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Bacterial Synthesis of Metallic Nanoparticles
Published in Ramesh Raliya, Nanoscale Engineering in Agricultural Management, 2019
Shweta Agrawal, Mrinal Kuchlan, Jitendra Panwar, Mahaveer Sharma
The role of these reductases has been elucidated during the formation of ZnSNPs by Rhodobacter sphaeroides. Initially, a soluble sulfate is carried to the interior membrane of R. sphaeroides cell facilitated by the enzyme sulfate permease. The sulfate is then subsequently reduced to sulphite by the enzyme ATP sulfurylase and phosphoadenosine phosphosulfate reductase. The next step in the sequence is the reduction of sulphite to sulphide by the enzyme sulphite reductase. The sulphide reacts with O-acetyl serine in order to synthesize cysteine via O-acetylserine thiolyase, and then cysteine produces S2− by a cysteine desulfhydrase in the presence of zinc. After this process, S2− reacts with the soluble zinc salt and the ZnS NPs are synthesized (Bai et al. 2006, Iravani 2014).
Zymornonas rnobilis for Ethanol Production
Published in Yoshikatsu Murooka, Tadayuki Imanaka, Recombinant Microbes for Industrial and Agricultural Applications, 2020
Hideshi Yanase, Nobuo Kato, Kenzo Tonomura
We had previously isolated a spontaneous mutant, Z6C, derived from Z. mobilis IFO 13756, which overproduced extracellular levansucrase and invertase. This mutant can ferment fructose liberated from raffinose with extracellular invertase. However, melibiose, an alternative hydroly-zed product of raffinose, remains in the culture medium. Therefore, we next tried to improve the Zymornonas strain genetically to ferment melibiose. Since the lactose permease of E. coli catalyzes the uptake of melibiose, we tried to introduce the genes for lactose permease and α-galactosidase from E. coli into Z. mobilis Z6C.
Transport of Nutrients and Carbon Catabolite Repression for the Selective Carbon Sources
Published in Kazuyuki Shimizu, Metabolic Regulation and Metabolic Engineering for Biofuel and Biochemical Production, 2017
The inducer exclusion has also been reported for Gram positive bacteria, and HPr is the major player in these organisms. In Lactobacillus brevis, HPr (Ser-P) is formed when glucose is present and binds and inactivate permease (Djordjecic et al. 2001). By contrast, the lactose permease of Streptococcus thermophilus is controlled by HPr-(His-P-)dependent phosphorylation. In the absence of glucose, HPr (His-P) can phosphorylate PTS-like domain, thereby activating the permease for lactose transport (Poolman et al. 1995). When glucose is present, HPr becomes phosphorylated on Ser46 and can no longer activate the lactose permease (Gunnewijk and Poolman 2000).
Process intensification for the enhancement of growth and chlorophyll molecules of isolated Chlorella thermophila: A systematic experimental and optimization approach
Published in Preparative Biochemistry & Biotechnology, 2023
Sreya Sarkar, Sambit Sarkar, Tridib Kumar Bhowmick, Kalyan Gayen
The effect of carbon sources on biomass and chlorophyll productivity was obtained by growing the culture in dextrose, fructose, lactose, sucrose, cellulose, sodium acetate and other organic sources from biomass such as rice powder, rice straw in optimized physicochemical and BG-11 media culture condition mentioned earlier. The experimental results showed that the organism was not able to grow in presence of dextrose, fructose, and sodium acetate (Figure 6c). This might be due to the absence of transport enzymes in the cell membrane or inability to oxidize these carbon compounds or the lack of appropriate permease enzyme in the cell membrane.[59] Among the remaining carbon sources, sucrose supported maximum biomass and chlorophyll productivity and cellulose-supplemented media resulted in a significant reduction in biomass and chlorophyll productivity. The presence of carbon source obtained rice powder caused a significant increase in biomass and chlorophyll productivity than optimum culture conditions. However, rice straw and banana stem extract have no significant effects on biomass and chlorophyll productivity.
Insights into four helical proteins folding via self-guided Langevin dynamics simulation
Published in Molecular Physics, 2021
Shuheng Dong, Song Luo, Kaifang Huang, Xiaoyu Zhao, Lili Duan, Hao Li
Unlike high-temperature simulations that accelerate all thermal motions, the SGLD method, initially proposed in 2003, is a mighty tool for ameliorating conformational sampling of proteins without modifying energy surfaces or rising temperatures [39]. In SGLD simulation, it selectively enhances the low-frequency degrees of freedom that is important for conformational searching and sampling by redistributing energy into them from high-frequency motions. Thus, it can increase the searching efficiency by enhancing systematic conformational changes. This method has been extensively employed in various researches [41–45], including the studies of the staphylococcal nuclease in hydration state and rotameric substrates [42], conformational transitions in nitrogen regulatory protein C (NtrC) [43] and lactose permease (LacY) [44], as well as backbone relaxation coupled to the ionisation of internal groups in proteins [45].
Potential of “coalho” cheese whey as lactose source for β-galactosidase and ethanol co-production by Kluyveromyces spp. yeasts
Published in Preparative Biochemistry & Biotechnology, 2020
Catherine Teixeira de Carvalho, Sérgio Dantas de Oliveira Júnior, Wildson Bernardino de Brito Lima, Fábio Gonçalves Macêdo de Medeiros, Ana Laura Oliveira de Sá Leitão, Everaldo Silvino dos Santos, Gorete Ribeiro de Macedo, Francisco Caninde de Sousa Júnior
The genes LAC12 and LAC4 are found in the strain K. lactis NRRL Y-8279, and they are responsible for the codification of lactose-permease and ß-galactosidade enzymes, respectively, which play different roles in this process. Lactose-permease enzymes promote the lactose transport through the plasma membrane into the yeast cells, while the β-gal is responsible for the hydrolysis of lactose (disaccharide) into two monosaccharides, glucose and galactose. These two sugars are metabolized via glycolysis, however, before attending this metabolic route, galactose is converted into a glycolytic intermediate, the glucose-6-phosphate, via the Leloir pathway, by the action of three enzymes galactokinase, galactose-1-P-uridil transferase and UDP-galactose-4-epimerase.[39,40]