查看更多>>摘要：? 2021 Jieyang Shen, Yihui Liu, Jiahao Xu, Shenbo Ye, Xiaoxiao Xu, Yang Liu, Lixue Zheng and Yang Zhang.Oviductus Ranae (OR) is a traditional Chinese medicinal material that is listed in Chinese Pharmacopeia with proteins the most abundant ingredients. In present work, pepsin/trypsin-based stepwise hydrolysis was applied to extract Antioxidant Peptides from OR (APOR) using hydroxyl radical-scavenging capacity as evaluation index. After single-factor experiment, response surface method coupled with Box-Behnken design were used for optimizing process parameters and achieved the optimal conditions: Pepsin amount of 2.0%, pepsin incubation time of 3.5 h, trypsin amount of 2.0% and trypsin incubation time of 3.0 h, under these conditions, the hydroxyl radical-scavenging rate of obtained APOR was 75.52±1.92%, which was extremely similar to the predicated value with relative deviation of ±1.42%. The half inhibitory concentration of APOR against hydroxyl radical was 3.71±0.71 mg.ml-1, which was lower than that of proteins from OR (4.85±0.06 mg.mL-1, disclosed in our previously published paper). The higher antioxidant capacity of APOR could be related to the presence of rich antioxidant amino acids and relatively lower molecular weights, which deserve to be explored in the next future.
查看更多>>摘要：? 2021 Xiaojie Ren, Qi Yan, Baoyue Liu, Yu Du, Xinhe Zhao and Yuanda Song.Thraustochytrium has a relatively high lipid content in the cell and its lipid content can account up to 70% of the dry cell weight. It is an important raw material for the third-generation biodiesel production and the production of functional fatty acid Docosahexaenoic Acid (DHA). However, the high cost of traditional fermentation medium has hindered the industrial production of lipid. Therefore, searching for raw materials that can be used by thraustochytrid with a wide range of sources and low prices has become a research hotspot in the production of lipids by thraustochytrid. In this study, corn steep liquor was applied for lipid production in thraustochytrid Aurantiochytrium SW1, various factors of corn medium were optimized by using Response Surface Methodology (RSM), including glucose concentration, Rotation Speed, Kinetin concentration and dilution rate of corn steep liquor. The optimal conditions were finally obtained as 72.37 g/L glucose, 2.28 mg/L kinetin, 270 rpm of rotation speed and 15 times of corn pulp dilution. The biomass, lipid and DHA yields obtained under the optimized conditions were 13.5, 7.9 and 42% of total fatty acids, respectively. Comparison with the traditional medium, the biomass, lipid and DHA production were promoted by 14.8, 31.6 and 31.3% respectively. The optimized medium using cheap corn steep liquor showed a better production level, which proved the feasibility of culturing Aurantiochytrium SW1 with cheap raw materials.
查看更多>>摘要：? 2021 Xiulan Chu, Qianfeng Chen, Tong Wang, Xinyu Bai, Chen Pan, Yang Zhang and Lixue Zheng.In this study, the extraction optimization, characterization, antioxidant evaluation and preliminary inhibitory mechanism against Escherichia coli of the essential oil from dried Medicago hispida (EOMH) were explored to uncover the pending questions that had been raised in our previous work and to enlarge the industrial potential of EOMH production. The optimal parameters for EOMH extraction were: Extraction time of 7 h, particle size of 20 mesh and liquid-to-solid ratio of 30: 1 (mL/g), under which the highest yield of EOMH reached 0.31%. Nineteen constituents were identified in EOMH by gas chromatography mass spectrometry analysis, among which phytol content was up to 53.6%. These structures were further confirmed by infrared spectroscopy analysis. EOMH exerted similar scavenging capacities against Diphenyl Picryl Hydrazinyl (DPPH) and hydroxyl radicals with those of phytol. However, EOMH elicited stronger inhibitory effect on E. coli than that of phytol via shrinking E. coli cells, indicating that other factors, in addition to the antioxidant mechanism would equally affect the inhibitory effect of EOMH against E. coli, which should be deepened in the near further. In summary, present work would provide evidence for the industrial production and application of EOMH.
查看更多>>摘要：? 2021, Science Publications. All rights reserved.The present research provided a formula for the optimization of rosemary/collagen/chitosan blend membrane. Rosemary Extract (RE) was used as additive and membrane was prepared using tensile strength, elongation at break and elongation length as the indexes. The results of single factor experiment showed that the addition ratio of collagen to chitosan, additive content, glycerol content and drying temperature all affected the mechanical properties and thickness of the blend membrane, among which the addition ratio of collagen to chitosan and glycerol content had a great influence. Box-Behnken Design (BBD) of Response Surface Methodology (RSM) was used to optimize the process and the parameters were obtained as follows: The ratio of collagen to chitosan (39:61, v/v), the addition of RE (0.6 mg/mL) and the glycerol content (30.2%). The mechanical properties and thickness of the optimized formula were verified, which proved the feasibility of the scheme and the broad application prospect of rosemary/collagen/chitosan blend membrane in meat packaging industry. The optimal data of tensile strength, elongation at break, elongation length and thickness were 2789.65 g, 49.92%, 117.55 and 0.143 mm, respectively. In the future, the research of blend membrane in food industry will more meet the diversified and high-performance market demand.
查看更多>>摘要：? 2021 Ganghui Ye, Liting Zheng, Chang Meng, Yuefeng Dong, Hongyan Xu and Qinglu Wang.Background and purpose: Bisphenol A (BPA) is a pervasive environmental toxicant with known adverse effects on human immune system and nervous system et al. Although, BPA is widely known to affect endocrine function in animals, the linkage between human exposure to BPA and human reproductive function is still not clearly clarified. Results: Systematic review of all articles about BPA and human reproductive function identified in SCOPUS and PubMed. Literature was summarized in narrative form and results are presented per category. Some observational surveys investigating the relationship between BPA exposure and human reproductive and/or endocrine function are inconsistent. Conclusion: Our review integrates the studies of BPA on reproductive and/or endocrine system in recent years, mainly explains the effects of BPA on these systems and provides the basis for subsequent studies on BPA.
查看更多>>摘要：? 2021 Xiaojie Ren, Chao Huang, Xin Shan, Heng Ban, Baoyue Liu, Yu Du, Yuanda Song and Xinhe Zhao.The natto kinase in natto has obvious thrombolytic effect, has the advantages of low cost, small side effects, long half-life and can be taken orally, so it has attracted much attention. At present, the research on natto kinase in our country mainly focuses on the selection of natto fermentation strains, the optimization of gene expression conditions and the exploration of thrombolytic mechanism. However, most natto products show that the number of viable bacteria is not high. Natto Kinase activity is low and no breakthrough has been made so far. For this reason, this topic has launched a study on how to improve the activity of natto kinase. This topic optimizes the traditional natto fermentation process and obtains the best fermentation parameters on the basis of enhancing the activity of natto kinase. The experiment first compared and selected two different fermentation strains and determined that Bacillus natto was the dominant fermentation strain. Considering that the water content of soybeans can indirectly affect the activity of natto kinase, the experiment explored the effects of soaking and steaming beans on the water content of soybeans and determined that soaking beans is an influencing factor for the fermentation process. During the fermentation process, soaking time, fermentation temperature, fermentation time and inoculation amount of superior species, were designed to explore the optimal fermentation process that make the highest nano kinase activity. The TAME method is used to accurately detect the activity of natto kinase in the samples after fermentation and the physical properties of the natto before and after fermentation are measured with a physical property test set. The data obtained can quantify the subjective sensory evaluation. Finally, the design-export 11.0 software was used to analyze and optimize the optimal fermentation process parameters with a soaking time of 15 h, a fermentation temperature of 37°C, a fermentation time of 30 h and an inoculum of 6 mL and the natto kinase activity under the combined conditions was measured to be 3 μ·mL-1.
查看更多>>摘要：? 2021 Xiaojie Ren, Heng Ban, Chao Huang, Baoyue Liu, Yuanda Song, Xinhe Zhao and Jiangsen Pei.RNA-seq technique was used to analyze the transcriptomics of Yarrowia lipolytica control strain Po1g, an erythritol-producing natural isolate Yarrowia lipolytica Y 22 and an erythritol high-yielding mutant strain Y44 derived from Y 22. Functional annotation of genes and classification of metabolic pathways were carried out to identify Differentially Expressed Genes (DEGs). These DEGs were classified into related metabolic pathways to explain the molecular mechanism of high yield of erythritol production. The results showed that the upregulated genes in erythritol-producing natural isolate Y 22 and erythritol-producing mutant strain Y 44 were mainly involved in pentose phosphate pathway, Tricarboxylic Acid Cycle (TCA) and malic acid cycle. The downregulated genes were mainly involved in amino acid synthesis and oxycarboxylic acid metabolism. The synergistic regulation of the above metabolic pathways can increase the input and reduce the output of erythrose-4-P (E-4-P), which is the precursor of erythritol, promoting erythritol production. In addition, compared with the natural isolate Y 22, the genes related to cell wall synthesis were down-regulated and the expression of transmembrane transporter protein was up-regulated in high-yield mutant strain Y 44. In this way, the permeability of yeast cells is enhanced and the synthesized erythritol can be quickly transported to the outside of the cell, which reduces the decomposition of erythritol and further promotes its yield.
查看更多>>摘要：? 2021 Rongbin Li, Xu Shi, Yaqiong Liu, Haoran Wang, Xiaofang Fu, Huanxiang Wang, Jianlou Mu and Jie Wang.This study examined the microbial diversity in soil, grape must and wine fermentation of Cabernet Sauvignon inoculated with three different starters (S01: Xinjiang Saccharomyces cerevisiae CEC01; SCA: Ningxia Saccharomyces cerevisiae CECA; S96: Saccharomyces cerevisiae AWRI 796) using a high-throughput sequencing technique. The results showed that 227 bacterial genera and 20 fungi genera were shared in all samples, consisting of Saccharomyces, Filobasidium, Colletotrichum, Alternaria by Venn diagram analysis. Principle component analysis showed the microbiota structures between S01, SCA and S96 fermentation were similar, the major bacterial genera were Pseudomonas, unclassified_f_Enterobacteriaceae and Lactobacillus, whereas the major fungi genus was Saccharomyces. The biomarkers of bacterial genera in S01, SCA and S96 groups were detected using LEfSe analysis, in which Komagataeibacter, Micromonospora, Streptomyces, Brevibacterium and Agromyces were core microorganisms in the S01 group, SCA fermentation increased the relative abundance of Lactobacillus and Oenococcus, family Ruminococcaceae was dominant in the S96 group. The distinctions in fungi communities between S01, SCA and S96 group were not observed during the fermentation. Understanding of microbial diversity could aid to promote the formation of regional characteristics and the development of high-quality wines through the management of existing microorganisms in future.
查看更多>>摘要：? 2021 Lin Gao, Jiawei Yuan, Yuhuan Cheng, Mengling Chen and Jihong Wu.Alcohol Use Disorder (AUD) is one of leading external causes of mortality. Selenium-enriched Peanut Protein (SePP) is a type of Se compound present in Se-enriched plants. Our previous studies showed that SePP possesses potential therapeutic properties and could alleviate alcoholinduced AML-12 cytotoxicity. It spurred us to determine the underlying mechanisms and roles of SePP on gut microbiota. Here, ICR mice were fed either standard diet or ethanol (30%, v/v, 10 mL/kg bw/day) intragastric administration for 8 weeks. The intervention groups were divided into different doses of SePP groups and Se compounds groups, like Selenomethionine (SeMet) group, sodium selenite group. The composition of the gut microbiota was investigated by analyzing 16S rRNA gene sequences. Body weight, lipid metabolism markers, serum insulin and oxidative stress were assessed. Treatment with SePP at a certain dosage (25 μg/kg bw/day in Se) and SeMet reversed diversity loss and community alterations in the gut microbiota of the AUD group, as evidenced by an increased abundance of Firmicutes and decreased abundances of Bacteroidetes and Verrucomicrobia in AUD mice. SePP suppressed the relative abundance of the Rikenellaceae_RC9 gut group and increased those of Lachnospiraceae and Ruminococcaceae, which are associated with lipid metabolism and Short-Chain Fatty Acids (SCFAs) production. The study suggested that SePP has the potential to be used as a supplement for alleviating alcohol-induced liver damage.
查看更多>>摘要：? 2021 Xiaojie Ren, Zhuangzhuang He, Huihui Peng, Jing Zhang, Sihua Wang, Yubin Zhao, Xiaoyu Li, Yuanda Song, Xinhe Zhao and Chengye Ma.Corn Steep Liquor (CSL) is wastewater from corn starch industry. The huge amount generation made it as a serious environmental problem. But CSL is nutrient-rich with diverse amino acids and other trace elements. In this study, symbiotic biofertilizer was studied using CSL as main substrate. In this study, 9 industrial strains, which were recognized as high performance species in the biofertilizer industry were collected, including four bacillus, four fungus and one yeast species. Three dominant strains were selected finally, depending on the ability to dissolve phosphorus, ability for protein hydrolysis and cell growth. They were Bacillus subtilis 3301, Bacillus licheniformis and Aspergillus Niger. The results expressed that the highest growth cell count of Bacillus subtilis 3301 reached 3.1×109 CFU/mL, the highest protein hydrolysis capacity of Bacillus licheniformis reached 600 mg/L and the highest phosphorus-dissolving capacity of Aspergillus Niger reached 1100 mg/L respectively. Then, symbiotic fermentation of the three strains was carried out both in shake-flask culture and fermentation tank (5 L). Interestingly, series of significant data of symbiotic fermentation were obtained, which were different from individual cultures. Especially, the total growth cell count in the 5 L scale fermenter culture was higher than individual cultures, which proved the mutual promotion effect between different strains. This research would provide a new view to utilize the waste of corn steep liquor as high value-added agricultural products.
NSTL