Effects of Harvest Time on Grinding Quality, Appearance Quality and Physical and Chemical Quality of Japonica Rice.

Harvest time is very important to rice due to its high correlation to rice yield, eating quality, etc.; however, the impact of harvest time on quality is still unclear. In this study, Nangeng 5718, a japonica rice planted in three regions in Jiangsu Province of China, was used to analyze and compare the milling quality, appearance quality, and physicochemical quality of japonica rice at different harvest times. The results showed that the 1000-grain weight of Nangeng 5718 exhibited no significant change at different harvest times (p > 0.05). The brown rice rate and rice yield at different harvest times were 82.3-85.4% and 66.3-76.1%, respectively. Harvest time had no significant effect on the brown of rice (p > 0.05). However, Nangeng 5718 planted in Nanjing had the highest rice yield at 50 days after heading, which was significantly different from that of rice harvested 65 days after heading (p < 0.05). Nangeng 5718 planted in Huai'an had the highest rice yield at 55 days after heading, which was significantly different from that of rice harvested 60 days after heading (p < 0.05). Harvest time had little effect on the length, width, and thickness of rice. The immature grain rate showed a decreasing trend with the increase in maturity. There were little differences in the protein content of Nangeng 5718 at different harvest times. Nangeng 5718 planted in Nanjing had the highest protein content at 50 days after heading. There was a significant difference between the rice harvested and the rice harvested 60 days after heading (p < 0.05). There were no significant differences between the other two regions (p > 0.05). The accumulated temperature in Nanjing was relatively high, and the RVA curve and RVA eigenvalues of rice varied greatly. The setback value of rice harvested at 50 days was significantly lower than that at 55 days and 60 days (p < 0.05). Rice has good gelatinizing properties. Therefore, timely harvesting and appropriate accumulated temperature could increase 1000-grain weight and rice yield, reduce the immature grain rate, and improve the gelatinization characteristics. Overall, the quality of Nangeng 5718 reached a good level when it was harvested 50 days after heading, with the accumulated temperature reaching 1051 °C. In fact, the harvest time should be chosen flexibly according to the weather conditions. Nangeng 5718 planted in Nanjing should be harvested earlier than 50 days, and rice from Huai'an and Lianyungang was of better quality when the harvest time was 50 days.

Mechanistic insight for improving butenyl-spinosyn production through combined ARTP/UV mutagenesis and ribosome engineering in Saccharopolyspora pogona.

Butenyl-spinosyn is a highly effective, wide-spectrum and environmentally-friendly biological insecticide produced by Saccharopolyspora pogona. However, its scale-up is impeded due to its lower titer in wild-type strains. In this work, ARTP/UV mutagenesis and ribosome engineering were employed to enhance the butenyl-spinosyn production, and a stable mutant Saccharopolyspora pogona aG6 with high butenyl-spinosyn yield was successfully obtained. For the first time, the fermentation results in the 5 L bioreactor demonstrated that the butenyl-spinosyn produced by mutant Saccharopolyspora pogona aG6 reached the maximum value of 130 mg/L, almost 4-fold increase over the wild-type strain WT. Furthermore, comparative genomic, transcriptome and target metabolomic analysis revealed that the accumulation of butenyl-spinosyn was promoted by alterations in ribosomal proteins, branched-chain amino acid degradation and oxidative phosphorylation. Conclusively, the proposed model of ribosome engineering combined with ARTP/UV showed the improved biosynthesis regulation of butenyl-spinosyn in S. pogona.

MSC derived EV loaded with miRNA-22 inhibits the inflammatory response and nerve function recovery after spinal cord injury in rats.

Our previous research has found that miRNA-22 can inhibit the occurrence of pyroptosis by targeting GSDMD and decrease the production and release of inflammatory factors. In consideration of the therapeutic effects of mesenchymal stem cells (MSCs), MSCs-EV were loaded with miRNA-22 (EV-miRNA-22) to investigate the inhibitory effect of EV-miRNA-22 on the inflammatory response in SCI in rats in this study. LPS/Nigericin (LPS/NG) was used to induce pyroptosis in rat microglia in vitro. Propidium iodide (PI) staining was performed to observe cell permeability, lactate dehydrogenase (LDH) release assay was adopted to detect cytotoxicity, flow cytometry was conducted to detect pyroptosis level, immunofluorescence (IF) staining was utilized to observe the expression level of GSDMD (a key protein of pyroptosis), Western blot was performed to detect the expression of key proteins. For animal experiments, the T10 spinal cord of rats was clamped by aneurysm clip to construct the SCI model. BBB score, somatosensory evoked potential (SEP) and motor evoked potential (MEP) were performed to detect nerve function. HE staining and Nissl staining were used to detect spinal cord histopathology and nerve cell damage. EV-miRNA-22 could inhibit the occurrence of pyroptosis in microglia, suppress the cell membrane pore opening, and inhibit the release of inflammatory factors and the expression of GSDMD. In addition, EV-miRNA-22 showed higher pyroptosis-inhibiting ability than EV. Consequently, EV-miRNA-22 could inhibit the nerve function injury after SCI in rats, inhibit the level of inflammatory factors in the tissue and the activation of microglia. In this study, we found that miRNA-22-loaded MSCs-EV (EV-miRNA-22) could cooperate with EV to inhibit inflammatory response and nerve function repair after SCI.

Growth and survival of microencapsulated probiotics prepared by emulsion and internal gelation.

Efficient microencapsulation of probiotics by most existing methods is limited by low throughput. In this work, Saccharomyces boulardii and Enterococcus faecium were microencapsulated by a method based on emulsion and internal gelation. The growth and survival of microencapsulated microbes under different stressors were investigated using free non-encapsulated ones as a control. The results showed that the prepared micro-beads by emulsion and internal gelation exhibited a spherical and smooth shape, with sizes between 300 and 500 µm. Both S. boulardii and E. faecium grew well and survived better when encapsulated in micro-beads. The survival rates were increased 25% and 40% for microencapsulated S. boulardii and E. faecium respectively when compared with non-encapsulated controls under high temperature and high humidity. The increases of survival rates were 60% for microencapsulated S. boulardii and 25% for E. faecium in simulated gastric juice. And the increases were 15% and 20% respectively when the survival rates of the microencapsulated S. boulardii and E. faecium were determined in simulated intestinal juice. The microencapsulation by emulsion and internal gelation offers an effective way to protect microbes in adverse in vitro and in vivo conditions and is promising for the large-scale production of probiotics microencapsulation.

Enzymatic Modification of Rice Bran Polysaccharides by Enzymes from Grifola Frondosa: Natural Killer Cell Cytotoxicity and Antioxidant Activity.

Rice bran polysaccharides (RBPSs) are the major active constituents of rice bran (RB). In this study, we utilized intracellular enzymes from Grifola frondosa to modify RBPSs, which were extracted from RB using ultrasound. To enhance the effect on natural killer (NK) cell cytotoxicity of modified polysaccharides (mRBPSs) generated from RBPSs, an orthogonal test (L9 [3]4 ) was employed to optimize the modification conditions. Based on the results of a single-factor test, the enzyme to polysaccharide ratio, reaction temperature, reaction pH, and reaction time were the main factors affecting mRBPSs-enhanced NK-cell cytotoxicity. The best conditions were determined to be an enzyme to polysaccharide ratio of 1:5, a reaction temperature of 40 °C, a reaction pH of 4, and a reaction time of 4 hr. By optimizing the conditions, the NK-cell cytotoxicity induced by mRBPSs6 was the highest, increasing by 12.01% ± 0.08%. Gas chromatographic analysis revealed that mRBPSs6 consists of rhamnose, arabinose, xylose, mannose, glucose, and galactose at a molar ratio of 7:21:6:5:53:48, which was 8:13:8:5:44:44 before modification. High-performance liquid chromatography results indicated molecular weights for the RBPSs of approximately 106 Da, which decreased to 104 to 105 Da after modification. Antioxidant activity tests revealed high capacity of mRBPSs6 for scavenging 1,1-diphenyl-2-picrylhydrazyl radicals and hydroxyl free radicals at 1.0 mg/mL. PRACTICAL APPLICATION: Rice bran polysaccharides (RBPSs) contain compounds with many biological activities. However, these polysaccharides difficult to absorb due to high molecular weights and unexposed active sites, which are the main factors that limit their use in functional foods. The results of this study demonstrate that modification of RBPSs using intracellular enzymes from an edible fungus alters the molecular weights and monosaccharide composition of RBPSs. In addition, immune and antioxidant activities of RBPSs were increased. The findings provide a new and beneficial application for rice bran.

Genistein and daidzein induce apoptosis of colon cancer cells by inhibiting the accumulation of lipid droplets.

AIM: The purpose of this study was to investigate the possible mechanisms of genistein (GEN) and daidzein (DAI) in inducing apoptosis of colon cancer cells by inhibition of lipid droplets (LDs) accumulation. METHODS: HT-29 cells were used and treated by GEN or DAI in this paper. LDs accumulation was induced and inhibited by oleic acid (OA) and C75, respectively. The expression changes of LDs-related markers were confirmed by semiquantitative real time-PCR (RT-PCR), Western blotting, and immunofluorescence staining. RESULTS: GEN and DAI effectively reduced the LDs accumulation and downregulated the expression of Perilipin-1, ADRP and Tip-47 family proteins and vimentin levels. GEN and DAI significantly induced the mRNA expression of PPAR-γ, Fas, FABP, glycerol-3-phosphate acyltransferase (GPAT3), and microsomal TG transfer protein (MTTP), and reduced the mRNA expression of UCP2. Furthermore, the results showed a decrease of PI3K expression by GEN and DAI when compared with OA treatment, and both GEN and DAI can increase the expression of FOXO3a and caspase-8 significantly when these proteins were decreased by OA treatment. GEN is more effective than DAI in inducing cell apoptosis. CONCLUSION: Our results demonstrated that GEN and DAI inhibit the accumulation of LDs by regulating LDs-related factors and lead to a final apoptosis of colon cancer cells. These results may provide important new insights into the possible molecular mechanisms of isoflavones in anti-obesity and anti-tumor functions.

Rice bran polysaccharides and oligosaccharides modified by Grifola frondosa fermentation: Antioxidant activities and effects on the production of NO.

Rice bran polysaccharides (RBPSs) are valuable compounds with many biological activities. In this work, a fungus called Grifola frondosa, was selected to ferment defatted rice bran water extracts and modify the RBPSs, which were then isolated by ethanol precipitation and deproteinization. GC analysis of fermented products suggested they are composed of glucose, arabinose, galactose, mannose, and xylose at a molar ratio of 9:5:8:2:5, which was 32:4:6:2:5 before fermentation. HPLC analysis revealed that the molecular weight of unfermented RBPS was distributed mainly from 103 to 104Da, and it changed to 102 to 103Da after fermentation. Antioxidant activities and effects on the production of NO were analyzed and it indicated that the scavenging ratios of hydroxyl and DPPH radicals by the fermented products were significantly enhanced compared to the unfermented ones, and also the products fermented for 9days exhibited two-way adjusting effects on the production of NO in macrophages.

Optimization of Culture Medium for Maximal Production of Spinosad Using an Artificial Neural Network - Genetic Algorithm Modeling.

BACKGROUND: Spinosyns, products of secondary metabolic pathway of Saccharopolyspora spinosa, show high insecticidal activity, but difficulty in enhancing the spinosad yield affects wide application. The fermentation process is a key factor in this case. METHODS: The response surface methodology (RMS) and artificial neural network (ANN) modeling were applied to optimize medium components for spinosad production using S. spinosa strain CGMCC4.1365. Experiments were performed using a rotatable central composite design, and the data obtained were used to construct an ANN model and an RSM model. Using a genetic algorithm (GA), the input space of the ANN model was optimized to obtain optimal values of medium component concentrations. RESULTS: The regression coefficients (R(2)) for the ANN and RSM models were 0.9866 and 0.9458, respectively, indicating that the fitness of the ANN model was higher. The maximal spinosad yield (401.26 mg/l) was obtained using ANN/GA-optimized concentrations. CONCLUSION: The hybrid ANN/GA approach provides a viable alternative to the conventional RSM approach for the modeling and optimization of fermentation processes.

Overexpression of metK shows different effects on avermectin production in various Streptomyces avermitilis strains.

The S-adenosylmethionine synthetase gene (metK) from Streptomyces avermitilis was cloned into multi-copy vector pIJ653 and integrative vector pSET152 yielding two metK expression plasmids pYJ02 and pYJ03, respectively. When wild-type strain ATCC31267 was transformed with these two plasmids, avermectin production was increased about 2.0-fold and 5.5-fold, respectively. The introduction of integrative expression plasmid pYJ03 into the engineered strain GB-165, which produces only avermectin B, promoted the production of avermectin approximately 2.0-fold. However, introduction of pYJ02 did not influence avermectin accumulation in GB-165. Moreover, transformation of the avermectin-overproducing industry strain 76-05 with these two plasmids did not stimulate avermectin production. These results showed that there were different effects of metK expression levels on avermectin production in various S. avermitilis strains. Additionally, the transcript levels of metK, aveR (the avermectin pathway-specific regulatory gene) and aveA1 (one avermectin biosynthesis gene) meet the expectation of fermentation levels of avermectin in wild-type strain and its recombinant strains. The gene expression levels of metK, aveR and aveA1 in GB-165 and 76-05 were much higher then those in wild-type strain, which probably limited the increasement of avermectin by overexpression of metK.

Activation of the extrinsic caspase pathway in cultured cortical neurons requires p53-mediated down-regulation of the X-linked inhibitor of apoptosis protein to induce apoptosis.

Cultured cortical neurons exposed to the Human Immunodeficiency Virus gp120 coat protein undergo apoptosis involving activation of both caspase-8 and caspase-9. Additionally, gp120-mediated neuronal apoptosis requires the pro-apoptotic transcription factor p53. As caspase-8-induced apoptosis does not typically require p53, we examined the possibility of a novel role for p53 in caspase-8 activation initiated by gp120. We observed that gp120 treatment of cultured cortical neurons induced caspase-8 activity and Bid cleavage independently of p53, but induction of caspase-3 enzymatic activity required p53 expression. These findings suggested the possibility that p53 down-regulates a caspase-3 inhibitor. We observed high-level expression of the caspase-3/9 inhibitor X-linked inhibitor of apoptosis protein (XIAP) in cultured cortical neurons. Adenoviral expression of p53 or induction of endogenous p53 by camptothecin treatment reduced XIAP protein in neurons. Infection with a p53 expressing adenovirus increased expression of the mRNA for Omi/HtrA2, a protease that cleaves and inactivates XIAP. These findings suggest that p53 regulates neuronal apoptosis, in part, by suppressing the anti-apoptotic protein XIAP via transcriptional activation of Omi/HtrA2.

HIV associated neurodegeneration requires p53 in neurons and microglia.

HIV infection of the central nervous system leads to HIV-associated dementia (HAD) in a substantial subset of infected individuals. The pathogenesis of neuronal dysfunction in HAD is not well understood, but previous studies have demonstrated evidence for activation of apoptotic pathways. The tumor suppressor transcription factor p53 is an apical mediator of neuronal apoptosis following a variety of injurious stimuli. To determine whether p53 participates in HAD, we exposed cerebrocortical cultures from wild-type and p53 deficient mice to the neurotoxic HIV envelope protein gp120. Using neuron/microglia co-culture of mixed p53 genotype, we observed that both neurons and microglia require p53 for gp120 induced neuronal apoptosis. Additionally, accumulation of p53 protein in neurons was recently reported in post-mortem cortical tissue from a small group of HAD patients. Using a much larger cohort of HAD cases, we extend this finding and report that p53 protein also increases in non-neuronal cells, including microglia. Taken together these findings demonstrate a novel role for p53 in the microglial response to gp120. Additionally, these findings, in conjunction with a recent report that monocytes expressing HIV-Tat also secrete neurotoxins that promote p53 activation, suggest that distinct HIV proteins may converge on the p53 pathway to promote neurotoxicity.

p53-dependent cell death signaling in neurons.

The p53 tumor suppressor gene is a sequence-specific transcription factor that activates the expression of genes engaged in promoting growth arrest or cell death in response to multiple forms of cellular stress. p53 expression is elevated in damaged neurons in acute models of injury such as ischemia and epilepsy and in brain tissue samples derived from animal models and patients with chronic neurodegenerative diseases. p53 deficiency or p53 inhibition protects neurons from a wide variety of acute toxic insults. Signal transduction pathways associated with p53-induced neuronal cell death are being characterized, suggesting that intervention may prove effective in maintaining neuronal viability and restoring function following neural injury and disease.