Next Generation Nutrition: Genomic and Molecular Breeding Innovations for Iron and Zinc Biofortification in Rice

Global efforts to address malnutrition and hidden hunger, particularly prevalent in low- and middle-income countries, have intensified, with a focus on enhancing the nutritional content of staple crops like rice. Despite serving as a staple for over half of the world's population, rice falls short in meeting daily nutritional requirements, especially for iron(Fe) and zinc(Zn). Genetic resources, such as wild rice species and specific rice varieties, offer promising avenues for enhancing Fe and Zn content. Additionally, molecular breeding approaches have identified key genes and loci associated with Fe and Zn accumulation in rice grains. This review explores the genetic resources and molecular mechanisms underlying Fe and Zn accumulation in rice grains. The functional genomics involved in Fe uptake, transport, and distribution in rice plants have revealed key genes such as OsFRO1, OsIRT1, and OsNAS3. Similarly, genes associated with Zn uptake and translocation, including OsZIP11 and OsNRAMP1, have been identified. Transgenic approaches, leveraging transporter gene families and genome editing technologies, offer promising avenues for enhancing Fe and Zn content in rice grains. Moreover, strategies for reducing phytic acid(PA) content, a known inhibitor of mineral bioavailability, have been explored, including the identification of low-PA mutants and natural variants. The integration of genomic information, including whole-genome resequencing and pan-genome analyses, provides valuable insights into the genetic basis of micronutrient traits and facilitates targeted breeding efforts. Functional genomics studies have elucidated the molecular mechanisms underlying Fe uptake and translocation in rice. Furthermore, transgenic and genome editing techniques have shown promise in enhancing Fe and Zn content in rice grains through the manipulation of key transporter genes. Overall, the integration of multi-omics approaches holds significant promise for addressing global malnutrition and hidden hunger by enhancing the nutritional quality of rice, thereby contributing to improved food and nutritional security worldwide.

Foliar application of micronutrients enhances crop stand, yield and the biofortification essential for human health of different wheat cultivars

Globally about half of the world’s population is under micronutrient malnutrition due to poor quality food intake.To overcome this problem,fortification and biofortification techniques are often used.Biofortification is considered a better option than fortification due to the easy control of nutrient deficiencies present in daily food.This field experiment was conducted to evaluate the effects of foliar application of a micronutrient mixture(MNM)consisting of zinc(Zn),iron(Fe),copper(Cu),manganese(Mn)and boron(B)on yield and flour quality of wheat.The results show the effectiveness of foliar feeding for growth and yield parameters,in addition to the enriching of wheat grains with Zn,Cu,Fe,Mn and B.Compared to the control without foliar feeding,foliar application on wheat crop increased tillering ability,spike length,grain yield and the contents of Zn,Cu,Mn,Fe and B by 21,47,22,22 and 25%in wheat flour,respectively.Therefore,foliar feeding of micronutrients could be an effective approach to enrich wheat grains with essential nutrients for correcting malnutrition.

Performance of common buckwheat(Fagopyrum esculentum M.) supplied with selenite or selenate for selenium biofortification in northeastern China

Selenium(Se)deficiency commonly occurs in soils of northeastern China and leads to insufficient Se intake by humans.A two-year field study of Se biofortification of common buckwheat supplied with 40 g Se ha^(-1)as selenite(Se(IV)),selenate(Se(VI)),or a combination(1/2 Se(IV+VI))was performed to investigate Se accumulation and translocation in plants and determine the effects of different forms of Se on the grain yield,biomass production,and Se use efficiency of plants and seeds.Se application increased seed Se concentrations to 47.1–265.1μg kg^(-1).Seed Se concentrations following Se(VI)or 1/2 Se(IV+VI)treatment exceeded 100μg kg^(-1),an amount suitable for crop Se biofortification.Se concentration in shoots and roots decreased with plant development,and Se translocation from root to shoot in Se(IV)-treated plants was lower than that in plants treated with 1/2 Se(IV+VI)and Se(VI).Both grain yield and biomass production increased under 1/2 Se(IV+VI)treatment,with grain yields reaching 1663.8 and 1558.5 kg ha^(-1)in 2015 and 2016,respectively,reflecting increases of 11.0% and 10.3% over those without Se application.The Se use efficiency of seeds and plants under Se(VI)treatment was significantly higher than those under 1/2 Se(IV+VI)and Se(IV)treatments.Thus,application of selenate could result in higher Se accumulation in buckwheat seeds than application of the other Se sources,but the combined application of selenate and selenite might be an alternative approach for improving buckwheat grain yield by Se biofortification in northeastern China.

Effects of Different Selenium Application Methods on Wheat (Triticum aestivum L.) Biofortification and Nutritional Quality

Mineral nutrient malnutrition,especially deficiency in selenium(Se),affects the health of approximately 1 billion people worldwide.Wheat,a staple food crop,plays an important role in producing Se-enriched foodstuffs to increase the Se intake of humans.This study aimed to evaluate the effects of different Se application methods on grain yield and nutritional quality,grain Se absorption and accumulation,as well as 14 other trace elements concentrations in wheat grains.A sand culture experiment was conducted via a completely randomized 3×2×1 factorial scheme(three Se levels×two methods of Se application,foliar or soil×one Se sources,selenite),with two wheat cultivars(Guizi No.1,Chinese Spring).The results showed that both foliar Se and soil Se application methods had effects on wheat pollination.Foliar Se application resulted in early flowering of wheat,while soil Se application caused early flowering of wheat at low Se levels(5 mg kg^(−1))and delayed wheat flowering at high selenium levels(10 mg kg^(−1)),respectively.For trace elements,human essential trace elements(Fe,Zn,Mn,Cu,Cr,Mo,Co and Ni)concentrations in wheat grains were dependent of Se applica-tion methods and wheat cultivars.However,toxic trace elements(Cd,Pb,Hg,As,Li and Al)concentrations can be decreased by both methods,indicating a possible antagonistic effect.Moreover,both methods increased Se concentrations,and improved grain yield and nutritional quality,while the foliar application was better than soil.Accordingly,this study provided useful information concerning nutritional biofortification of wheat,indicating that it is feasible to apply Se to conduct Se biofortification,inhibit the heavy metal elements concentrations and improve yield and quality in crops,which caused human health benefits.

Inaccuracies in Phytic Acid Measurement: Implications for Mineral Biofortification and Bioavailability

Biofortification of commonly eaten staple food crops with essential mineral micronutrients is a potential sustainable solution to global micronutrient malnutrition. Because phytic acid (PA;1,2,3,4,5,6-hexakis myo-inositol) reduces mineral micronutrient bioavailability, reduction of PA levels could increase the bioavailability of biofortified iron (Fe), zinc (Zn), calcium (Ca), and magnesium (Mg). PA is viewed as an anti-nutrient, yet PA and other inositol phosphates have also demonstrated positive health benefits. Phytic acid analysis in the agricultural, food, and nutritional sciences is typically carried out by colorimetry and chromatographic techniques. In addition, advanced techniques such as nuclear magnetic resonance and synchrotron X-ray absorption spectroscopy have also been used in phytic acid analysis. The colorimetric analysis may overestimate PA levels and synchrotron X-ray absorption techniques may not detect very low levels of inositol phosphates. This short communication discusses the advantages and disadvantages of each widely used phytic acid analysis method, and suggests high performance anion exchange (HPAE) chromatography with conductivity detection (CD) based analysis can achieve greater accuracy for the identification and quantification of inositol phosphates. Accurate characterization and quantification of PA and inositol phosphates will inform PA reduction and biofortification efforts, allowing retention of the benefits of non-phytic inositol phosphates for both plants and humans.

Can Improve Iron Biofortification Antioxidant Response,Yield and Nutritional Quality in Green Bean?

The aim of this study was to evaluate the effect of iron biofortification on antioxidant response, yield and nutritional qualityof green bean (Phaseolus vulgaris L.) under greenhouse conditions. Fe was applied using two forms (FeSO4 and Fe-EDDHA) at four doses of application (0, 25, 50 and 100 μm) added under a hydroponic system, and were tested over a period of 40 days. The Fe content was assessed in seeds, as well as the activity of antioxidant enzymes, production of H2O2, yield and nutritional quality. The results being obtained indicated that the accumulation of Fe in bean seeds enhanced with the application of Fe-EDDHA at the dose of 25 μm. This demonstrated that low Fe application dose was enough to increase Fe levels in seeds of common bean. In addition, Fe-EDDHA application form at 50 μmol was the best treatment to improve crop yield. Respect to antioxidant system, chelated form of Fe (Fe-EDDHA) was more effective in the activation of antioxidant enzymes (CAT, SOD and GSH-PX), and a lower content of H2O2 in green bean seeds. Finally, to raise the Fe concentration in bean under biofortification program was a promising strategy in cropping systems in order to increase the ingestion of iron and antioxidant capacity in the general population and provided the benefits that this element offered in human health.

Genetics of carotenoids for provitamin A biofortification in tropical-adapted maize

Yellow maize contains high levels of β-carotene(βC), making it an important crop for combating vitamin A deficiency through biofortification. In this study, nine maize inbred lines were selected at random from 31 provitamin A(PVA) maize inbred lines and crossed in a partial diallel mating design to develop 36 crosses. The crosses were evaluated in the field in two locations(Samaru and Kerawa) and their seed carotenoid content were determined by high-performance liquid chromatography. The modes of gene action, heritability, and correlations between agronomic traits and carotenoid content were estimated. Additive genetic variances(σ~2a) were lower than non-additive genetic variances(σ~2d) for all the carotenoids, plant height(PH), and grain yield(GY), suggesting a preponderance of non-additive gene action. Broad-sense heritability(H^2) was high(H^2> 60%) for zeaxanthin,days to anthesis, and PH, moderate(30% < H^2< 60%) for lutein and GY, and low(H^2< 30%)for alpha carotene, beta cryptoxanthin, βC, and PVA. Genetic advance as a percentage of mean, considered with H^2, also suggests a preponderance of non-additive gene action for PVA carotenoids. Hybrid variety development is thus an appropriate approach to improving grain yield and PVA. GY showed no significant genotypic correlations with carotenoid content, suggesting that these traits can be improved concurrently. Thus, there is ample scope for improvement of PVA and GY in the sample of tropical-adapted maize.

Application of Zinc, Iron and Boron Enhances Productivity and Grain Biofortification of Mungbean

Deficiencies of essential vitamins,iron(Fe),and zinc(Zn)affect over one-half of the world’s population.A significant progress has been made to control micronutrient deficiencies through supplementation,but new approaches are needed,especially to reach the rural poor.Agronomic biofortification of pulses with Zn,Fe,and boron(B)offers a pragmatic solution to combat hidden hunger instead of food fortification and supplementation.Moreover,it also has positive effects on crop production as well.Therefore,we conducted three separate field experiments for two consecutive years to evaluate the impact of soil and foliar application of the aforementioned nutrients on the yield and seed biofortification of mungbean.Soil application of Zn at 0,4.125,8.25,Fe at 0,2.5,5.0 and B at 0,0.55,1.1 kg ha−1 was done in the first,second and third experiment,respectively.Foliar application in these experiments was done at 0.3%Zn,0.2%Fe and 0.1%B respectively one week after flowering initiation.Data revealed that soil-applied Zn,Fe and B at 8.25,5.0 and 1.1 kg ha−1,respectively,enhanced the grain yield of mungbean;however,this increase in yield was statistically similar to that recorded with Zn,Fe and B at 4.125,2.5 and 0.55 kg ha−1,respectively.Foliar application of these nutrients at flower initiation significantly enhanced the Zn contents by 28%and 31%,Fe contents by 80%and 78%,while B contents by 98%and 116%over control during 2019 and 2020,respectively.It was concluded from the results that soil application of Zn,Fe,and B enhanced the yield performance of mungbean;while significant improvements in seed Zn,Fe,and B contents were recorded with foliar application of these nutrients.

Advocacy and Use of Advocates as a Quick Win in Scaling Up Biofortification in Nigeria: The Case of Building Nutritious Food Basket (BNFB) Project

The Building Nutritious Food Baskets (BNFB) Project explored advocacy and the use of advocates as a model strategy for scaling up biofortification in Nigeria during its three-year implementation. In addition to its direct advocacy efforts, the BNFB project identified and selected key personnel across disciplines, gender and sectors, based on some selected criteria, as Advocates to support the scaling up of biofortification by raise of investments, resource mobilization, the inclusion of biofortification in relevant policy documents, strategies and plans of action. To realize these, the selected 32 Advocates were empowered to mainstream biofortification into their existing and/or potential programs/projects, as well as create awareness and demand for biofortified crops within their spheres of influence. Training and retreats were organized for the Advocates to strengthen their capacities in advocacy and promotion of biofortification and biofortified crops, while a social platform was launched to share opportunities, experiences and address issues around biofortification within the Advocates. As a result of these efforts, biofortification was included in three key national policies, strategies/plans of actions with resource allocation, and investments, over USD3 million were raised for biofortification. The Federal Government of Nigeria and some external governments became committed to biofortification programs while biofortified crops were mainstreamed in at least two national programs in Nigeria. Biofortified crops were included in the Home-Grown School Feeding Program of two states. The use of Advocates proved to be a resultful strategy in the biofortification scaling up model of BNFB as the advocates, upon being trained, looked out within their sectors and disciplines to mainstream biofortification into their programs. They gave timely information on potential opportunities to follow up with in influencing favorable policies;they mobilized resources nationally, regionally and locally;they facilitated wider coverage of biofortification within a short time. However, the influence of the Advocates was limited to their number and locations;thus, for a quick win in Nigeria, there is a need to raise advocates in all the 36 states of the country while giving equal priority to national and state level advocacy. As a lesson, to engender adoption of biofortification, participation/leveraging on existing programs in advocacy works faster and easier than starting afresh in Nigeria.

Linking Agriculture with Health through Genetic and Agronomic Biofortification

Malnutrition and associated health problems are partly related to minerals and vitamins deficiencies where anemia and stunting are the major diseases affecting nearly half of pregnant women and about 20% children under age of five, respectively in developing countries. Despite the significant progress made in recent decades, prevalence of stunting in Ethiopia remains high (44%, among children) that necessitate the country yet to make significant investment in nutrition and health. Strategies designed to overcome the problem range from micronutrient rich foods supplement to complementing foods with vegetables and fruits. However, such strategies are expensive as well as not sustainable to reach the poor households of developing countries. The persistence of the problem calls for agriculture based alternative solutions such as agronomic biofortification and micronutrients biofortification through plant breeding. Utilization of crop wild relatives, local landraces and old cultivars are proved to contain sufficient grain micronutrients and their utilization in breeding programs can solve the deficiency of micronutrients such as zinc and iron. Similarly, agronomic biofortification could improve grain Zn and Fe contents in several folds. Application methods and crop developmental stages during which fortification applied significantly determine the efficiency of fortification. Foliar application at heading and milking stages could accumulate very high Zn and Fe in cereal grains. The synergistic effect of genetic and agronomic fortification could also be utilized to produce Zn and Fe rich food crops. Hence, linking agriculture with nutrition and health could offer equitable, effective, sustainable and cheap solutions to micronutrients malnutrition and their deficiency related health problems.

石灰性土壤小麦籽粒锌硒生物强化理论技术与推广面临的挑战

锌与硒是人类生命活动必需的两种微量元素,摄入不足会引发多种疾病。我国小麦主产区恰好处于锌硒缺乏或潜在缺乏的石灰性土壤地带,籽粒中锌硒含量难以达到人体需求标准,导致缺锌缺硒人口数量庞大,已成为我国严重的公共营养与健康问题。本文综述了小麦籽粒锌硒农艺生物强化措施,强化籽粒中锌硒的分布、安全形态、生物可给性及叶面喷施的应用现状。国内外研究大多认为,在极缺锌土壤上采用土施或土施与叶面喷施锌肥结合的方式是最有效的小麦锌强化策略;而最新研究表明,在我国潜在缺锌的石灰性土壤上,叶面喷施硫酸锌的强化效果远优于土施,在小麦灌浆前期喷施2~3次0.3%~0.4%的Zn SO_(4)·7H_(2)O (喷锌总量约2.5 kg/hm^(2))并添加表面活性剂,可以实现籽粒锌含量达40~60 mg/kg的富锌目标。小麦籽粒中锌含量由外到内逐渐降低,人体摄入最多的中心胚乳部分锌含量最低,故需更为关注胚乳中锌含量及生物有效性,制定胚乳富锌标准。此外,食物中无机态元素毒性较大,生物有效性低,吸收利用效果不理想,而有机态对人体更为安全有效,因此还需明晰强化小麦籽粒中是否将外源无机Zn转化为有机态储存。小麦硒生物强化通过土施或叶面喷施亚硒酸盐或硒酸盐均能实现,由于土施硒肥易受土壤pH、有机质等因素影响,硒肥利用率低,因此,通行的硒强化措施是在小麦灌浆前期,喷施2 0~3 0 g/h m 2的亚硒酸钠或硒酸钠,能够实现籽粒硒含量达0.2 5~0.30 mg/kg的富硒目标。与锌不同,硒在籽粒中分布相对均匀,胚乳中硒占全粒总硒的96.2%~97.4%。同时硒强化小麦籽粒中对人体安全的有机硒占总硒的80%以上,且不同有机硒在人体中的作用不同。虽然叶面单独喷锌或硒的理论技术体系完善且实际强化效果良好,但其经济效益没有充分体现,影响了该技术的应用推广。近年来,将叶面喷施锌硒与“一喷三防”农艺措施相结合的研究不断增多,与小麦实际生产形成有效对接,为小麦锌硒强化提供了可行途径。然而,锌硒与不同农药及多种微量元素共同喷施时多种物质之间的互作效应,叶面喷施进行锌硒生物强化及籽粒锌硒储存的生理及分子机制还未明晰,值得进一步探讨。

不同外源硒对番茄的硒生物强化效果

【目的】比较土壤中施用不同量硒肥(亚硒酸盐和硒酸盐)对番茄生物量、不同部位硒含量及果实品质的影响,为生产优质的富硒番茄和开发其他富硒蔬菜品种提供参考。【方法】供试番茄品种为金美丽娜,采用盆栽试验,通过在土壤中拌施0.5,1,2和5 mg/kg亚硒酸钠和硒酸钠溶液对番茄进行硒生物强化,以不施用硒肥处理作为对照,测定不同处理成熟番茄的果实生物量、不同部位(果实、茎下部、茎上部、叶下部、叶上部和根)硒含量,以及果实品质参数(有机酸、可溶性糖组成及其含量,维生素C含量等),比较2种硒肥对番茄的硒生物强化效果。【结果】与对照相比,土壤中施用2种外源硒均增加了番茄果实生物量。与对照相比,0.5~5 mg/kg外源硒均显著增加了番茄果实的硒含量(P<0.05),且当土壤中施用硒肥量相同时,硒酸钠处理番茄果实的硒含量极显著高于亚硒酸钠处理(P<0.01)。各施硒处理番茄茎下部、茎上部、叶下部、叶上部和根中硒含量均显著高于对照(P<0.05),且这5个部位的硒含量均随外源施硒量的增加而显著增高(P<0.05)。外源施用硒肥番茄果实中有机酸的组成(草酸、酒石酸、苹果酸、柠檬酸、琥珀酸)几乎没有变化,各处理番茄果实均以苹果酸和柠檬酸为主,但各有机酸组分含量变化较大。与对照相比,外源施0.5~2 mg/kg硒均可显著提高番茄果实中的果糖和葡萄糖含量。与对照相比,土壤中施用0.5~2 mg/kg亚硒酸钠和硒酸钠后,番茄果实总有机酸、总可溶性糖、维生素C含量及糖酸比均显著升高(P<0.05)。【结论】土壤中施入0.5~2 mg/kg硒酸钠既可确保硒富集效果,又能提高果实品质。基于人体健康的考虑,推荐以在土壤中施用0.5 mg/kg硒酸钠的方式进行番茄的硒生物强化。

植物维生素B_(1)生物合成及生物强化的研究进展

维生素B_(1)是所有生物所必需的微量元素,其作为多个酶的辅因子,参与重要的细胞代谢途径。人体缺乏维生素B_(1)会增加罹患心血管及神经失调性疾病的风险。与植物和微生物不同,人类和其他动物不能从头合成维生素B_(1),必须从饮食中获取。因此,研究植物中维生素的生物合成途径,并在此基础上对植物中的维生素B_(1)含量进行生物强化具有重要意义。维生素B_(1)合成途径中有许多酶的参与,如嘧啶合成酶(THIC)、噻唑合成酶(THI1)、硫胺素磷酸合成酶(TH1)、硫胺素单磷酸酶(TH2)和硫胺素焦磷酸激酶(TPK)等。结合相关研究,对维生素B_(1)在植物中的生物学功能、生物合成途径及合成相关基因的功能进行总结,并介绍了通过代谢工程实现生物强化的研究进展,以期为进一步提高植物中维生素B_(1)含量提供参考。

Pichia kudriavzevii生物强化对酱香型白酒酒醅微生物群落结构及挥发性风味组分的影响

乙酸苯乙酯具有玫瑰花香、蜂蜜香、苹果香等风味特征,是酱香型白酒的重要风味物质。高产乙酸苯乙酯酵母菌的筛选及发酵应用对于改善酱香型白酒风味,提高白酒品质具有重要意义。从酱香型白酒酿造过程的酒醅样品中筛选得到1株乙酸苯乙酯产量相对较高的菌株Pichia kudriavzevii X-8,将其应用于酱香型白酒模拟发酵实验。结果表明:A组(未添加菌株Pichia kudriavzevii X-8)和B组(添加菌株Pichia kudriavzevii X-8)酒醅样品中挥发性化合物分别有60、65种,其中B组的酯类、醇类、酸类及其他风味物质的种类及含量均高于A组。发酵30 d后,B组乙酸苯乙酯质量比(0.214μg/g)约为A组(0.121μg/g)的2倍。B组特有的优势属为Weissella和Pichia,2组酒醅样品中Lactobacillus和Pediococcus,Saccharomycopsis和Saccharomyces的菌落丰度也存在差异。加入Pichia kudriavzevii X-8后,对酒醅的理化指标影响不大,增强了水质量分数、酸度及风味物质与真菌属微生物的相关性,提高了乙酸苯乙酯及其他重要风味物质的含量。研究结果旨在为酱香型白酒品质提升和功能菌株在酱香型白酒中的实际应用提供理论参考。

叶面喷施硒肥对香榧幼苗叶片代谢组的影响

[目的]分析亚硒酸钠叶面喷施后对香榧(Torreya grandis)幼苗叶片代谢组的影响,探究亚硒酸钠喷施后香榧叶片次生代谢物的累积情况及其对果实品质的影响。[方法]以苗龄2年的香榧幼苗为供试材料,叶面喷施亚硒酸钠(浓度为100μg·L^(-1))2次,间隔15 d。第二次喷施后15 d,采取1年生叶片进行代谢组分析,以色谱-质谱研究香榧幼苗叶片代谢物差异。[结果]在正离子模式下,处理组和对照组之间有909种差异代谢物,其中69种显著变化(27种显著上调,42种显著下调)。在负离子模式下,出现433种差异代谢物,其中43种显著变化(11种显著上调,32种显著下调)。对人体有益的一些次生代谢物显著增加,如车前苷(2.827倍)、川芎内酯(2.524倍)、6-唾液乳糖(2.021倍)、阿齐沙坦(1.931倍)。[结论]香榧叶片喷施亚硒酸钠有利于促进对人体有益的次生代谢物的生物合成及其在叶片中的累积。

功能菌对石油烃降解及微生物群落结构变化的影响

该研究以天津地区某污染场地为依托,利用筛选得到的石油烃降解功能菌,设计了加菌组和对照组2根土柱对比试验。通过检测石油烃、HCO3-、CO32-的浓度,结合16S高通量测序探讨了功能菌对石油烃降解的影响,对比分析了反应前后的微生物群落结构并对测序结果进行功能预测。结果发现,功能菌的加入对石油烃的降解效果较为显著。柱内物种组成情况表明功能菌的加入改变了土柱内的微生物群落多样性,促进了脱硫杆菌门的增长,抑制了放线菌门的繁殖。Desulfoprunum主要存在于在2组试验的进水口,推测在2组试验的进水端均存在着硫酸盐还原反应,Thermincola在加菌组出水口的相对丰度较高,加菌组伴随着强烈的反硝化、铁还原反应。α多样性分析表明2组试验出水口的微生物群落多样性较高,β多样性分析则表明微生物群落结构可能与试验柱的空间位置有关。此外,生态网络分析发现变形菌门为试验的关键菌门,功能菌的加入促进了物种间的协同合作关系,PICRUSt2功能预测分析结果表明功能菌的加入仅增强了进水口中bamB、bamC和出水口中的badA、badDEFG的丰度。

好氧反硝化细菌Burkholderia sp.ZH8的脱氮特性与生物强化作用

针对传统生物脱氮处理含氮废水工艺流程复杂、脱氮效率低的问题,从实验室运行稳定的生物滤池筛选得到一株好氧反硝化菌株ZH8,该菌株具有较强的异养硝化和好氧反硝化能力.通过形态学、生理生化特征及16S rDNA序列分析,鉴定菌株ZH8为伯克氏菌(Burkholderia sp.).单因素试验表明,好氧反硝化菌株ZH8的最佳培养条件为:碳源为丁二酸钠,C/N为15,温度为30℃,转速为160r/min和pH值为7~8.此外,菌株ZH8不仅能以NH_(4)^(+)-N、NO_(3)^(-)-N或NO_(2)^(-)-N分别为单一氮源进行生长,而且在混合氮源条件下也可实现同步硝化反硝化作用.通过全基因组分析,菌株ZH8的异养硝化脱氮为谷氨酸脱氢酶途径的铵同化过程,好氧反硝化途径为:NO_(3)^(-)-N→NO_(2)^(-)-N→NO→N_(2)O→N_(2),碳代谢途径包括三羧酸循环、乙醛酸循环、糖酵解和戊糖磷酸.在采用纯菌ZH8为菌种培养的生物膜反应器中,反应运行至8~15d即可完成挂膜,系统可维持高效稳定的脱氮性能,NH_(4)^(+)-N、NO_(3)^(-)-N及TN的去除率均可达到90%以上.该菌株为生物处理领域提供了新型菌种资源,能够有效处理含氮废水,具有实际应用价值.

强化异常威客汉姆酵母对白酒酿造中微生物结构及酯类合成的影响

异常威客汉姆酵母在白酒酿造中利于酯类化合物的合成。酯类是白酒的重要风味物质,其种类、含量对白酒的品质起至关重要的作用。采用模拟固态发酵技术研究白酒生产中人工添加异常威客汉姆酵母改善白酒风味物质的机制。试验共分为两组:空白组(a组)和添加异常威客汉姆酵母Y-1(b组),取不同发酵时期的酒醅样进行GC-MS分析,结果表明添加Y-1菌株可显著提高酒醅样品中酯类及其它风味物质的含量,其中b组中浓香型白酒主体酯己酸乙酯含量显著高于a组(P<0.05),发酵25 d时b组中己酸乙酯含量(856.1±4.00)mg/L。分别对发酵过程中两组酒醅进行高通量测序,Alpha多样性结果表明b组细菌群落多样性和丰富程度皆高于a组,而真菌的多样性和丰度较相似,各属间丰度有一定差异。结论:利用异常威客汉姆酵母发酵生产白酒,通过生物强化作用改变乙酸乙酯含量,从而导致其它风味物质的变化,该变化主要是由添加异常威客汉姆酵母引起微生物结构的变化所致,说明异常威客汉姆酵母Y-1具有提升固态发酵白酒风味物质的能力,尚需在实际生产中做进一步验证。

Enhanced protective effect of selenium-biofortified peptide RYNA(Se)MNDYT compared with its native peptide RYNAMNDYT in lipopolysaccharide-injured murine gut microbiota

Selenopeptides may be a valuable bioactive compound to promote gut microbiota-targeted therapeutic methods for intestinal disease and hepatopathy.However,limited information is available on the utilization of selenopeptides by gut microbiota,especially Selenium(Se)function.For this purpose,the present study aimed to investigate the protective effect of selenopeptide(RYNA(Se)MNDYT,Se-P2,purity of≥95%)and its original peptide(RYNAMNDYT,P2,purity of≥95%)in vivo by the microbiota-metabolite axis and further analyze the potential contribution of Se biofortification to Se-P2 bioactivity.The results showed that Se-P2 exhibits a higher protective effect on lipopolysaccharide(LPS)-induced inflammation than P2,including pathology of the colon and liver,which suggested that the bioactivity of P2 was promoted by the organic combination of Se.Notably,gut microbiota composition tended to be a healthy structure by Se-P2 pretreatment in LPS-injured mice,which had a positive effect on LPS-induced gut microbiota dysbacteriosis.Additionally,only Se-P2 promoted an increase in the relative abundance of Lactobacillus,Alistipes,and Roseburia and a decrease in the relative abundance of Akkermansia,Erysipelatoclostridium,and Bacteroides in LPS-injured mice.The changes in gut microbiota were obviously correlated with the changes in metabolites and affected the metabolic pathways of valine,leucine,isoleucine,phenylalanine,tyrosine,and tryptophan biosynthesis and phenylalanine metabolism.This may be one of the key reasons for Se-P2 to exert bioactivity through the microbiota-metabolite axis.Furthermore,Se-biofortification in Se-enriched Cordyceps militaris affected the parental proteins of Se-P2 to modulate mitogen-activated protein kinase,GPI anchored protein,and carbohydrate metabolism,translation,folding,sorting and degradation,which may contribute to the bioactivity of Se-P2.Our study provides information on the effect of Se on selenopeptides in vivo,which further promotes the prospective applications of selenopeptides as dietary supplements.

Synthesis of betanin by expression of the core betalain biosynthetic pathway in carrot

Betalain has received increased attention because of its high nutritional value and crucial physiological functions.Based on the elucidation of its core biosynthetic pathway,betalain can be produced in additional plants by metabolic engineering.Synthesis of betalain in carrot(Daucus carota L.)can improve its nutritional quality and economic value by extracting betalain from the fleshy root,non-edible part,and processing residue of carrot.In this study,two different constructs,namely,pYB:mCD(AomelOS,BvCYP76AD1S,and BvDODA1S)and p YB:CDD(BvCYP76AD1S,BvDODA1S,and MjcDOPA5GTS),were introduced into carrot for betanin synthesis by Agrobacterium-mediated transformation.Betanin can be synthetized in both transgenic calli,and p YB:m CD-transgenic callus can be used to produce betacyanin by suspension culture.However,pYB:mCD-transgenic seedlings can synthetize betanin only by tyrosine feeding.The p YB:CDD-transgenic lines can synthetize betanin in whole plants.The betanin content in fleshy root of pYB:CDD-transgenic carrot was(63.4±9)μg·g^(-1)fresh weight according to quantitative analysis.These betanin-producing carrot plant materials can be used to synthesize betanin for industrial application or consumption as dietary sources.