The Mutation Breeding and Mutagenic Effect of Air Plasma on Penicillium Chrysogenum

Low temperature air plasma was used as the mutation tool for penicillin-producing strain Penicillium chrysogenum. The discharge conditions were RF power of 360 W, temperature of 40℃ in a sealed chamber, and pressure of 10 Pa to 30 Pa. The result showed that the kinetics of the survival rate followed a typical saddle-shaped curve. Based on a statistic analysis, at the treating duration of 10 min, the positive mutation rate was as high as 37.5% while the negative mutation rate was low. The colonial morphology changed obviously when the plasma treating duration reached or exceeded 45 min. After both primary and secondary screening, a mutant designated as aPc051310 with high productivity of penicillin was obtained, and a strong mutagenic effect on P. chrysogenurn was observed in the process. It was proved that after five generations, the mutant aPc051310 still exhibits a high productivity. All the results prove that the plasma mutation method could be developed as a convenient and effective tool to breed high-yield strains in the fermentation industry, while expanding the plasm application at the same time.

Penicillium chrysogenum的低温空气等离子体诱变研究

以产黄青霉菌(Penicillium chrysogenum)Pc05为出发菌株,利用物理诱变方法低温空气等离子体技术对其进行诱变处理,结果表明:在处理时间为30 min内时,产黄青霉孢子的存活率随处理时间变化呈现出明显的"马鞍型"曲线;正突变株占所有突变株比例为44.19%,且负突变率很低。经过初筛、复筛获得突变株aPc051310,最终其青霉素效价比出发菌提高了42.1%。化学活性粒子和带电粒子的协同作用被认为是诱变发生的原因。实验结果证明低温空气等离子体技术作为一种新的工业微生物菌种诱变方法,具有应用潜力。

Integrative Extraction of Ergosterol, （1→3）-α-D-Glucan and Chitosan from Penicillium chrysogenum Mycelia

Ergosterol,(1→3)-α-D-glucan and chitosan are important biomaterials.In this research,a process has been developed to integratively extract ergosterol,(1→3)-α-D-glucan,and chitosan from Penicillium chrysongenum mycelium.First,the mycelia are pretreated with 0.1mol·L-1 of NaOH.After recovery by centrifugation,the solid portion is made to undergo saponification and deacetylation reactions by addition of 2mol·L-1 NaOH and ethanol. After reaction,extraction is carried out by addition of petroleum ether,which separates the reaction mixture into two phases.The upper layer of petroleum ether contains extracted ergosterol,and the bottom layer of NaOH solu-tion contains(1→3)-α-D-glucan;the chitosan is on the mycelia residuum.After isolation,the recovery yield of er-gosterol is 0.52%of dry mycelium.That of(1→3)-α-D-glucan is about 8.2%;and chitosan is 5.7%with 86% deacetylation.The compositions have been characterized by IR,HPLC analyses.

Preliminary bioleaching of heavy metals from contaminated soil employing indigenous Penicillium Chrysogenum strain F1

Bioleaching is an environment-friendly and economical technique to remove heavy metals from contaminated soil.The objective of this work is to find out an indigenous strain to remedy soil contaminated by Zn,Pb,Cu and Cd.A strain which was selected from the soil of a local smelting industry was found to be able to produce many organic acids and degrade pH value of the liquid medium.The fungus strain is identified as Penicillium Chrysogenum (P.Chrysogenum) by sequencing 18srDNA and ITS.Bioleaching condition using P.Chrysogenum is optimized.Glucose is the best carbon source for P.Chrysogenum and inorganic nitrogen is better than organic nitrogen.In addition,neutral solution and room temperature are fit for P.Chrysogenum to bioleach.In the one-step bioleaching,the bioleaching ratios are 39.95% for Zn,9.4% for Pb,34.89% for Cu and 49.59% for Cd,which are 53.89% for Zn,14.44% for Pb,55.53% for Cu and 62.81% for Cd in the two-step bioleaching.The efficiency of two-step bioleaching is better than the one-step bioleaching.P.Chrysogenum is effective in removing heavy metals from the contaminated soil.

Comparative study on production,purification of penicillin by Penicillium chrysogenum isolated from soil and citrus samples

Objective:To explore various unexplored locations where Penicillium spp.would be available and study the production of penicillin from the isolated Penicillium spp.in different media with altered carbohydrate source.Methods:The collected soil samples were screened for the isolation of Penicillium chrysogenum(P.chrysogenum) by soil dilution plate.The isolated Penicillium species were further grown in different production media with changes in the carbohydrate source.The extracted penicillin from various isolates was analyzed by HPLC for the efficacy of the product.Further the products were screened with various bacterial species including methicillin resistant Staphylococcus aureus(MRSA).And the work was extended to find the possible action on MRSA,along with characterization using other pathogens.Results:From the various soil and citrus samples used for analysis,only the soil sample from Government General Hospital of Bangalore,India,and Sanjay Gandhi Hospital,Bangalore,India,showed some potential growth of the desired fungi P.chrysogenum.Different production media showed varied range of growth of PenicilUum.Optimum production of penicillin was obtained in maltose which proved maximum zone of inhibition during assay.Characterization of penicillin on pathogens,like wild Escherichia coli strain,Klebsiella spp.,and MRSA,gave quite interesting results such as no activity on the later strain as it is resistant.HPLC data provided the analytical and confirmation details of the penicillin produced.Accordingly,the penicillin produced from the soil sample of Government General Hospital had the high milli absorbance unit of 441.5 mAu compared with that of the penicillin produced from Sanjay Gandhi Hospital sample,8S.S2 mAu.Therefore,there was a considerable change in quantity of the penicillin produced from both the samples.Conclusions: The Penicillium spp.could be possibly rich in hospital contaminants and its environments.This research focuses on various unexplored sources of medical ailments,and also shows that the growth of penicillin is high in maltose rich media that could possibly enhance the growth.

Influence of heavy metal stress on morphology and physiology of Penicillium chrysogenum during bioleaching process

In order to improve the efficiency of bioleaching heavy metal from the contaminated soil using Penicillium chrysogenum(P.chrysogenum),experiment was conducted to evaluate the influence of heavy metal stress on P.chrysogenum during bioleaching.The morphology and physiology of P.chrysogenum were observed.Assuming that the heavy metals are all leached out from the experiment soil,heavy metals are added into the agar medium by simulating the heavy metal content in the soil.It is concluded that the survivable heavy metal contaminated soil mass range for P.chrysogenum is 2.5-5.0 g.As for biomass determination,the contaminated soil is added into the liquid medium directly.The soil mass that P.chrysogenum can be survivable is in the range of 2.5-8.75 g.In this mass range,the biomass of P.chrysogenum is bigger than that of the control sample.10 g soil mass is the threshold of the growth of P.chrysogenum.102.2 mg/L gluconic acid,156.4 mg/L oxalic acid,191.6 mg/L pyruvic acid,0.02 mg/L citric acid,0.03 mg/L malic acid and 70.6 mg/L succinic acid are determined after 15 d bioleaching.The mycelium is broken into fragments,and heavy metals are adsorbed on the cell wall or transported into the cytoplasm during bioleaching.The GOD activity declines from 1.08 U/mL to 0.2 U/mL under 400 mg/L of multi-metal stress.The influence of Pb on GOD activity is bigger than that of Cr and Cd,and the GOD activity is not influenced apparently by Mn,Zn and Cu.

Cloning, expression and characterization of a feruloyl esterase C from Penicillium chrysogenum

Objective:To clone feruloyl esterase gene C from Penicillium chrysogenum and characterize the general properties of the enzyme.Methods:The feruloyl esterase C gene was amplified by PCR based on the Penicillium chrysogenum feruloyl esterase C gene sequence and cloned into the expression vector p PIC9K,resulting the recombinant plasmid p PIC9K-Pcfae C.The recombiant plasmid was linerized and transformed into P.pastoris by electroporation.The transformants was screened based on the transparent zone technology.The screened transformants was then induced by methanol.the enzymatic properties of the protein were then measured.Results:SDS-PAGE analysis showed that the molecular mass of the enzyme was about 30 k D.The length of the gene was 762 bp.It comprised one open reading framwork(ORF)and annotated to encode 249 amino acid.The optimal temperature and p H was found to be 40℃and 6,respectively.Moreover,the recombinant enzyme was stable at 40-50℃and p H 5-7.Conclusion:The enzyme successfully expressed in P.pastoris could laid theoretical foundation in food,fodder and paper making industry.

Penicillium chrysogenum Thom液体培养中C/N比较研究

从土壤中分离到一菌株经鉴定属于PenicilliumchrysogenumThom。通过单因子试验统计分析 ,优化筛选了PenicilliumchrysogemumThom的适宜培养基和摇瓶培养条件 ,结果表明 ,其适宜的液体培养基中C/N比在 3 3— 2时对其孢子的萌发 。

1株海洋真菌Penicillium chrysogenum次级代谢产物及其抗菌活性研究

目的研究1株南海来源真菌Penicillium chrysogenum的次级代谢产物及其抗菌活性。方法运用硅胶柱层析、Sephadex LH-20凝胶柱层析和HPLC半制备等方法对次级代谢产物进行分离和纯化;通过NMR、MS等方法鉴定化合物结构;利用抗菌活性模型对其进行活性评价。结果从真菌P.chrysogenum中分离鉴定了5个化合物,包括1个生物碱taichunamide H(1),1个带有脂肪链的蒽醌1-O-methyl-averantin(2),2个聚酮化合物versicones A–B(3~4)以及1个联苯醚diorcinol(5);其中,2对致病菌Canidia albicans和Staphylococcus aureus具有较强的抑制活性,MIC值分别为6.25和12.5μmol·L^-1;5对海洋污损菌Photobacterium halotolerans显示抑制活性,MIC值为50μmol·L^-1。结论化合物2显示较强的抗菌活性,具有潜在的开发研究价值,且化合物3和4为首次从青霉属真菌中分离得到。

1株柳珊瑚来源真菌Penicillium chrysogenum中生物碱化合物研究

目的对1株南海柳珊瑚来源真菌Penicillium chrysogenum(CHNSCLM-0019)中的生物碱类化合物进行研究。方法综合运用正、反相硅胶柱层析、高效液相色谱(HPLC)及重结晶等方法对真菌粗提物进行分离纯化,并通过现代波谱学方法、单晶衍射及核磁共振变温实验并结合文献对所得化合物进行结构鉴定。结果鉴定了6个苯并二氮杂卓类生物碱1~6,分别为7-methoxycyclopenin (1),cyclopenin (2),7-methoxycyclopeptin(3),(3S)-1, 4-benzodiazepine-2, 5-diones (4),7-methoxydehydrocyclopeptin (5),(+)-cyclopenol (6)。并通过核磁共振变温实验验证了化合物1以互变构象异构体形式存在。结论柳珊瑚来源真菌P. chrysogenum(CHNSCLM-0019)是苯并二氮杂卓类生物碱的重要来源。

黄河三角洲耐盐真菌Penicillium chrysogenum HK14-01的次生代谢产物

【目的】从黄河三角洲耐盐微生物的代谢产物中寻找具有抗菌和抗肿瘤活性的化合物。【方法】应用化学与生物活性相集成的筛选方法,从耐盐微生物中筛选获得代谢产物丰富并具有生物活性的目标菌株;通过高盐胁迫目标菌株,利用硅胶柱色谱、凝胶柱色谱和高效液相色谱等方法对发酵产物进行分离、纯化,运用波谱解析、钼靶X-射线单晶衍射分析、圆二色散谱(CD)和密度泛函数(DFT)-ECD的计算鉴定化合物的结构。【结果】从采自黄河三角洲的泥土样品中得到一株耐盐真菌HK14-01,鉴定为产黄青霉Penicilliumchrysogenum;从其发酵产物中分离鉴定了8个化合物:(2S,3R)-oxaline(1,主产物)、(3R,4R)-3,4,8-trihydroxy-3,4-dihydronaphthalen-1(2H)-one(2)、(Z)-N-(4-hydroxystyryl)formamide(3)、(E)-N-(4-hydroxystyryl)formamide(4)、emodin(5)、4-(2-hydroxyethyl)benzene-1,2-diol(6)、methyl 2-(4-hydroxyphenyl)acetate(7)和2-(4-hydroxy phenyl)acetonitrile(8);化合物1、3和4对大肠杆菌以及化合物1和5对金黄色葡萄球菌表现出抑菌活性,化合物5对P388细胞表现出微弱的细胞增殖抑制活性。【结论】首次确定了化合物2的绝对构型、首次报道了化合物1和2的CD数据;从黄河三角洲的耐盐微生物的次生代谢产物中可以得到活性化合物,这一区域的耐盐微生物资源值得深入研究。

蛇足石杉内生真菌Penicillium chrysogenum MT-12中2个新二苯醚类成分

目的研究蛇足石杉内生真菌Penicillium chrysogenum MT-12经固体发酵培养后的代谢产物。方法利用硅胶、Sephadex LH-20及半制备液相色谱等方法进行分离纯化,根据化合物的理化性质及IR、MS、NMR等光谱数据鉴定化合物的结构;利用体外模型进行抗炎、乙酰胆碱酯酶抑制活性筛选。结果从P.chrysogenum MT-12固体发酵培养后的代谢产物中共分离鉴定8个二苯醚类化合物,分别为黄青霉内酯A(1)、黄青霉内酯B(2)、talaromyone A(3)、isopenicillide(4)、penicillide(5)、hydroxypenicillide(6)、purpactin A(7)、黄青霉内酯C(8)。结论化合物1、2为新化合物,化合物3为首次从青霉属中分离得到,化合物4~8为首次从产黄青霉菌中分离得到;化合物1、2对脂多糖(LPS)诱导的小鼠巨噬细胞RAW264.7的NO产生有一定抑制活性,半数抑制浓度(IC50)值分别为(72.6±2.3)、(41.2±1.4)μmol/L,而所有化合物在100μmol/L时对乙酰胆碱酯酶不显示抑制活性。

Amplification of an MFS Transporter Encoding Gene penT Significantly Stimulates Penicillin Production and Enhances the Sensitivity of Penicillium chrysogenum to Phenylacetic Acid

Penicillin is historically important as the first discovered drug against bacterial infections in human. Although the penicillin biosyn- thetic pathway and regulatory mechanism have been well studied in Penicillium chrysogenum, the compartmentation and molecular transport of penicillin or its precursors are still poorly understood. In search of the genomic database, more than 830 open reading frames （ORFs） were found to encode transmembrane proteins of P. chrysogenum. In order to investigate their roles on penicillin production, one of them （penT） was selected and cloned. The deduced protein ofpenTbelongs to the major facilitator superfamily （MFS） and contains 12 transmembrane spanning domains （TMS）. During fermentation, the transcription of penT was greatly induced by penicillin precursors phenylacetic acid （PAA） and phenoxyacetic acid （POA）. Knock-down of penT resulted in significant decrease of penicillin production, while over-expression of penT under the promoter of trpC enhanced the penicillin production. Introduction of an additional penT in the wild-type strain of P. chrysogenurn doubled the penicillin production and enhanced the sensitivity of P. chrysogenum to the penicillin precursors PAA or POA. These results indicate that penT stimulates penicillin production probably through enhancing the translocation of penicillin precursors across fungal cellular membrane. Penicillin is historically important as the first discovered drug against bacterial infections in human. Although the penicillin biosyn- thetic pathway and regulatory mechanism have been well studied in Penicillium chrysogenum, the compartmentation and molecular transport of penicillin or its precursors are still poorly understood. In search of the genomic database, more than 830 open reading frames （ORFs） were found to encode transmembrane proteins of P. chrysogenum. In order to investigate their roles on penicillin production, one of them （penT） was selected and cloned. The deduced protein ofpenTbelongs to the major facilitator superfamily （MFS） and contains 12 transmembrane spanning domains （TMS）. During fermentation, the transcription of penT was greatly induced by penicillin precursors phenylacetic acid （PAA） and phenoxyacetic acid （POA）. Knock-down of penT resulted in significant decrease of penicillin production, while over-expression of penT under the promoter of trpC enhanced the penicillin production. Introduction of an additional penT in the wild-type strain of P. chrysogenurn doubled the penicillin production and enhanced the sensitivity of P. chrysogenum to the penicillin precursors PAA or POA. These results indicate that penT stimulates penicillin production probably through enhancing the translocation of penicillin precursors across fungal cellular membrane.

产黄青霉Penicillium chrysogenum S-3-25的次级代谢产物及其活性研究

目的阐明南极深海来源真菌产黄青霉Penicillium chrysogenum S-3-25的次级代谢产物及其活性。方法利用各种色谱技术分离纯化次级代谢产物,根据理化和波谱数据(核磁共振、质谱和单晶衍射技术)鉴定化合物结构,采用3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)法评价细胞毒活性。结果从真菌S-3-25的大米发酵产物中分离鉴定了7个单体化合物:meleagrin(1),cyclo(dehydrohistidyl-L-tryptophyl)(2),sohirnone A(3),dihydrodemethylsorbicillin(4),2’,3’-dihydrosorbicillin(5),脑苷脂A(6)及脑苷脂B(7)。其中化合物1对小鼠小胶质BV2细胞和人乳腺癌MCF-7细胞的IC_(50)分别为0.9、20.3μmol·L^(-1)。结论从极地深海来源真菌产黄青霉S-3-25中分离得到7个单体化合物,其中化合物2、4、6、7未见从该菌分离的报道。化合物1对BV2、MCF-7细胞显示出中等细胞毒活性。

蛇足石杉内生真菌Penicillium chrysogenum MT-40的代谢产物研究

目的研究蛇足石杉Huperziaserrata内生真菌PenicilliumchrysogenumMT-40的代谢产物。方法利用硅胶、SephadexLH-20及半制备液相色谱等方法进行分离纯化,根据化合物的理化性质及IR、MS、NMR等数据鉴定化合物的结构;利用体外模型进行抑制血小板ATP释放及抗乙酰胆碱酯酶活性筛选。结果从P.chrysogenumMT-40固体发酵培养后的代谢产物中分离得到了20个化合物,分别鉴定为(±)-N-(3a,4,5,6,7,8,9,10,11,12,13,13a-dodecahydrocyclododeca[d]oxazol-2-yl)-4-hydroxybenzamide(1)、cyclo-(Trp-Tyr)(2)、cyclo-(Trp-Phe)(3)、meleagrin(4)、alternariol(5)、alternariol methyl ether(6)、altenuene(7)、koninginin B(8)、koninginin F(9)、koninginin D(10)、过氧化麦角甾醇(11)、β-谷甾醇(12)、volemolide(13)、4-hydroxy-17R-methylincisterol(14)、4-hydroxy-3,6-dimethyl-2H-pyran-2-one(15)、对羟基苯甲酸(16)、对羟基苯甲醛(17)、香草酸(18)、对羟基苯乙酸(19)、酪醇(20)。结论化合物1为新化合物,命名为(±)-盘尼西碱A;化合物5在100μmol/L时有一定的抑制血小板释放ATP作用,抑制率为(40.6±5.2)%;所有化合物在100μmol/L时未表现出乙酰胆碱酯酶抑制活性。

产黄青霉Penicillium chrysogenum S-3-25人工海水培养基发酵次级代谢产物研究

目的阐明南极深海来源真菌产黄青霉Penicillium chrysogenum S-3-25人工海水培养基的发酵次级代谢产物及其活性。方法利用各种色谱技术分离纯化次级代谢产物,根据理化和波谱数据(核磁共振、质谱技术和Marfey分析)鉴定化合物结构,采用3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)法评价细胞毒活性。结果从真菌S-3-25人工海水培养基发酵产物中分离鉴定了8个单体化合物:L-Ala-2-aminobenzoic acid(1)、L-Ala-2-aminobenzoic acid-methyl ester(2)、2S-(2-hydroxypropanamido)benzamide(3)、3-(p-hydroxyphenyl)-N-methylpropionamide(4)、4-hydroxycinnamamide(5)、cyclo-(L-Pro-L-Tyr)(6)、脑苷脂A(7)及脑苷脂B(8)。细胞毒活性测试结果表明化合物1~8在50μmol/L浓度下对3种受试细胞(人乳腺癌MCF-7,人肺癌A549以及小鼠小胶质BV2细胞)的抑制率均低于50%。结论从极地深海来源真菌产黄青霉S-3-25人工海水培养基发酵产物中分离得到8个单体化合物,其中化合物1和2为新天然产物,未见有文献数据的报道。化合物1~8均未呈现较强的细胞毒活性。

柳珊瑚来源真菌Penicillium chrysoygenum中的1个新的α吡喃酮发现

目的柳珊瑚来源真菌Penicillium chrysogenum(TA10-16)次级代谢产物及其生物活性研究。方法通过广泛的波谱数据,包括1D/2D NMR,HRESIMS和ECD谱从而确定化合物的结构。结果共分离获得7个聚酮化合物,包括1个新的α-Pyrone(1)和6个已知化合物(2~7),分别是pyrenocine E(2)、zanthopyranone(3)、emodin 8-O-methylether(4)、questinol(5)、(2S,3S)-1-(4-hydroxyphenyl)butane-2,3-diol(6)和4-hydroxybenzaldehyde(7)。化合物1和6对白色念珠菌表现出中等的抗真菌活性,最低抑菌浓度(MIC)为12.5μmol/L,而化合物7对白色念珠菌的MIC则为25.0μmol/L。结论化合物1的结构通过1D/2D NMR、HRESIMS和ECD等综合光谱数据进行了鉴定。同时,通过活性测试,化合物1和6具有潜在的抗真菌活性。

手工雪茄主要霉菌的分离鉴定及其生物学特性研究

【目的】为探究引起手工雪茄烟支霉变的主要霉菌种类及其生物学特性。【方法】本研究以市场反馈的易霉变手工雪茄为材料,采用选择性培养基检测样品中霉菌含量,根据数量占比确定主要霉菌,结合形态学、产孢结构和分子生物学手段对主要霉菌进行鉴定,并研究其生物学特性。【结果】(1)引起手工雪茄霉变的霉菌菌属为曲霉属、青霉属和拟青霉属,主要霉菌菌种为聚多曲霉和产黄青霉。(2)2种主要霉菌(聚多曲霉、产黄青霉)在DG18培养基上生长较快,孢子悬浮液在60℃热处理10min失活,紫外照射对其无显著影响。聚多曲霉最适生长温度为30℃,湿度为90%;产黄青霉最适生长温度为25℃,湿度为70%。【结论】聚多曲霉和产黄青霉在手工雪茄烟支霉变过程中起主要作用,在适宜的环境条件下生长繁殖进而诱发雪茄烟支霉变发生。

产黄青霉菌对不同难溶性磷酸盐的溶解能力及作用机制

【研究目的】探究了产黄青霉菌(Penicillium chrysogenum)对不同难溶性磷酸盐(磷酸铁、磷酸铝和磷酸三钙)的溶解效率及机理。[试验方法]供试产黄青霉菌株为本研究筛选的高效解磷真菌菌株。试验采用蒙金娜液体培养基,分别加入磷酸铁(FePO_(4)·2H_(2)O,Fe-P)、磷酸铝(AlPO_(4),Al-P)和磷酸三钙[Ca_(3)(PO_(4))_(2),Ca-P]作为难溶性磷源,接种产黄青霉菌孢子悬液培养。在培养1、3、5天后,过滤培养液,测定滤液pH、溶磷量、有机酸含量及酶活性,采用红外光谱和扫描电镜–能谱分析Fe-P、Al-P和Ca-P处理滤渣的矿物官能团和形貌变化。【结果】青霉菌对难溶性磷酸盐的溶解量随着培养时间的延长而增加。在培养5天后,Fe-P、Al-P和Ca-P的溶磷量分别为153.8、215.9和569.4 mg/L,对Ca-P的溶解量最高。红外光谱图显示,Fe-P、Al-P和Ca-P的PO_(4)^(3−)振动吸收峰强度发生了不同程度的减弱。随着培养时间的延长,培养液pH均呈下降趋势,在培养5天后,Fe-P、Al-P和Ca-P处理的培养液pH由培养初期的6.5分别下降至2.0、2.3和5.0。对于不同难溶性磷酸盐,青霉菌分泌的丙酮酸脱氢酶、柠檬酸合成酶活性以及有机酸含量不同,与Al-P和Ca-P处理相比,Fe-P处理显著增强了青霉菌中丙酮酸脱氢酶和柠檬酸合成酶活性,草酸和柠檬酸分泌量分别为1086.6和806.4 mg/L,而在Al-P和Ca-P处理中,分泌的有机酸主要是草酸,分泌量分别为261.1和201.3 mg/L。草酸对Fe-P、Al-P和Ca-P的释放率分别为14.8%、32.4%和39.6%,分别比柠檬酸高出37、3和2倍。通过扫描电镜发现,草酸可与Ca-P螯合形成草酸钙(CaC_(2)O_(4))。【结论】产黄青霉菌对不同难溶性磷酸盐的释放能力表现为Ca-P>Al-P>Fe-P。与Al-P和Ca-P相比,Fe-P能够提高产黄青霉菌丙酮酸脱氢酶和柠檬酸合成酶的活性,从而促进产黄青霉菌分泌更多的草酸和柠檬酸。虽然草酸溶解难溶性磷酸盐的能力强于柠檬酸,但是与Fe-P相比,Ca-P抑制了产黄青霉菌分泌草酸的能力。因此,利用产黄青霉菌活化土壤难溶性磷酸盐时,可通过添加Fe-P诱导提高其分泌柠檬酸和草酸的能力。

固定化产黄青霉废菌体吸附铅与脱附平衡

研究固定化产黄青霉废菌体对Ｐｂ２＋的吸附与脱附平衡的结果表明，Ｐｂ２＋的生物吸附受ｐＨ值的影响很大，温度的影响则很小．ＥＤＴＡ是洗脱固定化产黄青霉废菌体上所吸附Ｐｂ２＋的最佳脱附剂．在保持脱附率为１００％的条件下，ＥＤＴＡ的初浓度、固定化废菌颗粒的吸附量与最大固液比之间存在正相关关系．０．１ｍｏｌ／Ｌ的ＥＤＴＡ在脱附Ｐｂ２＋时终浓度最高可达２０７００ｍｇ／Ｌ，最大固液比可达２９０以上，浓缩因子可达１１３。