Effects of laccase incubated from white rot fungi on the mechanical properties of fiberboard

White rot fungi were optimized to cultivate highly active laccase. The characteristics of laccase incubated by continuous culture were compared with those of direct culture. The enzyme activity of laccase incubated by continuous culture technology reached a higher value on the fifth day of the growth. The optimization incubation time of high activity laccase was the eleventh day. A large amount of highly active laccase can be obtained in a relatively short time by continuous culture to replace traditional laccase. After laccase treatment, the lignin composition of wood fibers were oxidation-catalyzed by laccase. The number of chemical-bonding points between the wood fibers was increased. The wood fibers treated by laccase were fabricated into boards and their mechanical properties improved with the laccase-incubation times. Compared with the fiberboards made from fibers that were pre-treated by laccase of incubation 5 days, the static bending strength of those that were pre-treated by laccase of incubation 11 days was increased by 18.95%, the elastic modulus was increased by 35.49%, and the internal bond strength was increased by 44.11%.

层孔菌产漆酶的摇瓶最适培养条件研究

筛选到一株高产漆酶的层孔菌W 1 ,对其液体产漆酶的培养条件进行了优化 ,确定了最适的碳源、氮源 ,并用正交试验确定了培养基中碳源和氮源的浓度。在最优化的培养条件下 ,培养 7d后 ,W 1产生的漆酶活力可以达到 7 1U/mL。采用补料的方法 ,可以得到大量的漆酶粗酶液。

漆酶高产菌的筛选及产酶优化

采用愈创木酚初筛平板从干枯的木头中筛选得到一株产漆酶活力较高的菌株SYBC-L3(以下简称L3),在含有愈创木酚的PDA平板上生长时菌落周边出现明显的铁红色变色圈。通过对L3发酵产漆酶的单因素试验及L9(34)正交试验,确定了最适发酵条件,优化后的培养基为:麦芽糖12g/L,豆粕6g/L,CuSO40.5g/L,KH2PO41g/L,Na2HPO40.2g/L,MgSO4.7H2O0.5g/L,MnSO40.034g/L,愈创木酚0.8mmol/L,吐温-800.5g/L;优化后的培养条件为:接种量10%(V/V),装液量80mL/250mL,起始pH4,转速200r/min,温度30℃,以DMP为底物在第8天时酶活可达60130U/L,比优化前提高42倍。

白腐真菌对四氯化碳的生物降解特性研究

主要研究了白腐真菌对四氯化碳(CT)的降解效果,通过培养和驯化实验,得到了能降解四氯化碳的白腐真菌,验证了白腐真菌处理四氯化碳的可行性,并确定生物降解的最佳运行参数。研究表明:当四氯化碳添加量6 ug,稻壳浸出液50 mL,葡萄糖浓度15 g/L,温度30℃,转速140 r/min,pH 4.5,降解时间为6 d时降解四氯化碳效果最佳,降解率达到0.823。

Effect of nitrogen concentration in culture mediums on growth and enzyme production of Phanerochaete chrysosporium

Effect of different nitrogen concentration in the mediums on growth and enzyme production of Phanerochaete chrysosporium was studied when glucose concentration was 10 g/L. The results showed that the medium contained 0.8 g/L ammonium tartrate is the best. It not only supply abundant nutrients for the growth of Phanerochaete chrysosporium, which make mycelia the best grow compared with the other medium, but also produce higher manganese-dependent peroxidase(Mnp) and laccase(Lac) activity. In addition, it is observed that the variation of mycelia surface is related to ligninolytic enzyme secreted by Phanerochaete chrysosporium. When the surface of mycelium pellets appeared burs, it predicts secondary metabolism begin. This experimentation demonstrated that when the ratio of carbon and nitrogen in nitrogen limited medium is equal to 100∶8, growth and enzyme production of Phanerochaete chrysosporium is the best, it could achieve the maximum Mnp and Lac activity.

白腐真菌产木聚糖酶的筛选及其发酵条件研究

从白腐真菌中筛选产木聚糖酶菌株,并研究其产酶条件。从保存的白腐真菌中筛选出了一株产木聚糖酶活较高的菌株。通过单因素和正交试验对该菌株的发酵条件进行了研究。结果表明,5%麸皮和玉米芯(1∶1)为最佳碳源,0.5%蛋白胨为最佳氮源,接种量为每50mL发酵液接4块菌丝块,发酵时间为8.5d,pH值为5.4。优化后的发酵条件显著提高了该菌株产木聚糖酶酶活力。

黄孢原毛平革菌产木素过氧化物酶发酵条件的优化

对白腐菌(Phanerochaete chrysosporium)产木素过氧化物酶的发酵条件进行了研究。在单因素试验的基础上用正交试验进行工艺参数的优化。结果表明,木素过氧化物酶的最佳培养条件为培养13 d、接种0.5 mL,料液比1∶2.5(W/V,g∶mL)、培养温度25℃,酶活为771 U/mL。

白腐真菌发酵玉米秸秆饲料的工艺研究

以玉米秸秆为原料,采用白腐真菌发酵玉米秸秆降解纤维素制备饲料,以白腐真菌降解玉米秸秆纤维素酶活为考察指标,通过L9 3(4)正交实验确定玉米秸秆饲料发酵的最佳条件:发酵时间72 h、温度30℃、pH值8.5和固液比1??15。

白腐真菌Hyprocrea lixii AH的产酶特性研究

为了确定白腐真菌(H.lixii AH)在SMA培养基中的最佳产酶条件,利用正交试验研究了藜芦醇、Cu2+以及表面活性剂(吐温)的用量对真菌H.lixii AH生长和产酶的影响。发现吐温80和低浓度Cu2+对真菌的生长有促进作用,过氧化物酶和多酚氧化酶受Cu2+影响最大,优选浓度均是0.2g/L。LiP、MnP和Lac受吐温的影响较显著,添加吐温60后,LiP和MnP活性分别提高了11.7%和38%,而Lac有所下降。

落叶松附毛孔菌稻草液态发酵产漆酶条件优化

以木质纤维素类物质为主要基质,培养白腐真菌液态发酵产漆酶具有重要应用前景。筛选到一株漆酶高产菌,鉴定为落叶松附毛孔菌Trichaptumlaricinum,优化培养条件的基础上,考察稻草和硫酸铜对该菌漆酶产量的影响。正交试验获得T.laricinum最适产漆酶条件为:麦芽浸粉为氮源,其浓度为7g/L,硫酸铜浓度为80mg/L,pH值4。液态发酵15d时该菌漆酶产量达到19.2U/mL;稻草作为主要营养基质可以显著提高该菌漆酶产量,稻草添加量为4.5g/L时,漆酶量最大;发酵前期,无Cu^2+的培养环境有利于T.laricinum营养生长,在发酵中后期Cu^2+加入有利于漆酶分泌,第5d加入Cu^2+效果最好,发酵15d时漆酶产量为23.5U/mL。T.laricinum可以利用稻草为主要基质发酵产漆酶,是一株具有潜在应用价值的漆酶工业生产菌株。

Cooperation between ligninolytic enzymes produced by superior mixed flora

Since the ability to degrade lignin with one kind of white-rot fungi or bacteria was very limited, superior mixed flora's ability to degrade lignin was investigated by an orthogonal experiment in this paper. The results showed that superior mixed flora reinforced the ability to degrade lignin, the degradation rates of both sample 9 and 10 were beyond 80% on the day 9 The cooperation between lignin peroxidase(LiP), Mn-dependent peroxidase(MnP) and laccase (Lac) for lignin degradation was also studied. By examining the activities of three enzymes produced by superior mixed flora, it was found that Lac was a key enzyme in the process of biological degradation of lignin but Lip was not; the enzyme activity ratios of Lac/MnP and Lac/LiP were significantly correlative with the degradation rate of lignin at the 0 01 level; and the ratio of MnP/LiP was an important factor affecting the degradation rate of lignin.

菌核多孔菌培养特性及驯化栽培

为了充分开发利用菌核多孔菌Polyporus tuberaster资源,对采自吉林省露水河东升林场的野生菌核多孔菌进行分离纯化获取纯菌株作为实验材料,采用十字划线法研究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,从以上4个单因素实验中选出3个最优水平进行正交实验。结果表明,菌核多孔菌P.tuberaster的最适培养条件为:碳源糊精粉(20mg/mL)、氮源酵母浸粉(2mg/mL)、pH 5.0、温度25℃。在最适培养条件下采用试剂盒测定液体培养条件下菌株的产酶活力,结果表明,菌核多孔菌产漆酶能力较强,酶活力最高可达386.96U/L;木质素过氧化物酶活力仅为5.23U/L;未检测到锰过氧化物酶。出菇实验中,二级种选用麦粒菌种,500mL罐头瓶装干料160g,每瓶接种蚕豆大小菌块3–4块,25℃培养,菌丝满瓶时间为20d;栽培种配方为阔叶树木屑78%、麦麸20%、石灰粉1%、石膏1%、含水量65%左右,17cm×33cm×0.05cm栽培袋装干料520g,每袋接种蚕豆大小二级种3–4块,菌丝发菌时间为26d;在92%–95%空气湿度、一定散射光和20–21℃低温刺激下培养13d后原基分化形成菇蕾,此后加大空气湿度至97%–98%并保持温度24–25℃培养32d后子实体成熟。