天然螯合微肥增效作用及机理的研究

目前由人工合成的有机螯合微量元素肥料，因价格昂贵不能在农业生产中广泛应用。本研究采用丰富廉价的有机肥料，经转化提取的天然螯合剂与微量元素螯合研制的天然螯合微肥，在多种作物上施用，证明能促进作物对Ｎ、Ｐ、Ｋ和Ｆｅ、Ｍｎ、Ｚｎ、Ｃｕ等微量元素的吸收。明显提高作物的产量，改善品质，并不同程度地提高作物的抗病能力．     

聚丙烯酰胺肟-羧酸螯合纤维对多种微量元素富集性能及机理的研究

近年来,利用巯基及它种螯合基纤维素富集测定多种微量元素的研究报导较多,但将螯合基团接在合成纤维上作为富集剂的报导尚少。我们曾用腈纶为原料合成聚丙烯酰胺肟-羧酸螯合纤维富集测定过数种微量元素。本文较系统地研究了该螯合纤维对30余种微量元素的定量富集酸度、吸附速度、洗脱酸度、饱和吸附量和共存离子的干扰,讨论了螯合纤维的稳定性、耐酸碱性、再生使用和富集机理,并进行了低浓度元素的富集和样品分析。实验表明,该螯合纤维是一种良好的高分子富集剂,它可以定量富集多种微量元素,具     

门诊儿童微量元素现状分析

为调查门诊儿童微量元素现状及相关疾病的发病率，检测了248例门诊儿童血锌、钙、铁、铜、铅值，并分析了相关疾病患病率。结果表明，本地区门诊儿童锌缺乏率76．2％，钙缺乏率71．37％，铜缺乏率19．29％，铅中毒率39．19％，全血铁测定缺铁比例87．92％。提示门诊儿童存在微量元素失衡现象，应采取适当措施予以纠正。     

微量元素与脱发130例临床分析

分析了１３０例脱发病人头发中的微量元素含量，结果证明，虽其临床分型、病理机制有所差异，但均与体内微量元素异常关系密切，并与锌、铁的缺乏关系最明显。以采用微量元素制剂为主，对重症者或兼杂证明显者配以其他疗法，时间缩短，疗效提高。临床有效率达９２．１％，显效率在８０％左右。     

聚胺-聚脲螯合纤维的合成及性能研究——ICP化学光谱测定应用

利用螯合吸附剂从溶液中将金属离子进行选择性吸附,富集分离的方法已有文章详述。近年来用巯基棉及聚丙烯酰胺肟-羧酸螯合纤维富集多种微量元素的性能,机理研究及测试报道不少。本文利用氯纶为原料合成聚胺-聚脲螯合纤维,研究了在pH=5微酸性介质条件下,对铬、钛、钒、镓、铟、铅、锡等微量元素的富集性能进行了研究。此螯合纤维可定量吸附多种微量元素,具有富集倍数高,饱和吸附容量大,解脱性能及选择性好等特点,与ICP光谱测定结合,样品分析得到较满意的结果。     

兴宁市儿童及成人微量元素水平调查分析

为提高人口素质，促进儿童身体健康，对广东省兴宁市儿童及成人的微量元素水平进行了调查。结果表明，本地区微量元素异常率达85．16％。提示必须防止铅污染，排铅补锌。     

1 332例儿童头发微量元素检测分析

为了解信宜市城区幼儿园儿童体内微量元素含量情况,回顾性分析了2003年信宜市城区幼儿园3至7岁儿童头发微量元素普查资料。结果表明,本区儿童缺锌率20．42％,缺碘率14．26％,缺钙率8．86％,缺铁率3．00％,铅高率42．04％。提示该市城区幼儿园儿童体内微量元素失衡相当普遍,必须加强幼儿园管理,监测和指导儿童微量元素营养,开展健康教育,提高群卫生保健意识,普通城区也要开展儿童铅中毒防治工作。     

用于分离稀土的螯合纤维的制备及性能的研究（Ⅰ）

用反应性纤维ＰＰ（ＰＶＡ，ＰＡ６）－ｇ－ＰＧＭＡ与二乙氧基亚膦酸钠反应可制得含二乙氧基亚膦酸酯的螯合纤维。研究表明，反频性纤维以接枝率１２００％的ＰＰ－ｇ－ＰＧＭＡ较子，在１４０℃下和ＮａＰＯ（ＯＥｔ）２反应１２小时，增重率可达７４％。螯合纤维ＰＰ－ｇ－ＰＧＭＡ－ＰＯ（ＯＥｔ）２对稀土离子的吸附量差异较大，其顺序为ＨＯ＾３＾＋＞Ｙｂ＾３＾＋＞Ｎｄ＾３＾＋＞Ｔｂ＾３＾＋＞Ｓｍ＾３＾＋＞Ｄｙ＾３＾＋     

聚乙烯醇胺肟螯合纤维吸附钯的研究

用动态法研究了聚乙烯醇胺肟（ＰＶＡＡＯ）螯合纤维对钯的吸附。讨论了影响吸附率和回收率的因素，确定了最隹吸附条件。用５％硫脲＋０．５０ｍｏｌ／Ｌ硝酸溶液可以解吸。ＰＶＡＡＯ螯合纤维对钯的饱和吸附容量为４５１．９ｍｇ／ｇ干纤维。     

298例儿童血清中微量元素含量分析

为了解各年龄组儿童血清中微量元素缺乏情况，检测了湖南省龙山县人民医院门诊298例儿童血清中微量元素含量。结果表明，各年龄组儿童均有Ca、Zn、Fe的缺乏，其中以婴幼儿明显；随年龄增长微量元素缺乏率显降低趋势，但各年龄组仍有较高的缺乏率。因此，适量补充微量元素非常重要。     

改性羽毛对锌离子的吸附

使用单宁酸对禽类羽毛进行化学改性.研究了改性前后羽毛对金属锌离子的吸附及解吸性能,探讨了羽毛上单宁酸负载量,锌盐溶液的pH值等因素对羽毛金属离子吸附性能的影响.结果表明,经单宁酸化学改性的羽毛在碱性环境下能明显增加对金属锌离子的吸附,此时对应Zn2 的最大吸附量为O.97mmol/g,而未改性羽毛在相同条件下的最大吸附量为0.64mmol/g.在酸性环境中,改性羽毛中金属锌离子的解吸附率为16.8%,未改性羽毛的锌离子解吸附率为64.0%,表明改性羽毛的金属复合物具有较高的稳定性.羽毛作为一种廉价的重金属吸附材料,对整治环境污染具有应用前景.     

Keratinolytic enzyme-mediated biodegradation of recalcitrant feather by a newly isolated Xanthomonas sp. P5

We isolated and characterized a novel feather-degrading Xanthomonas sp. P5 with keratinolytic activity. In improved medium containing 0.1% (w/v) feather, maximal keratinolytic activity was observed at 5 days (69.0 ± 0.6 U/mL). This value was 7.1-fold higher than the yield in basal feather medium. The strain P5 degraded feather completely after 7 days. Feather degradation resulted in free thiol group, soluble protein and amino acids formation, indicating that sulfitolysis and proteolysis may be responsible for feather degradation by the strain P5. Total free amino acid concentration in the cell-free supernatant was around 188.6 μM. Asparagine, methionine, histidine and threonine were the major amino acids released in the culture. Xanthomonas sp. P5 exhibited multiple plant growth-promoting attributes such as siderophore, indoleacetic acid, ammonia, hydrolytic enzyme and antifungal activity. Our results indicate that Xanthomonas sp. P5 could be not only used to upgrade the nutritional value of recalcitrant feather waste but is also a potential candidate for the development of biofertilizer or biocontrol agent applicable to crop plant soil.     

基于植酸改性的羽毛吸附材料的制备及其性能

以含环氧基的羽毛接枝共聚物(Feather-g-PGMA)为原料、植酸(PA)为改性剂,利用环氧基的开环反应,将PA中的磷酸根基团引入到Feather-g-PGMA表面,制得含有高密度磷酸根的羽毛吸附材料。采用红外光谱(FT-IR)、热重分析(TG)和X衍射图谱(XRD)对改性前后的羽毛进行表征。重点研究了羽毛吸附材料的制备过程及其吸附量的主要影响因素。结果表明:PA成功改性了Feather-g-PGMA。当PA体积分数为25%、温度为70℃、时间为4h时,改性条件最佳。制备的羽毛吸附材料与Pb~(2+)之间可产生配位作用,对Pb~(2+)有强吸附力,吸附容量可达54.4mg/g。与羽毛相比,热稳定性下降;与Feather-g-PGMA相比,热稳定性增强。     

ClonedBacillus subtilis alkaline protease (aprA) gene showing high level of keratinolytic activity

TheBacillus subtilis alkaline protease(aprA) gene was previously cloned on a pUBHO-derivative plasmid. High levels of expression and gene stability were demonstrated whenB. subtilis cells were grown on the laboratory medium 2XSG.B. subtilis cells harboring the multicopyaprA gene were grown on basal medium, supplemented with 1 % chicken feather as a source of energy, carbon, and nitrogen. Proteolytic and kera-tinolytic activities were monitored throughout the cultivation time. A high level of keratinolytic activity was obtained, and this indicates that alkaline protease is acting as a keratinase. Furthermore, considerable amounts of soluble proteins and free amino acids were obtained as a result of the enzymatic hydrolysis of feather. Biodegradation of feather waste using these cells represents an alternative way to improve the nutritional value of feather, since feather waste is currently utilized on a limited basis as a dietary protein supplement for animal feedstuffs. Moreover, the release of free amino acids from feather and the secreted keratinase enzyme would promote industries based on feather waste.     

Food engineering residues: amino acid composition of hydrolysates and application for the decontamination of metal polluted soils

Several residues of the brewing industry and slaughtering offals were investigated in order to evaluate their potential as raw materials for the hydrolytic preparation of amino acid containing solutions, applicable as extractants in amelioration processes for metal polluted soils. The residues were hydrolysed with 6 mol/L hydrochloric acid and the hydrolysates were analysed for their total nitrogen, TOC, amino acid and heavy metal contents. Then, the leaching capacities of the hydrolysates were examined in a series of batch tests with a contaminated soil.High amino acid yields in relation to the weight of the air-dried raw materials were achieved with blood meal (72.5%) and poultry feather meal (56.6%). The portion of the detected amino acids of the total organic carbon content of the hydrolysates ranged from 38.9% (brewer's spent grain) to 93.6% (blood meal). In extraction tests with hydrolysates adjusted to a total amino acid concentration of 60 mmol/L and to a pH value of 7.0, maximum extraction yields of 50.3% for copper (soil content 279 mg kg^–1) and 38.7% for nickel (soil content 54 mg kg^–1) were reached. An increase of the hydrolysate concentration and of the pH of an amino acid mixture resulted in higher solubilisation of the metals.Dedicated to Prof. Dr. Dieter Klockow on the occasion of his 60th birthday     

Production of Keratinase by Free and Immobilized Cells of <Emphasis Type="Italic">Bacillus halodurans</Emphasis> Strain PPKS-2: Partial Characterization and Its Application in Feather Degradation and Dehairing of the Goat Skin

An extremely alkaliphilic bacterial strain, Bacillus sp. PPKS-2, was isolated from rice mill effluents and screened for the production of extracellular keratinase. The maximum production of keratinase occurred after 48 h in shaking culture at pH 11.0 and 37 °C in a medium containing 0.5% soybean flour. The strain grew and produced alkaline keratinase using chicken feather and horn meal as the sole source of carbon and nitrogen. An addition of 0.1% soybean flour or feather hydrolysate and sodium sulfite to feather medium increased the production and complete solubilization of feather took place within 5 days under solid-state fermentation conditions. The partially purified enzyme displayed maximum activity at pH 11.0 and 60 °C in a broad range of NaCl, 0–16%, and was not inhibited by sodium dodecyl sulfate (10%), ethylenediaminetetraacetic acid (10 mM), H₂O₂ (15%), and other commercial detergents. Immobilization of the whole cells proved to be useful for continuous production of keratinase and feather degradation. The enzyme was effectively used to remove hair from goat hide. The strain PPKS-2 can be effectively used for solid waste management of poultry feather in submerged as well as solid-state fermentation.     

PHOTOCHEMICAL DEGRADATION OF KERATINS

Abstract— Twenty-nine samples of fur, hair. wool and feathers have been irradiated with a Sunlamp (Λ max. 310 nm) and with a 2 kW mercury vapour lamp emitting mixed U.V. and visible radiation resembling sunlight. Photodegradation is accompanied by progressive yellowing when irradiated with the Sunlamp. It is accompanied by bleaching followed by yellowing, or by bleaching throughout irradiation if the initial yellowness is high, when exposed to the 2 kW lamp. A group of nine fur and hair samples, representing four different orders of mammals, are the most sensitive to yellowing, followed by a group of ten wool and hair samples from the Artiodactyla and finally by the feather keratins which are less susceptible than the α-keratins. Amino acid analysis of the keratins before and after Sunlamp irradiation shows strong correlation of yellowing both with the initial concentration of tryptophan and with its destruction during irradiation. Similar correlations of yellowing with destruction of other amino acids are less significant. Preliminary washing with non-ionic detergent increases susceptibility to u.v. yellowing.     

Sorption of Cu<Superscript>2+</Superscript> and Zn<Superscript>2+</Superscript> by Natural Biomaterial: Duck Feather

Feather fibers were modified by treatment with 5% tannic acid (TA) solution. Kinetics of the modification was investigated as a function of the reaction time. The maximum loading of TA on feather reached 8.3% after being treated by TA for 9 h. The adsorption of metal cations (Cu²⁺, Zn²⁺) by unmodified and TA-modified feather fibers was investigated as a function of fiber weight gain, temperature, and pH of the metal solution. The adsorption was enhanced at alkaline pH and ambient temperature and increased with the weight gain of TA. The maximum uptake of metal cations (Cu²⁺, 0.77 mmol/g; Zn²⁺, 0.95 mmol/g) was obtained by TA-modified feather at weight gain: 8.3%, pH 11, while at the acidic pH, the adsorption of metal cations by either unmodified or TA-modified feather was negligible. The influence of anions on the adsorption of metal cations was also studied. The uptake of Cu²⁺ from chloride was higher and faster than that from nitrate. Desorption of the metals was performed at acidic pH 2.5 for 48 h. The feather–TA–metal complexes exhibited higher stability for metal cations than the feather–metal complexes. All these experiments reveal that TA-modified feather fibers have good adsorption to metal cations and can be used as metal adsorbent in wastewater treatment.     

SPECTRAL MODIFICATIONS OF BACTERIAL ANTENNA COMPLEXES BY LIMITED PROTEOLYSIS

The spectral effects of a number of endo- and exoproteases to the detergent-solubilized antenna complexes B802–858(sphaeroides like) of strain Rhodopseudomonas acidophila 10050 and B802–824of strain 7050 were analyzed. Upon protease digestion the time course of spectral modification between 250 and 900 nm was recorded. In addition, circular dichroism (CD) signals were measured between 450 and 950 nm. The endoprotease elastase as well as the exoprotease carboxypeptidase A (CP A) altered the B802–858antenna complex, by changing the 858 nm band hypochromically (30-50%) with an additional small hypsochromic shift (3–6nm). A combined carboxypeptidase digestion, e.g. CP A and CP B, yielded a further modification to a complex with absorption bands at 800 nm and ?840 nm (ε? 50% of the 800 nm band). By exposing the isolated B803–824antenna complex to the different proteases no significant spectral change was observed. The B802–858antenna complex, modified by CP A, exhibits a60–70% decrease of the biphasic CD signal in the near infrared. The limited proteolysis experiments provide conclusive experimental evidence that the C-terminal domains of the antenna polypeptides α and β contribute to the formation of (dimeric) bacteriochlorophyll (BChl) a molecules absorbing at around 850 nm. This agrees with the hypothesis, based on comparative amino acid sequence analysis, that in purple bacterial antenna complexes the structural requirements (specific amino acids in the vicinity of the BChl molecules, e.g. aromatic amino acids) for batho- and hyperchromicity of BChl molecules apparently reside to a considerable extent in the C-terminal portions of their antenna apoproteins.     

NAK-12树脂脱除蚕蛹复合氨基酸异味及褐变物质的研究

本文研究了用NAK－12吸附树脂脱除蚕蛹复合氨基酸异味及褐变色素的条件，初步分析了蚕蛹复合氨基酸异味产生的原因，实验结果表明：当流速为3BV／h时，1ml NAK-12吸附树脂能吸附1．75g蚕蛹复合氨基酸中的异味物质；能吸附1．45g蚕蛹复合氨基酸中的褐变物质。甲醇是异味物质和褐变物质的良好洗脱剂，用pH1．0的甲醇以1BV／h流速洗脱，仅用3．5BV的洗脱剂即可完全洗脱异味物质和褐变物质，蚕蛹复合氨基酸异味产生的可能机理是：加热蚕蛹复合氨基酸液时，其苯丙氨酸，蛋氨酸，蛋氨酸，异亮氨酸，亮氨酸，苏氨酸被氧化脱氨，生成挥发性醛，而其褐变则是赖氨酸，精氨酸与还原糖发生Maillard反应生成褐变物质引起的。