uncovers low-dimensional trajectories and captures essential informational (i.e., classification related) properties of brain dynamics. Finally, saliency maps and lesion analysis were employed to characterize brain-region/voxel importance, and uncovered how dynamic but consistent changes in fMRI activation influenced decoding performance. When applied at the level of voxels, our framework implements a dynamic version of multivariate pattern analysis. Our approach provides a framework for visualizing, analyzing, and discovering dynamic spatially distributed brain representations during naturalistic conditions. 相似文献
107.
Isolation, structural elucidation and immunomodulatory activity of fructans from aged garlic extract 总被引:1,自引:0,他引:1
Traditionally, garlic (Allium sativum) is known to be a significant immune booster. Aged garlic extract (AGE) possesses superior immunomodulatory effects than raw garlic; these effects are attributed to the transformed organosulfur compounds. AGE is also known to contain fructans; the amount of fructans in AGE represents a small fraction (0.22%) of the total fructans in raw garlic. In order to evaluate the biological activity of fructans present in AGE, both high molecular weight (>3.5 kDa; HF) and low molecular weight (<3 kDa; LF) fructans were isolated. The structures of purified HF and LF from AGE determined by (1)H NMR and (13)C NMR spectroscopy revealed that both have (2→1) β-D-fructofuranosyl bonds linked to a terminal glucose at the non-reducing end and β-D-fructofuranosyl branching on its backbone. Biological activity of fructans was assessed by immunostimulatory activity using murine lymphocytes and peritoneal exudate cells (source of macrophages). Both HF and LF displayed mitogenic activity and activation of macrophages including phagocytosis. These activities were comparable to that of known polysaccharide immunomodulators such as zymosan and mannan. This study clearly demonstrates that garlic fructans also contribute to the immunomodulatory properties of AGE, and is the first such study on the biological effects of garlic fructans. 相似文献
108.
Singh NK Wang D Kundumani-Sridharan V Van Quyen D Niu J Rao GN 《The Journal of biological chemistry》2011,286(25):22478-22488
109.
Venkatesh J Yoshifuji H Kawabata D Chinnasamy P Stanevsky A Grimaldi CM Cohen-Solal J Diamond B 《Journal of immunology (Baltimore, Md. : 1950)》2011,186(9):5304-5312
Systemic lupus erythematosus is an autoimmune disease characterized by autoantibodies and systemic inflammation that results in part from dendritic cell activation by nucleic acid containing immune complexes. There are many mouse models of lupus, some spontaneous and some induced. We have been interested in an induced model in which estrogen is the trigger for development of a lupus-like serology. The R4A transgenic mouse expresses a transgene-encoded H chain of an anti-DNA Ab. This mouse maintains normal B cell tolerance with deletion of high-affinity DNA-reactive B cells and maturation to immunocompetence of B cells making nonglomerulotropic, low-affinity DNA-reactive Abs. When this mouse is given estradiol, normal tolerance mechanisms are altered; high-affinity DNA-reactive B cells mature to a marginal zone phenotype, and the mice are induced to make high titers of anti-DNA Abs. We now show that estradiol administration also leads to systemic inflammation with increased B cell-activating factor and IFN levels and induction of an IFN signature. DNA must be accessible to B cells for both the production of high-affinity anti-DNA Abs and the generation of the proinflammatory milieu. When DNase is delivered to the mice at the same time as estradiol, there is no evidence for an abrogation of tolerance, no increased B cell-activating factor and IFN, and no IFN signature. Thus, the presence of autoantigen is required for positive selection of autoreactive B cells and for the subsequent positive feedback loop that occurs secondary to dendritic cell activation by DNA-containing immune complexes. 相似文献
110.
Irnayuli R. Sitepu Mingjie Jin J. Enrique Fernandez Leonardo da Costa Sousa Venkatesh Balan Kyria L. Boundy-Mills 《Applied microbiology and biotechnology》2014,98(17):7645-7657
Microbial oil is a potential alternative to food/plant-derived biodiesel fuel. Our previous screening studies identified a wide range of oleaginous yeast species, using a defined laboratory medium known to stimulate lipid accumulation. In this study, the ability of these yeasts to grow and accumulate lipids was further investigated in synthetic hydrolysate (SynH) and authentic ammonia fiber expansion (AFEX?)-pretreated corn stover hydrolysate (ACSH). Most yeast strains tested were able to accumulate lipids in SynH, but only a few were able to grow and accumulate lipids in ACSH medium. Cryptococcus humicola UCDFST 10-1004 was able to accumulate as high as 15.5 g/L lipids, out of a total of 36 g/L cellular biomass when grown in ACSH, with a cellular lipid content of 40 % of cell dry weight. This lipid production is among the highest reported values for oleaginous yeasts grown in authentic hydrolysate. Preculturing in SynH media with xylose as sole carbon source enabled yeasts to assimilate both glucose and xylose more efficiently in the subsequent hydrolysate medium. This study demonstrates that ACSH is a suitable medium for certain oleaginous yeasts to convert lignocellullosic sugars to triacylglycerols for production of biodiesel and other valuable oleochemicals. 相似文献