Isolation and Identification of Selenium-tolerant Strains from Selenium-rich Soil in Guangxi

To provide reference for selenium resource exploitation of soil,many selenium-tolerant strains were isolated from selenium-rich soil in Guangxi. The dilution spread plate method and selenium-added culture method were used to screen the selenium-tolerant strains from the soils which were sampled from the main Selenium-rich areas such as Yongfu,Bama,Yulin Hanshan,Guiping and Tengxian. The results showed that 8 strains with high selenium tolerance were obtained,which could tolerate the selenium concentration above 10 000 μg/m L in solid medium. Among the 8 strains,YLB1-33 showed the highest selenium tolerance,and it could still grow weakly in the solid medium with selenium concentration of 29 000 μg/m L. The sequencing of 16 S rD NA and phylogenetic analysis showed that YLB1-6 was identified as Bacillus cereus,BMB2-1 and TXB1-8 were identified as Bacillus pumilus,GPB2-5 was identified as Bacillus thuringiensis,YLB1-26 and YLB1-33 were identified as Bacillus licheniformis,and YLB1-2 and YFB1-8 were identified as Serratia marcescens. The finding of selenium-tolerance strains had potential application value on promoting the utilization of selenium soil resources and the development of selenium-rich agricultural products in Guangxi.

Technical Regulations for Planting of Forage Millet Rich in Selenium in Hebei Province

According to the summary of many years of experiments, the application scope, basic demands, preparation before seeding, seeding demands, field management, mowing, transportation, storage, ledger management and other technical requirements of technical regulations for planting of forage millet rich in selenium were studied, and specific measures and technical indicators of the technical regulations were analyzed, aiming to provide normalized, standardized, industrial and marketization technical support for the planting of forage millet rich in selenium.

Preliminary Study on the Standard of Selenium Content in Agricultural Products

With the improvement of living standards, people pay more attention to the agricultural products with health protection function, and the selenium-rich agricultural products attract more and more consumers. The main biological role of selenium is to resist oxidation and inflammatory response, mainly focusing on resisting aging, preventing cardiovascular disease, protecting eyesight, counteracting or destroying the toxic properties, preventing cancer and thyroid disease. In most areas of China, there is a widespread shortage of selenium, thus producing selenium-rich agricultural products to provide natural selenium-rich health food to the areas in need of selenium, has gradually become a new hot spot of China's health food industry, but high content of selenium in food is detrimental to human body, even leads to selenium intoxication, and artificially adding inorganic selenium is difficult to guarantee that the selenium content of agricultural products is not exceeded. According to human body's daily demand for selenium in dietetics and the content of selenium in agricultural products in the Chinese food composition table, we put forward the recommendations on the standard of selenium in agricultural products, in order to provide the basis for China to formulate the health standard of selenium content in selenium-rich agricultural products.

Effects of Plant-derived Humic Acid Organic Fertilizer on Selenium Content of Rice in Northern Guangxi

This study was to find out the suitable application amount of plant-derived humic acid organic fertilizer for selenium-rich rice production in northern Guilin area by applying the fertilizer at different amounts.The results showed that plant-derived humic acid organic fertilizer could effectively activate selenium in selenium-rich soil,and then promote the uptake of selenium by rice.With costs,selenium enrichment and rice yield as the main evaluation indicators,A4 was chosen as the best treatment,that is,the application of 4 500 kg/hm^2 of plant-derived humic acid organic fertilizer as base fertilizer could achieve the best benefit.

Distribution of Soil Nutrients in Se-rich Areas of Hainan Island

[Objectives] The aim was to reveal the distribution of soil nutrients in Se-rich area of Hainan and to clarify their specific contents, so as to provide references for the development of Se-rich area agriculture in Hainan.[Methods] With the se-rich area in Hainan as the object, field investigation and indoor analysis were combined to elucidate the nutrient status of cultivated soil in the area and analyze its nutrient distribution.[Results] The soil in the se-rich area in Hainan province was generally acidic with the average soil pH value of 5.0. The difference in soil pH between different landforms and different altitudes was not significant, ranging from 4.9 to 5.3. Soil available P and available K contents were low to intermediate, and the soil available N content was moderate. The farming system, chemical fertilizer application structure and meteorological factors were the main causes of the distribution of soil nutrient elements. The soil exchangeable calcium and magnesium content was rich, and the distribution of trace elements in the arable soil of different terrains and elevations was closely related to the distribution of soil parent material in the region. The increase of soil organic matter content in arable land could be achieved by increasing the application of organic fertilizer and guiding the farmers to enhance the application of straws to fields.[Conclusions] The application of soil N, P and K fertilizers should be combined with the application of soil organic fertilizers to improve the soil fertility of cultivated land.

福建富硒红壤区土壤硒含量特征及作物对硒的吸收

在调查我国南方红壤区土壤及农产品中硒含量状况的基础上,分析了富硒红壤中硒的分布特征及其所产农产品中硒含量的变化规律。结果表明:我国南方富硒红壤面积较大,但在地理空间分布上具有一定破碎度;土壤中的硒虽伴生一定量的重金属和稀土等元素,但与重金属或稀土元素的相关性不大;在富硒土壤上生产的农作物总体表现为可食部位的硒含量低于非可食部位的,并且农作物中的硒含量与土壤有效态硒含量相关性显著。依据我国南方富硒红壤区土壤自身特性,可以通过调控富硒红壤区农田土壤的酸碱度、水分含量、施肥种类、施用调理剂等来提高土壤硒的有效性,达到农产品中硒含量增加的目的;同时,对外源补硒的技术和相应农产品硒的健康效应,需进一步研究与规范。

皖西南富硒土壤分布及富硒农产品调查

本文以土地质量地球化学调查数据为基础,分析了皖西南富硒土壤的分布、无公害绿色富硒土壤、无公害富硒农产品产地适宜区、绿色富硒农产品产地适宜区及绿色富硒食品等情况。结果表明,富硒土壤面积占总评价面积的4.97%,主要分布在CS、SH、GZ、TZS和TF等乡镇。无公害绿色富硒土壤面积约占富硒土壤总量的85.57%,富硒土壤达到无公害农产品产地环境标准和绿色食品产地环境标准的面积一致。无公害富硒农产品产地适宜区占评价区总面积的4.25%。绿色富硒食品产地适宜区占评价区总面积的4.24%,其中AA级适宜区占1.80%,A级适宜区占1.78%。富硒土壤主要为自然背景成因,且富硒土壤具有有机质含量较高的特征,推测富硒土壤成因为吸附型富硒。查明了特色农产品绿色富硒水稻、茶叶和栝楼生产区。该结果为研究区天然富硒土地资源开发利用提供参考。

富硒中药材及其有机硒形态的研究进展

Se是人体不可或缺的微量元素,具有提高人体免疫、抗癌、降低重金属毒性、降血压、抗动脉硬化等多种生理作用。药用植物富硒后,通过Se的富集作用使存在于土壤或硒肥中的无机硒通过生物转化最终得到安全高效的有机硒,增加中药的Se含量和次生代谢产物,具有潜在的药用价值,对中药资源的开发具有重要意义。文章对近年来富硒中药的主要种类和其中提纯的有机硒化合物,如硒多糖、硒蛋白、硒核酸的研究进行了综述。

云南施甸土地质量地球化学空间分布特征

基于云南省施甸县1∶5万土地质量地球化学调查评价相关数据成果,分析了土壤pH、土壤养分、土壤环境质量、土壤质量、土地质量及一般富硒土等级划分标准及空间分布特征,并在调查区划定了一般富硒土地资源(Se平均值0.5mg/kg),面积233.32km 2,为发展富硒特色农业奠定了基础。

施甸县水长-姚关富硒土地资源分布与开发利用探讨

2022年中国地质学会评审认定“云南省施甸县(姚关镇、旧城乡)天然富硒地块”为天然富硒土地。施甸县共圈定一般富硒土地面积255.43km^(2),表层土壤中Se元素含量平均值0.45mg/kg,平均含量大于滇西地区表层土壤平均值(0.41 mg/kg)和全国土壤A层平均值(0.29 mg/kg)。一般富硒耕地划分了5大特色农业种植区,24个特色农业种植小区,打造出施甸特色富硒品牌,将资源优势转化为产业和经济优势,促进乡村振兴。

硒的来源、富集及富硒食物资源研究进展

富硒食物具有提供营养物质和有机硒的双重作用,在全民缺硒的大环境下,了解硒的来源及其在自然环境和生物系统中的循环相当重要。当前富硒食品的研究主要针对化学合成与生物有机转化,专业性较强,不利于多种类富硒食品进行横向对比。关于硒的循环、多种类富硒食品含量及作用对比等方面的研究总量较小。本文综述硒的来源和循环代谢,阐明富硒食物中天然硒的来源和形式,介绍植物、动物和微生物对硒的吸收和代谢途径,并对硒的吸收和代谢进行横向比较,对多种来源富硒食品的最新研究现状进行评价,并对富硒食品的未来发展进行展望,为深入对比不同硒来源的食品提供参考依据,并根据不同种类食品特性为创新研发新型高效、健康的富硒产品提供科学指导。

硒肥施用方式对红阳猕猴桃果实的影响

【目的】筛选适合红阳猕猴桃富硒的硒肥施用方式。【方法】以3年生红阳猕猴桃为材料,设置根施、叶面施和根施+叶面施3种硒肥施用方式,在生育期观察各处理的抗病性,成熟期测定各处理的果实硒含量、商品性相关指标。【结果】3种施肥方式中,根施+叶面施的果实硒含量为0.032 mg/kg,富硒效果显著,且提升了果实单果质量与商品性,综合表现优秀,是红阳猕猴桃富硒较好的硒肥施用方式;叶面施富硒综合表现良好,硒肥用量少、经济有效,具有一定的成本优势。【结论】推荐根施+叶面施、叶面施两种硒肥施用方式,具体可根据实际需要选择。

富硒啤酒酵母的选育及有机硒含量的测定

为了进一步研究微生物富硒的能力,得到富硒能力较强的啤酒酵母,以啤酒酵母WX-01为出发菌,通过高浓度亚硒酸钠初筛,再经过常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变处理以及亚硒酸钠抗性平板筛选,观察菌株的生长状况结合对其生物量与硒含量的测定,选育出一株富硒优势啤酒酵母。通过培养条件为添加质量浓度35 mg/L,加硒时间8 h,培养时间36 h,得到的酵母WX-1的生物量提高到(5192±36)mg/L,较原始菌株WX-01提高了201%,硒含量达到(1475±33)μg/g,较原始菌株提高了330%,其有机硒产量和转化率分别为7658μg/L和97.1%。扫描电镜分析酵母菌富集后表面有少量单质硒析出。另外红外光谱在特定区域出现不同强度的吸收峰表明酵母细胞参与了硒蛋白的合成。

四川汶川-茂县河谷地区土地质量地球化学调查成果及其意义

对四川阿坝州汶川茂县优选耕地区开展了土地质量地球化学评价工作,结果表明,研究区土地质量总体以无风险土壤为主,占总面积的86.69%。土壤养分总体呈丰富和较丰富状态,仅磷和钾在局部地区较缺乏;土壤环境质量整体良好;研究区土壤质量以优质土壤为主,占全区面积的86.7%;研究区绿色食品产地、绿色富硒土地资源较丰富,分别有74 576亩和8 218亩。土地质量地球化学评价成果对土地利用、规划布局、发展现代农业、提高耕地质量等方面具有重要指导意义。

江西宜春袁州农用地富硒土壤分布及重金属环境容量研究

江西省宜春市袁州区拥有丰富的土壤硒资源,但由于城镇化和工业化的迅速推进所导致的土壤重金属种类和数量的增多,以及土壤硒与重金属伴生关系的存在,使得富硒土壤一定程度上受到重金属威胁,限制了富硒农产品的开发利用。采集检测袁州区162份表层土壤样品中铅(Pb)、铬(Cr)、镉(Cd)、砷(As)、汞(Hg)、铜(Cu)、锌(Zn)、镍(Ni)8种重金属的含量,通过土壤重金属环境容量估算以及运用环境容量指数法和空间插值法评价得到袁州区农用地富硒土壤重金属环境容量水平及空间分布情况,据此分析袁州区农用地富硒土壤重金属污染状况。结果表明:(1)整个袁州区农用地可以划分为富硒、潜在富硒和足硒3种土壤,分别占袁州区农用地的74.04%、16.00%和9.96%。(2)Pb、Cr、As、Hg、Cu、Zn和Ni 7种重金属在8个年限内的平均静态年容量和平均动态年容量大小排序相同,从大到小依次为Zn、 Cr、Pb、Ni、As、Cu、Hg,7种重金属的平均静态和动态年容量都随着控制年限的增长而减小,且7种重金属的平均动态年容量都比平均静态年容量大。(3)研究区富硒土壤中的Pb、Cr、As、Hg、Cu、Zn和Ni 7种重金属都以中容量区为主,而Cd主要为超载区。综合来看,研究区85%以上为低容量区,整体容量较小,土壤受到中度污染,为提高研究区土壤重金属环境容量,降低污染程度,保证富硒农产品的安全,可针对不同容量区采取土壤污染防控和修复等措施。

江西富硒功能农业现状及高质量发展对策

[目的]了解江西富硒功能农业发展整体情况,并提出相应的对策,以期为推动江西富硒功能农业高质量发展提供参考。[方法]通过系统梳理江西富硒功能农业在资源禀赋、政策创设、平台建设、市场需求等方面的多重优势及其发展所取得的成效,剖析其在科技支撑、产业融合、标准化程度和品牌建设等方面的不足之处。[结果]江西省在发展富硒功能农业方面具有显著优势,应从推进科技创新、推动产业融合、实施标准引领、培育龙头企业、强化品牌建设等五方面,进一步推进富硒功能农业高质量发展。[结论]建议将富硒功能农业作为推动江西现代农业发展的突破口,积极推进“硒+X”发展战略,高标准建设富硒农业基地,实现富硒功能农业的规模化、产业化、市场化发展。

外源硒对鸡腿菇菌丝生长及合成主要营养素的影响

以1株鸡腿菇菌株Cc-900为试材,采用平板培养和液体发酵培养的方法,研究不同浓度的外源硒对鸡腿菇菌株Cc-900的生长、富硒效果和菌丝合成蛋白质和多糖的影响,以期为富硒鸡腿菇的栽培和产品的开发提供参考依据。结果表明:鸡腿菇菌丝可耐受10 mg·kg^(-1)硒浓度的固体培养基和最大硒浓度为3 mg·L^(-1)的液体培养基,高浓度硒对菌丝活性损伤较大;当液体培养基中硒浓度为3 mg·L^(-1)时,菌丝干质量可达1.97 g·L^(-1),菌丝干粉的硒含量为38.24 mg·kg^(-1),其硒富集系数可达12.75,菌丝中粗蛋白和多糖含量分别为2.58%和3 081.82μg·g^(-1),发酵液中可溶性蛋白质和多糖含量分别为50.98μg·mL^(-1)和266.38μg·mL^(-1)。液体发酵培养中硒浓度在3 mg·L^(-1)以下可促进鸡腿菇菌丝的生长和硒的富集,同时促进菌丝中蛋白质的合成和释放,但会抑制菌丝中多糖的合成。

富硒稻谷在35℃条件下储藏品质、糊化特性及食用品质的变化规律

为研究富硒稻谷储藏期间的品质变化规律,以湖北恩施(‘稻晶两优’(E0、E1))及湖北荆州生产(‘鄂中6号’(X0、X1))的富硒稻谷和非富硒稻谷为研究对象,模拟高温储藏条件(35℃、相对湿度50%),放入人工气候培养箱中加速陈化180 d,每30 d测定其储藏特性、糊化特性及食味品质并进行分析。结果表明:随着储藏时间的延长,富硒稻谷和非富硒稻谷的各指标的变化趋势一致,但变化程度不同。储藏到180 d时,非富硒稻谷(X0、E0)的发芽率分别为69.7%和65.7%,脂肪酸值分别上升了40.43%、59.74%,α-淀粉酶活力分别为0.26、0.22 U/g;富硒稻谷(X1、E1)的发芽率分别为66.7%和64.0%,脂肪酸值分别上升了53.99%和78.47%,α-淀粉酶活力分别为0.24、0.19 U/g,与对照组相比,富硒稻谷的发芽率低、α-淀粉酶活力较低,脂肪酸值高,表明富硒稻谷在储藏品质上未表现出明显优势。储藏180 d时,非富硒稻谷(X0、E0)的丙二醛含量分别为0.36μmol/g和0.28μmol/g,游离酚含量分别为341.78μg/g和371.59μg/g,游离巯基含量分别为0.68μmol/g和0.64μmol/g;富硒稻谷(X1、E1)的丙二醛含量分别为0.31μmol/g和0.24μmol/g,游离酚含量分别为368.33μg/g和399.22μg/g,游离巯基含量分别为0.89μmol/g和0.74μmol/g,与对照组相比,富硒稻谷的丙二醛含量低,游离酚和游离巯基含量高,表明富硒稻谷在储藏过程中具有一定的抗氧化能力。在糊化特性、质构特性及食用品质上,与对照组相比,在相同的储藏期,富硒稻谷的峰值黏度高、糊化温度低,米饭硬度小、黏性大、弹性大,食味评分高。综上,富硒的稻谷在35℃下储藏过程中具有更好的抗氧化能力和食味值,但在抗陈化方面并未展现出优势。

微波消解-氢化物原子荧光光谱法测定胡萝卜硒含量

硒是人体内各种含硒酶及含硒蛋白的合成过程中必不可少的一种微量元素,能提高身体的免疫功能。硒对人体有一定的防癌作用,硒不但对肿瘤有抑制作用而且还能影响致癌物质的新陈代谢,素有“防癌之王”之称。采用人工栽培方式生产的富硒胡萝卜是一种较为理想的富硒型蔬菜。该文以胡萝卜为研究对象,利用微波消解-氢化物原子荧光光谱法测定胡萝卜中总硒的含量,探讨不同微波消解溶剂和消解条件对含硒胡萝卜消解效果的影响,并优化氢化物原子荧光光谱法测定条件。结果表明,最佳消解体系为HNO_(3)-H_(2)O_(2)体系(5 mL∶2 mL);最佳微波消解条件为,第一工步为2 min、0.2 MPa;第二工步为6 min、0.5 MPa和6 min、0.7 MPa;第三工步为5 min、1 MPa;在最优条件下,测硒的线性范围为0~50μg/L。对样品空白荧光值进行10次测定,RSD=2.24%,最低检出限为0.90μg/kg。土壤中施硒能够显著提高胡萝卜中总硒的含量,较空白对照组提高6.50%(地上)和10.30%(地下),可食用(地下)部位的最高硒含量为445.90μg/kg。