Phenol-sulfuric Acid Method Research Articles

Optimisation of Bioflocculation Using Anabaena sp. and Navicula sp. for Harvesting of Glagah Microalgae Consortium

One of the problems in microalgae is harvesting. Currently, many chemical methods are used that impact the environment. Not all of them can be used as a filter, so bioflocculation is used because there is no need to change the medium. This method is an environmentally friendly and efficient alternative to chemical flocculants that usually cause contamination of biomass and health. Previous studies have shown that different ratios of auto-flocculated microalgae in cocultures affect the flocculation rate. This research was carried out by the Glagah Consortium bioflocculation using Anabaena sp. and Navicula sp., which had never been done before. The study aims to study the effect of the mixing ratio on the flocculation rate, carbohydrates, and lipid content of the Glagah Consortium. The consortium uses Anabaena sp. and Navicula sp. as bioflocculants. Glagah and Anabaena sp. consortium was cultured in Bold Basal Medium, while Navicula sp. was cultured in F/2 medium. Cell density was measured every 24 hr for 8 days with a hemocytometer. The cultures were harvested in the stationary phase, then mixed between non-flocculated microalgae (Glagah Consortium) and flocculated microalgae (Anabaena sp., Navicula sp.) in a ratio of 1:1, 1:0.5, and 1:0.25 for 24 hr. Bioflocculation was measured by spectrophotometer at 750 nm 0 and 24 hr after mixing. Carbohydrate levels were measured using the phenol sulfuric acid method, while lipid measurements were performed using the Bligh and Dyer method. The addition of Anabaena sp. and Navicula sp. as bioflocculant in Glagah Consortium culture results in an increase in flocculation rate with an effective ratio of 1:0.25 for Anabaena sp. (81%) and 1:1 for Navicula sp. (95%). Mixing of Anabaena sp. and Glagah Consortium results in carbon source competition, reducing carbohydrate content at higher mixing ratios (0.172, 0.364, and 0.500 mg/ml on 1, 1:0.5, and 1:0.25) while increasing lipid content as a result of lipid production in stationary phase (highest on ratio 1:1 = 0.011 mg/ml). Navicula sp. and Glagah Consortium mixture caused no significant changes to carbohydrate content but showed an increased amount of lipid at all ratios as a result of osmotic stress on Glagah Consortium from saline F/2 medium (highest on ratio 1:1 = 0.162 mg/ml).

Optimization of microplate-based phenol-sulfuric acid method and application to the multi-sample measurements of cellulose nanofibers

The phenol-sulfuric acid (PSA) method is a widely used colorimetric method for determining the total saccharides. Microplate-based PSA methods have been developed to handle a large number of samples and reduce the use of hazardous chemicals. However, the optimal procedures and measurement conditions for this method have not yet been fully established. To address this gap, we investigated the optimal procedure for microplate-based PSA. In addition to glucose (Glc), two types of cellulose nanofibers (CNFs) were also evaluated as they are a new type of nanomaterial, and a technique to quantify the concentration of CNFs is required in their safety assessment. The results showed that the thermal reaction with sulfuric acid before the addition of phenol resulted in a higher coloration than was shown after the addition of phenol. Furthermore, the longer the resting time after shaking with phenol, the greater the coloration and smaller the variation, with a resting time of 60 min or longer being optimal. This research provides valuable insights into improving the reliability and efficiency of the PSA method, which can facilitate the analysis of saccharides and other substances in a range of applications.

Accession variation in starch, chlorophyll, and antioxidant content of cardamom (Amomum cardamomum) leaves

Cardamom (Amomum cardamomum) is a herbal plant with various phytochemical compounds such as phenols, starch, tannins, terpenoids, flavonoids, and antioxidants. Cardamom of the same type but originating from different regions can produce variations in the content of metabolites. This study aimed to select cardamom accession containing high starch, chlorophyll, and antioxidant capacity. The research was conducted at Biopharmaca Experimental Garden, Cikabayan IPB University from March to August 2022 using four cardamom accessions, i.e., Bogor Hijau, Bogor Merah, Ciamis and Sukabumi. Three leaves were taken for each accession, with three replications. The leaves taken were numbers 5, 6, and 7 counted from the tops of the cardamom plant. The methods used in this study were the phenol-sulfuric acid method, the DMSO method, the DPPH method, and the CUPRAC method. The results showed that the highest starch content was produced by the cardamom of Bogor Merah accession, with an average of 3.63 g (100 g)-1 FW. The highest total chlorophyll content was found in the cardamom of Bogor Hijau accession, with an average of 1.9 mg g-1 FW. At the same time, the highest antioxidant capacity using the DPPH method was produced by the cardamom of the Sukabumi accession with an average of 1.28 μmol TE g-1 FW. In comparison, the highest antioxidant capacity of the CUPRAC method was produced by the cardamom of the Bogor Hijau accession with an average of 5.71 µmol TE g-1 FW. Thus, it is recommended to use Bogor Merah dan Bogor Hijau accession for further evaluation.
 Keywords: accession, antioxidant activity, cardamom leaves, chlorophyll, starch

Different carbon source alternative medium improves Euglena sp. growth and paramylon production

Euglena sp. is a type of microalgae are widely recognized for producing an important compound called paramylon. If Euglena sp. is grown in a medium containing a carbon source, it can produce more paramylon. The culture medium alternative must be optimized to maximize biomass production and specifically targeted metabolites. This study aims to compare the effects of glucose and glutamic acid as carbon sources on the growth rate, biomass, and paramylon (β-1,3-glucan) content of Euglena species. The treatment that carried out as the different organic carbon sources were glucose and glutamic acid. About one g/l of each treatment were added to Cramers and Myers (CM) culture medium to see how they affected growth rate, biomass, and paramylon content in Euglena sp. culture. The optical density based on absorbance was used to calculate the density of the cells, biomass was known by measuring the dry weight, and paramylon content produced was analyzed using the phenol-sulfuric acid method. The CM medium treatment with glucose added (CM+Glucose) had the highest specific growth rate, biomass, and paramylon content, with values of 2.902±0.338 (OD680/dx10-1), 0.476±0.023 g/l, and 2.416±0.129 mg/ml Euglena sp. can be utilized to produce paramylon on an industrial scale, so it is necessary to carry out further identification process regarding the species of Euglena sp. local strain, and it is hoped that there will be further research on other possible methods to increase the paramylon content in Euglena sp., such as using organic waste to replace the organic carbon source in the medium.

Selection of oleaginous yeasts isolated from sugarcane bagasse as the potential producers of single cell oils and other metabolites

PurposeThe microorganisms that possess diverse and improved traits for biotechnological applications provide an opportunity to address some of the current industrial challenges such as the sustainability of fuel energy and food. The aim of this study was to isolate and select the potential yeast isolates from sugarcane bagasse for single oil production.MethodsThe oleaginocity of the yeasts was confirmed through a gravimetric analysis of lipids, Nile red, sulfo-phosphovanillin (SPV) and a gas chromatography method for fatty acid methyl esters (FAME). The identification of the selected yeasts was carried out through a 5.8S of the ribosomal internal transcribed spacer (ITS) and 26S ribosomal DNA (rDNA) sequences. The carbohydrate and protein contents were estimated using phenol-sulfuric acid and hot trichloroacetic acid method, respectively.ResultsThe yeast isolates accumulated lipids of between 28% and 67% of the dry cell weight, and 22–33% based on the SPV assay, qualifying them as oleaginous yeasts. The selected yeasts were identified as Candida ethanolica and Pichia manshuriica. The lipids contained high levels of fatty acids in the following order: oleic acid, palmitic acid, stearic acid, and linoleic acid, which made up 82% of the total lipids.ConclusionAll the six selected yeast strains have the potential to produce single cell oils and other metabolites. The fatty acids composition of the selected yeast species was found to be suitable for the applications in biofuel, nutraceutical, and food industry. The yeast strains require evaluation in lignocellulosic hydrolysate for the production of single cell oils to be cost effective.

Major Active Metabolite Characteristics of Dendrobium officinale Rice Wine Fermented by Saccharomyces cerevisiae and Wickerhamomyces anomalus Cofermentation.

Rice, supplemented with Dendrobium officinale, was subjected to cofermentation using Saccharomyces cerevisiae FBKL2.8022 (Sc) and Wickerhamomyces anomalus FBKL2.8023 (Wa). The alcohol content was determined with a biosensor, total sugars with the phenol-sulfuric acid method, reducing sugars with the DNS method, total acids and total phenols with the colorimetric method, and metabolites were analyzed using LC-MS/MS combined with multivariate statistics, while metabolic pathways were constructed using metaboAnalyst 5.0. It was found that the quality of rice wine was higher with the addition of D. officinale. A total of 127 major active substances, mainly phenols, flavonoids, terpenoids, alkaloids, and phenylpropanoids, were identified. Among them, 26 substances might have been mainly metabolized by the mixed-yeasts fermentation itself, and 10 substances might have originated either from D. officinale itself or from microbial metabolism on the newly supplemented substrate. In addition, significant differences in metabolite could be attributed to amino acid metabolic pathways, such as phenylalanine metabolism and alanine, aspartate, and glutamate metabolism. The characteristic microbial metabolism of D. officinale produces metabolites, which are α-dihydroartemisinin, alantolactone, neohesperidin dihydrochalcone, and occidentoside. This study showed that mixed-yeasts cofermentation and fermentation with D. officinale both could increase the content of active substances in rice wine and significantly improve the quality of rice wine. The results of this study provide a reference for the mixed fermentation of brewer's yeast and non-yeast yeasts in rice wine brewing.

Lactic Acid Bacteria Screening of High-yield LAB-EPS and its Application in Steamed Buns

In this experiment, the lactic acid bacteria ZH-7 with the strongest ability to produce exopolysaccharides were isolated and screened from the sourdough, and after 16s RNA identification, it was determined to be a Class I lactic acid bacterium (ZH-7), and the yield of its exopolysaccharides was determined by phenol-sulfuric acid method. The effects of fermentation characteristics and steamed bun quality were explored by combining the fermentation characteristics of dough and the quality of steamed buns by combining different lactic acid bacteria (ZH-3), Class I lactic acid bacteria (ZH-7) and Class III lactic acid bacteria (ZH-2). Through single-factor test and orthogonal test, according to the sensory evaluation of steamed bun and the texture of steamed bun, the best time for fermentation of steamed bun and the best combination of culture compound were explored.

Enhacment of biomass, carbohydrates, lipids, and proteins content using co-culture of Glagah consortium and Lipomyces starkeyi

Microorganisms have a high potential as biofuel sources. Co-culture of microalgae and yeasts can result in high lipid production as a modification treatment. The goal of this study was to see how the co-culture of the Glagah consortium (diversity of associated microalgae and bacteria from Glagah Lagoon, Yogyakarta) and Lipomyces starkeyi affected the production of biomass, lipids, proteins, and carbohydrates. The culture was performed under airtight conditions on a shaker at 127 rpm, with a light intensity of 27.75 mol/m2/s and a temperature of 30°C. The culture was subjected to a dark: light (6:18) treatment. Biomass was measured by dry weight, lipids by the Bligh and Dyer method, proteins by the Bradford method and carbohydrates by the phenol-sulfuric acid method. On day 3, L. starkey culture produced the most biomass, yielding 2.21 g/L with a productivity of 0.49 g/L/day. On day 4, the highest lipids produced from co-culture treatment yielded 1.03 g/g with a productivity of 0.21 g/L/day. The highest protein yield was obtained from L. starkeyi culture treatment on day 4, yielding 0.60 g/g with a productivity of 0.12 g/L/day. On day 6, co-culture produced the total carbohydrates, yielding 4.78 g/g with a productivity of 0.68 g/L/day. The co-culture treatment produced the highest lipids and carbohydrates production (1.03 g/g and 4.78 g/g) and productivity (0.21 g/L/day and 0.68 g/L/day), while L. starkeyi culture produced the highest total biomass and protein production (2.21 g/L and 0.6 g/g) and productivity (0.49 g\L\day and 0.12 g/L/day). In microalgae culture, CO2 generally given directly through the aeration process. In this study, the source of CO2 was yeast, whereas yeast also obtained O2 from microalgae in the consortium for their metabolic process. This mutualism symbiosis will help in providing benefits in reducing the costs for the cultivation process, especially in optimizing the production of biomass an lipids.

Anti-biofilm and bacteriostatic effects of three flavonoid compounds on Streptococcus mutans

Streptococcus mutans (S. mutans) is the main cariogenic pathogen associated with dental caries. Orientin-2''-O-β-L-galactoside, orientin and vitexin are natural flavonoids compound. In this study, the antibacterial ability of these flavonoids and their mechanisms in inhibiting S. mutans biofilm formation were investigated. Inhibition zone and 2-fold-dilution tests showed that these flavonoids exerted inhibitory effects on S. mutans. Phenol sulfuric acid method and lactate dehydrogenase (LDH) test revealed that they could reduce EPS formation and stimulate S. mutans to release LDH. Moreover, crystal violet and live/dead bacterial staining test showed that they inhibited biofilm formation. Finally, qRT-PCR test indicated that the down-regulated the transcription levels of spaP, srtA, brpA, gtfB and luxS genes of S. mutans. In conclusion, orientin-2''-O-β-L-galactoside, orientin and vitexin had antibacterial and anti-biofilm activities.

Metabolomics-Based Analysis of the Effects of Different Cultivation Strategies on Metabolites of Dendrobium officinale Kimura et Migo.

Dendrobium officinale Kimura et Migo is a famous plant with a high medicinal value which has been recorded in the Chinese Pharmacopoeia (2020 Edition). The medicinal properties of D. officinale are based on its chemical composition. However, there are no reports on how different cultivation methods affect its chemical composition. In order to reveal this issue, samples of the D. officinale were collected in this study through tree epiphytic cultivation, stone epiphytic cultivation, and greenhouse cultivation. Polysaccharides were determined by phenol sulfuric acid method and secondary metabolites were detected by the UPLC-MS technique. In addition, with regards to metabolomics, we used multivariate analyses including principal component analysis (PCA) and orthogonal partial least squares analysis (OPLS-DA) to screen for differential metabolites which met the conditions of variable importance projection values >1, fold change >4, and p < 0.05. The differential metabolites were taken further for metabolic pathway enrichment analysis, which was based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and validated by antioxidant activity. Comparing the three groups of samples according to the standards of the ChP (2020 edition), the results showed that the polysaccharide content of the samples from stony epiphytic cultivation and greenhouse cultivation was significantly higher than that of the samples from live tree epiphytic cultivation. Metabolomic analysis revealed that there were 185 differential metabolites among the 3 cultivation methods, with 99 of the differential metabolites being highest in the stone epiphytic cultivation. The results of the metabolic pathway enrichment analysis showed that the different cultivation strategies mainly effected four carbohydrate metabolic pathways, five secondary metabolite synthesis pathways, six amino acid metabolic pathways, one nucleotide metabolism pathway, three cofactor and vitamin metabolism pathways, and one translation pathway in genetic information processing. Furthermore, D. officinale from stone epiphytic cultivation which had the best antioxidant activity was implicated in differential metabolite production. This study revealed the effects of different cultivation methods on the chemical composition of D. officinale and also provided a reference for establishing the quality control standards to aid its development and utilization.

An improved phenol-sulfuric acid method for the quantitative measurement of total carbohydrates in algal biomass

Total carbohydrate analysis with phenol‑sulfuric acid method is the simplest method among many colorimetric and modern instrument analytical methods. It has great potential to be used as a rapid screening method for characterization of algal biomass for algae-based biofuel research. The reproducibility and accuracy of the conventional phenol‑sulfuric method remain to be improved when applied directly to algal biomass. In the present study, several important factors that influenced the colorimetric determination were characterized and methods to eliminate the influences were further developed. Results indicated that system temperature and the addition mode of sulfuric acid and phenol were the key parameters which affected the color development and reproducibility of the conventional methods. A new design using the premixed reagent replacing the individual phenol and sulfuric acid solution solved this problem ideally. The color inferences caused by algal pigments including chlorophylls and carotenoids were quantitatively analyzed. Solutions for reducing overestimation of total carbohydrates were also addressed. In addition, hydrolysis conditions for algae biomass such as type of acids, temperature, and time were also investigated and optimized in this study. The new modified phenol‑sulfuric acid method has been shown to be more reproducible and reliable than the conventional methods for the analysis of total carbohydrates from algal biomass.

Functional improvements in β-conglycinin by preparing edible bioconjugates with ε-polylysine and dextran.

β-Conglycinin was conjugated with ε-polylysine (PL) by means of microbial transglutaminase (MTGase) to improve its function. The β-conglycinin-PL conjugate was purified by dialysis. Composition of the β-conglycinin-PL was β-conglycinin:PL = 1:18 (molar ratio) which was confirmed by amino acid analysis. The β-conglycinin-PL was further conjugated with dextran (Dex) by the Maillard reaction. The β-conglycinin-PL-Dex conjugate was purified by dialysis. Conjugation was confirmed by SDS-PAGE and PAS staining. Composition of the β-conglycinin-PL-Dex was β-conglycinin-PL:Dex = 1:41 (molar ratio) which was confirmed by UV spectra measurement and phenol sulfuric acid method. Solubility of β-conglycinin in the acidic range was much improved by conjugation with PL and further improved by further conjugation with Dex. Emulsifying property of β-conglycinin in acidic pH range was much improved by conjugation with PL and Dex. Immunogenicity of β-conglycinin was decreased by conjugation with PL and Dex.

Production and Optimization of Exopolysaccharide from Thermophilic Bacteria

Exopolysaccharides (EPS) are the large molecular weight carbohydrate polymers extracted from higher plants, algae, fungi and bacteria. The thermophilic Bacillus zhangzhounesis 2CA and Bacillus licheniformis 2CS used in the present study were isolated from Çermik hot springs. The growth conditions of the strains designated as 2CA and 2CS in different basal media (M1, M2 and M3), different carbon sources and different concentrations of yeast extract (%w v-1: 0.05, 0.1, 0.15 and 0.2) and the amount of EPS produced were investigated. In addition, the phenol-sulfuric acid method and the Lowry method were used to determine the amount of carbohydrates and proteins within the EPS produced by the bacteria, respectively. The highest total EPS dry weight for B. licheniformis 2ÇS was obtained as 121 mg in M3 medium (0.2% yeast extract + 1% sucrose), carbohydrate content in EPS was 333.28 µg mL-1 and protein content was 0.19 µg mL-1. When these two bacteria were compared in terms of the amount of carbohydrates in the EPS produced, the highest amount of carbohydrates was found in EPS of B. zhangzhounesis 2CA (1087.03 µg mL-1). The antibacterial effects of EPS were investigated against pathogenic microorganisms (E. coli, S. aureus, K. pneumoniae and P. aeruginosa). It was determined that the highest antibacterial activity against E. coli (with 16 mm zone diameter) was obtained with EPS produced by B. licheniformis 2ÇS bacteria in M3 medium (0.2% yeast extract + 1% sucrose).

Green acidic catalyst from cellulose extracted from sugarcane bagasse through pretreatment by electron beam irradiation and subsequent sulfonation for sugar production

The objective of this research is to prepare a green acidic catalyst from cellulose derived from sugarcane bagasse (SB). Initially, SB was pretreated by electron beam irradiation with a dose of 50 kGy to 200 kGy and subsequent acid hydrolysis to obtain cellulose. The cellulose derived from SB was carbonized at different temperatures for 4 h and then sulfonated with heating at 120°C under reflux. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to confirm the successful preparation of acidic catalyst by irradiation pretreatment and subsequent sulfonation. The cellulose derived from irradiated SB at the lowest dose of 50 kGy was used as a representative irradiated sample for comparison with non-irradiation. Scanning electron microscope image of sulfonated biochar was observed pores with various sizes. The existence of sulfur atom onto sulfonated biochar surface was investigated by Energy dispersive X-ray spectroscopy. After sugar production by sulfonated biochar as an acidic catalyst, the total sugar content was measured by a phenol-sulfuric acid method using a UV-Vis spectrophotometer. The total sugar with 94.51 ± 1.35% content was found when the acidic catalyst was performed. It was remarkable to note that sulfonated biochar prepared from cellulose derived from SB after pretreatment and sulfonation exhibited outstanding result for being as an acidic catalyst for sugar production.

Functional improvements in β-conglycinin by edible bioconjugation with carboxymethyl dextran.

β-Conglycinin was conjugated with carboxymethyl dextran (CMD) by the Maillard reaction to improve its function. The β-conglycinin-CMD conjugate was purified by dialysis. Conjugation was confirmed by SDS-PAGE with CBB and PAS staining. Composition of the β-conglycinin-CMD was β-conglycinin:CMD = 1:2.7 (molar ratio) which was confirmed by BCA method and phenol sulfuric acid method. Solubility of β-conglycinin in the range of pH 2.0-7.0 was much improved by conjugation with CMD. Emulsifying property of β-conglycinin at pH 7 and in presence of salt was improved by conjugation with CMD. Immunogenicity of β-conglycinin was reduced by conjugation with CMD. Conjugation method performed in this study was considered to be valuable in that it can be used in food processing.

The enhanced expression of genes encoding diguanylate cyclases under cold stress contributes to the adhesion and biofilm formation of Shewanella putrefaciens WS13.

Shewanella putrefaciens is a special spoilage bacterium of seafood during cold storage, which is easy to form biofilm and bring serious hazard to the seafood quality. Life cycle of biofilm starts after bacterial adhesion, which is essential for the formation and development of biofilm. As a ubiquitous second messenger in bacteria, c-di-GMP regulates the conversion between bacterial planktonic state and biofilm state. In this study, the adhesion and biofilm formation of S. putrefaciens WS13 under 4°C were compared to those under 30°C. Atom force microscope and scanning electron microscope were used to study the bacterial adhesion. Biofilm was analyzed by Fourier transform infrared spectroscopy, Bradford assay and phenol-sulfuric acid method. High-performance liquid chromatographic-tandem mass spectrometric and quantitative real-time PCR were applied to study c-di-GMP level and genes encoding diguanylate cyclases in cells, respectively. Results showed that the swarming mobility of S. putrefaciens WS13 was weaker under 4°C, however, the adhesive force under 4°C was 4-5 times higher than that under 30°C. Biofilm biomass, extracellular polysaccharides and extracellular proteins were 2.5 times, 3 times, and 1.6 times more than those under 30°C, respectively, but biofilm composition formed under both temperatures were similar. c-di-GMP level in S. putrefaciens WS13 under 30°C was no more than half of that in the corresponding growth stage under 4°C. Quantitative real-time PCR analysis also showed that the expression of genes encoding diguanylate cyclases were significantly enhanced under 4°C than that under 30°C. S. putrefaciens WS13 adapted to the cold stress by enhancing the expression of genes encoding diguanylate cyclases to promote bacterial adhesion and biofilm formation. This study provides a theoretical foundation for the research on the cold adaptation mechanism of specific spoilage bacteria of seafood based on c-di-GMP, and also provides a new idea to control seafood quality from the perspective of microbial molecular biology.

Rapid Determination of Polysaccharides in Cistanche Tubulosa Using Near-Infrared Spectroscopy Combined with Machine Learning.

Cistanche tubulosa, as a homology of medicine and food, not only has a unique medicinal value but also is widely used in healthcare products. Polysaccharide is one of its important quality indicators. In this study, an analytical model based on near-infrared (NIR) spectroscopy combined with machine learning was established to predict the polysaccharide content of C. tubulosa. The polysaccharide content in the samples determined by the phenol-sulfuric acid method was used as a reference value, and machine learning was applied to relate the spectral information to the reference value. Dividing the samples into a calibration set and a prediction set using the Kennard-Stone algorithm. The model was optimized by various preprocessing methods, including Savitzky-Golay (SG), standard normal variate (SNV), multiple scattering correction (MSC), first-order derivative (FD), second-order derivative (SD), and combinations of them. Variable selection was performed through the successive projections algorithm (SPA) and stability competitive adaptive reweighted sampling (sCARS). Four machine learning models were used to build quantitative models, including the random forest (RF), partial least-squares (PLS), principal component regression (PCR), and support vector machine (SVM). The evaluation indexes of the model were the coefficient of determination (R2), root-mean-square error (RMSE), and residual prediction deviation (RPD). RF performs best among the four machine learning models. R2c （calibration set coefficient of determination） and RMSEC （root mean square error of the calibration set）, %, were 0.9763. and 0.3527 for calibration, respectively. R2p （prediction set coefficient of determination）, RMSEP （root mean square error of the prediction set）, %, and RPD were 0.9230, 0.5130, and 3.33 for prediction, respectively. The results indicate that NIR combined with the RF is an effective method applied to the quality evaluation of the polysaccharides of C. tubulosa. Four quantitative models were developed to predict the polysaccharide content in C. tubulosa, and good results were obtained. The characteristic variables were basically determined by the sCARS algorithm, and the corresponding characteristicgroups were analyzed.

Virulence and biofilm inhibition of 3-methoxycinnamic acid against Agrobacterium tumefaciens.

In the current study the anti-virulence and anti-biofilm activities of the cinnamic acid derivative, 3-methoxycinnamic acid, was investigated against Agrobacterium tumefaciens. Based on the disc diffusion test and β-galactosidase activity assay, 3-methoxycinnamic acid was shown to interfere with the quorum sensing (QS) system of A. tumefaciens. Crystal violet staining assay, phenol-sulfuric acid method, Bradford protein assay and confocal laser scanning microscopy (CLSM) revealed that the biofilm formation of A. tumefaciens was inhibited after the treatment of 3-methoxycinnamic acid. Employing high-performance liquid chromatography (HPLC) analysis of culture supernatant revealed that the production of 3-oxo-octanoylhomoserine lactone (3-oxo-C8-HSL) decreased concentration-dependently after treatment with 3-methoxycinnamic acid. Swimming and chemotaxis assays also indicated that 3-methoxycinnamic acid had a good effect on reducing the motility and chemotaxis of A. tumefaciens. In addition, the RT-qPCR, molecular docking and simulations further demonstrated that 3-methoxycinnamic acid could competitively inhibit the binding of 3-oxo-C8-HSL to TraR and down-regulate virulence-related genes. 3-Methoxycinnamic acid is proved to have good anti-virulence and anti-biofilm activities against A. tumefaciens. This is the first study that investigates the anti-virulence and anti-biofilm activities of 3-methoxycinnamic acid against A. tumefaciens. With its potential QS-related virulence and biofilm inhibitory activities, 3-methoxycinnamic acid is expected to be developed as a potent pesticide or adjuvant for the prevention and treatment of crown gall caused by A. tumefaciens.

Huaier Polysaccharide Attenuates Doxorubicin-Induced Acute Cardiotoxicity by Regulating Ferroptosis

We studied the effects of Huaier polysaccharide (HP) in doxorubicin-induced myocardial injury in mice. The content of HP in Trametes robiniophila Murr medicinal fungus determined by the phenol-sulfuric acid method was 85.25%. In the in vitro model, the viability of H9c2 cells was significantly increased after HP treatment compared to the control, while doxorubicin (DOX) decreased this parameter. The inhibitory effect of DOX on cell viability was attenuated after HP treatment. In the in vivo model, the body weight of mice in DOX and DOX+HP groups was significantly decreased compared to the control group. ECG showed significantly elevated ST segment in the DOX group, while in the DOX+HP group, ECG was close to normal. The levels of cardiotoxicity markers cTnI and lactate dehydrogenase in the DOX+HP group were significantly lower than in the DOX group. In the DOX group, the myocardial tissue had obvious structural disorder and interfibrillar vacuoles. In the DOX+HP group, the cardiomyocytes were neatly arranged without interfibrillar vacuoles. The expression of the ferroptosis marker glutathione peroxidase 4 was increased in the DOX+HP group compared to the DOX group. Thus, our study reveals that HP attenuated DOX-induced myocardial injury in mice probably by regulating ferroptosis.

Acid Hydrolysis of Pectin and Mucilage from Cactus (Opuntia ficus) for Identification and Quantification of Monosaccharides

Pectin and mucilage are polysaccharides from the cactus Opuntia ficus-indica, which are also known as hydrocolloids, with useful properties in industries such as food, pharmaceuticals, and construction, among others. In the present work, cactus hydrocolloids were hydrolyzed characterized using two techniques: first, thin-layer chromatography, to identify the monosaccharides present in the sample, followed by the phenol–sulfuric acid method to determine the monosaccharide content. The hydrolyzing method allowed us to reduce the processing time to 180 min and, considering the identification and quantification procedures, the proposed methodology is much simpler and more cost-effective compared to other methods, such as high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and mass spectrometry. The analysis of the results revealed that the maximum concentration of monosaccharides was obtained after hydrolyzing for 90 min. Under such conditions, with pectin being the main component contained in the cactus hydrocolloids analyzed here, galacturonic acid was found in the largest quantities.