Metagenomic analysis revealing the metabolic role of microbial communities in the free amino acid biosynthesis of Monascus rice vinegar during fermentation

Free amino acid(FAA)is the important component of vinegar that infl uences quality perception and consumer acceptance.FAA is one of the major metabolites produced by microorganisms;however,the microbial metabolic network on FAA biosynthesis remains unclear.Through metagenomic analysis,this work aimed to elucidate the roles of microbes in FAA biosynthesis during Monascus rice vinegar fermentation.Taxonomic profiles from functional analyses showed 14 dominant genera with high contributions to the metabolism pathways.The metabolic network for FAA biosynthesis was then constructed,and the microbial distribution in different metabolic pathways was illuminated.The results revealed that 5 functional genera were closely involved in FAA biosynthesis.This study illuminated the metabolic roles of microorganisms in FAA biosynthesis and provided crucial insights into the functional attributes of microbiota in vinegar fermentation.

Effect of vinegar supplementation on patients with esophageal lesions lightly stained with Lugol’s iodine solution:Prospective single-centre trial

BACKGROUND Esophageal chromoendoscopy with iodine solution is important for detecting early esophageal cancer.The effect of routine treatment for lesions lightly stained with Lugol’s iodine solution is limited,and the addition of natural substances to a regular diet is becoming increasingly common.Vinegar has antitumor effects as reported in previous studies.AIM To evaluate whether vinegar supplementation could improve the prognosis of patients with lightly stained esophageal lesions.METHODSThis prospective single-centre trial included consecutive patients with lightly stained lesions between June 2020 and April 2022.Patients in the experimental group received increased amounts of vinegar for 6 months.The primary outcome of the study was the clinical therapeutic effect.Complications related to vinegar ingestion and adverse events were also recorded in detail.RESULTS A total of 166 patients were included in the final analysis.There was no significant difference in the baseline data between the two groups.Intention-to-treat(ITT)analysis demonstrated that the rates at which endoscopic characteristics improved were 33.72%in the experimental group and 20.00%in the conventional group(P=0.007);and the rates at which biopsy pathology improved were 19.77%and 8.75%,respectively(P=0.011).Additional vinegar consumption had a statistically protective effect on the rate at which endoscopic characteristics improved[hazard ratio(HR)_(ITT)=2.183,95%CI:1.183-4.028;HR_(per-protocol(PP))=2.307,95%CI:1.202-4.426]and biopsy pathology improved(HR_(ITT)=2.931,95%CI:1.212-7.089;HR_(PP)=3.320,95%CI:1.295-8.507).No statistically significant effect of increased vinegar consumption on preventing high-grade intraepithelial neoplasia or early cancer was observed(HR_(ITT)=0.382,95%CI:0.079-1.846;HRPP=0.382,95%CI:0.079-1.846).The subgroup analyses indicated that the overall therapeutic improvement of endoscopic characteristics and biopsy pathology seemed more obvious in older(age>60)male patients with small lesions(lesion size≤0.5 cm).Three patients in the experimental group reported acid regurgitation and heartburn.No adverse event during gastroscopy were recorded during follow-up.CONCLUSION A moderately increased ingestion of vinegar could not directly reduce the risk of esophageal cancer in the mucosa dysplasia population,but it improved the endoscopic characteristics and ameliorated the biopsy pathology to a certain extent.Further research is needed to verify the effect of nutritional intervention on precancerous esophageal lesions.

Production of Vinegar Mango Using Acetobacter tropicalis CRSBAN-BVA1 and CRSBAN-BVK2 Isolated from Burkina Faso

Production and quality of vinegar from mango juice was evaluated using a two steps production procedure. The first step of fermentation was done using Saccharomyces cerevisae KVL013 for 7 days. The second step, an acetic fermentation was realized using two acetic acid bacteria: A. tropicalis CRSBAN-BVA1 and A. tropicalis CRSBAN-BVK2 for 21 days. Several parameters of the vinegar produced such as physico-chemical and sensory properties were determined. Microbial density during each step was monitored. Results showed that pH, alcoholic and acetic acid contents of vinegar were respectively 2.97%, 7% and 4.54% g/ml respectively by using A. tropicalis CRSBAN-BVA1 and 3.02%, 7% and 4.32% g/ml with A. tropicalis CRSBAN-BVK2. Sensory evaluation revealed that the vinegar was acceptable to the panellists. Results of microbial density showed that the maximum concentration of cell biomass produced was 4.32 × 108 and 4.25 × 108 CFU/ml respectively for CRSBAN-BVA1 and CRSBAN-BVK2.

Response Surface Methodology as an Approach for Optimization of Vinegar Fermentation Conditions Using Three Different Thermotolerant Acetic Acid Bacteria

This study aimed to investigate optimal fermentation conditions of biological acetic acid fermentation for vinegar production. Optimization was performed on 3 acetic acid bacteria strains namely VMA1, VMA7 and VMAO using Response Surface Methodology (RSM). A Box-Behnken-Design (BBD) was achieved with three different independent process parameters involving: fermentation temperature, original alcohol concentration and original acetic acid concentration and one dependent variable (acetic acid yield). The results showed that the mathematical models describe correctly the relationship between responses and factors (F values of the models (p R2 (coefficient of correlation) respectively 0.96, 0.94, 0.98, and adjusted R2 0.95, 0.92, 0.98). The maximum acidity was obtained respectively at fermentation temperatures, original alcohol concentrations and original acetic acid concentrations ranging from [37.5°C - 45°C], [16% - 20% (v/v)], [1.5% - 2% (w/v)] for VMA1, [40°C - 45°C], [14.5% - 20% (v/v)], [1.7% - 2% (w/v)] for VMA7 and [42°C - 45°C], [17% - 20% (v/v)], [1.5% - 2% (w/v)] for VMAO. The use of these acetic strains in the production of vinegar may seriously lead to a decrease or even an ablation of the costs related to the cooling of bioreactors especially in warm and hot countries, in the context of global warming.

Impacts of dietary supplementation of bamboo vinegar and charcoal powder on growth performance,intestinal morphology,and gut microflora of large-scale loach Paramisgurnus dabryanus

Although accumulating data demonstrate that dietary supplementation of bamboo vinegar and charcoal powder(BVC)can significantly strengthen the immunity and boost the growth of domestic animals,its application potency still awaits verification in commercial fish species such as the large-scale loach Paramisgurnus dabryanus.The impacts of 90-day dietary supplementation of 1%and 2%BVC on survival and growth performance of the loach,and on the intestinal morphological characteristics and gut microflora were analyzed.Our data show that the large-scale loach supplied with BVC at the experimental doses had significant higher survival rates and better growth performance(indicated by greater weight gain(1.13–1.14 times),higher specific growth rate(1.04 times),and lower feed conversion ratio(0.88–0.89 times))compared to that of the control(P<0.05).Histological examination revealed significant longer villus(3.22–5.54 times),deeper crypt(1.77–1.87 times),and thicker muscle(1.59–3.17 times)in the intestines of large-scale loach fed with BVC(P<0.05).Furthermore,we found that the gut microflora consisted of significantly fewer proportions of potential pathogenic bacterial species(Aeromonas veronii and Escherichia coli),but significantly greater proportions of beneficial microbes(Lactococus raffinolactis and Faecalibacterium prausnitzii).Therefore,dietary intake of BVC can promote intestinal tract development and optimize gut microflora,by which the survival and growth of large-scale loach may be improved.

Effects of Biochar and Wood Vinegar on Labile Phosphorus Pool in Soda Saline-Alkaline Soil

A pot experiment was conducted to research the effect of biochar and wood vinegar on labile phosphorus fractions in saline-alkali soil.There were eight treatments,including CK(0 kg•hm-2 biochar+0 kg•hm-2 wood vinegar),C1(0.6 t•hm-2 biochar),C2(0.6 t•hm-2 wood vinegar),C3(1.2 t•hm-2 wood vinegar),C4(1.8 t•hm-2 wood vinegar),C5(0.6 t•hm-2 biochar+0.6 t•hm-2 wood vinegar),C6(0.6 t•hm-2 biochar+1.2 t•hm-2 wood vinegar),and C7(0.6 t•hm-2 biochar+1.8 t•hm-2 wood vinegar).The results showed that biochar without wood vinegar and the co-application of biochar and wood vinegar significantly increased soil total phosphorus content.Meanwhile,compared with CK,all of treatments increased resin phosphorus and sodium bicarbonate-extracted inorganic phosphorus(NaHCO3-Pi)contents in saline-alkali soil.Especially,the contents of resin phosphorus and NaHCO3-Pi under C5,C6,and C7 treatments were higher than those of C2,C3,and C4 treatments,respectively,indicating that the increases of labile phosphorus contents under the co-application of biochar and wood vinegar were better than those of the alone application of biochar and wood vinegar.Each treatment increased the proportion of labile phosphorus pool in saline-alkali soil and the proportion of labile phosphorus pool increased with the increase of the amount of wood vinegar.In addition,the application of biochar and wood vinegar increased the 100-grain weight of rice,and C6 treatment had the best effect,increasing the 100-grain weight by 134.35%.Therefore,the application of biochar and wood vinegar in saline-alkali soil could improve the soil phosphorus availability,increase the weight of rice grains,thereby realizing the resource utilization of agricultural waste and the sustainable development of agriculture.

Effect of Mongolian Vinegar Soaked Licorice on Liver Fibrosis Induced by Carbon Tetrachloride Combined with High-fat Diet in Rats

[Objectives]To determine the improvement effect of vinegar soaked licorice on liver fibrosis induced by carbon tetrachloride(CCl_(4))combined with high-fat diet in rats.[Methods]Subcutaneous injection of 40%-60%CCl_(4)olive oil solution(0.3 mL/100 g)combined with a high-fat diet was used for 5 weeks to establish the rat model with liver fibrosis.After the modeling,the rats were divided into a low dose(0.8 g/kg),a medium dose(2.5 g/kg),a high dose(5 g/kg)group,a colchicine(1.5 mg/kg)positive group,and a vinegar group(2 mL/kg).The serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)levels in the rats were measured automatically.The serum hyaluronic acid(HA)was detected by radioimmunoassay,and the serum laminin(LN)and procollagen type III peptide(PIIIP)levels were measured by enzyme-linked immunoassay.Liver histopathological morphological changes were observed by HE and Masson staining,and expressions of cytochrome CYP2E1 and transcription factor Nrf2 were detected by immunohistochemistry.[Results]The rat liver fibrosis model was established successfully at the 6~(th)week.Compared with the model group,the levels of ALT,AST,HA,LA,PIIIP,CYP2E1 and Nrf2 of all the examined indexes in the dosing group were decreased(P<0.05).As shown in the pictures of liver pathological tissue sections,the liver fibrosis was significantly alleviated in the positive group and the 3 administration groups.[Conclusions]Vinegar soaked licorice can significantly improve the liver fibrosis induced by carbon tetrachloride combined with high-fat diet in rats,and the effect of the high-dose group was similar to that of the positive group.

Effects of Different Sterilization Conditions on Active Components and Flavor of Apple Vinegar

[Objectives]To explore the effects of different sterilization conditions on nutrition and flavor of apple vinegar.[Methods]Five kinds of high temperature short time(HTST)sterilization conditions were selected to treat apple vinegar,and the volatile aroma components and the content of active components in apple vinegar before and after sterilization were analyzed.[Results]Compared with the control,the contents of total acid and malic acid in the samples after sterilization changed little,but the contents of citric acid increased significantly(P<0.01),and the contents of total phenols,ascorbic acid and total flavonoids decreased.Ethyl acetate,isopentyl acetate,ethyl caprylate,phenethyl acetate,1-pentanol,phenylethyl alcohol,acetic acid,and sec-butyl ether were the characteristic aroma components which contributed to the flavor of apple vinegar.As sterilization temperature increased,the content of esters decreased,while the content of acids,alcohols and aldehydes increased.The contents of nutrition,active components and volatile aroma components in apple vinegar under 100℃and 30 s sterilization conditions had little change compared with other sterilization conditions,so 100℃and 30 s were the optimal sterilization conditions.[Conclusions]Under different sterilization conditions,the content of flavor components in apple vinegar will change greatly,which will affect the quality of apple vinegar.

Optimization and pharmacodynamic evaluation of stir-frying with bran for Tangshen processing

Background:Traditional Chinese medicine requires special processing before it can be effectively used for clinical treatment of diseases.In particular,Tangshen stir-fried with wheat bran smoke has been found to enhance the function of the stomach and spleen.However,there is limited research on the technology and pharmacodynamic effects of Tangshen fried with bran.Therefore,the objective of this article is to optimize the method of stir-frying with bran for Tangshen processing and to compare the anti-fatigue and hypoxia-resistance effects of Tangshen before and after bran-frying.Methods:The response surface methodology was utilized to optimize the frying temperature,frying time,and the bran-to-Tangshen ratio,using lobetyolin as the indicator.The swimming time of mice and the levels of blood urea nitrogen,lactate dehydrogenase,and blood glucose in fatigued mice were compared before and after Tangshen was fried with bran.Additionally,the hypoxic resistance ability of Tangshen before and after bran-frying was determined through normobaric hypoxia test and sodium nitrite poisoning test.Results:The optimal bran-frying conditions for Tangshen processing were determined as:frying temperature of 167°C,frying time of 2.67 min,and the bran-to-Tangshen ratio of 50:100.Pharmacodynamic analysis results indicated that Tangshen significantly increased the GLU content(P<0.01)and significantly reduced the LDH content(P<0.01)both before and after bran-frying.While both traditional and new bran-frying methods significantly increased the content of muscle glycogen(P<0.05),the optimized method in this study also significantly elevated the content of liver glycogen(P<0.05).The traditional method significantly prolonged the survival time of mice from sodium nitrite poisoning(P<0.05).Conclusion:The response surface model proved to be highly effective in optimizing the stir-frying process with bran for Tangshen processing.The results of this study indicate that Tangshen possesses anti-fatigue and hypoxia-resistance effects both before and after bran-frying,with bran-fried Tangshen exhibiting significantly stronger effects.

基于小白鼠试验评价乳清醋增强免疫功能研究

用乳清醋饲喂小白鼠试验,分析检验其免疫学指标,评价乳清醋是否具有增强机体免疫的功能特性。试验鼠选用体质量(BW)为20 g的雄性小白鼠,共320只,从中每次随机取40只作为1个批次饲喂的试验鼠,分为4组,3个处理组和1个对照组,每组10只。实验室制备总酸为5.52 g/100 mL的乳清醋,乳清醋经稀释后的高、中、低浓度的剂量组,分别对处理组小鼠以剂量为10 mL/kg BW灌胃,对照组同步灌胃等量生理盐水,日饲1次,连续30 d为1个批次饲喂试验。研究以试验鼠的8项免疫学指标为检测目标:(a)免疫器官重量及胸腺脾脏指数,(b)迟发型超敏反应,(c)淋巴细胞转化率,(d)抗体生成细胞检测,(e)血清溶血素检测,(f)单核巨噬细胞攻击和吞噬能力,(g)碳粒廓清试验,(h)NK(Natural killer)细胞活性。每一批次饲喂试验结束后,针对其中1项免疫学指标要求对该批次的小鼠进行处置、解剖、检测。取平均数据为该批次各组鼠的该项免疫学指标数据。经8批次的饲喂试验,完成了试验鼠8项免疫学指标的检测。结果显示,处理组与对照组相比,除了(d)和(e)2项指标没有明显的统计学差异(P>0.05)外,中、高剂量组小鼠的其余6项免疫学指标均明显增强,均有统计学差异(P<0.05)。本研究发现,乳清醋饲喂白鼠后在促进和提高小鼠的免疫器官增重,细胞免疫功能,单核巨噬细胞吞噬功能和NK细胞活性等方面起了明显作用,可以判定乳清醋具有增强人体免疫力的功能。

不同酸化生物炭用量对滴灌棉田盐碱土水盐运移的影响

【目的】研究不同酸化生物炭用量对滴灌棉田盐碱土水盐运移的影响,确定改良棉田盐碱土的最佳木醋液酸化生物炭用量。【方法】基于一维土柱模拟试验,分别设置1%、2%、3%、4%和5%五个不同质量木醋液酸化生物炭处理(木醋液与生物炭质量比为2∶1),以空白处理作为对照CK_(1),以添加2%未酸化生物炭处理作为对照CK_(2),分析不同处理滴灌后湿润峰垂直运移距离、土壤pH值、含盐量、土壤碱化度和脱盐率的分布特征。【结果】添加酸化生物炭处理的土壤湿润峰垂直运移距离和下渗速度均显著高于CK_(2)和CK_(1);添加酸化生物炭处理下的各层土壤pH值均显著低于CK_(2)和CK_(1),且施用量越多pH值降幅越大;随着酸化生物炭施用量的增加,各土层土壤碱化度呈先降低后升高的变化趋势,2%酸化生物炭处理下的土壤碱化度降幅最大;添加未酸化生物炭和酸化生物炭处理的0~50 cm各层土壤脱盐率均有所增加,2%酸化生物炭处理下的整体脱盐效果最好。【结论】添加酸化生物炭对盐碱土的改良效果优于添加未酸化生物炭,以2%酸化生物炭用量下的效果最优。

添加部分水解罗望子胶对酸木瓜果醋品质的影响

该研究以酸木瓜(Chaenomeles speciosa)为原料,通过部分水解罗望子胶(PHTG)对6株乳杆菌的增殖活性测定,选用鼠李糖乳杆菌(Lactobacillus rhamnosus)与酵母菌混菌进行酒精发酵,并从灵石醋醅中筛选鉴定出一株高产醋酸的巴氏醋杆菌巴士亚种(Acetobacter pasteuranus subsp. pasteuranus)LS-4用于醋酸发酵制备酸木瓜果醋。以未添加PHTG为对照,考察在酒精发酵阶段添加PHTG对酸木瓜果醋品质的影响。结果表明,添加1.0%PHTG,酒精发酵36 h后酒精度达3.3%vol,比对照组提高17.4%;醋酸发酵72 h后总酸含量达42.0 g/L,比对照组提高8.0%。香气成分分析表明,添加PHTG酸木瓜果醋共检出22种香气成分,其中醇类7种、酯类4种、酸类6种、醛酮类3种、酚类和烯烃类各1种,比对照新增了3种香气成分(正丁酸、2-戊酮和壬醛)。感官评价表明,添加PHTG有效提升酸木瓜果醋的口感和气味评分,改善酸木瓜果醋的感官品质。

食用醋粉的制备工艺、营养成分及保健作用研究进展

综述了食用醋粉的制备工艺、营养成分和保健作用,并对其未来发展进行了展望,以期为食用醋粉的综合利用提供参考。

山西老陈醋多糖提取纯化及结构鉴定

以山西老陈醋为原料,采用乙醇沉淀法提取多糖,采用单因素及响应面试验优化山西老陈醋多糖(SAVP)提取条件,对粗多糖进行脱蛋白、脱色、透析、层析柱分离纯化,得精多糖及多糖组分。通过红外光谱鉴定多糖的结构并进行分子质量、单糖组成及热重分析。结果表明,最优醇沉条件为乙醇体积分数91%,醇沉时间16.3 h,乙醇倍数4倍。此优化条件下,粗多糖提取量为16.48 mg/g。粗多糖Sevag-三氯乙酸(TCA)法蛋白去除率为74.65%,多糖保留率为77.87%;大孔树脂法脱色率为64.02%,多糖保留率为84.55%。精多糖经DEAE-52纤维素及Sephadex G-100柱层析纯化后得到多糖组分SAVP-1,对其进行结构分析发现,SAVP-1为α-型多糖,分子质量为6.87 kDa,由鼠李糖、阿拉伯糖、半乳糖、葡萄糖、木糖和甘露糖六种单糖组成,热稳定性较好。

基于HPLC指纹图谱结合化学模式识别对葡萄醋的质量评价

目的建立葡萄醋中有机酸成分的高效液相(High performance liquid phase,HPLC)指纹图谱,并结合化学模式识别对葡萄醋质量进行评价及为临床应用提供参考。方法采用HPLC法,以甲醇(A)∶0.5%磷酸水溶液(D)=1∶99洗脱,建立葡萄醋指纹图谱,同时测定琥珀酸的含量;采用相似度评价、聚类分析(Cluster analysis,CA)、主成分分析(Principal component analysis,PCA)和偏最小二乘-判别分析(Partial least squares discriminant analysis,PLS-DA)等化学模式识别对差异性特征成分进行筛选。结果15批葡萄醋样品的指纹图谱共有峰有11个,通过与混合对照品色谱峰进行比对,指认出6个共有峰,分别是酒石酸(1号峰),苹果酸(2号峰),琥珀酸(3号峰),富马酸(4号峰),绿原酸(9号峰),乙酸(11号峰);CA结果表明15批葡萄醋样品中各个化合物之间含量差异较大,即使是同一生产企业生产的不同批次葡萄醋其含量差异也较大;PCA结果显示葡萄醋共有峰含量差异的主要成分并非单一成分,而是前4种主成分共同的影响;PLS-DA结果表明筛选出的7、3、9、4号峰可作为鉴别和区分葡萄醋质量差异的标志物,其中包括共有峰3号峰(琥珀酸)、4号峰(富马酸)。结论采用指纹图谱结合化学模式识别技术可快速、有效地筛选出葡萄醋的差异性特征成分,为葡萄醋质量评价及临床应用提供参考。

醋醅源非酿酒酵母的鉴定及其对葡萄酒品质的影响

为改善传统商业酿酒酵母酿造葡萄酒的风味与口感,以醋醅中分离的菌株JM为研究对象,对其进行形态学观察、分子生物学鉴定和耐受性分析;以菌株JM、商业酿酒酵母(SC)和安琪活性生香干酵母(ADY)单菌及混菌发酵酿造葡萄酒,并对其品质进行分析。结果表明,经鉴定,菌株JM被鉴定为扁平云假丝酵母(Candida humilis),在发酵液中总酯产量为2.64 g/L,其可耐受3.0%柠檬酸、温度35℃、体积分数6%的乙醇及4%NaCl。在不同组别葡萄酒样品中,JM+SC混菌制备的葡萄酒品质最佳,其酒体颜色为紫红色,L*值、a*值、b*值分别为53.93、20.38、4.85;糖度为7°Bx,总酸含量为3.38 g/L,还原糖含量为22.00 g/L,pH为3.58,花色苷含量为205.52 mg/L,酒精度为12.60%vol,总酯含量为1.47 g/L;1,1-二苯基-2-三硝基苯肼(DPPH)、2,2'-联氮-双(3-乙基苯并噻唑啉-6-磺酸)(ABTS)自由基清除率分别为42.21%、32.86%;酒样富含丙酸乙酯和乙酸戊酯,果香浓郁,清爽可口,具备酿造高品质葡萄酒的潜力。

酵母菌混合发酵乳清液及其乙醇发酵阶段工艺优化

选择马克斯克鲁维酵母CGMCC13907(以下简称马氏酵母CGMCC13907)和酿酒酵母AS2.119为混合发酵剂发酵乳清液制备乳清醋,并采用Plackett-Burman Design(PBD)和Box-Behnken Design(BBD)试验优化乙醇发酵阶段的工艺。结果表明:乙醇发酵阶段的最优工艺为马氏酵母CGMCC13907接种量4.0×10^(6) CFU/mL,酿酒酵母AS2.119接种量4.5×10^(6) CFU/mL,发酵时间151 h,发酵温度40.0℃,发酵pH值5.6,姜粉用量0.09 g/100 mL,在此条件下,发酵液中乙醇浓度可达8.70%vol,比优化前增加了56.2%。因此,选用马氏酵母CGMCC13907结合酿酒酵母AS2.119混合发酵乳清液,可有效解决乳清醋制作过程中的乳糖发酵难题,并获得较理想的乙醇浓度。

黄芪、枸杞、沙果果醋的研制及其抗氧化活性研究

以黄芪、枸杞为原料,经混合、煎煮、抽滤、离心制取黄芪枸杞汁;将黄芪枸杞汁和沙果汁按比例混合,利用酵母菌和醋酸菌对其进行发酵,制备果醋。采用单因素试验与正交试验得到了最适工艺条件。研究结果表明,黄芪枸杞汁的最适制备工艺为黄芪与枸杞的比例1∶2、料液比1∶20、煎煮时间60 min;黄芪枸杞汁与沙果汁的最适比例为1∶5;最适酒精发酵条件为酵母菌接种量8%、发酵温度28℃、初始糖度14%、发酵时间6 d;最适醋酸发酵条件为醋酸菌接种量10%、发酵温度32℃、初始酒精度8%、摇床转速200 r/min;果胶酶添加量为200 mg/L时,果醋的透光率达到90.16%,在此条件下制得的产品颜色淡黄、酸甜适中、气味芳香,具有较强的抗氧化活性。

甘草柑橘皮果醋发酵工艺研究

以柑橘皮为主料,甘草为辅料,采用液态发酵法制备甘草柑橘皮果醋。先以总黄酮含量为指标,在单因素试验的基础上通过响应面法优化酒精液制备工艺;再在最佳酒精液制备条件下,以总酸含量和感官评分为指标,通过响应面法优化果醋制备工艺,并对其理化及微生物指标进行分析。结果表明:酒精液最佳工艺参数为酵母菌接种量0.5%(以原料液体积为基准)、原料液糖度16%、发酵时间9 d,在此条件下果醋总黄酮含量为5.37%。最佳果醋制备参数为醋酸菌接种量2.0%(以酒精液体积为基准)、发酵温度35℃、初始乙醇体积分数8.5%、发酵时间9 d,在此条件下果醋总酸含量为5.61 g/100 mL,感官评分为8.74,微生物指标符合相关标准要求。

木醋液的抑菌活性及其对连作番茄根际土壤微环境生态的影响

为探索木醋液对番茄根际土壤微生态的作用,以番茄为供试材料,连续3 a常规种植于相同田块,设置木醋液稀释300倍(A)、稀释600倍(B)、稀释900倍(C)处理,以无菌去离子水为对照(CK),探究不同稀释度木醋液的抑菌活性及其对连作番茄植株根系生长、根际土壤细菌和真菌群落结构的影响。结果显示:不同稀释度木醋液对青枯病菌和枯萎病菌均具有显著的抑制作用;3种稀释度的木醋液中,稀释600倍的木醋液浇灌不仅有利于连作番茄根系的生长,而且有助于提高番茄连作根际土壤细菌和真菌的多样性;与对照(CK)相比,不同稀释度木醋液处理均不同程度地降低了放线菌门(Actinobacteriota)细菌的相对丰度,提高了酸杆菌门(Acidobacteriota)细菌以及子囊菌门(Ascomycota)、新赤壳属(Neocosmospora)、曲霉属(Aspergillus)、青霉属(Penicilli⁃um)、木霉属(Trichoderma)、毛壳菌属(Chaetomium)和镰刀菌属(Fusarium)真菌等有益微生物的相对丰度。结果表明,木醋液具有显著抑制番茄青枯病及枯萎病病原微生物的作用,浇灌稀释木醋液有利于连作番茄根系生长,改善连作番茄根际土壤微环境生态的作用;其中,以稀释600倍(B)木醋液的改良效果最佳。