一株高效解磷真菌新菌株的筛选鉴定及解磷特性

从辽宁省辽中县多年耕种的日光温室番茄根际土壤中筛选出一株解磷真菌,通过菌落形态特征和ITS rDNA序列对比,鉴定该菌株为草酸青霉菌的一株新菌株,将其命名为PSF1.该菌株能利用葡萄糖、蔗糖、乳糖、半乳糖、可溶性淀粉等多种碳源和硫酸铵、氯化铵、硝酸铵、硝酸钾、尿素等多种氮源进行生长代谢并表现出较强的解磷能力,在C/N 10∶1~60∶1、初始pH 7~8的条件下生长情况较好且解磷能力较高.该菌株有很强的产酸能力,在培养过程中培养液pH由7.00~7.50下降至2.06~4.87;在4种磷源培养液中的最高解磷量分别为磷酸三钙(869.62 mg·L^-1)>磷矿粉(233.56 mg·L^-1)>磷酸铝(44.77 mg·L^-1)>磷酸铁(28.42 mg·L^-1).Pearson相关分析表明,菌株在磷酸三钙、磷矿粉和磷酸铁培养液中的解磷量与pH的变化之间呈极显著负相关关系,在磷酸铝培养液中无显著相关关系.菌株PSF1解磷能力强,生长条件广,推测其在土壤中有较强的解磷能力.     

应用气升式反应器培养草酸青霉菌菌丝球的研究

应用0.5L气升式反应器成功实现了对高效染料吸附丝状真菌——草酸青霉菌(Penicillium oxalicum)的颗粒化,初步解决了菌体与培养液分离的问题。以OD600为0.23的孢子悬浊液接种时,菌丝成球的最佳接种量为2.5%,最佳通气量为0.5L/min。菌球直径及沉降速度随时间均呈线性增长。在最佳接种量（2.5%）和最佳通气量（0.5L/min）下,30℃培养72h后,菌球的直径和沉降速度分别为(4.0±0.8)mm和(14±3)mm/s。     

Newly isolated Penicillium oxalicum A592-4B secretes enzymes that degrade milled rice straw with high efficiency

An enzyme producing micro-organism, which can directly saccharify rice straw that has only been crushed without undergoing the current acid or alkaline pretreatment, was found. From the homology with the ITS, 28S rDNA sequence, the strain named A592-4B was identified as Penicillium oxalicum. Activities of the A592-4B enzymes and commercial enzyme preparations were compared by Novozymes Cellic CTec2 and Genencore GC220. In the present experimental condition, activity of A592-4B enzymes was 2.6 times higher than that of CTec2 for degrading milled rice straw. Furthermore, even when a quarter amount of A592-4B enzyme was applied to the rice straw, the conversion rate was still higher than that by CTec2. By utilizing A592-4B enzymes, improved lignocellulose degradation yields can be achieved without pre-treatment of the substrates; thus, contributing to cost reduction as well as reducing environmental burden.     

Recombinant production of <Emphasis Type="Italic">Penicillium oxalicum</Emphasis> PJ3 phytase in <Emphasis Type="Italic">Pichia Pastoris</Emphasis>

The 1,332 bp phytase gene of Penicillium oxalicum PJ3 was inserted into the expression vector, pPICZαA and expressed in the methylotrophic yeast, Pichia pastoris as an active, extracellular phytase. The recombinant phytase reached a maximum yield of 12 U/ml of medium at 120 h of cultivation after methanol induction under shake-flask conditions. The enzyme was glycosylated, with a molecular mass of about 62.5 kDa. The Michaelis constant (K _m) and maximum reaction rate (V _max) for sodium phytate was 0.37 mM and 526.3 U/mg of protein, respectively. The optimal activity occurred at pH 4.5 and 55°C. Jaecheon Lee and Yunjaie Choi contributed equally to this work.     

氯氰菊酯降解菌草酸青霉SSCL-5分离鉴定及降解特性

为解决土壤中残留的菊酯类农药问题,通过富集筛选法从70余份土壤中获得一株高效分解利用菊酯类农药的微生物菌株SSCL-5,该菌株可在含1 000 mg/L的氯氰菊酯无机盐培养基中正常生长。经形态学及ITS测序鉴定,确定该菌为草酸青霉(Penicillium oxalicum),对多种高浓度菊酯类农药耐受。经紫外分光光度法及HPLC验证该菌株草酸青霉SSCL-5在无机盐培养基、28℃、180 r/min摇瓶培养24 h的条件下,对400 mg/L氯氰菊酯的降解率为97%。土壤室内试验证明该菌在土壤中,温度20-34℃、水分含量保藏40%-60%条件下,30 d可将土壤中400 mg/L的氯氰菊酯降解67.6%。     

草酸青霉中新型线性五肽的发现及对柑橘采后致腐菌拮抗活性研究

【背景】柑橘是我国南方农村地区的一种重要经济作物,每年因采后真菌感染导致大量柑橘腐烂和劣变,造成了巨大的经济损失,严重影响柑农的积极性。【目的】丝状真菌SG-4对柑橘采后致腐菌橘青霉(Penicillium citrinum)和指状青霉(Penicillium digitatum)具有很强的拮抗作用,为明确其抑菌的物质基础,对该菌进行了生物学鉴定和活性成分分析。【方法】将SG-4菌株的核糖体DNA的内转录间隔区进行测序,结合菌株形态进行鉴定;对其菌体相和培养液进行抑菌活性追踪,利用醇沉淀和反相高效液相色谱分离得到主效物质,通过高分辨质谱和核磁共振等波谱分析方法确定结构;采用离体的牛津杯抑菌圈法和柑橘的体内接种试验来评价其抑菌活性;通过液相分析测定了活性物质在发酵液中的含量。【结果】分子和形态鉴定表明SG-4是一株草酸青霉(Penicillium oxalicum),其抑制柑橘采后致腐菌的活性物质位于培养液的水相提取物中,且具有强极性。进一步研究表明其活性成分为一种新型线性醇溶五肽,含3个具羟基的氨基酸,并且富含甲基化修饰,构成寡肽的第一个氨基酸为β-氨基丁酸(beta-aminobut...     

草酸青霉液体发酵产果胶酶条件的优化及其产物的酶学性质

采用响应面分析法对草酸青霉（Penicillium oxalicum）L5菌株液体发酵产果胶酶条件进行了优化。结果表明：桔皮粉、米糠及硫酸铵的添加量分别为4.85%、5.89%、0.97%,摇瓶初始pH为6.0~8.0,接种量为9%时,优化后的果胶酶活达54 391.70 U,是初始酶活18 148.00 U的3倍。另外,对其果胶酶性质进行了初步探讨,结果表明：该酶较适反应温度和pH分别为50℃和5.0;30~50℃时有较好的热稳定性,pH值为5.0时稳定性最佳。     

A metal-independent hydrolase from a Penicillium oxalicum strain able to use phosphonoacetic acid as the only phosphorus source

A Penicillium oxalicum strain was capable of the phosphate-sensitive utilization of phosphonoacetic acid as the sole source of phosphorus. A carbon-to-phosphorus bond-cleavage enzyme yielding acetic acid and inorganic phosphate was detected and characterized in extracts from cells grown on this phosphonate. Contrary to bacterial phosphonoacetate hydrolases, the fungal enzyme neither required nor was stimulated by divalent cations.