一株高产黑色素香灰菌菌株的鉴定、筛选及培养条件的优化

为筛选一株产黑色素能力强的菌株并优化其培养条件。通过ITS测序鉴定11株供试菌株,以菌丝生长速度、平板L值等指标筛选出一株产黑能力强的香灰菌,并对其生长所需碳源、氮源、pH等培养条件进行优化。研究表明,11株供试菌株均为香灰菌（Hypoxylon sp.）,其中Hp.sp0006菌丝生长速度较快、菌球大且均匀、L值最低,并且发酵液黑色素含量最高。该菌株最优培养条件是,以葡萄糖为碳源、牛肉浸膏为氮源、碳氮比20∶1并添加10 mg维生素B₁,黑色素含量可达（1.21±0.17）g/L。香灰菌Hp.sp0006是一株产黑色素较高的菌株,优化后的培养基更有利于黑色素的合成,为香灰菌黑色素的开发利用奠定基础。     

Rhodococcus phenolicus sp. nov., a novel bioprocessor isolated actinomycete with the ability to degrade chlorobenzene, dichlorobenzene and phenol as sole carbon sources

The aerobic degradation of phenol, chlorobenzene and dichlorobenzene as a sole carbon source has been observed in bacterial Gram-positive strain G2P^T isolated from a wastewater bioprocessor. Cells display branching mycelia fragmenting into rod and coccoid elements when grown on TSA. Aerial hyphae formation occurs when grown on phenol and chlorinated aromatics as the sole carbon source. Growth was observed at up to 0.75% phenol as a sole carbon source, indicating a strong tolerance for the compound. The 16S rRNA gene sequence shares the greatest similarity with members of the Rhodococcus genus, with the closest shared nucleotide identity of 98% with the aromatic toxin degrading bacteria Rhodococcus zopfii DSM 44108^T. Neighbor-joining and parsimony analysis of Corynebacterineae 16S rRNA gene sequences consistently places strain G2P^T in a clade shared with R. zopfii within the Rhodococcus rhodochrous subclade. Based on a unique polyphasic profile involving phenotypic, ribosomal DNA sequence analysis, DNA–DNA hybridization, mol% DNA G+C content and fatty acid composition, G2P^T is proposed to represent a previously uncharacterized, novel species in the genus Rhodococcus. The name Rhodococcus phenolicus is proposed for the isolate with the type strain G2P^T (=DSM 44812) (=NRL B-24343).     

野生柳生金针菇和金针菇的分离、生物学特性及驯化栽培

采自滇西北地区的2份野生大型真菌标本,通过形态学及内转录间隔区(ITS)序列的分子系统发育分析鉴定为柳生金针菇Flammulina rossica和金针菇F.filiformis。以分离纯化保藏的菌株Mdr-02和Mdr-09作为实验材料,进行生物学特性和驯化栽培研究,采用碳源、氮源、无机盐、pH和温度5个因素进行单因素实验,从中挑选出4个较优因素的3个最优水平进行正交试验,研究不同培养条件对菌丝生长的影响。结果表明,柳生金针菇菌丝的最适生长碳源为麦芽浸粉,最适生长氮源为豆饼粉,最适无机盐为碳酸钙,最适生长温度为24℃,最适pH为6.0;金针菇菌丝最适碳源为麦芽浸粉,最适氮源为酵母粉,最适无机盐为硫酸镁,最适生长温度为24℃,最适pH为6.0。此外,本研究首次成功驯化了柳生金针菇并获得了一株可选育的金针菇菌株,为野生金针菇种质资源开发及新品种选育提供参考。     

猴头菌高产麦角甾醇液体发酵工艺优化

以菌丝体中麦角甾醇产量为考察指标,在单因素实验的基础上用响应面分析法考察碳源、氮源和无机盐3个因素对麦角甾醇发酵产量的影响,以获得猴头菌液体发酵产麦角甾醇最优工艺,建立高产、稳定的猴头菌液体发酵产麦角甾醇生产工艺.经响应面分析,各因素按照对响应值的影响顺序为:氮源＞碳源＞无机盐,且氮源对麦角甾醇产量的影响极显著,碳源和...     

粗糙脉孢菌中甾醇还原酶基因erg24对麦角甾醇合成的影响

粗糙脉孢菌为子囊菌中的高效纤维素降解菌,可以直接以纤维素为营养源进行生长.本研究以粗糙脉孢菌为实验对象,利用基因工程技术构建甾醇还原酶基因erg24的高表达菌株,分别以蔗糖、麦麸、玉米秸秆、小麦秸秆、杨树木屑、水稻秸秆6种物质的粉末为碳源培养野生型粗糙脉孢菌和erg24高表达菌株,利用半定量RT-PCR测定在不同培养条...     

薄皮干酪菌生物学特性及驯化栽培

大型真菌种质资源是国家种质资源库建设重要组成部分,为了充分开发利用大型真菌资源,对采自吉林省寒葱岭的一株野生菌进行分离纯化,并将获取的纯菌株作为实验材料。通过形态学和ITS序列分析,将其鉴定为薄皮干酪菌Tyromyces chioneus。本实验研究了固体培养条件下不同碳源、氮源、pH和温度对其菌丝生长的影响,并从4个单因素实验中选出3个最优水平进行正交实验。同时,在对其菌丝体最适培养条件研究结果的基础上,对其进行驯化栽培研究。结果表明,薄皮干酪菌的最适培养条件为：果糖(20 g/L)、酵母浸粉(2 g/L)、pH 4.0、温度30 ℃。正交实验结果表明,氮源对其菌丝体生长的影响最大,其次是碳源、pH和温度。驯化栽培结果表明,菌丝发菌时间为21 d;空气湿度为85%-95%,适量的散射光,降低温度至18-20 ℃刺激后原基逐步变成菇蕾,将温度、湿度分别提高至24-25 ℃、90%-98%,30 d后子实体成熟。通过本实验的研究为薄皮干酪菌的后续开发利用提供了基础实验数据。     

固定化乳白耙齿菌脱色茜素红的研究

利用海藻酸钙法对乳白耙齿菌进行固定化,检测固定化乳白耙齿菌（固定化菌）对几种染料的脱色能力。同时,考察pH值、染料浓度、金属离子、碳源种类、氮源种类、盐浓度对固定化菌脱色茜素红的影响。结果表明,固定化菌的优化条件为海藻酸钠3%、氯化钙5%、固定化时间6h、接菌量10g/100mL;固定化菌对6种染料均可脱色,其中对茜素红染料的脱色效果最为明显;固定化菌对茜素红的脱色率随染料浓度的增加而下降,当染料浓度高于250mg/L时,其脱色效果明显下降;固定化菌对茜素红脱色的适宜pH为7,适宜碳源为可溶性淀粉、适宜氮源为硝酸铵。另外,固定化菌对茜素红的脱色率随盐浓度的升高,呈下降趋势,当盐浓度高于3%时,脱色率下降明显;固定化菌于生理盐水中保存10d后,脱色率维持在较高水平,达94.20%;固定化菌重复利用5次后,脱色率仍高达88.70%。     

Microbial synthesis of 3-dehydroshikimic acid: a comparative analysis of D-xylose, L-arabinose, and D-glucose carbon sources.

3-Dehydroshikimic acid is a hydroaromatic precursor to chemicals ranging from L-phenylalanine to adipic acid. The concentration and yield of 3-dehydroshikimic acid microbially synthesized from various carbon sources has been examined under fed-batch fermentor conditions. Examined carbon sources included D-xylose, L-arabinose, and D-glucose. A mixture consisting of a 3:3:2 molar ratio of glucose/xylose/arabinose was also evaluated as a carbon source to model the composition of pentose streams potentially resulting from the hydrolysis of corn fiber. Escherichia coli KL3/pKL4.79B, which overexpresses feedback-insensitive DAHP synthase, synthesizes higher concentrations and yields of 3-dehydroshikimic acid when either xylose, arabinose, or the glucose/xylose/arabinose mixture is used as a carbon source relative to when glucose alone is used as a carbon source. E. coli KL3/pKL4.124A, which overexpresses transketolase and feedback-insensitive DAHP synthase, synthesizes higher concentrations and yields of 3-dehydroshikimic acid when the glucose/xylose/arabinose mixture is used as the carbon source relative to when either xylose or glucose is used as a carbon source. Observed high-titer, high-yielding synthesis of 3-dehydroshikimic acid from the glucose/xylose/arabinose mixture carries significant ramifications relevant to the employment of corn fiber in the microbial synthesis of value-added chemicals.     

Biodegradation of Phenol by Actinobacillus Sp.: Mathematical Interpretation and Effect of Some Growth Conditions

Models of the cultivation process of Actinobacillus sp. cells in two media, rich (NB) and minimal (M9) that includes phenol as a sole carbon source, have not been described in the available literature. For these reasons, several single-substrate inhibition models (Monod, Andrew, and Tesseir) were investigated in order to determine the mathematical expression of Actinobacillus sp. growth rate. The experimental data for both nutrient broth and M9 media were fitted to the above models mentioning that Andrews' model best fits these data adequately for both media with regression coefficient of 0.973 and 0.962, respectively. The maximum predicted growth rate by this model is 0.37 h^{- 1} for both media obtained when the initial concentration of phenol is 100 mg/L. The half-saturation concentration constant, K_P, is 1.00 mg/L, which represents the phenol concentration when μ is equal to half μ_max. On the other hand, the inhibition constant, K_p is 13,000.00 mg/L for broth medium and 12,000 mg/L for M9 medium, which is a measure of sensitivity to inhibition by inhibitory substances. When cells are grown in nutrient broth and minimal media, the rate of cell production with time can be expressed by the Reccati and Voltera models. Voltera model better fits in the case of M9 minimal medium plus phenol as sole carbon source. The pH of 7, the incubation temperature of 35°C to 37°C, and the agitation rate of 150 rpm are the optimal conditions for achieving the higher percentage of phenol degradation by Actinobacillus sp. Succinic acid and glycine as carbon and nitrogen source, respectively, were the most efficient of the cosubstrates (out of 10 substrates tested) for removal of phenol on an mg/L basis.     

Biodegradation of xanthan by newly isolated Cellulomonas sp. LX, releasing elicitor-active xantho-oligosaccharides-induced phytoalexin synthesis in soybean cotyledons

A Cellulomonas sp. LX newly isolated from soil samples could degrade the extracellular polysaccharide (xanthan) of Xanthomonas campestris. Such degradation was inhibited by glucose addition. Xanthan-degrading enzyme activity was found in the culture supernatant when Cellulomonas sp. LX was grown in the medium with xanthan as carbon source. The optimal pH and temperature for the xanthan-degrading reaction was 6.0 and 40 °C, respectively. The bioactivity of the xantho-oligosaccharide was examined with the soybean cotyledon bioassay and found it was an active elicitor.     

牡蛎形拟层孔菌生物学特性、驯化栽培及抗氧化活性

对采自江西省萍乡市的野生牡蛎形拟层孔菌Fomitopsis ostreiformis子实体分离的菌株进行生物学特性的单因素及正交试验,在对其菌丝体最适培养条件研究结果的基础上,对其进行驯化栽培研究.通过水提醇沉法对获得的牡蛎形拟层孔菌栽培子实体进行粗多糖提取,并通过测定其粗多糖对DPPH自由基和羟自由基的清除率,讨论该...     

不同诱导培养基对糙皮侧耳液体发酵产漆酶活性的影响

利用1株糙皮侧耳Pleurotus ostreatus栽培菌株为材料,研究添加碱性木质素或者配合简单碳源或氮源后对其液体发酵产漆酶活性的影响。结果表明,不同诱导培养基对糙皮侧耳漆酶活性具有极显著的影响（P<0.001）,而且不同诱导培养基对糙皮侧耳菌丝生物量也产生了极显著的影响（P<0.001）。此外,只利用碱性木质素或者是再添加碳源葡萄糖均有利于糙皮侧耳产漆酶,既包括产漆酶酶活性的提升,同时也包括产漆酶时间的提前,但只利用碱性木质素诱导不利于菌丝生物量的积累;而富含简单碳/氮源的诱导培养基,无论是否含碱性木质素,均有利于菌丝生物量的积累,其中,富含简单碳/氮源的培养基中再添加碱性木质素后的菌丝生物量和漆酶活性均高于不添加碱性木质素时的菌丝生物量和漆酶活性。相比而言,含碱性木质素的培养基中测得的漆酶活性大部分时间下都要高于不含木质素的简单碳/氮源培养基,含碱性木质素的培养基对糙皮侧耳菌株产漆酶的诱导作用更强。     

红松胚性愈伤组织增殖的激素配比、糖源类型和增殖周期效应研究

为了解决红松（Pinus koraiensis）胚性愈伤组织增殖过程中生长状态差、体胚产量不高等问题,本研究利用红松胚性愈伤组织1-100细胞系为材料,通过调节红松增殖培养基中激素、碳源和增殖培养周期,探索其对红松体胚发生能力的影响及其生理生化特性变化。结果如下：①红松胚性愈伤组织最佳增殖条件激素浓度为 1 mg·L^-1 NAA+0.25 mg·L^-1 6-BA,最佳碳源为蔗糖,最佳增殖培养周期为14 d,在此条件下获得的体胚产量最多（166个·g^-1）;②在优化增殖培养过程中,储藏物质为红松体胚发生提供了能量来源;激素种类及其浓度、碳源种类、增殖培养周期之间可溶性蛋白质量分数没有显著差异;③红松愈伤组织中CAT活性过高不利于愈伤组织的体胚发生,可能是H₂O₂等代谢产物积累过多,产生毒害作用。     

贡嘎山峨眉冷杉成熟林碳利用效率季节动态及其影响因子

碳利用效率(CUE)是植被生态系统的一个重要功能参数, 反映了植被生态系统的固碳能力, 适用于分析不同时间段内器官、个体和群落等不同层次的碳收支趋势, 因而有助于对陆地生态系统碳功能的确定与预测, 引起了广泛关注。该研究采用生物计量法, 测定和计算了川西贡嘎山东坡峨眉冷杉(Abies fabri)成熟林树木不同器官的呼吸与净生产力动态, 分析了乔木层及其各器官CUE动态及主要影响因子, 并估算了乔木层不同径级树木CUE。主要结果: (1)乔木层各器官月呼吸速率与温度呈正相关关系, 以细根月呼吸速率为最大; 不同径级树木年呼吸量无显著差异, 以小径级树木树干的年呼吸量为最小。(2)乔木层细根和树干月净初级生产力(NPP)均随温度增加而增加, 以细根月NPP为最大。小径级树木年NPP最大, 其针叶年NPP也显著高于中径级和大径级树木。(3)林分乔木层及其各器官CUE大多集中在0.30-0.60之间, 其中细根、树干CUE具有相似的月变化动态, 均随温度的升高而上升。不同径级树木CUE及树干和针叶CUE均随树木个体的增大而明显下降。(4)气温和土壤温度与乔木层树干和细根CUE呈正相关关系, 而降水量与针叶CUE呈负相关关系。细根CUE与树干CUE呈正相关关系,与针叶CUE呈负相关关系。峨眉冷杉成熟林乔木层CUE主要取决于树干和细根CUE。该研究证实了川西亚高山暗针叶成熟林仍具有较强的碳汇功能, 在区域碳储存和森林生态系统碳循环中发挥着极其重要的作用。     

Season dynamics of carbon use efficiency and its influencing factors in the old-growth Abies fabri forest in Gongga Mountain,western Sichuan,China

碳利用效率(CUE)是植被生态系统的一个重要功能参数, 反映了植被生态系统的固碳能力, 适用于分析不同时间段内器官、个体和群落等不同层次的碳收支趋势, 因而有助于对陆地生态系统碳功能的确定与预测, 引起了广泛关注。该研究采用生物计量法, 测定和计算了川西贡嘎山东坡峨眉冷杉(Abies fabri)成熟林树木不同器官的呼吸与净生产力动态, 分析了乔木层及其各器官CUE动态及主要影响因子, 并估算了乔木层不同径级树木CUE。主要结果: (1)乔木层各器官月呼吸速率与温度呈正相关关系, 以细根月呼吸速率为最大; 不同径级树木年呼吸量无显著差异, 以小径级树木树干的年呼吸量为最小。(2)乔木层细根和树干月净初级生产力(NPP)均随温度增加而增加, 以细根月NPP为最大。小径级树木年NPP最大, 其针叶年NPP也显著高于中径级和大径级树木。(3)林分乔木层及其各器官CUE大多集中在0.30-0.60之间, 其中细根、树干CUE具有相似的月变化动态, 均随温度的升高而上升。不同径级树木CUE及树干和针叶CUE均随树木个体的增大而明显下降。(4)气温和土壤温度与乔木层树干和细根CUE呈正相关关系, 而降水量与针叶CUE呈负相关关系。细根CUE与树干CUE呈正相关关系,与针叶CUE呈负相关关系。峨眉冷杉成熟林乔木层CUE主要取决于树干和细根CUE。该研究证实了川西亚高山暗针叶成熟林仍具有较强的碳汇功能, 在区域碳储存和森林生态系统碳循环中发挥着极其重要的作用。     

Use of Pleurotus dryinus for lignocellulolytic enzymes production in submerged fermentation of mandarin peels and tree leaves

It has been shown that the wood-rotting mushroom Pleurotus dryinus IBB 903 is able to effectively produce cellulases, xylanase, laccase, and manganese peroxidase in submerged fermentation of mandarin peels and tree leaves. Gradual increasing of lignocellulosic substrates concentration from 1 to 4–6% enhanced enzyme accumulation in culture liquid. A simple and inexpensive medium containing mandarin peels and yeast extract as sole carbon and nitrogen sources allowed simultaneous production of high levels of both hydrolases and oxidases by P. dryinus IBB 903. Supplementation of this medium by copper and manganese caused earlier and faster accumulation of laccase and manganese peroxidase increasing their yield by 1.5 and 7.5 times, respectively. In addition, by adding manganese to the medium it is possible to regulate the ratio of laccase and MnP in enzyme preparation. The presence of lignocellulosic substrate is the requisite for MnP production by P. dryinus IBB 903 since there was no production of MnP when mushroom has been cultivated in the synthetic medium with different carbon source. Among carbon source tested only utilization of glucose resulted to 21-fold increase of fungus laccase specific activity compared to control medium without carbon source. Carboxymethyl cellulase and xylanase appeared to be inducible enzymes.     

Commensalism during submerged mixed culture of Geotrichum candidum and Penicillium camembertii on glutamate and lactate

Geotrichum candidum and Penicillium camembertii were cultivated in pure and mixed cultures on glutamate- and lactate-based medium. In pure culture, P. camembertii assimilated simultaneously glutamate, as a nitrogen and carbon source for biosynthesis, and lactate as an energy source. On the contrary, G. candidum grew on glutamate alone. The mixed culture led to higher growth rates and then higher rates of substrate consumption and metabolite production than each pure culture; however, the behaviour recorded was similar to that observed during G. candidum pure culture, in particular the absence of lactate assimilation during growth, illustrating a commensalism between both species. The presence of G. candidum induced a form of “competition” and then a better assimilation by P. camembertii of the sole nitrogen source, glutamate, which was therefore used as an energy source in addition to be a carbon (and nitrogen) source. Lactate was only used for energy supply during stationary state, as also recorded during G. candidum pure culture.     

采自祁连山的冷杉侧耳生物学特性及栽培条件探索

以采自甘肃省祁连山国家级自然保护区菌物保育区的野生侧耳作为试验材料,通过形态学及系统发育分析方法将其鉴定为冷杉侧耳Pleurotus abieticola。对该菌株生物学特性及栽培条件进行初步研究,结果表明：菌丝体最适生长温度为25℃;最适pH为7.0;最适碳源为玉米粉;最适氮源为豆粉;在以棉籽壳、木屑和麸皮为栽培料时,可获得子实体。