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Hyperlipidemia significantly increases the risk of cardiovascular disease, and the number of patients is gradually increasing and tends to be younger. The prevalence factors and pathogenesis of hyperlipidemia are the hotspots of current research. Research has shown that abnormal blood lipids are closely related to gut microbiota and dietary habits. We investigated the association between gut microbiota typing and lipid indices in hyperlipidemic patients by 16s rRNA and resolved the differences with gut microbiota in healthy populations, and compared the experimental results using Meta-analysis. The results displayed that the gut microbiota of hyperlipidemic patients could be classified into two enterotypes (Bac and Bla) and there was a significant difference such as Faecalibacterium , Bacteroides , and Agathobacter between the two groups. There was a high similarity in the composition of gut microbiota between Bac enterotype patients and healthy individuals, and the TG levels of the patients in the Bac group were also less different from those of the healthy population. However, the relative abundance of Faecalibacterium and Bacteroides was lower appreciably in patients with Bla enterotypes compared to patients with Bac enterotypes and healthy populations, suggesting that TG levels may influence changes in gut microbiota. Furthermore, the results of Mate-analysis did not reveal a significant correlation between Bacteroides and TG, whereas this study has detected a negative correlation between the abundance of Bacteroides and TG content. And the changes in Faecalibacterium abundance in the gut microbiota of hyperlipidemic patients and healthy people in this cohort population were consistent with the results of Meta-analysis. Therefore, they may be potential strains for the treatment of hyperlipidemia caused by elevated TG. [Display omitted] [ABSTRACT FROM AUTHOR]

Lacticaseibacillus casei is a common bacterium, due to its small genome and relatively simple metabolism, it will process the potential to become a cell factory. Although CRISPR has been successfully applied to the gene editing of L. casei , the technology is limited by the size of the knock-in gene and cannot achieve efficient integration of large fragments, which has impeded the application of L. casei in synthetic biology. Here, we develop a genome integration tool applicable to L. casei. Three possible phage integrases were screened and introduced into L. casei AR1088. A highly active integrase in L. casei was screened. Based on this, a single plasmid-based efficient gene integration tool for L. casei was established. With the assistance of CRISPR-Cas9 editing system, we realized multi-site integration of genome. Then, homologous modeling of integrase φA2 was conducted to explore its core amino acid site and minimum functional region. Two core sites of H334 and T366 were identified, and it was confirmed that the full-length protein of integrase was essential for integration. As a proof of concept, the bile salt hydrolase gene from Lactiplantibacillus plantarum was integrated into AR1088 genome at multiple sites, which improved the acid and bile salt tolerance of the engineered strain. The system developed in this study overcomes the deficiencies of currently available genetic tools in the multi-site chromosomal integration of large DNA fragment in L. casei , and may be extended to other lactobacillus. [ABSTRACT FROM AUTHOR]

Bifidobacterium can be used as probiotic that confers various health benefits to its host. The functional analysis of specific genes can help elucidate the probiotic mechanism of Bifidobacterium. However, the low transformation efficiency has hindered the in-depth study of its function by genetic manipulation. In this study, we optimized transformation methods for Bifidobacterium animalis AR668 to improve the transformation efficiency up to 2.15 ×105 CFU/μg DNA. Additionally, the expression of competence gene ssb2 could enhance the transformability which was the first attempt to apply it to B. animalis. Moreover, the transformation efficiency was increased after the plasmids were modified by gene0033 and gene1509 which limited the interference of the restriction-modification system in the uptake of foreign DNA by cells. Based on the above optimization, the transformation efficiency of 7.2 ×105 CFU/μg DNA for AR668 was obtained, which was more than 100 times higher than that of the original condition. Together, we successfully improved the transformation efficiency of B. animalis AR668, contributing to its genetic manipulation and modification. [ABSTRACT FROM AUTHOR]

[Display omitted] • L. salivarius AR809 could be used as adjunct culture to accelerate cheese ripening. • L. salivarius AR809 promoted the synthesis of methyl ketones for cheese maturation. • Monascus strengthened fatty acids metabolism and lysine degradation in the cheese. • AR809 and Monascus co-fermentation promote the metabolisms of amino acids and lipid. Adjunct cultures strongly determined the distinguishing sensorial and nutritional characteristics of cheeses. Metabolites, flavor profiles and ripening characteristics of Monascus -ripened cheese enhanced by the co-fermentation of Ligilactobacillus salivarius AR809 were investigated. The AR809 significantly increased the contents of soluble nitrogen, small peptides (<1200 Da), free amino acids, and casein degradation degree in the resulting cheese. Furthermore, AR809 significantly promoted the formation of methyl ketones during cheese maturation. Based on untargeted metabolomics analysis, metabolites related to fatty acids metabolism and lysine degradation were highly enriched in Monascus -rich region of cheese. AR809 was primarily engaged in amino acid metabolism, promoting the synthesis of amino acids and dipeptide. L. salivarius and Monascus co-fermentation produced more beneficial bioactive metabolites involved in amino acids and lipid metabolisms than Monascus used alone in cheese ripening. Therefore, as adjunct culture, L. salivarius AR809 exhibited tremendous potential in improving nutrition and flavor quality during cheese ripening. [ABSTRACT FROM AUTHOR]

Highlights • Chinese rice wine treated at 400/600 MPa for 10 min exhibited similar flavor to untreated wine. • After wine was processed by thermal treatment, cereal aroma and astringency were highlighted. • Fruit aroma, continuation and full body were dominant in high-hydrostatic-pressure-treated wines. • 600 MPa for 10 min could notably enhance the sensory profile of wine. Abstract Traditional sterilization leads to poor vinosity of Chinese rice wine (CRW). Effects of boiling, ultra-high temperature (UHT) and high hydrostatic pressure (HHP) on CRW quality were investigated. Thermal treatment resulted in a decrease of total free amino-acids (FAA), whereas HHP-treatment caused an increase. However, UHT and HHP treatments had little effect on FAA with sweet and umami-like flavor. HHP-treated CRW contained 7.35% higher content of flavors relative to untreated wine, while thermally-treated CRW revealed 4.68–8.61% losses. Based on principal component analysis, CRW processed at 400 or 600 MPa for 10 min exhibited similar flavor to the untreated wine, which was highly associated with long-chain fatty acid ethyl esters (C 13 –C 18). Moreover, partial least squares regression demonstrated that sensory attributes of cereal aroma and astringency were highlighted after thermal treatment, while fruit aroma, continuation and full body were dominant after HHP treatment. HHP treatment effectively enhanced the quality of CRW, which could be applied in other alcoholic beverages. [ABSTRACT FROM AUTHOR]

Producing alcoholic beverages with novel flavor are desirable for winemakers. We created fermenting yeast with superior ethanol tolerance and fermentation activity to improve the flavor profiles of Chinese rice wine. Strategies of ethanol domestication, ultraviolet mutagenesis (UV) and protoplast fusion were conducted to create yeast hybrids with excellent oenological characteristic. The obtained diploid hybrid F23 showed a cell viability of 6.2% under 25% ethanol, whereas its diploid parental strains could not survive under 20% ethanol. During Chinese rice wine-making, compared to diploid parents, F23 produced 7.07%–12.44% higher yield of ethanol. Flavor analysis indicated that the total content of flavor compounds in F23 wine was 19.99–26.55% higher than that of parent wines. Specifically, F23 exhibited higher capacity in producing 2-phenylethanol, short-chain and long-chain fatty-acid ethyl-ester than diploid parents. Compared to diploid parents, F23 introduced more flavor contributors with odor activity values (OAVs) above one to Chinese rice wine, and those contributors were found with higher OAVs. Based on principal component analysis (PCA), the flavor characteristic of F23 wine was similar to each of parent wine. Additionally, sensory evaluation showed that F23 wine was highly assessed for its intensive levels in fruit-aroma, alcohol-aroma and mouthfeel. Hybrid F23 not only displayed superior flavor production and oenological performance in making Chinese rice wine, but also could act as potential “mixed-like” starter to enrich wine style and differentiation. [ABSTRACT FROM AUTHOR]

To improve the safety of Chinese pickles, lactic acid bacteria were isolated from traditional fermented foods to test for nitrite degradation during the pickling process. Lactobacillus brevis AR123 was screened out as a starter culture for pickle fermentation. L. brevis AR123 has a high tolerance to nitrite and salt. During pickle fermentation, the nitrite peak appeared from 12 to 24 h in the pickle juice and was delayed to 24–48 h in the pickles. In 6% salt, L. brevis AR123 and a commercial starter could rapidly lower the pH of the pickles, and the nitrite contents were 0.83 mg kg −1 and 3.05 mg kg −1 , respectively, in pickles at 72 h. Meanwhile, no obvious nitrite peak was observed for the pickle inoculated with a mixed starter; it had a low nitrite level (0.88 mg kg −1 at 72 h). However, the concentration of nitrite was as high as 17.92 mg kg −1 in the spontaneous fermentation group. During pickle fermentation, Lactic acid bacteria (LAB) population increased significantly when salt concentration was 4%–8%, and sensory analysis shown that the L. brevis AR123 inoculated pickle exhibited better sensory evaluation results than spontaneous fermentation pickle. In conclusion, inoculation with L. brevis AR123 alone or combined with a commercial starter (mixed starter) is effective in removing nitrites and enhancing the sensory properties of pickle. LAB could accelerate degradation of nitrite significantly and shorten the fermentation time for pickle process. [ABSTRACT FROM AUTHOR]

• We propose a analytical method for the DFIGWT's fault current characteristics in Whole LVRT Process considering control strategy switching between RSC and Crowbar. • The fault process is divided into two stages, RSC control stage and crowbar activating stage. • The activation time of crowbar is obtained, especially the activation of crowbar due to over-voltage of DC bus. • The last value of stator and rotor flux linkages at the first stage are calculated and used as the initial value of the stator and rotor flux linkages at the second stage. • The research results are helpful to the construction of adequate relaying protection for the power grid with penetration of DFIGWTs. In order to address the relaying protection issues of the full renewable energy grid, the fault characteristics of the DFIGWT in whole LVRT process should be studied. Currently, researches on fault characteristics of DFIGWT considering crowbar generally assume that crowbar is activated at the moment of fault. However, in fact, the DFIGWT's fault current characteristics are mainly affected by both (rotor-side converter) RSC and crowbar. The crowbar does not act instantaneously at the moment of fault due to the control system. The DFIGWT is mainly controlled by the RSC before the crowbar is activated. In this paper, the fault process was divided into two stages, namely RSC control stage and crowbar activating stage. The fault characteristics of DFIGWT were analyzed at RSC control stage. Then, the activation time of crowbar was obtained, especially the activation of crowbar due to over-voltage of DC bus was considered. The last values of stator and rotor flux linkages at the first stage were calculated and used as the initial values of the stator and rotor flux linkages at the second stage. Then, the analytical expressions of rotor flux linkage were deduced by Laplace and inverse Laplace transformations. Based on this, the fault mechanism of DFIGWT is resolved and analytical expression of DFIGWT's short circuit characteristics considering whole LVRT process was proposed. The expression of DFIGWT's fault current characteristics was verified by the simulation results.The research results are helpful to the construction of relaying protection system for a full-renewable-based system. [ABSTRACT FROM AUTHOR]

Lactobacillus salivarius is an important probiotic lactic acid bacterium that plays a major role in innate and acquired immunity. It has gained much attention in metabolic engineering and synthetic biology owing to its probiotic properties. However, few well-characterized constitutive promoters are available to modulate L. salivarius gene expression. Here, a pool of L. salivarius endogenous constitutive promoters was identified using RNA sequencing analysis. The promoters were sorted based on their transcript levels. The application potential of the promoters was evaluated using a fluorescence reporting system. This study provides the first well-characterized endogenous constitutive promoter library from L. salivarius , which has a potential for use as a basic toolbox in various lactic acid bacteria applications. • A pool of constitutive promoters was screened by RNA-seq analysis.. • Ten strong promoters, 16 medium-strong promoters, and 6 weak promoters were identified. • The red reporting protein was used to characterized the promoters of the pool. [ABSTRACT FROM AUTHOR]

A lactic acid bacteria strain AR333 with high - production of exopolysaccharides (EPS) was screened out from 350 bacteria strains isolated from naturally fermented dairy products. It was identified as Streptococcus thermophilus by morphological observation, physiological and biochemical characteristics, and 16S rDNA sequence determination. The EPS from AR333 were purified through DEAE-Sepharose Fast Flow and Sepharose CL-6B, and the purified fraction was designated as EPS333. In vitro test showed that EPS333 could stimulate macrophage RAW 264.7 to release NO significantly ( p < 0.05). The further work tried to elucidate the structural features of EPS333 via FT-IR spectrum, high-performance anion exchange chromatography (HPAEC) and high-performance size exclusion chromatography (HPSEC). The results showed that EPS333 was a pure neutral polysaccharide with monosaccharide composition of galactose and glucose in a molar ratio of 6:5. A certain amount of acetyl groups might exist in EPS333 according to the FT-IR spectrum. The molecular weight (Mw) was estimated to be 332 kDa. Current study suggested that the lactic bacteria strain AR333 could be a potential source of immunoregulatory polysaccharide. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mucin genes significantly affects the adhesion ability of L. plantarum to HT-29 cells. • Integration of RFP gene into the genome of L. plantarum , fluorescence stability and convenient detection. • Mucin genes significantly shortens the colonization time of L.plantarum in vivo. • Simplification of mouse intestinal microbes (PEG treatment) is more beneficial for L. plantarum colonization in the intestine. Lactiplantibacillus plantarum is an important member of the probiotic family and colonization of the host intestinal is essential for its continued probiotic function. The mechanism of L. plantarum intestinal colonization has not been elucidated until now, an important reason being that the colonization process is influenced by a number of factors. In this study, to confirm the influences of adhesion ability and host intestinal environment on L. plantarum intestinal colonization, knockouts of L. plantarum AR113 mucin genes were constructed using CRISPR/Cas9 gene editing technology, and polyethylene glycol was used to reduce the intestinal flora abundance. The knockout of L. plantarum AR113 mucin genes barely altered the strain's tolerance to acid and bile salts. Notably, the adhesion number of AR113Δ Lp _1431Δ Lp _2233Δ Lp _2792 to HT-29 cells was reduced from 175 to 114 per 100 cells. Through in vivo colonization experiments, an increase in the fluorescence intensity of AR113 and AR113Δ Lp _1431&2233&2792 was detected the day after the mice were fed, while the deletion of Lp _1431, Lp _2233 and Lp _2792 genes reduced the intestinal tract colonization time from 14 to 11 days. Both AR113 and AR113Δ Lp _1431Δ Lp _2233Δ Lp _2792 were reproduced in the intestine by labeling with 5-(6)-carboxyfluorescein diacetate N-succinimidyl ester. The results showed that the change in fluorescence intensity was closely dependent on the number of adhesions. Finally, compared to the control group, the prolonged intestinal colonization time of AR113Δ Lp _1431Δ Lp _2233Δ Lp _2792 increased mice intestinal flora abundance, with distributions in the duodenum, jejunum, ileum and colon. Collectively, both the intestinal environment and the adhesion ability of L. plantarum AR113 affected intestinal colonization, and the host's intestinal genetic background may be a key factor in the intestinal colonization of L. plantarum. [ABSTRACT FROM AUTHOR]

Abstract: By taking the nonlinear deformation properties of coal into consideration, the nonlinear constitutive equation was founded. And in view of the compressible property of gas, the idea of compressive energy of gas was introduced. According to the continuous damage theory and mesoscopic damage theory, it is assumed that the damage variable has a power function relation with the porosity. By applying the thermodynamics energy conservation laws, a new nonlinear damage constitutive model of coal containing gas was deduced, and the correctness of the new model was verified by comparing with the former experimental results. This model can provide theoretical reference for understanding and solving these dynamic gas disasters such as coal and rock outburst. Moreover, based on this theory, prevention and control measures will be adopted to deal with the dynamic gas disasters according to ever-changing mining conditions. [Copyright &y& Elsevier]

Abstract: The fouling on the condenser water-side wall is an important factor that impacts the cleanness coefficient of condenser in the optimization of designing, operation and improvement of opening cooling water circulation system. Based on the mechanism of foul-forming, a comprehensive prediction model of fouling growth on condenser water-side wall is constructed in this paper. Through analyzing the simplified theoretical model of fouling growth, the characteristic of fouling deposit, effects of working time and cooling water velocity are discussed. Taking a 600MW supercritical steam power plant''s condenser as an example, the accurate estimation and prediction of cleanness coefficient can be obtained with this model. The effects of the temperature difference and condenser pressure are analyzed at the same time, and the work conditions of water circulating with different cleanness coefficient are obtained. With the evidence of some condenser fouling growth, it can be concluded that the present model is validity and would be contributed to water circulating optimization of condenser. [Copyright &y& Elsevier]

[Display omitted] • Osteoporosis-related fracture causes morbidity and mortality. • Intestinal health has been linked to osteoporosis prevention. • Probiotics improved intestinal flora and exerted anti-osteoporotic effects. • Probiotics modulated ovariectomy-induced osteoporosis with strain differences. Osteoporosis is a common skeletal disease in which bone resorption exceeds bone formation. Intestinal health has been linked to reduced osteoporosis. The aim of this study was to compare the anti-osteoporotic and intestinal health effects of two strains of Lactobacillus plantarum (AR237 and AR495) in ovariectomized (ovx) C57BL/6 mice. The results showed that AR495 significantly inhibited ovx-induced bone loss, reduced intestinal permeability, increased the expression of tight junction proteins, claudin-family proteins, zonula occludens-1 (ZO-1), and junctional adhesion molecule 3 (JAM-3) in ovx mice. Furthermore, AR495 inhibited bone resorption by modulating the receptor activator for nuclear factor kappa B (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system, and ameliorated ovx-induced intestinal inflammatory responses. AR495 improved intestinal microbial stability, and increased the abundance of short-chain fatty acids (SCFA)-producing bacteria and fecal SCFA content of ovx mice. Overall, the findings of this study showed that AR495 was more effective than AR237 at treating osteoporosis. [ABSTRACT FROM AUTHOR]

The gut microbiota plays a vital role in human health. Many studies have shown that an imbalance of in the intestinal flora not only can cause intestinal diseases; but also is closely related to obesity, diabetes and other chronic metabolic diseases. Probiotics are defined as live microorganisms, that can colonize the human intestinal tract to improve the microbiological balance and migigate diabetes and other metabolic diseases. Therefore, approaches that aim to target the intestinal flora and thus alleviate diabetes have unique advantages, although the underlying mechanisms are complex and diverse. From this perspective, this review summarize here the relationship between the intestinal flora, probiotics and diabetes. Particularly, it focuses on the mechanism by which probiotics relieve diabetes by targeting the intestinal microbiota from the aspects of oxidative stress, immune responses, amino acid metabolism, intestinal permeability and short-chain fatty acids. [ABSTRACT FROM AUTHOR]

Antroquinonol (AQ) as one of the most potent bioactive components in Antrodia cinnamomea (Fomitopsidaceae) shows a broad spectrum of anticancer effects. The lower yield of AQ has hampered its possible clinical application. AQ production may potentially be improved by genetic engineering. In this study, the protoplast-polyethylene glycol method combined with hygromycin as a selection marker was used in the genetic engineering of A. cinnamomea S-29. The optimization of several crucial parameters revealed that the optimal condition for generating maximal viable protoplasts was digestion of 4-day-old germlings with a mixture of enzymes (lysing enzyme, snailase, and cellulase) and 1.0 M MgSO 4 for 4 h. The ubiA and CoQ2 genes, which are involved in the synthesis of 4-hydroxybenzoate polyprenyltransferase, were cloned and overexpressed in A. cinnamomea. The results showed that ubiA and CoQ2 overexpression significantly increased AQ production in submerged fermentation. The overexpressing strain produced maximum AQ concentrations of 14.75 ± 0.41 mg/L and 19.25 ± 0.29 mg/L in pCT74-gpd-ubiA and pCT74-gpd-CoQ2 transformants, respectively. These concentrations were 2.00 and 2.61 times greater than those produced by the control, respectively. This research exemplifies how the production of metabolites may be increased by genetic manipulation, and will be invaluable to guide the genetic engineering of other mushrooms that produce medically useful compounds. [Display omitted] • PEG-mediated transformation was used in genetic engineering of Antrodia cinnamomea. • The ubiA and CoQ2 genes were cloned and functionally analyzed. • The ubiA and CoQ2 overexpression significantly increased antroquinonol production. [ABSTRACT FROM AUTHOR]

• Monascus fumeus x08 can be used as adjunct starter to make Monascus -ripened cheese. • Monascus fumeus x08 could promote the extent and depth of proteolysis significantly. • The lipolysis in Monascus -ripened cheese was moderate. • Monacolin K and GABA levels were increased and enrich Monascus -ripened cheese functionality. Monascus spp. are fungi that have been applied in food production for centuries and produce a range of bioactive metabolites. The objective of this study was to investigate the characteristics of proteolysis, lipolysis, textural and sensory properties of internal mold-ripened cheese ripened by Monascus fumeus x08. The contents of pH 4.6-soluble nitrogen, 12% trichloroacetic acid-soluble nitrogen and 5% phosphotungstic acid-soluble nitrogen changed significantly during the ripening of the Monascus -ripened cheese. The peptides in the Monascus -ripened cheese were evaluated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and reversed-phase high-performance liquid chromatography. During ripening, many low-molecular-weight peptides (MW < 14400) were found to increase significantly and the ratio of hydrophobic to hydrophilic peptides decreased to 0.81 and 0.34 in the Red-O (outer) and Red-I (interior) parts of the cheese, respectively. The content of total free fatty acids (15 acids, C4:0–C18:3) was significantly increased and the content of unsaturated fatty acids reached 47.89 mg/g fat on day 42 of ripening. The sensory attributes of the Monascus -ripened cheese was assessed using quantitative descriptive analysis. Compared with blue cheese, purchased from a local market, the odor and taste intensity of the Monascus -ripened cheese were significantly lower, while the color intensity and overall receptivity were significantly higher. M. fumeus x08 can be used as a secondary starter to make Monascus -ripened cheese and may be particularly acceptable to consumers in China. [ABSTRACT FROM AUTHOR]

• L. plantarum AR113 could alleviate symptoms of colitis and prevent tissue damage effectively. • L. plantarum AR113 could maintains intestinal barrier by recover goblet cell and tight junction. • HO-1 upregulated could inhibit TLR4/MyD88/NF-κB pathway and reduce pro-inflammatory factors. • L. plantarum AR113 could mitigate dysbiosis of gut microbiota induced by DSS. Probiotics are a potential treatment agent for IBD. In this study, the effects of probiotics on intestinal immune responses and gut microbiota in colitis were investigated. The result showed that L. plantarum AR113 and L. casei AR342 were 2–3 times more effective than other strains to alleviate epithelial damage indicators, improve colon length (+10–30%) and maintain the integrity of the epithelial barrier, as compared to DSS-treatment mice. The supplementation downregulated expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) and upregulated that of the colonic anti-inflammatory cytokine (IL-10). The results strongly suggested that anti-inflammatory effect of probiotics is associated with the increase in HO-1 expression and the decrease in TLR4/MyD88/NF-κB pathway expression in mouse colonic tissues. Further, Microbiota analysis and the correlation of microbiota with colitis parameters revealed that the dysbiosis of gut microbiota induced by DSS treatment could be mitigated to a certain extent by supplementation with L. plantarum AR113. [ABSTRACT FROM AUTHOR]

[Display omitted] • A CRISPR/nCas9 genome editing method was developed for single and multiplex gene editing in Streptococcus thermophilus. • The epsA , epsB and epsE were key genes in exopolysaccharide biosynthesis based on CRISPR/nCas9 analysis. • The epsC , epsE and epsG could alter molecular weight and monosaccharide composition of exopolysaccharide, respectively. Streptococcus thermophilus is an economically prominent starter for common dairy products due to its potential health and nutritional benefits. However, lack of precise genetic manipulation approaches has greatly hampered the industrial application of S. thermophilus.. Herein, we developed an efficient genome editing toolbox (pKLH353) based on CRISPR/nCas9 (Cas9 nickase) in S. thermophilus to seamlessly edit single or multiple genes. A native constitutive promoter library was used to optimize the nCas9 and sgRNA expression with gene deletion efficiencies of 14–60%. The epsA , epsB and epsE were identified as key genes affecting exopolysaccharide (EPS) biosynthesis in S. thermophilus S-3 using the CRISPR/nCas9 toolbox. Moreover, compared to the wild-type, knockout of epsC , epsE or epsG led to a decrease of EPS titer with reducing in its molecular weight (>2.5-fold) and intrinsic viscosity (>19.8-fold). The ratio of monosaccharide composition of the mutants has also changed, suggesting that these eps genes are involved in the chain length synthesis and repeat unit assembly. Taken together, this CRISPR/nCas9 system can serve as a basic toolkit for precise genetic engineering of S. thermophilus and facilitate strain engineering to produce bio-based products. [ABSTRACT FROM AUTHOR]

Streptococcus thermophilus is used extensively in the dairy industry and has shown great promise as a chassis cell for the biosynthesis of high-value metabolites. However, metabolic engineering in S. thermophilus lacks effective genetic modification tools to modulate gene expression to relieve metabolic burden and maximize the production of desired compounds. Here, we developed a clustered regularly interspaced short palindromic repeats interference (CRISPRi) system for efficient gene transcriptional modulation in S. thermophilus. Our CRISPRi system typically achieved 66 to 98% knockdown of single or multiple gene expression. We used CRISPRi for the biosynthesis of a new exopolysaccharide (EPS) as a paradigm model. Repression of galK at module of uridine diphosphate glucose sugar metabolism and overexpression of epsA and epsE at EPS synthesis module resulted in an approximately 2-fold increase in EPS titer (277 mg/L) when compared with a control strain. This study demonstrated the effectiveness of CRISPRi as a powerful metabolic engineering tool and synthetic biology strategy for S. thermophilus. [Display omitted] [ABSTRACT FROM AUTHOR]

With the increasing integration of renewable and non-synchronous resources, the declining level of inertia poses a threat to the stability of power systems. This paper delves into the mechanism of time-varying inertia within mainstream non-synchronous devices and proposes a real-time estimation technique to estimate the constant and time-varying inertia associated with them. By applying the numerical integration method, this technique utilizes observations and their integrals over a continuous timeframe to formulate a system of equations, enabling the estimation of inertia at any given moment. Based on the linear operator analysis, the relationship between the aforementioned system of equations and linear operators is investigated to downscale the original high-dimensional system and extract the inertia. A significant addition is the introduction of the streaming dynamic mode decomposition (sDMD) algorithm, which updates linear operators based on snapshots composed of observations. Its update merely necessitates a small snapshot length, resulting in efficient data storage utilization and space conservation. Case studies on mainstream non-synchronous devices under various controls demonstrate its effectiveness and accuracy for real-time estimation of time-varying inertia. The remarkable advantage of this technique over the existing state-of-the-art method lies in its ability to operate without setting any hyperparameters. [Display omitted] • A real-time estimation technique of time-varying inertia is proposed. • The numerical integration method was used to eliminate extremes caused by noise. • The linear operator analysis method was applied to downscale the device model. • Updating linear operators by the streaming dynamic mode decomposition algorithm. • The proposed technique remains robust without setting hyperparameters. [ABSTRACT FROM AUTHOR]

Freeze drying is one of the most convenient ways to preserve microorganisms, but in the freeze-drying process, strains will inevitably suffer varying degrees of damage under different conditions. The deterioration of cell membrane integrity is one of the main forms of damage. The type and ratio of fatty acids in the cell membrane affect its characteristics. Therefore, it is worth investigating whether certain fatty acids can increase freeze-drying resistance. In this study, we found that adding a low concentration of oleic acid to a cryoprotectant could increase survival rate of strains of Lactiplantibacillus plantarum following freeze drying, and the optimal concentration of oleic acid was determined to be 0.001%. When 0.001% oleic acid was added to phosphate-buffered saline, the freeze-drying survival rate of L. plantarum increased by up to 6.63 times. Adding 0.001% oleic acid to sorbitol, the survival rate of L. plantarum increased by as much as 3.65 times. The 0.001% oleic acid–sucrose cryoprotectant resulted in a freeze-drying survival rate of L. plantarum of about 90%, a 2.26-fold improvement compared with sucrose alone. Although the effect of oleic acid depends on the cryoprotectants used and the strain treated, addition of oleic acid showed significant improvement overall. Further experiments showed that adding a low concentration of oleic acid to the cryoprotectants improved the freeze-drying survival rate of L. plantarum by maintaining cell membrane integrity and lactate dehydrogenase activity. Our findings provide a new strategy for safeguarding bacterial viability in commonly used cryoprotectants by the addition of a common food ingredient, which may be extensively applied in the food industry. [ABSTRACT FROM AUTHOR]

Freeze-drying is one of the most commonly used methods of bacteria preservation. During this process, cryoprotectants can greatly reduce cellular damage. Micromolecular cryoprotectants have been widely adopted but have limited selectivity and protective effects. Therefore, explorations of other types of cryoprotectants are needed. This study aimed to explore the possibility of the macromolecular cryoprotectants and combinations of cryoprotectants to maintain bacterial activity. We found that the survival rate of Lactiplantibacillus plantarum AR113 after freeze-drying was 19% higher in the presence of soy polysaccharides than with trehalose, the best-performing micromolecular cryoprotectant. Moreover, a 90.52% survival rate of L. plantarum WCFS1 was achieved using the composite cryoprotectant containing soy polysaccharide and trehalose, which increased by 31.48 and 36.47% compared with adding solely trehalose or soy polysaccharide, respectively. These results demonstrate that macromolecular and micromolecular cryoprotectants have similar effects, and that combinations of macromolecular and micromolecular cryoprotectants have better protective effects. We further observed that the composite cryoprotectant can increase Lactobacilli survival by improving cell membrane integrity and lactate dehydrogenase activity. Our finding provides a new type of cryoprotectant that is safer and more effective, which can be extensively applied in the relevant food industry. [ABSTRACT FROM AUTHOR]

Tamarind seed polysaccharide (TSP) is commonly used as a stabilizer, suspending agent, and thickener. In this study, the effects of tamarind seed polysaccharide on gelatinization, and the rheological and structural properties of waxy (WCS), normal (CS), and high amylose corn starch (HACS) were investigated. Rapid visco analysis (RVA) and thermal property analysis demonstrated that TSP molecules bind with starch granules to retard gelatinization. Steady flow test results showed that corn starch with different amylose/amylopectin ratios in the absence or presence of TSP presented non-Newtonian fluid properties. Further, the CS or WCS with TSP mixtures exhibited a typically rheological behavior of weak gel. TSP molecules enhanced the elastic properties of high amylose corn starch gels. The presence of TSP also influenced water distribution in the starch-TSP mixture system. Structural characteristic analysis suggested that TSP bound with starch molecules to change their conformation, and influence the gelatinization of starch, especially for amylopectin. The results demonstrated that TSP changes the physicochemical and structural properties of starch through interaction with it, and facilitates the effective bonding with amylopectin. Image 1 • Effects of TSP on physicochemical properties of corn starch were investigated. • TSP inclusion affected physicochemical properties of corn starch paste. • TSP inclusion changed the conformation and structure of starch molecules. • TSP was more easy to bind with amylopectin molecules. [ABSTRACT FROM AUTHOR]

A polysaccharide from tamarind seeds (TSP) was characterized in terms of backbone and side chain structural features, as well as conformational property using methylation and GC–MS analysis, 2D NMR, MALDI-TOF MS, and high performance size exclusion chromatography (HPSEC). Results showed that TSP was a galactoxyloglucan (GXG) consisting of glucose, xylose, and galactose in a molar ratio of 3.1: 1.7: 1.0. The Mw was determined to be 524.0 kDa with radius of gyration (R g) of 55.6 nm. The chemical structure was confirmed as a classical β-(1 → 4)-glucan with short side chains of T-β-Gal p -(1 → 2)-α-Xyl p -(1 → and T-α-Xyl p -(1 → attached to O -6 position of glucose. MALDI-TOF MS analysis indicated that TSP mainly composed of nonasaccharide (XLLG) and octasaccharide (XLXG or XXLG) blocks in periodic or interrupted sequence in a ratio of 3: 2, occasionally interrupted by heptasaccharide (XXXG), hexasaccharide (XLG or XXGG), or even hendesaccharide blocks. Conformational study indicated that TSP was in a random-coil shape with relative extended stiff chain in aqueous solution. This study provided more evidences to make an amendment to the fine structure of tamarind GXG. Unlabelled Image • A classic cellulosic backbone of β-(1 → 4)-glucan was confirmed for TSP. • Short branches consisted of Xyl p and Gal p were distributed along the backbone. • TSP composed of XLLG and XLXG/XXLG units with slight XXXG, XLG/XXGG, and hendesaccharide blocks. • TSP showed as relative extended stiff random coil in aqueous solution. [ABSTRACT FROM AUTHOR]

Exopolysaccharides (EPSs) from lactic acid bacteria have great effect on the quality of fermented milk products. However, the mechanism for the quality improvement has not been well described. This study aimed to investigate the molecular binding kinetics and interactions between EPS obtained from Streptococcus thermophilus AR333 (EPS333) and casein of milk (CM) in a simulated acidifying process. The results indicated that EPS333 had a significant effect on the stability of casein micelles at acidic pH (6.0–4.5) according to the turbidity, ζ-potential, particle size and distribution analysis. The adsorption-desorption study by bio-layer interferometry identified the direct affinity binding between EPS333 and CM, the interactive moiety of casein was α-casein, rather than β- or κ-casein. Fluorescence quenching analysis revealed that the force types of interaction between EPS333 and CM were dynamically changeable during the acidifying process, mainly from electrostatic interaction at pH 7.0–6.5, to hydrophobic or hydrogen bonding at pH 6.5–5.5, and then transferred to electrostatic interaction again at pH 5.5–5.0. Conclusively, EPS333 could bind with CM directly via different binding forces during acidifying process to stabilize the properties of casein micelles. EPS333 from Streptococcus thermophilus AR333 interacts with casein of milk directly in a simulated acidifying process to stabilize the properties of casein micelles. Unlabelled Image • EPS333 had significant effects on the stability of casein micelles (CM) in a simulated acidifying process. • BLI technique was used for the study of affinity binding between EPS333 and CM. • The interactive moiety of casein was α-casein to bind with EPS333 directly. • The dynamically changeable force type of interaction were determined by the fluorescence quenching method. [ABSTRACT FROM AUTHOR]

Abstract A high purity of β- D -glucan (80.8%) from hull-less barley (Hordeum vulgare L. var. nudum Hook. f.) (HBBG) was isolated by alkali extraction and multi-precipitation with ethanol. The molecular weight (Mw) of HBBG was determined as 571.4 kDa with a broad distribution (Mw/Mn = 1.6) by using HPSEC. According to methylation and GC-MS analysis, HBBG was identified to be composed of (1 → 4)- and (1 → 3)-glucopyranosyl (Glc p) residues with a ratio of (3.19 ± 0.01). The MALDI-TOF MS and NMR spectroscopy were further conducted to analyze the enzyme hydrolysate released by lichenase digestion on HBBG. The results suggested that HBBG possessed a typical chemical structure of cereal β- D -glucans, namely linear homopolysaccharides formed by β-D-Glc p units via (1 → 4)-linkages and occasionally single (1 → 3)-linkage. The trisaccharide and tetrasaccharide of HBBG accounted for 66.6% of total cellulosyl units, accompanying with a ratio of cellotriosyl to cellotetraosyl units = 1.0, which were significant different from those reported for the other cereal β-glucans. Rheological property analysis revealed that HBBG showed a shear-thinning behavior and thermal resilience during heating-cooling process. Graphical abstract Image 1 Highlights • A production method for high purity of HBBG was proposed. • The fine structure of HBBG was identified by MALDI-TOF MS and NMR. • The content of β-(1. → 4)-linkages in HBBG were higher than other cereals • HBBG showed the thermal resilience and good heat resistance. [ABSTRACT FROM AUTHOR]

This study was to identify active pectin fragments of high in vitro anti-proliferation activities against human colon adenocarcinoma Caco-2 cells, using various pectin fragment preparations dominant with rhamnogalacturonan I (RG-I), rhamnogalacturonan II (RG-II), and galacturonic acid oligomers (GAOS). The samples were prepared from citrus high and low methoxy pectins ( HPE and LPE ) by endo-α-D-(1,4)-polygalacturonase action coupling with a green process as ultrafiltration (membrane molecular weight cut off > 10k, 1k-10k, and < 1k, giving fragment preparations I , II , and III , respectively). It is indicated that, in the fragment preparations HPE-I , II , and III , the molecular fractions HPE-F1 (RG-I), HPE-F2 (RG-II), and HPE-F3 (GAOS) showed an averaged M w  = 26.7k, 3.4k, and 0.3k, respectively, notably higher than their LPE counterparts. All fragment preparations exhibited concentration-dependent, inhibition effects on Caco-2 cells, where HPE-II (RG-II-domain) revealed an interesting inhibition effect, significantly higher than those did HPE-I (RG-I domain) and HPE-III (GAOS). The HPE-F2 (RG-II) was elucidated and found of IR  = 88% at 1.0 mg/mL and half-inhibition concentration ( IC 50 ) = 0.12 mg/mL, doubling the effect of HPE-F1 (RG-I) ( IR  = 45% at 1.0 mg/mL). Conclusively, citrus RG-II fragment showed a promisingly high anti-Caco-2 activity, significantly higher than did RG-I and GAOS, possibly attributed to its special branched structure and low molecular size. [ABSTRACT FROM AUTHOR]

An exopolysaccharide EPS333 was produced by a ropy Streptococcus thermophilus strain AR333 when grown on reconstituted skim milk. The molecular weight, radius of gyration (Rg), hydrodynamic radius (R h ) and intrinsic viscosity ([ η ]) of EPS333 were determined as 313.7 kDa, 33.96 nm, 25.98 nm, and 1.874 dL/g, respectively by high performance size exclusion chromatography (HPSEC). The conformational analysis demonstrated that EPS333 presented as compact and semi-stiff or stiff chain in aqueous solution. Monosaccharide analysis identified that EPS333 was composed of galactose, glucose and galactosamine in a molar ratio of 3: 2: 1. The backbone of EPS333 consisted of β-(1→3)-Gal p , β-(1→3,6)-Glc p , α-(1→3)-2-Gal p NAc, and α-(1→4)-Glc p . The branch chain was terminated at O -6 position of β-(1→3,6)-Glc p by α-T-Gal p . With the help of 1D & 2D NMR spectroscopy, the repeating unit of EPS333 was proposed. Further studies revealed that the in situ produced EPS333 could improve the quality of fermented milk to be close to the commercial product. [ABSTRACT FROM AUTHOR]

The cryptic plasmid pLC2W was isolated from Lactobacillus casei CP002616. Nucleotide sequence analysis revealed that 4 putative open reading frames (ORF) were responsible for DNA replication. Four Escherichia coli-Lactobacillus shuttle vectors were constructed using different lengths of the pLC2W replicon to identify the shortest functional replicon. The length of the pLC2W replicon did not affect the stability of the plasmids. Green fluorescent protein (GFP) as a reporter was expressed successfully in several lactobacilli using our constructed vectors. The results suggested that the expression vectors pUE-F0GFP and pUE-F1GFP are potential molecular tools for heterologous gene cloning and expression in lactobacilli. Moreover, 2 plasmid-curing methods were used to eliminate pLC2W from L. casei. We detected no difference between L. casei CP002616 and L. casei CP002616 pLC2WΔ-IC (mutant strain cured by plasmid incompatibility method) in production of exopolysaccharide (EPS) or acid. However, EPS and acid production were both reduced in L. casei CP002616 pLC2WΔ-HT (mutant strain cured by high-temperature heat treatment method), demonstrating a difference between these 2 curing methods. Sequence analysis of pLC2W and plasmid curing data suggest that plasmid pLC2W is not involved in EPS synthesis. [ABSTRACT FROM AUTHOR]

Leaves of herb Graptopetalum paraguayense E. Walther are considered to be applied for functional drinks or isolated for nutraceutical ingredients. This study was to preliminarily elucidate the antioxidant activities and potentials for anti-colon cancer cells and anti-neuroinflammation of the hot-water extracts and its macromolecular hydrocolloids from freeze-dried G. paraguayense leaves, in relation to detectable polysaccharide compositions and associated phenolic and non-phenolic compounds. It is indicated that the 100 o C-water extract ( GW100 ) form G. paraguayense leaves contained glucans at a molar ratio of glucose (Glc): fucose (Fuc): xylose (Xyl): ribose (Rib) = 1:0.29:0.13:0.13 and a major macromolecular species with an averaged molecular weight ( M w ) = 2172. The macromolecular GW100E , i.e. 72%-ethanol precipitate of GW100 , contained pectin substance like arabino-rhamnogalactans at a molar ratio of galactose (Gal): arabinose (Ara): rhamnose (Rha): Glc = 1:0.81:0.34:0.32, and only one macromolecular species with an averaged M w = 2405. Both GW100 and GW100E exhibited excellent antioxidant activities in scavenging α, α-diphenyl-β-picrylhydrazyl radicals (DPPH⋅), 2,2-azino-bis [3-ethylbenzthiazoline-6-sulfonic acid] radicals (ABTS + ), and superoxide anions (O 2 − ), great potential in anti-proliferation against human colon adenocarcinoma Caco-2 cells, and significant immunomodulatory activities on murine microglia BV-2 cells. Comparatively, GW100 was outstanding in scavenging ABTS + and O 2 − and inhibiting significantly tumor necrosis factor-α (TNF-α) and interleukine-6 (IL-6) production by lipopolysaccharide (LPS)-treated BV-2 cells. GW100E excelled in scavenging DPPH⋅ and anti-Caco-2 proliferation. Conclusively, GW100 and GW100E could be good candidates for anti-neuro-inflammation potentials and anti-Caco-2 proliferation, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • A high-throughput screening (HTS) method was developed based on congo red staining. • The mutants with different yields of exopolysaccharide (EPS) were obtained by HTS. • The HTS method is efficient for isolating EPS-producing Streptococcus thermophilus. As a thickening or stabilizing agent, exopolysaccharide (EPS) can significantly enhance food texture. However, the conventional analytical and screening methods of EPS have been unable to meet the current needs of industrial production, owing to low efficiency and heavy time-consumption. A simple and rapid qualitative/quantitative method is needed to accelerate the selection of high EPS-producing strains. Here, a high-throughput screening (HTS) program for EPS production was established in S. thermophilus by combining Congo red agar method (CRA, primary screening) and microplate colorimetric assay (MPC, secondary screening). The correlation coefficient (R2) between CRA/MPC and the phenol-sulfuric acid assay (a classical EPS quantification method) were 0.779 and 0.862, respectively, suggesting the feasibility of this HTS method. A mutant library (>300 colonies) of S. thermophilus was constructed using ribosome engineering strategy, and EPS-producing mutants with the titer from 50 mg/L to 200 mg/L were rapidly obtained by our developed HTS method, confirming that the HTS method is simple and efficient for the isolation of EPS-producing S. thermophilus. Taken together, this HTS method was developed for rapidly screening of EPS-producing S. thermophilus , which could be a valuable tool not only for the rapid detection of EPS production capabilities, but also for the screening of strain libraries from genetic engineering with desirable characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Low field-NMR was firstly used in the age discrimination of Huangjiu. • Flavor compounds with ordor activity value (OAV) higher than 1 dominated the aging aroma of Huangjiu. • Basic amino acids greatly contributed to the flavor formation of Huangjiu during aging. • Molecular association promoted the accumulation of flavor compounds with OAV > 1. Aging is an essential operation to perfect the flavor quality of Hungjiu. In this study, formation mechanism of flavor compounds responsible for the characteristic flavor of aged Huangjiu was investigated. The contents of umami and bitter free amino acids (FAA) increased with the storage period prolonged, while that of sweet FAA showed downward trend. Gas chromatograph-mass spectrometry and principal component analysis indicated that the volatile flavor compounds with OAV exceed 1, especially middle-chain fatty-acid-ethyl-esters and aromatic compounds, dominated the characteristic flavor of aged Huangjiu. Low field-NMR was firstly applied to characterize the molecular association between water and dissolved flavor compounds in aged Huangjiu. The results showed that basic amino acids contributed greatly to the flavor formation of aged Huangjiu via molecular association. In addition, the molecular association significantly promoted the accumulation of flavor compounds with OAV > 1, especially ethyl esters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structure of TSPs determined their effects on physicochemical properties of CS. • HPH changed M w , conformational structure, and Gal/Glc ratio of TSP. • Different structural TSP had different effects on physicochemical properties of CS. • M w and Gal/Glc ratio of TSP influenced CS retrogradation and water distribution. In this work, structural characteristics of TSPs treated by high-pressure homogenization (HPH) and their effects on physicochemical properties of corn starch were analyzed. HPH induced monosaccharides change, Gal/Glc ratio decrease from 0.32 to 0.25, and molecular weight (M w) decrease from 10.55 to 4.47 × 105 Da through damaging glycosidic linkages in the backbone and side-chain of TSPs. Furthermore, 90 MPa homogenized TSP (higher Gal removal) showed inhibitory effects on starch paste retrogradation, and TSPs with a lower M w (homogenized at 60 and 90 MPa) could limit water precipitation during the long-term storage. Moreover, M w and Gal/Glc ratio were the major factors for the determined effects of TSPs on physicochemical properties of corn starch. The results could provide new insights into the relationship between TSP structure and their effects on the physicochemical properties of starch. [ABSTRACT FROM AUTHOR]

• R. vinosa polysaccharides (WRP) were efficiently fractionated by gradient ethanol precipitation and gel chromatography. • WRP-1 was a branched β-(1→3)-glucan and formed helical structure in aqueous solution. • WRP-2 and WRP-3 were considered as galactoglucan with incompact flexible conformation. • WRP-1 was superior to WRP-2 and WRP-3 on the potential immunostimulatory activity. Water-extracted polysaccharides from Russula vinosa Lindblad (WRP) were separated into three fractions (WRP-1, WRP-2 and WRP-3) by gradient ethanol precipitation and gel chromatography. Structural characterization indicated that WRP-1 was a branched β-(1→3)-glucan and exhibited rigid helical conformation in aqueous solution with Mw of 2,180 kDa and radius of gyration (R g) of 123.4 nm. The galactoglucan of WRP-2 and WRP-3 were mainly composed of →6)-Gal p -(1→ and →4)-Glc p -(1→ terminated by glucose and mannose, presenting much lower Mw (392 and 93.6 kDa) and R g (57.6 and 42.6 nm), and more incompact flexible conformation than WRP-1. All fractions showed potential immunostimulatory activity by promoting macrophage proliferation, phagocytosis, as well as the release of nitric oxide and cytokines (TNF-α and IL-1β). WRP-1 with unique structure and conformation showed the best immunostimulatory effects among them. This study suggests that WRP could be explored as natural immunostimulator used in the food and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel copper-doped phosphomolybdic acid catalyst (Cu-HPMo/TiO 2) for low temperature selective catalytic reduction with NH 3 was developed. • Cu(3)-HPMo/TiO 2 with strong surface acidity could restrain the SO 2 adsorption and improve its SO 2 resistance. • Density functional method was used to study the adsorption state and competitive adsorption of SO 2 and H2O molecules on the catalyst surface. • The Cu(3)-HPMo/TiO 2 exhibits a typical core-shell structure which could improve its sulfur and water resistance. The selective catalytic reduction with NH 3 (NH 3 -SCR) catalyst for de-NO x is usually inhibited by SO 2 and water vapor at low temperature. The copper-doped phosphomolybdic acid (Cu-HPMo) was supported on titanium dioxide (TiO 2) and a novel catalyst Cu-HPMo/TiO 2 with good resistance to SO 2 and water vapor was developed. Experimental results show that the best catalytic activity of Cu-HPMo/TiO 2 was obtained at the Cu/Mo molar ratio of 3. The denitration efficiency over the Cu(3)-HPMo/TiO 2 catalyst was approximately 99 % at 200 ℃ and remained almost constant in the presence of 200 ppm SO 2 and 4 × 104 ppm H 2 O. Cu(3)-HPMo/TiO 2 with strong surface acidity suppressed SO 2 adsorption and showed good SO 2 resistance. SO 2 in the gas phase diffused more strongly at the concentration of 600 ppm than at 400 ppm. The catalytic activity of Cu(3)-HPMo/TiO 2 decreased in the presence of 600 ppm of SO 2 and the FT-IR and TG results indicated that copper sulfate was formed. Density functional theory (DFT) calculation was used to study the adsorption states of SO 2 and H 2 O on the catalyst surface, and the results indicated that SO 2 could not form chemical adsorption on the HPMo surface. Based on the results of experiments, characterization and DFT calculation, the core-shell structure of active components was speculated. This structure was related to the anti-sulfur and anti-water properties of Cu-HPMo/TiO 2. [ABSTRACT FROM AUTHOR]

An acidic polysaccharide was isolated from immature peach (Prunus persica) exudates (designated as PGP). The primary structure and conformational properties were characterized by methylation and GC-MS analysis, NMR spectra, and high performance size exclusion chromatography (HPSEC) coupled with multiple detectors. Results showed that PGP was mainly consisted of arabinose (48.5%, w/w) and galactose (33.8%, w/w), with small amount of xylose (4.0%, w/w), glucuronic acid (4.3%, w/w) and galacturonic acid (2.3%, w/w) as well as trace mannose. A β-(1 → 6)-galactan backbone with branches of long α-(1 → 3)-arabinan at O -4 position of galactose, and α-(1 → 5)-Ara f at O -3 position of galactose terminated by α-Ara f and occasionally β-4-OMe-Glc p A was proposed to PGP. Conformational studies revealed that PGP presented as hyper-branched compact spherical conformation, with weight average molecular weight (Mw) of 1.40 × 104 kDa, radius of gyration (R g) of 223.4 nm, and intrinsic viscosity ([ η ]) of 2.76 dL/g in aqueous solution. High concentrations of PGP (5% and 10%, w/v) demonstrated good emulsifying stability on the O/W emulsion by inhibiting coalescence and flocculation, stabilizing the particle size, and increasing the zeta-potential of emulsion system, suggesting it could be an alternative material as emulsion stabilizer used in food industry. Image 1 • A hyper-branched β-(1. → 6)-galactan-core arabinogalactan was proposed for PGP. • PGP presented as compact spherical conformation with high Mw in aqueous solution. • High concentration of PGP showed good emulsifying stability on O/W emulsion. • The highly branched and spherical structure were the pivotal factors for its emulsifying function. [ABSTRACT FROM AUTHOR]