The production of chitosan from the mycelia of Absidia coerulea was studied to improve cell growth and chitosan productivity Culture conditions were optimized in batch cultivation (pH 4.5, agitator speed of 250 rpm, a...
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The production of chitosan from the mycelia of Absidia coerulea was studied to improve cell growth and chitosan productivity Culture conditions were optimized in batch cultivation (pH 4.5, agitator speed of 250 rpm, and aeration rate of 2 vvm) and the maximum chitosan concentration achieved was 2.3 g/L under optimized conditions. Continuous culture was carried out successfully by the formation of new growth spots under optimized conditions, with a chitosan productivity of 0.052 g L-1h-1, which is the highest value to date, and was obtained at a dilution rate of 0.05 h-1. Cell chitosan concentrations reached about 14% in the steady state, which is similar to that achieved in batch culture. This study shows that for the continuous culture of Absidia coerulea it is vital to control the medium composition.
Over the past few years, extractive fermentation techniques have been studied extensively for the successful production of plant-derived chemicals. Extractive fermentation may prevent the degradation of plant products...
Over the past few years, extractive fermentation techniques have been studied extensively for the successful production of plant-derived chemicals. Extractive fermentation may prevent the degradation of plant products and often may also enhance secondary product secretion or production. Even so, many technical problems remain for the application of these techniques to the commercial production of valuable products.
Sorghum is crucial in Baijiu brewing. Previous studies have shown that glutinous sorghum (LS) and non-glutinous sorghum (FS) significantly affect Zaopei's lipid metabolism and lipids affect flavor perception. This...
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Some non-coding small RNAs, known as microRNAs (miRNAs), have been shown to play important roles in gene regulation and various biological processes. The abnormal expression of some specific miRNA genes often results ...
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The removal of organic nitrogen compounds present in crude petroleum and shale oils poses a challenging problem in petroleum industries. The deleterious effect of nitrogen compounds on cracking catalysts and the indic...
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The removal of organic nitrogen compounds present in crude petroleum and shale oils poses a challenging problem in petroleum industries. The deleterious effect of nitrogen compounds on cracking catalysts and the indication that they contribute to gum formation in gasolines are some of these aspects. Pyridine, a representative nitrogen compound in heavy oil - was degraded by Rhodococcus sp. KCTC 3218 in a water-heavy oil two-phase system. The pyridine degradation rate was affected by the presence of hydrocarbons such as n-hexadecane. This microorganism formed floes which could be a barrier to mass transfer between the cells in floes and the pyridine dissolved in water. This problem could be overcome by the addition of a surfactant such as Triton X-100. The ratio of water to heavy oil was important to separate the heavy oil phase from the water phase after treating the heavy oil. The culture medium was emulsified by a sort of biosurfactant secreted by this microorganism. The emulsified oil phase returned to its natural state when the ratio of water to heavy oil was 1.5. Above this ratio, the emulsified oil phase remained an emulsion after decantation. Pyridine in heavy oil was completely degraded in 15 hr at this water to heavy oil ratio of 1.5 when the concentration of pyridine in heavy oil was 700 ppm and the cell concentration was 0.32 g DCW/L.
Studies on the lung cancer genome are indispensable for developing a cure for lung ***-genome resequencing,genome-wide association studies,and transcriptome sequencing have greatly improved our understanding of the ca...
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Studies on the lung cancer genome are indispensable for developing a cure for lung ***-genome resequencing,genome-wide association studies,and transcriptome sequencing have greatly improved our understanding of the cancer ***,dysregulation of longrange chromatin interactions in lung cancer remains poorly *** better understand the three-dimensional(3D)genomic interaction features of the lung cancer genome,we used the A549 cell line as a model system and generated high-resolution chromatin interactions associated with RNA polymerase II(RNAPII),CCCTC-binding factor(CTCF),enhancer of zeste homolog 2(EZH2),and histone 3 lysine 27 trimethylation(H3K27me3)using long-read chromatin interaction analysis by paired-end tag sequencing(ChIA-PET).Analysis showed that EZH2/H3K27me3-mediated interactions further repressed target genes,either through loops or domains,and their distributions along the genome were distinct from and complementary to those associated with ***-related genes were highly enriched with chromatin interactions,and chromatin interactions specific to the A549 cell line were associated with oncogenes and tumor suppressor genes,such as additional repressive interactions on FOXO4 and promoter–promoter interactions between NF1 and *** of an anchor associated with chromatin interactions reversed the dysregulation of cancer-related genes,suggesting that chromatin interactions are essential for proper expression of lung cancer-related *** findings demonstrate the 3D landscape and gene regulatory relationships of the lung cancer genome.
The eukaryotic genome has a hierarchicalthree-dimensional(3D)organization with functional implications for DNA replication,DNA repair,and transcriptional *** the past decade,scientists have endeavored to elucidate the...
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The eukaryotic genome has a hierarchicalthree-dimensional(3D)organization with functional implications for DNA replication,DNA repair,and transcriptional *** the past decade,scientists have endeavored to elucidate the spatial characteristics and functions of plant genome architecture using high-throughput chromatin conformation capturing technologies such as Hi-C,ChlA-PET,and ***,we systematically review current understanding of chromatin organization in plants at multiple *** also discuss the emerging opinions and concepts in 3D genome research,focusing on state-of-the-art 3D genome techniques,RNA-chromatin interactions,liquid-liquid phase separation,and dynamic chromatin *** propose the application of single-cell/single-molecule multi-omics,multiway(DNA-DNA,DNA-RNA,and RNA-RNA interactions)chromatin conformation capturing methods,and proximity ligation-independent 3D genome-mapping technologies to explore chromatin organization structure and function in *** methods could reveal the spatial interactions between trait-related SNPs and their target genes at various spatiotemporal resolutions,and elucidate the molecular mecha-nisms of the interactions among DNA elements,RNA molecules,and protein factors during the formation of key traits in plants.
Genome-scale metabolic models (GEMs) are valuable in describing an organism's entire metabolism using genomic information and have made huge impact on systems biology and metabolic engineering. Here we review curr...
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Fed-batch cultures of L. erythrorhizon hairy root were carried out by controlling sucrose concentration and media conductivity in a shake flask and a modified stirred tank reactor. For the efficient product recovery f...
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Fed-batch cultures of L. erythrorhizon hairy root were carried out by controlling sucrose concentration and media conductivity in a shake flask and a modified stirred tank reactor. For the efficient product recovery from the culture, in situ adsorption by XAD-2 was also conducted. When sucrose was used as a carbon source, the highest shikonin production and hairy root growth were obtained. When glucose or fructose was used instead, the growth was severely inhibited. In addition, it was found that alternating feeding of sucrose could be used as an effective strategy for enhancing the productivity of shikonin derivatives. As the XAD-2 amount was increased up to 1.5 g/L, shikonin production was enhanced by removing shikonin produced and other products which might be inhibitory to cell growth. Most amount of shikonin produced was successfully recovered in XAD-2 (Over 99%). Using hairy-root culture in a modified stirred tank reactor, the shikonin productivity and hairy root growth rate on the average were 9.34 mg/L · day and 0.49 g DCW/L · day, respectively.
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