Food Biotechnology最新文献_第9页

Diversity of lactic acid bacteria in Moutai-flavor liquor fermentation process 酱香型白酒发酵过程中乳酸菌的多样性

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-07-02 DOI: 10.1080/08905436.2020.1789475

Yaoling Wu, Fei Hao, Xibin Lv, Biduan Chen, Yubo Yang, Xianglian Zeng, Fan Yang, Heyu Wang, Li Wang

{"title":"Diversity of lactic acid bacteria in Moutai-flavor liquor fermentation process","authors":"Yaoling Wu, Fei Hao, Xibin Lv, Biduan Chen, Yubo Yang, Xianglian Zeng, Fan Yang, Heyu Wang, Li Wang","doi":"10.1080/08905436.2020.1789475","DOIUrl":"https://doi.org/10.1080/08905436.2020.1789475","url":null,"abstract":"ABSTRACT Maotai-flavor liquor, derived from a multi-stage solid fermentation process, is one of the most popular liquors in China. Its quality and flavor are closely related to diverse lactic acid bacteria (LAB). It is therefore significant to characterize LAB for the manufacturing of Maotai-flavor liquor. In this study, LAB in solid state fermentation stages were analyzed through high-throughput sequencing and cultivation-dependent methods during the fermentation process. In total, 65 LAB species were identified in the fermented matrix, showing a much higher LAB diversity than other types of Chinese liquor. In addition, discrepancies were found to exist in the dominant LAB community structures during different fermentation stages, and strains of the Lactobacillus genus were found to be the most dominant LAB. Furthermore, 33 LAB species were identified from the fermentation matrix through the cultivation and 16 S rRNA analysis of single isolates, thus representing 50.8% coverage of the detected LAB species. The relative abundance of isolated LAB in the total abundance of LAB was 95.9% during the fermentation process. In doing so, Lac2 and Lac13, two potentially new LAB species, were isolated. To the best of our knowledge, this study represents the identification of the highest number of LAB species by cultivation-dependent methods from fermented grains of Chinese liquor. In summary, this study monitored the LAB species composition of solid fermented matrix during the fermentation of Maotai-flavor liquor and has highlighted the potential importance of the higher abundance of LAB and the effect it has on the unique flavor of Maotai liquor.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"212 - 227"},"PeriodicalIF":1.8,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2020.1789475","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46060011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Genome sequencing and flavor compound biosynthesis pathway analyses of Bacillus licheniformis isolated from Chinese Maotai-flavor liquor-brewing microbiome 中国茅台味酿酒微生物群地衣芽孢杆菌基因组测序及风味化合物生物合成途径分析

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-07-02 DOI: 10.1080/08905436.2020.1789474

Fan Yang, Yanfeng Liu, Liangqiang Chen, Jianghua Li, Li Wang, G. Du

{"title":"Genome sequencing and flavor compound biosynthesis pathway analyses of Bacillus licheniformis isolated from Chinese Maotai-flavor liquor-brewing microbiome","authors":"Fan Yang, Yanfeng Liu, Liangqiang Chen, Jianghua Li, Li Wang, G. Du","doi":"10.1080/08905436.2020.1789474","DOIUrl":"https://doi.org/10.1080/08905436.2020.1789474","url":null,"abstract":"ABSTRACT Maotai- flavor liquor is one of the most popular distilled liquors in China that contains various flavor substances produced by a specialized brewing microbiome. Bacillus licheniformis is one of the major bacterial species in the Maotai-flavor liquor-brewing microbiome. However, the whole genome sequence of the B. licheniformis brewing strain has not been reported, which hampers further understanding of its effects on brewing. In this study, whole genome sequencing of B. licheniformis MT-B06 isolated from Maotai Daqu, a fermented wheat starter containing brewing microorganisms, was carried out using the Pacific Bioscience RS II platform. The sequence had a length of 4,440,765 bp with 45.7% GC content, encoding 5023 CDS sequences, 81 tRNAs, and 24 rRNAs. Next, genome annotation was performed based on four high-quality databases, including the COG, KEGG, GO/IPR, and Swiss-Prot databases. The genome sequence obtained was comparatively analyzed with that of B. licheniformis ATCC 14580, which is used for industrial enzyme production, which revealed that 69.95% of the differential genes are metabolically related, suggesting that these genes may be closely related to the flavor compounds biosynthesis. Therefore, the flavor compounds biosynthesis pathways and 26 relevant genes of B. licheniformis MT-B06 was analyzed, including alsS and alsD for 3-hydroxy-2-butanone synthesis, ispD, and ispE for terpenoids synthesis. This is the first report of high-quality whole genome sequencing of B. licheniformis MT-B06. Our results provide an important foundation for investigating metabolic pathways of desired compounds, such as C4 compounds and pyrazines, in Maotai-flavor liquor to improve its taste and quality.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"193 - 211"},"PeriodicalIF":1.8,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2020.1789474","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42547375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Isolation, Identification, and Characterization of Phytase Producing Probiotic Lactic Acid Bacteria from Neonatal Fecal Samples Having Dephytinization Activity 从具有脱植酸活性的新生儿粪便样品中分离、鉴定和鉴定产植酸酶的益生菌乳酸菌

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-04-02 DOI: 10.1080/08905436.2020.1746332

B. Sharma, G. Shukla

{"title":"Isolation, Identification, and Characterization of Phytase Producing Probiotic Lactic Acid Bacteria from Neonatal Fecal Samples Having Dephytinization Activity","authors":"B. Sharma, G. Shukla","doi":"10.1080/08905436.2020.1746332","DOIUrl":"https://doi.org/10.1080/08905436.2020.1746332","url":null,"abstract":"ABSTRACT Phytic acid, the main phosphate storage component of plant-based diet, is one of the prime causes of micronutrient deficiency in vegetarians due to the formation of non-degradable cation-phytic acid complex in gastrointestinal tract of monogastric animals that are devoid of phytase enzyme. Therefore, the present study was designed to isolate phytase producing probiotic from neonatal feces which may enhance the bioavailability of phosphorous micronutrient. Experimentally, 13 phytase producing lactic acid bacteria (LAB) were isolated from 28 neonatal fecal samples and characterized both phenotypically and for probiotic attributes. Among these, Isolate 5b exhibited potent probiotic potential with significant (p < .01) phytase activity (4.55 U/mL) and was identified phylogenetically using both 16S rRNA and MALDI-TOF MS analysis as Pediococcus acidilactici BNS5B. Interestingly, it was found that phytase from P. acidilactici BNS5B significantly dephytinized phytic acid from modified diet (96.59%) and brown bread (88.89%) after 15 min of phytase treatment at 37°C. Therefore, this provides an opportunity to develop P. acidilactici BNS5B as a probiotic to be used as a supplement in feed/food of monogastric animals and humans. This also provides the rationale for further in vivo studies to use phytase producing probiotic in relation to maintaining and improving health.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"151 - 171"},"PeriodicalIF":1.8,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2020.1746332","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47615513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Effect of soaking and germination conditions on γ-aminobutyric acid and gene expression in germinated brown rice 浸泡和发芽条件对发芽糙米γ-氨基丁酸及其基因表达的影响

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-04-02 DOI: 10.1080/08905436.2020.1744448

S. Z. Hussain, R. Jabeen, B. Naseer, A. Shikari

{"title":"Effect of soaking and germination conditions on γ-aminobutyric acid and gene expression in germinated brown rice","authors":"S. Z. Hussain, R. Jabeen, B. Naseer, A. Shikari","doi":"10.1080/08905436.2020.1744448","DOIUrl":"https://doi.org/10.1080/08905436.2020.1744448","url":null,"abstract":"ABSTRACT Four pigmented land races (Madew Zag-1, Madew Zag-2, Tangdhar Zag and Karnah Zag) and one high yielding variety (cv. Jhelum) were tested for production of γ-aminobutyric acid (GABA) rich brown rice through germination. Central composite rotatable design was used to determine the effect of germination conditions, i.e., soaking time (h), germination time (h), germination temperature (°C), and relative humidity (%) on GABA content. Regression model developed was highly significant (P < .0001) with high coefficient of determination (R2 = 0.98). The optimized conditions obtained were soaking time: 5.76 h; germination time: 40 h, and germination temperature: 35°C. The genetic variation among genotypes was also studied with respect to three glutamate decarboxylase cDNAs; OsGAD1, OsGAD2, and OsGAD3. The maximum GABA synthesis during germination was recorded in Jhelum (48.18 mg/100 g) followed by Tangdhar Zag (44.40 mg/100 g). Gene expression of OsGAD3 was also upregulated maximum in Jhelum followed by Tangdhar Zag with a fold change of 22.368 and 19.472, respectively.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"132 - 150"},"PeriodicalIF":1.8,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2020.1744448","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44022104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Microbiological, physicochemical and sensory studies of coffee beans fermentation conducted in a yeast bioreactor model 在酵母生物反应器模型中进行咖啡豆发酵的微生物学、物理化学和感官研究

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-04-02 DOI: 10.1080/08905436.2020.1746666

D. P. de Carvalho Neto, Gilberto Vinícius de Melo Pereira, Ana M. O. Finco, C. Rodrigues, J. C. Carvalho, C. Soccol

{"title":"Microbiological, physicochemical and sensory studies of coffee beans fermentation conducted in a yeast bioreactor model","authors":"D. P. de Carvalho Neto, Gilberto Vinícius de Melo Pereira, Ana M. O. Finco, C. Rodrigues, J. C. Carvalho, C. Soccol","doi":"10.1080/08905436.2020.1746666","DOIUrl":"https://doi.org/10.1080/08905436.2020.1746666","url":null,"abstract":"ABSTRACT Coffee growers use a traditional method of fermentation to remove the cherry pulp surrounding the beans. The aim of this study was to evaluate the microbiological, physicochemical, and sensory aspects of coffee beans fermentation conducted in a controlled yeast bioreactor model (New Brunswick™ BioFlo®). Fermentations were conducted with or without the addition of a selected yeast starter culture (viz., Pichia fermentans YC5.2) and different parameters, including microbial growth, bacterial diversity, inoculum persistence, sugar consumption, and metabolic compounds formation (organic acids, ethanol, and ethyl acetate), were investigated. The chemical composition of resulting fermented coffee beans was assessed by high‐performance liquid chromatography and gas chromatography–mass spectrometry, and sensorial analysis of coffee beverage was performed using the cupping test (SCA – specialty coffee association). The yeast bioreactor model enabled efficient yeast starter culture growth and ethanol (0.136 g/L.h) and ethyl acetate (1.039 mg/L.h) formation. The bacterial population was mainly represented by Pediococcus sp. and Leuconostocaceae family, as revealed by Illumina high-throughput 16S rRNA gene sequencing. The fermentation system also enabled the production of coffee beans with rich aroma composition (including D-Limonene, phenyl-acetaldehyde, and phenylethyl alcohol) and beverages with a remarkable increase in quality compared to the conventional process. With further refinements, the stirred-tank bioreactor (STR) model may be useful in designing novel bioreactors for the optimization of coffee fermentation with starter cultures.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"172 - 192"},"PeriodicalIF":1.8,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2020.1746666","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42556312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Quantitative species determination based on real time PCR–Can the results be expressed as weight/weight equivalents? 基于实时pcr的物种定量测定-结果可以用重量/重量当量表示吗?

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-04-02 DOI: 10.1080/08905436.2020.1743305

Liping Song, Zhikai Hu, Qinglong Wang, Jie Jiang, Yue Cao, Dan Wang, S. Rui, Long Li, Xuefeng Cai, Yantao Wu, Yi Suo

{"title":"Quantitative species determination based on real time PCR–Can the results be expressed as weight/weight equivalents?","authors":"Liping Song, Zhikai Hu, Qinglong Wang, Jie Jiang, Yue Cao, Dan Wang, S. Rui, Long Li, Xuefeng Cai, Yantao Wu, Yi Suo","doi":"10.1080/08905436.2020.1743305","DOIUrl":"https://doi.org/10.1080/08905436.2020.1743305","url":null,"abstract":"ABSTRACT Food adulteration is a common challenge in the meat industry. Polymerase chain reaction (PCR) has been used as a method to detect contamination from different species of meat. From a consumer perspective, a PCR method with measurements in terms of weight/weight (w/w) ratios will be more familiar. In this study, the focus was on how to convert the results of quantitative analysis from genome/genome (g/g) to w/w using real-time PCR. The mixtures with different ratios of mutton in pork were analyzed as test samples. The c values of different species, as a reflection of the key conversion factors, were established and evaluated. The effects of heat treatment on w/w conversion of PCR data were also assessed. The results indicated that the c value shows significant variability among individual samples. An average c value was found to cause a bias of more than 7% for mixtures in the range of 20–80%. For individual meat samples with pre-determined c-values, real-time PCR was useful for quantitative analysis of mutton contamination in pork within the range of 20–80%, with a bias of detection of less than 2%. However, this method was shown to have a limit of quantification of 5% with mutton in pork. Furthermore, heat treatment (121°C, 15 min) significantly reduced the accuracy of quantitative analyses. Because the c value is not available for most commercial samples, and some food products are subjected to heat treatment as a method of sterilization, accurate quantitative analysis (w/w) may not be an option for commercial samples using PCR-based technology.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"116 - 131"},"PeriodicalIF":1.8,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2020.1743305","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49092292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Expression and purification of catalytic domain of botulinum neurotoxin serotype ‘F’: immunological characterization and its application in detection F型肉毒杆菌神经毒素催化结构域的表达与纯化:免疫学特性及其在检测中的应用

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-04-02 DOI: 10.1080/08905436.2020.1740731

S. K. Yadav, Monika Singh, Ponmariappan Sarkaraisamy

{"title":"Expression and purification of catalytic domain of botulinum neurotoxin serotype ‘F’: immunological characterization and its application in detection","authors":"S. K. Yadav, Monika Singh, Ponmariappan Sarkaraisamy","doi":"10.1080/08905436.2020.1740731","DOIUrl":"https://doi.org/10.1080/08905436.2020.1740731","url":null,"abstract":"ABSTRACT Botulinum neurotoxin (BoNT) is the most toxic biomolecule known to the world (⁓100 times toxic than cyanide) and has been listed as category ‘A’ biowarfare agent. In the present investigation, we cloned the catalytic domain of BoNT type ‘F’. Maximum recombinant BoNT/F protein expression was achieved at 21°C, 0.75 mM IPTG at 6 h post induction. The rBoNT/F protein was purified and confirmed subsequently by MS-MS analysis as well as Western blot. High titer polyclonal antibodies were generated and elevated level of IgG1 isotypes was observed. Plate ELISA was developed for the detection of BoNT/F with the sensitivity of 3.9 ng/mL. Limits of Detection (LOD) was established for different fruit juices through spiking studies using rBoNT/F Lc protein as antigen and achieved a detection limit of 15.62 ng/mL for apple juice followed by 31 ng/mL for litchi and 62 ng/mL for grape, orange, and mango juices. The developed system has the potential for the detection of BoNT/F in food as well as environmental samples.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"101 - 115"},"PeriodicalIF":1.8,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2020.1740731","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44253969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Techno-functional traits and safety aspects of coagulase-negative Staphylococcus saprophyticus isolated from traditional fermented food 从传统发酵食品中分离的凝固酶阴性腐生葡萄球菌的技术、功能和安全性

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-01-02 DOI: 10.1080/08905436.2019.1711114

A. Khusro, C. Aarti, A. Salem, Alberto Barbabosa‐Pilego

{"title":"Techno-functional traits and safety aspects of coagulase-negative Staphylococcus saprophyticus isolated from traditional fermented food","authors":"A. Khusro, C. Aarti, A. Salem, Alberto Barbabosa‐Pilego","doi":"10.1080/08905436.2019.1711114","DOIUrl":"https://doi.org/10.1080/08905436.2019.1711114","url":null,"abstract":"ABSTRACT Ngari is a traditional-fermented fish food product of northeast India from which distinct bacteria were initially isolated and assessed for their antagonistic activities against wide spectrum of foodborne and enteric infection-causing pathogens. Among them, Staphylococcus saprophyticus strain AAS1 showed strong inhibitory activity against all the indicator pathogens, ranging from 81.14 ± 2.4 to 340.18 ± 2.1 AU/mL. In vitro techno-functional properties of strain AAS1 were further evaluated and confirmed by using standard methodologies. The AASI strain exhibited high tolerance at higher acidic conditions, simulated gastric juice of pH 2.0, and oxgall (0.5%, w/v). Furthermore, this strain showed noticeable hydrophobicity and auto-aggregation traits of 64.2 ± 1.3 and 44.3 ± 1.5%, respectively. The isolate depicted not only resistance to phenol and lysozyme but also exhibited 2,2-diphenyl-1-picrylhydrazyl degradation (16.6 ± 1.2–67.5 ± 1.1%), hydrogen peroxide tolerance (2.1 ± 0.04–1.1 ± 0.04), and hydroxyl radical scavenging (10.6 ± 1.2–57.5 ± 1.1%) properties. Strain AAS1 fermented varied carbohydrates and produced exopolysaccharide and lipase. The isolate exhibited significant rate of autolysis (48.6 ± 1.2%), catalase activity (18.14 ± 0.3 AU), and nitrate reductase production (26.32 ± 0.8 mM nitrite/mg dry weight). It has also showed negative results toward in vitro hemolytic, DNase, gelatinase, and biofilm formation tests, in addition to being susceptible to conventional antibiotics used. In a nutshell, strain AAS1 may be employed as quintessential candidate for its disparate applications in food and pharmaceutical industries if its probiotic function can be validated.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"77 - 99"},"PeriodicalIF":1.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2019.1711114","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49034743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Improved expression of recombinant sweet-tasting brazzein using codon optimization and host change as new strategies 以密码子优化和宿主改变为新策略改善重组甜味铜蛋白的表达

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-01-02 DOI: 10.1080/08905436.2019.1711113

V. Jafarian, K. Bagheri, J. Zarei, S. Karami, Parisa Ghanavatian

{"title":"Improved expression of recombinant sweet-tasting brazzein using codon optimization and host change as new strategies","authors":"V. Jafarian, K. Bagheri, J. Zarei, S. Karami, Parisa Ghanavatian","doi":"10.1080/08905436.2019.1711113","DOIUrl":"https://doi.org/10.1080/08905436.2019.1711113","url":null,"abstract":"ABSTRACT There is increased food industry attention to low-calorie natural sweeteners with good taste properties such as in plant-based sweet proteins. Brazzein is an attractive alternative to sucrose because of its intense sweetness, natural origin, and good stability at wide pH ranges and high temperature. In the present study, by using the minor form of brazzein as the basic sequence, the codon-optimized brazzein gene was designed based on appropriate GC content and preferred codon of E. coli. Then, the synthesized brazzein gene was cloned in pET28a vector and expressed in BL21(DE3) and SHuffle® T7 Express strains. Recombinant brazzein was expressed about 1.8 to 2.3 mg/L and 7.2 to 8.4 mg/L in BL21 (DE3) and SHuffle® T7 Express strain, respectively. Recombinant brazzein with His-tag lacked the sweetness. After the removal of the His-tag, it was shown that in addition to sweetness potency, the amount of brazzein proteins purified from SHuffle® T7 Express was higher than that from BL21. This improvement could be due to the better performance of SHuffle® T7 Express in the expression of the protein with high disulfide bridges and the effect of disulfide bonds on the sweetness of brazzein.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"62 - 76"},"PeriodicalIF":1.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2019.1711113","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47821717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Artisanal Pico cheese as reservoir of Enterococcus species possessing virulence and antibiotic resistance properties: implications for food safety 具有毒力和抗生素耐药性的人工皮干酪作为肠球菌的宿主：对食品安全的影响

IF 1.8 4区农林科学

Food Biotechnology Pub Date : 2020-01-02 DOI: 10.1080/08905436.2019.1710844

S. Câmara, A. Dapkevicius, C. C. Silva, F. Malcata, Maria L. N. Enes Dapkevicius

{"title":"Artisanal Pico cheese as reservoir of Enterococcus species possessing virulence and antibiotic resistance properties: implications for food safety","authors":"S. Câmara, A. Dapkevicius, C. C. Silva, F. Malcata, Maria L. N. Enes Dapkevicius","doi":"10.1080/08905436.2019.1710844","DOIUrl":"https://doi.org/10.1080/08905436.2019.1710844","url":null,"abstract":"ABSTRACT Enterococci are part of the dominant microbiota of artisanal Pico cheese and could be used as adjunct cultures for improving this traditional dairy product. However, the genus lacks Qualified Presumption of Safety (QPS) status. The aim of this study was to assess virulence factors, antibiotic resistance and biogenic amine production in 28 autochthonous Enterococcus from Pico cheese. Isolates were identified by sequencing of the 16S rRNA gene and physiological characteristics (hemolysis, DNase, gelatinase, biogenic amine production, and antibiotic resistance), prior to phenotypic and genotypic (asa1, gelE, cylA, esp, efaA, ace, tdc, odc, hdc1, and hdc2) testing for virulence properties. All enterococci displayed antibiotic resistance, mainly to high doses of aminoglycosides (kanamycin and netilmicin). Furthermore, two of the studied isolates displayed vancomycin resistance, not attributable to vanA and vanB. No isolate produced DNase and only one was β-hemolytic, but gelatinase production was observed in 54% of the isolates. The most frequently present virulence genes were efaA (100%), gelE and tdc (86%) and ace (71%). The less represented genes were esp (46%), asa1 (43%), cylA (21%) and hdc2 (4%). No isolate was devoid of virulence factors, making them unsuitable for use as Pico cheese adjunct cultures. Our results stress the importance of assessing the safety of each E. faecalis isolate from artisanal cheeses intended for use in food fermentations.","PeriodicalId":12347,"journal":{"name":"Food Biotechnology","volume":"34 1","pages":"25 - 41"},"PeriodicalIF":1.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/08905436.2019.1710844","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49399134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15