Effects of different culture conditions on biological potential and metabolites production in three Penicillium isolates

The genus Penicillium is well known for its importance in drug and food production. Certain species are produced on an industrial scale for the production of antibiotics (e.g. penicillin) or for insertion in food (e.g. cheese). In the present work, three Penicillium species, part of the natural mycobiota growing on various food products were selected – P. ochrochloron, P. funiculosum and P. verrucosum var. cyclopium. The objective of our study was to value these species from the point of view of production of bioactive metabolites. The species were obtained after inoculation and growth in Czapek and Malt media. Both mycelia and culture media were analyzed to monitor the production of different metabolites by each fungus and their release to the culture medium. The concentrations of sugars, organic acids, phenolic acids and tocopherols were determined. Antioxidant activity of the phenolic extracts was evaluated, as also the antimicrobial activity of phenolic acids, organic acids and tocopherols extracts. Rhamnose, xylose, fructose and trehalose were found in all the mycelia and culture media; the prevailing organic acids were oxalic and fumaric acids, and protocatechuic and p-hydroxybenzoic acids were the most common phenolic acids; γ-tocopherol was the most abundant vitamin E isoform. Generally, the phenolic extracts corresponding to the mycelia samples revealed higher antioxidant activity. Concerning the antimicrobial activity there were some fluctuations, however all the studied species revealed activity against the tested strains. Therefore, the in-vitro bioprocesses can be an alternative for the production of bioactive metabolites that can be used by pharmaceutical industry.     

α-松油醇对意大利青霉的抑制作用

测定α-松油醇对意大利青霉菌丝体形态及菌丝体生长的影响,并对其抑菌机制进行初步探讨。结果表明:α-松油醇能明显抑制意大利青霉菌丝体生长,最小抑菌浓度(minimal inhibitory concentration,MIC)和最小杀菌浓度(minimal fungicidal concentration,MFC)分别为2.00μL/mL和8.00μL/mL;经MIC和MFCα-松油醇处理后,意大利青霉菌丝体胞外pH值、胞外电导率及260 nm条件下吸光度显著增加,总脂质含量有显著下降。提示α-松油醇能改变细胞膜的通透性、破坏细胞膜结构的完整性,导致胞内成分泄露,从而抑制意大利青霉菌丝体生长。     

扩展青霉侵染对苹果果实膜磷脂代谢的影响

目的：研究扩展青霉侵染对苹果果实膜透性及膜磷脂代谢的影响。方法：以‘元帅’苹果为试材,测定扩展青霉损伤接种果实病健交界处组织的细胞膜透率、膜磷脂代谢关键酶活力以及相关底物和产物含量的变化。结果：扩展青霉侵染早期（2 d前）果实病斑直径无明显变化,侵染后期（2 d后）果实病斑直径和细胞膜透率明显增大。侵染期间,果实的磷脂酶A2、磷脂酶C和磷脂酶D活力,以及磷脂酸含量持续升高,磷脂酰胆碱和磷脂酰肌醇含量逐渐降低;磷脂酰胆碱、磷脂酰肌醇和磷脂酸与对照组的显著差异出现在侵染后期。此外,侵染早期果实的不饱和脂肪酸含量迅速升高,第2天时油酸、亚油酸和亚麻酸含量分别高出对照组31.58%、55.57%和43.67%;侵染后期果实的饱和脂肪酸含量快速升高,第6天时的棕榈酸和硬脂酸含量分别高出对照组49.46%和43.39%。侵染果实的脂肪酸不饱和度早期高于对照组,后期低于对照组。相关性分析表明,侵染果实细胞膜透率与磷脂酶A2、磷脂酶C和磷脂酶D活力,以及磷脂酸、棕榈酸和硬脂酸含量呈极显著正相关,但与磷脂酰胆碱和磷脂酰肌醇含量呈极显著负相关。结论：扩展青霉侵染激活了果实的磷脂酶,促进了膜磷脂的降解和脂肪酸的释放,破坏了细胞膜的完整性。侵染早期不饱和脂肪酸的迅速释放可能与果实抗性相关。     

一株药用红树尖瓣海莲内生真菌Penicillium sp.化学成分研究

综合运用硅胶柱层析、Sephadex LH-20凝胶柱层析等色谱分离技术,对一株来源于药用红树尖瓣海莲（Bruguiera sexangula var.rhynchopetala）的青霉属真菌Penicillium sp.的发酵产物的化学成分进行分离和纯化.结合理化性质和NMR等技术,并通过与文献对照,从该菌发酵产物中分离鉴定了5个化合物,分别为过氧化麦角甾醇（1）、豆甾-5-烯-3β-醇-7-酮（2）、（3β,5α,6β,22E）-麦角甾-7,22-二烯-3,5,6-三醇（3）、（20S,22E,24R）-麦角甾-7,22-二烯-3β,5α,6β,9α-四醇（4）和β-胡萝卜苷（5）.化合物2-5为首次从尖瓣海莲内生真菌中分离得到.     

圆弧青霉PG37碱性脂肪酶的发酵工艺条件

研究了圆弧青霉PG3 7碱性脂肪酶的发酵工艺条件 ,优化了PG3 7的摇瓶最适产酶条件 .其中 ,发酵培养基的组成为 (g/dL) :豆饼粉 3 .0 ,玉米浆 3 .0 ,磷酸氢二钾 1 .0 ,硫酸镁 0 .1 ,大豆磷脂0 .5,柠檬酸钠 0 .0 5,花生油 0 .2 ;发酵培养基起始 pH 7.5,发酵温度 (2 9± 1 )℃ ,摇床转速 2 50r/min ,发酵周期 96h ,发酵期间于 3 6,54,72h分别流加 0 .4 g/dL花生油 .在此条件下 ,PG3 7的脂肪酶产率为 2 0 60 μmol/ (min·mL) .PG3 7在 2 5L的实验室小罐中的产酶水平为 1 90 0 μmol/ (min·mL) .     

Citrus phenylpropanoids and defence against pathogens. Part II: Gene expression and metabolite accumulation in the response of fruits to Penicillium digitatum infection

The effect of infection of Citrus sinensis (var. Navelina) fruits with Penicillium digitatum was studied at gene expression and metabolite levels. In this study, expression of genes involved in the phenylpropanoid pathway was studied in the flavedo (outer coloured part of the peel) and albedo (inner white part) in response to pathogen infection. Results of the time-course experiment showed that maximal expression of 10 out of 17 phenylpropanoid genes analysed occurred at 48 h post-inoculation, when decay symptoms started to appear, and mRNA levels either kept constant or decreased after 72 h post-inoculation. To further investigate the putative involvement of the phenylpropanoid pathway in the defence of citrus fruit, changes in the metabolic profile of both tissues infected with P. digitatum was studied by means of HPLC-PDA-FD. Metabolite accumulation levels along the time course suggest that flavanones, flavones, polymethoxylated flavones and scoparone are induced in citrus fruit in response to P. digitatum infection, although with different trends depending on the tissue.     

Fungal Bioleaching of Metals From Mine Tailing

The present study was undertaken to develop an economically feasible and environmental-friendly technique to recover metals (Ni, Cu, Co, Zn, Mg) from mine tailing by employing Penicillium chrysogenum strain KBS3. The potential of Penicillium chrysogenum in generating a variety of organic acids was studied and the effect of different organic wastes as substrates was evaluated. Maximum solubilization of nickel (55%), copper (67%), magnesium (69%), cobalt (60%), and zinc (65%) was achieved in the media containing glucose, tea leaves, molasses, and waste winery grapes as substrates.     

冷藏过程中温州蜜柑角质层组分变化及其对指状青霉生长的影响

角质层在果实采后贮藏中具有多重重要的生理功能。本实验以温州蜜柑（Citrus unshiu）为材料,对其冷藏过程中角质层的变化特征及其对指状青霉（Penicillium digitatum）孢子萌发和菌丝生长的影响进行了分析。结果表明：温州蜜柑冷藏过程中蜡质、角质含量整体上呈先上升后下降的趋势,其中角质含量的变化幅度最大;脂肪酸是外蜡中含量最丰富的蜡质组分,在冷藏前10 d,脂肪酸含量从0.73 μg/cm2增加到3.09 μg/cm2,之后下降至0.64 μg/cm2（40 d）;萜类物质主要存在于内蜡中,内蜡中萜类物质含量在冷藏过程中呈下降-上升的反复波动状态;角质单体成分主要为肉桂酸和十六碳二酸,冷藏时,肉桂酸含量逐渐下降,在第40天时最低,为13.90 μg/cm2,十六碳二酸含量先增加到17.90 μg/cm2（10 d）,然后下降到6.60 μg/cm2（40 d）;体外实验表明,角质能显著抑制指状青霉孢子萌发,而内蜡能显著抑制菌丝生长（P＜0.05）。这些结果揭示了贮藏过程中角质层变化的生化基础及角质层各组分对指状青霉的影响,为提高温州蜜柑柑橘品种的耐贮性提供了参考。