卫星灵芝液体发酵富集硒锌的研究

研究不同浓度的硒、锌对卫星灵芝菌丝体生长的影响,初步探讨卫星灵芝菌丝体生物富集硒、锌的效应。采用平板培养法及液体发酵法研究锌、硒对卫星灵芝菌丝体生长的影响及富集效应。培养基中不同浓度的亚硒酸钠对菌丝体生长均具有不同程度的抑制作用,但灵芝菌丝体的富硒量随着硒浓度的增加而提高,当亚硒酸钠浓度为40 mg/L时,菌丝体中的生物量、富硒量及富硒转化率最高,分别为1.54%、2 131.55 mg/kg、32.91%;培养基中硫酸锌浓度低于150 mg/L的范围内对卫星灵芝菌丝体生长有明显的促进作用,硫酸锌浓度为60 mg/L时菌丝体中的锌含量和富锌转化率最高,分别为1 142.91 mg/kg、1.76%。培养基中同时添加40 mg/L的亚硒酸钠和60 mg/L硫酸锌,菌丝体生长量1.60%,富硒量301.85 mg/kg,富硒率4.84%;富锌量为540.41 mg/kg,富锌率为5.72%。     

Cadmium biosorption by yeast, Candida tropicalis CBL-1, isolated from industrial wastewater

The present study is aimed at assessing the ability of metal-resistant yeast, Candida tropicalis CBL-1, to uptake metal from liquid medium. The minimum inhibitory concentration of Cd(II) against Candida tropicalis CBL-1 was 2,800 mg/L. The yeast could also tolerate Zn(II) (3,100 mg/L), Hg(II) (2,400 mg/L), Ni(II) (2,200 mg/L), Cr(VI) (2,000 mg/L), Pb(II) (1,100 mg/L), and Cu(II) (2,200 mg/L). The yeast isolate showed typical growth curves but lag and log phases extended in the presence of cadmium. The yeast isolate showed optimum growth at 30oC and pH 7. The metal processing ability of the isolate was determined in a medium containing 100 mg/L of Cd(II). Candida tropicalis CBL-1, could reduce Cd(II) 59%, 64% and 70% from the medium after 48, 96 and 144 h, respectively. C. tropicalis CBL-1 was also able to remove Cd(II) 46% and 60% from the wastewater after 6 and 12 days, respectively. Cd produced an increase in glutathione and non-protein thiols level by 37% (17.50±0.8-24.0±1.2) and 18% (3.30±0.7- 3.90±0.8) at 100 mg/L concentration, respectively. Metal tolerance and accumulation together with changes in the GSH status and non-protein thiols under Cd exposure were studied in C. tropicalis.     

Somatic embryogenesis from leaf derived callus of Tylophora indica (Burm. f.) Merrill

Mature leaf explant derived callus of Tylophora indica (Burm. f.) Merrill yielded somatic embryos on MS medium supplied with BA(1-2 mg/L) or kinetin(1-5 mg/L) or kinetin/BA (1-2 mg/L) used along with IAA(0.1-1 mg/L). Maximum somatic embryos (30) could be recovered from 100 mg of embryogenic callus within 60 days at an optimum concentration of 2 mg/L of BA which was also best suited for providing the maximum conversion rate (90%) of embryoids to plantlets. Kinetin (1-5 mg/L), used as the sole growth hormone, induced the development of embryoids showing either shoot or root primordia in 30% of the cultures. However, embryoids with shoot primordia developed roots upon transfer to medium containing IAA(0.1 mg/L) and kinetin(2 mg/L). Embryoids from all cultures germinated in the initiation medium and were transplanted to sterile vermiculite for hardening. After two weeks of hardening, the plantlets were transferred to the green house where they grew and established well showing a high rate of survival (90%).     

云南龙竹的快速繁殖和离体保存研究

本研究以干冷保存（-20 ℃,相对湿度15%）150 d 的云南龙竹（Dendrocalamus yunnanicus）颖果为实验材料,通过种子萌发建成丛芽无菌无性系进行快繁和离体保存。研究表明,丛芽增殖的最佳培养基为MS + 6-BA 2 mg/L + NAA 0.2 mg/L,蔗糖浓度以3%为佳;生根培养的最佳培养基为MS + IBA 1 mg/L + NAA 1 mg/L,以单芽诱导生根为好;离体保存丛芽的最适培养基为MS + 6-BA 0.5 mg/L + NAA 0.2 mg/L;当培养温度由室温 (25±3)℃降低至(20±3)℃和12 ℃时,其继代周期可由原来的2 个月分别延长至4 个月和8 个月。在组织培养过程中发现白化苗或叶色变异现象。     

A Preliminary Study on Direct Regeneration of Flower Buds from Peduncle Calli in Dracaena fragrans cv. massangeana

Flower buds were directly regenerated from calli in vitro in the woody plant Dracaena fragrans cv. massangeana Hort. On modified MS medium supplemented with 1.0 mg/L 6-BA and 1.0 mg/L IBA, two kinds of calli, A and B, were formed from the peduncle explants cultured for 5 months. Calli A were loose and on their surface there were many irregular granule-like structures (GLC); Calli B were compact and had bigger tumor-like structures (TLC) on their surface. When the GLC and TLC were transferred onto the medium respectively with 0.4 mg/L 6-BA and 1.0 mg/L IBA, flower buds were differentiated directly from the GLC but only vegetative buds and roots were differentiated from the TLC after culturing for 4 weeks. The GLC could be partly transformed into TLC in the continuous passage culture. Assays on hormones revealed that at a fixed IBA concentration of 0.4 mg/L the defferentiation frequency of flower budding was increased as the 6-BA concentration was decreased from 2.0 mg/L to 10 mg/L. Alternatively, at a fixed 6-BA concentration of 2.0 mg/L, the flower budding frequency was increased when the IBA concentration was changed from 0.4 mg/L to 1.0 mg/L. Moreover, the addition of 2.0 mg/L zeatin to the culture medium containing 2.0 mg/L 6-BA and 0.4 mg/L IBA was favorable to the regeneration of the flower buds. Nevertheless supplementing 1.0 mg/L GA3 into the medium on which the calli had differentiated into flower buds, the flower buds would gradually wither after 2 weeks in culture.     

Effect of ammonium-N on malic enzyme and lipid production in Rhodotorula glutinis grown on monosodium glutamate wastewater

Rhodotorula glutinis, an oil producing strain, can utilize monosodium glutamate (MSG) wastewater as a raw material for lipid production. The effects of ammonium-N in the MSG wastewater (ammonium 15,000–25,000?mg/L, COD 30,000–50,000?mg/L) on cell growth, lipid accumulation and malic enzyme activity of R. glutinis have been studied. Four initial ammonium sulfate concentrations in the medium were set, which were 20, 60, 100, and 140?g/L. With an increase in the ammonium sulfate concentration, the uptake of ammonia nitrogen and lipid accumulation increased while the biomass decreased at 72?h. The maximum value of ammonia nitrogen consumption reached 5.77?g/L for an initial ammonium sulfate concentration of 140?g/L at 72?h. In addition, 60?g/L ammonium sulfate concentration may be an appropriate concentration for R. glutinis cultivation. The activity of the malic enzyme was measured and the results showed that there was a linear relationship between the intracellular lipid content and the total malic enzyme activity.     

花叶千年木花序梗愈伤组织直接再生花芽的初步研究

在离体条件下,诱导愈伤组织或外植体直接再生花芽已经在许多草本植物上取得成功［１～７］,而就木本植物来说,迄今尚未见到成功的报导。诱导愈伤组织或外植体直接再生花芽所形成的离体培养实验系统将十分有利于研究雌、雄性器官分化和发育所必需的条件［８］和找到所需...     

Tissue and intracellular localization of indican and the purification and characterization of indican synthase from indigo plants

Indican (indoxyl beta-D-glucoside) was found to accumulate only in green leaves of the indigo plant, and not in any other tissues. Comparisons of the indican content of protoplasts and vacuoles showed that indican was stored only in the vacuole of the cell. Indican content appeared and increased with the appearance and growth of leaves. In mature plants, the younger leaves contained larger amounts of indican than the older ones. Cell extracts of young leaves of indigo plant catalyzed the synthesis of indican from UDP-glucose and indoxyl. Indican synthase was extracted and purified from young leaves. The enzyme was separated into two fractions by anion-exchange chromatography. The enzyme in the fraction which was eluted by 0.1 M NaCl had a molecular weight of 53,000 by SDS-PAGE. Optimum pH of the enzyme was at about 10.0, indicating that the enzyme is likely localized in a different intracellular compartment from that of indican storage. The enzyme showed normal Michaelis-Menten kinetics and a K(m) value of 0.13 mM for UDP-glucose.     

绿巨人叶柄离体培养及植株再生

在MS基本培养基中添加不同植物生长调节剂(mg/L)对绿巨人无菌苗的叶柄进行离体培养,结果表明,MS+6-BA 1.0+NAA 2.0+2,4-D 1.0诱导效果最好,产生愈伤组织并分化出丛芽;MS+6-BA 2.0~3.0+NAA 0.2+0.2% PVP对芽的增殖效果好;附加0.2%PVP对防止褐变有一定效果;生根培养基选用1/2MS+NAA 0.1~0.5+IBA 1.0的组合。     

Acrylamide and Acrylic Acid Biodegradation by <Emphasis Type="Italic">Alcaligenes faecalis</Emphasis> 2 Planktonic Cells and Biofilms

The ability of the Alcaligenes faecalis 2 strain to utilize acrylamide and acrylic acid upon cultivation with these compounds as the only sources of carbon and energy has been investigated. Complete utilization of the acrylic acid present in the medium at concentrations below 0.113 g/L was observed by cultivation day 5, at a concentration of 0.225 g/L by day 7, and at a concentration of 0.45 g/L by day 17. Complete utilization of the acrylamide present in the medium at concentrations below 0.4 g/L was observed by day 5, at a concentration of 0.9 g/L by day 7, and at a concentration of 1.8 g/L by day 20. Importantly, bacterial growth did not start before complete transformation of acrylamide into acrylic acid. The rate of acrylamide transformation by growing bacteria and a cell suspension in the stationary growth phase amounted to 12.5 mg/L h at a cell concentration of 610 mg/L and 300 mg/L h, at a concentration of 1500 mg/L. A. faecalis 2 cells immobilized on BVV-22 basalt fibers and Carbopon-B-aktiv at concentrations of 3000 and 800 mg dry cells/L, respectively, transformed acrylamide at a rate of 1200 mg/L h.     

温度和氮磷浓度对平裂藻和栅藻生长及竞争的影响

为了解温度及氮磷浓度对平裂藻和栅藻生长及竞争的影响,分别在18、25和35℃条件下,以BG11培养基为基础,设置了不同的氮磷浓度组,进行了2种藻的单独培养试验和混合培养试验,结果表明:在纯培养条件下,低营养浓度组(磷浓度分别为0.1和0.5 mg/L)平裂藻在3种温度下基本停止生长,高营养盐浓度组(磷浓度分别为1.0和1.5 mg/L)除18℃1.0 mg/L组停止生长外,其余均能正常生长增殖,且细胞最大密度表现为25℃ 18℃ 35℃, 1.5和1.0 mg/L浓度组细胞生长差异不显著。栅藻在纯培养条件下,细胞密度总体表现为随着营养盐浓度升高而增加的趋势,细胞最大密度表现为18℃ 25℃ 35℃。在混合培养试验中,除35℃、1.5 mg/L组平裂藻对栅藻的竞争抑制参数大于栅藻对平裂藻的竞争抑制参数外,其余试验组均表现为栅藻受平裂藻影响较小。在混合培养体系中, 0.1 mg/L组平裂藻仍基本停止生长, 0.5 mg/L组受栅藻的刺激作用,生长优于纯培养体系。1.0和1.5 mg/L组均受栅藻的抑制作用,且浓度越高抑制作用越强。       

药用植物红根草种质资源的离体保存

以红根草试管苗为材料,研究了不同培养基(MS、1/2MS、1/4MS)、蔗糖浓度和植物生长抑制剂(CCC、PP333、ABA、MH)在红根草试管苗保存中的作用。结果表明:培养基1/2MS对红根草保存最好,保存270d后存活率最高。培养基中不添加蔗糖较添加一定浓度蔗糖时植株的形态和色泽差,但保存时间更长,转继代后能正常恢复生长。添加生长抑制剂能减缓生长速度,延长保存时间,最佳浓度分别为:CCC1.2～1.6mg/L;PP3331.6mg/L;ABA0.5～4.0mg/L;MH0.5mg/L。其中,ABA0.5～4.0mg/L对植株的生长最好,CCC浓度为1.2mg/L和1.6mg/L时,保存时间长,360d时,存活率达90%。     

地涌金莲组培快繁技术研究

以地涌金莲吸芽为外植体,在MS+6-BA 1.0mg/L+IBA 0.5mg/L培养基上培养30d后产生幼芽;丛芽增殖培养基为MS+6-BA0.3mg/L+IBA0.1mg/L,增殖系数达2.83以上;生根诱导最佳培养基为MS+NAA1.0mg/L,生根率达100%。移栽成活率95%以上。     

Influence of Selenium on the Production of T-2 Toxin by <Emphasis Type="Italic">Fusarium poae</Emphasis>

The objective of this study was to investigate the effects of selenium on the production of T-2 toxin by a Fusarium poae strain cultured in a synthetic medium containing different concentrations of selenium. The T-2 toxin contents in fermentative products were evaluated by a high performance liquid chromatography (HPLC). The results showed that the production of T-2 toxin was correlated with the concentration of selenium added to the medium. In all three treatments, the addition of 1 mg/L selenium to the medium resulted in a lower toxin yield than the control (0 mg/L); the yield of the toxin began to increase when selenium concentration was 10 mg/L, while it decreased again at 20 mg/L. In summary, T-2 toxin yield in the fermentative product was affected by the addition of selenium to the medium, and a selenium concentration of 20 mg/L produced the maximum inhibitory effect of T-2 toxin yield in the fermentative product of F. poae.     

不同浓度卡那霉素、潮霉素对楸树试管苗生长的影响

目的:将不同质量浓度的卡那霉素、潮霉素加入楸树培养基中,研究卡那霉素、潮霉素对楸树组培苗生长的影响,以确定抗生素对楸树茎段分化与生根的敏感质量浓度。方法:待楸树继代、生根培养基灭菌后温度降至30~50℃,将不同质量浓度的卡那霉素、潮霉素经抽滤式灭菌加入培养基中,在培养基中接入楸树组培无菌茎段培养,观测茎段继代(增殖芽数、芽长、叶数等)、生根(发根数、根长、芽长等)生长指标并统计分析。结果:楸树组培继代培养基添加卡那霉素质量浓度为100 mg/L时组培瓶苗生长缓慢,浓度为150 mg/L时叶片大部分发白并干枯,茎段基部无愈伤组织形成,瓶苗基本停止生长,楸树继代瓶苗对卡那霉素耐受性范围为100~150 mg/L;添加潮霉素质量浓度为5 mg/L时瓶苗生长较为缓慢,浓度为10 mg/L时叶片开始干枯,茎段基部愈伤组织较小,瓶苗基本停止生长,楸树继代瓶苗对潮霉素耐受性范围为10 mg/L左右。楸树组培生根培养基添加卡那霉素质量浓度为100 mg/L时大部分茎段干枯,少部分为绿但未分化芽与根,浓度为150 mg/L时大部分茎段干枯,极少上部为绿,基部干枯,但未分化芽与根,楸树组培瓶苗生根培养苗对卡那霉素耐受性范围为100~150 mg/L;添加潮霉素质量浓度为5 mg/L时少部分茎段干枯,浓度为10 mg/L时大部分茎段干枯,少部分为绿,茎段未出现芽的分化与根的萌发现象,楸树组培瓶苗生根培养苗对潮霉素耐受性范围为5~10 mg/L。结论:卡那霉素、潮霉素对楸树组培苗生长有明显的抑制作用且与抗生素浓度呈负相关,但低质量浓度(1 mg/L)的潮霉素对楸树继代分化芽数有促进作用;同一抗生素对楸树不同无性系间组培苗生长的影响无显著差异。     

Fluorite Dissolution by a Phosphate-Solubilizing Bacterium Isolated from Groundwater of Xianghuangqi County,Inner Mongolia,China

Abstract

Xianghuangqi County of Inner Mongolia is a typical high-fluoride area in China. Present work discussed a possible role of phosphate-solubilizing bacteria (PSBs) in the formation of high-fluoride groundwater in this area. An indigenous PSB was isolated from the local groundwater. Analysis of 16S rDNA sequence indicates that the bacterium belongs to the Pseudomonas genus. This bacterium caused acidification of the culture media under phosphate-limited conditions. HPLC analysis detected several metabolites that are likely to acidify the cultural media. Fluorite dissolution experiment with this bacterium in minimum medium containing 2?mg/L, 20?mg/L, and 200?mg/L glucose showed that the initial concentration of glucose has a large effect on pH of the culture medium and the fluorite dissolution rate. The pH of bacterial cell-free medium remained constant throughout the experiment. Introduction of the PSB caused an initial decrease in pH, followed by an increase. The measured pH minima were 4.8, 5.8, and 6.0 for culture media amended with 200?mg/L, 20?mg/L, and 2?mg/L glucose, respectively. A slow increase of the fluoride concentration in bacterial cell-free medium was observed, and inoculation of the PSB increased the rate of fluoride release causing the concentration of fluoride in bacterial-inoculated medium to markedly exceed that found in control medium. The highest fluorite dissolution rate was observed in culture medium amended with 200?mg/L glucose, while the rates observed in culture medium amended with 20?mg/L and 2?mg/L glucose were comparable. Given the ubiquity of PSBs in natural environment, these findings show PSBs could be important contributors to fluoride mobilization in high fluoride area.     

Co-expression of P450 BM3 and glucose dehydrogenase by recombinant <Emphasis Type="Italic">Escherichia coli</Emphasis> and its application in an NADPH-dependent indigo production system

P450 BM3 mutant can catalyze indole to indoxyl, and indoxyl can dimerize to form indigo. But the reaction catalyzed by P450 BM3 requires NADPH, as coenzyme regeneration is very important in this system. As we know, when glucose dehydrogenase oxidizes glucose to glucolactone, NADH or NADPH can be formed, which can contribute to NADPH regeneration in the reaction catalyzed by P450 BM3. In this paper, a recombinant Escherichia coli BL21 (pET28a (+)-P450 BM3-gdh0310) was constructed to co-express both P450 BM3 gene and glucose dehydrogenase (GDH) gene. To improve the expression level of P450 BM3 and GDH in E. coli and to avoid the complex and low-efficiency refolding operation in the purification procedure, the expression conditions were optimized. Under the optimized conditions, the maximum P450 BM3 and GDH activities amounted to 8173.13 and 0.045 U/mg protein, respectively. Then bioconversion of indole to indigo was carried out by adding indole and glucose to the culture after improved expression level was obtained under optimized conditions, and 2.9 mM (760.6 mg/L) indigo was formed with an initial indole concentration of 5 mM.     

不同浓度激素对野生细叶结缕草愈伤组织的诱导与分化的影响

以野生的细叶结缕草的匍匐茎为外植体,MS为基本培养基,研究2,4-D和BA及2,4-D和IAA不同浓度组合对其愈伤组织诱导与分化的影响。研究表明:(1)5.0mg/L的2,4-D对愈伤组织诱导有很大的促进作用;(2)匍匐茎诱导愈伤组织宜采用MS 2.0mg/L 2,4-D 4.0mg/L IAA,产生的愈伤组织分化情况也较好。     

Histidine decarboxylase production by Lactobacillus hilgardii: Effect of organic acids

Histidine decarboxylase production from Lactobacillus hilgardii 5w, isolated from wine, was inhibited by the presence of l-malic acid in the basal culture medium. The inhibition was related to l-malic acid concentration. The maximal production of the enzyme at 12 h of culture incubated at 30°C was inhibited 71% by 2 g/L l-malic acid and 47% by 0.5 g/L. In these conditions l-malic acid consumption was 16% and 20% respectively. The addition of 300 mg/L citric acid to the basal medium stimulated the enzyme production from 9 to 45 nmoles/min/mg dry weight, and the increase was correlated with citric acid concentration. When different concentrations of l-malic acid were added to the basal medium plus 200 mg/L citric acid, reversion of stimulation was observed, achieving the maximum at a concentration of 2 g/L. In this case, citric acid comsumption was not modified, whereas L-malic acid utilization was higher.     

Alteration of cell-wall composition ofFusarium oxysporum by copper stress

A strain ofFusarium oxysporum tolerated copper in the growth medium at concentrations up to 600 mg/L. The optimum growth was obtained at 200 mg Cu/L. The mycelium acquired a blue color in the presence of copper. The copper content of isolated cell walls obtained from mycelium grown in the presence of 600 mg Cu/L was 1.5 times higher than that of cell walls obtained from mycelium grown at 200 mg Cu/L and it contained 2.2 and 3.3% copper at 200 and 600 mg Cu/L, respectively. The amount of protein and total sugars increased in both the mycelium and its isolated cell walls in the presence of copper in the growth medium, chitin was also increased in the cell wall, reaching its maximum amount at 200 mg Cu/L— about 2.4 times higher than without copper. Most of amino acid concentrations in the cell wall were increased in the presence of 200 mg Cu/L and decreased above this concentration. Isoleucine, leucine, tyrosine, phenylalanine, and arginine showed the highest increase at this concentration. The altered cell walls obtained from mycelium grown at 200 and 400 mg Cu/L could rebind individual metals more than the control cell walls could. Rebinding of individual metals was in the order Zn>Fe>Ni>Cu>Co. Rebinding of copper by isolated cell walls depended on pH and temperature.