白腐菌与酶生物预处理对麦草NaOH-AQ制浆性能的影响

研究了麦草白腐菌预处理条件的优选以及白腐菌、木聚糖酶、漆酶生物预处理对麦草蒸煮性能的影响。结果表明：白腐菌预处理半个月优于一个月，漆酶生物预处理脱木素的选择性优于白腐菌、木聚糖酶。麦草经生物预处理后，均能改善后续蒸煮性能，改善程度漆酶好于木聚糖酶、白腐菌。在提高蒸煮得率、浆料强度方面漆酶优于木聚糖酶、白腐菌，与未处理浆和白腐菌生物化学浆相比，实际得率分别提高4．；59、5．49个百分点；裂断长分别提高55．59％、16．05％；,耐破指数分别提高42．86％、19．48％；撕裂指数分别提高4；5．91％、9．57％。木聚糖酶预处理对浆料白度的改善程度优于漆酶、白腐菌，与禾处理浆和漆酶生物化学浆相比白度分别提高4．2和2．0SBD。     

稻草粉基混合菌发酵产纤维素酶研究

以稻草粉为主要原料,对白腐菌(White-rot fungi)NS75和黑曲霉(Aspergillus niger)NS83进行固态混合发酵产纤维素酶进行研究。混合菌固态发酵与单菌固态发酵实验结果比较表明,混合菌发酵产生的纤维素酶总体酶活明显高于单菌种发酵,其β-葡萄糖苷酶(β-G)酶活较白腐菌NS75单菌发酵提高了120.9%;葡聚糖内切酶(CMC)酶活比黑曲霉NS83单菌发酵提高了140.8%。单因素实验和正交实验结果表明,当稻草粉麸皮质量比为9∶1,料水比为1∶2,白腐菌NS75与黑曲霉NS83的接种比例为1∶1(v∶v)时,培养第3d开始搅拌,每天搅拌一次,于30℃,培养5d,稻草粉基混合菌发酵产纤维素酶中CMC酶活达到16650U/g,β-G酶活为16108U/g、滤纸酶活(FPA)酶活为3164U/g。     

白腐真菌粗酶液对里氏木霉发酵玉米秸秆的影响

研究比较了不同白腐真菌[变色栓菌(Trametes versicolor)、粗毛革孔菌(Coriolopsis gallica)、爪哇漏斗状侧耳(Pleurotus sajor-caju)]预处理玉米秸秆得到的粗酶液对里氏木霉(Trichoderma reesei)产纤维素酶和木聚糖酶及糖化产生的影响。结果表明,3种白腐真菌粗酶液对里氏木霉产酶影响均为降低纤维素酶的酶活力,提高木聚糖酶的酶活力,作用效果依次为变色栓菌爪哇漏斗状侧耳粗毛革孔菌。加入变色栓菌制备的酶液后,里氏木霉产纤维素酶酶活降低60.61%,木聚糖酶酶活增长60.94%;糖化产葡萄糖量降低了38.84%,产木糖量增长了395%。研究证实白腐真菌粗酶液对里氏木霉发酵产纤维素酶和纤维素酶的糖化有抑制作用,对产木聚糖酶和木聚糖酶水解糖化有协同作用。     

活性氧对白腐真菌漆酶合成的影响

分别将不同活性氧在发酵第4天加入发酵产酶培养基中,一定时间后通过测生物量和漆酶酶活研究外界活性氧对白腐真菌漆酶合成的影响,并通过活性电泳进一步验证。结果表明:低浓度的活性氧可以通过信号传导方式调控漆酶合成,超氧阴离子抑制白腐真菌产漆酶,过氧化氢和羟自由基促进白腐真菌产漆酶。实验结果对漆酶合成调控、植物-病原菌相互作用以及生物防护具有重要意义。     

产漆酶真菌筛选及其固态发酵条件的初步研究

目的筛选产漆酶真菌,优化固态发酵培养基组成,研究粗酶的酶学性质.方法平板筛选获得菌株,通过测定漆酶活性优化培养基的组成.结果获得了固态发酵条件下产漆酶活性较高的菌株.优化后培养基的组成:豆粕和木屑比例1:1,木糖0.5%,酒石酸铵2.0%,培养基含水量65%.漆酶最适温度60℃,低于50℃时漆酶较稳定,最适pH 3.5,pH 6.5～9.0之间漆酶稳定性较好.结论得到了产漆酶活性较高的菌株,培养基优化后漆酶活性提高7倍.     

竹黄菌液态发酵产漆酶培养条件的优化

分离筛选到一株产漆酶的竹黄菌,采用单因子相互比较法,研究了该菌株的最适发酵产酶条件。确定了最适的碳源为2 g/dL可溶性淀粉、最适的氮源为0.8 g/dL的酵母膏,以及最适铜离子浓度为2.4 mmol/L,在自然pH 5.0,装液量为50 mL,30℃、200 r/min摇瓶振荡培养64 h下,产漆酶酶活水平达120 000 U/L,比优化前提高近17倍。该竹黄菌株与已报道的白腐真菌相比,具有发酵周期短且产漆酶酶活较高的优点。     

降解木素白腐菌产漆酶的研究进展

综述了近年来国内外对于白腐菌产漆酶的研究进展,对液体和固体发酵提高漆酶产量的技术和方法进行了讨论和评述,并对今后的研究工作提出了展望。     

蜜环菌产漆酶的发酵条件研究

对蜜环菌(Amillariella mellea)产漆酶的发酵条件作了研究。结果表明蜜环菌产漆酶的最佳培养基成分为:玉米粉30g/L,豆粕12g/L,微量元素混合液40mL/L,C/N2.5,吐温801g/L,木屑0.01g/L,CuSO4·5H2O0.05mmol/L。最佳发酵条件为培养基初始pH5.0,培养基装量为250mL三角瓶中35mL培养液,25℃条件下振荡培养(180r/min)18d。     

白腐菌发酵对麸皮性质的影响

为了提高麸皮的附加值,探究了白腐菌发酵对麸皮性质的影响。以白腐菌发酵麸皮为研究对象,以漆酶酶解和未处理麸皮为对照,测定溶胀性、持水性、膳食纤维含量、植酸含量等多种理化指标。结果表明:经白腐菌发酵和漆酶酶解的麸皮可溶纤维含量明显提高,持水性和持油性升高,溶胀性和植酸含量降低。白腐菌发酵后麸皮表面结构变得疏松多孔。为麸皮资源的开发利用提供理论依据。     

培养基及培养条件对Pycnoporus sp. SYBC-L1分泌漆酶的影响

从作者所在实验室保存的3株白腐真菌中筛选到一株液态发酵产漆酶的密孔菌Pycnop-orus sp.SYBC-L1,以漆酶活力为指标,采用正交试验法,优化了Pycnoporus sp.SYBC-L1分泌漆酶的培养基:麸皮水煮液60 g/L,葡萄糖60 g/L,豆粕粉15 g/L,CuSO_4·5H_2O 1.0 mmol/L;培养条件:初始pH 3.0,装液量50 mL/250 mL,30℃、200 r/min培养13 d,漆酶活力达24.95 U/mL,为优化前的36.16倍.     

Kinetics of polyphenol extraction from wood chips in wine model solutions: effect of chip amount and botanical species

The extraction of polyphenols from wood chips into a wine model system was described using kinetics, over a period of 20 days. The wood chips tested were made from oak (Quercus alba), false acacia (Robinia pseudoacacia) and cherry (Prunus avium) wood. Kinetics were established using nonlinear regression and the leaching of polyphenols into the liquid model systems was found to obey a second‐order model. The determination of basic kinetic parameters enabled the identification of leaching trends and comparison among the difference wood species used, as well as determination of the effect of the amount of chips added. Oak chips were found to enrich the model wine in polyphenolic substances significantly more compared with either acacia or cherry. Furthermore, the wine model treated with oak chips displayed a much higher reducing power on day 20 of the treatment. The correlation of the total polyphenol concentration at saturation with the amount of chips added, using nonlinear regression, revealed that in every case the maximum concentration of total polyphenols attained was linked with the amount of chips by a three‐parameter exponential growth function. Possible differences pertaining to wood botanical species and polyphenolic load are discussed on the grounds of theoretical considerations for diffusion. Copyright © 2015 The Institute of Brewing & Distilling     

Differentiation of Wines Treated with Wood Chips Based on Their Phenolic Content,Volatile Composition,and Sensory Parameters

The effects of both wood chips addition and contact time on phenolic content, volatile composition, color parameters, and organoleptic character of red wine made by a native Greek variety (Agiorgitiko) were evaluated. For this purpose, chips from American, French, Slavonia oak, and Acacia were added in the wine after fermentation. A mixture consisting of 50% French and 50% Americal oak chips was also evaluated. In an attempt to categorize wine samples, various chemical parameters of wines and sensory parameters were studied after 1, 2, and 3 mo of contact time with chips. The results showed that regardless of the type of wood chips added in the wines, it was possible to differentiate the samples according to the contact time based on their phenolic composition and color parameters. In addition, wood‐extracted volatile compounds seem to be the critical parameter that could separate the samples according to the wood type. The wines that were in contact with Acacia and Slavonia chips could be separated from the rest mainly due to their distinct sensory characters.     

响应面法优化酶辅助闪式提取二氢槲皮素工艺

目的：利用响应面法对纤维素酶辅助闪式提取二氢槲皮素的工艺条件进行优化。方法：以二氢槲皮素的提取率为指标,在单因素试验的基础上,应用Box-Behnken试验设计,对影响提取率的条件（乙醇体积分数、加酶量和液料比）进行优化。结果：最佳提取条件为乙醇体积分数60.93%、加酶量3.48 mg/g、液料比103.64∶1（mL/g）、提取时间120 s。结论：闪式提取操作简便、节能、省时,可应用于二氢槲皮素大规模生产。     

Über chemische Veränderungen in Holzspänen bei der Herstellung von Harnstoff-Formaldehydharz-gebundenen Spanplatten

Pressing of wood chips under particleboard production conditions leads to various chemical changes within the chips. Thermal treatment along leads to a decrease in pH-value as well as in acetyl group content. The action of thermal treatment is aggravated in the presence of a hardener and formaldehyde. Wood chips liberate different amounts of volatile acids depending on the wood species. In oak chips the amount of volatile acids is remarkably high. During the press cycle prehydrolysis occurs, due to which the hemicellulose content decreases and the soluble carbohydrate fraction increases. The extent of change in the above mentioned properties depends not only on wood species used but also on the location of the wood chips within the mat during the pressing cycle.     

Effect of artificial ageing using different wood chips on the antioxidant activity,resveratrol and catechin concentration,sensory properties and colour of two Greek red wines

Two Greek red wines (Syrah and Cabernet) were artificially aged with different wood chips (white oak, red oak, Turkey oak, chestnut, Bosnian pine, cherry, common juniper, common walnut, white mulberry, black locust and apricot). The influence of each wood species was tested for up to 20 days. The optimum duration for the extraction of total polyphenols was 20 days (Syrah) or 10 days (Cabernet) when chips of white oak, chestnut, cherry, white mulberry, black locust and apricot where used. Resveratrol and catechin concentrations ranged within the limits previously reported in literature. A high antioxidant activity was established after 10 days of artificial ageing. The sensory evaluation showed that the best results were produced by the apricot chips after 5 days (Syrah) or black locust and apricot after 5 days (Cabernet). Colour was seen to increase with both time of ageing and number of wood chips added.     

Presence of polycyclic aromatic hydrocarbons in woody chips used as adjuvant in wines, vinegars and distillates

Samples of 15 commercially available batches of wood chips, used in alcoholic beverage industry, were extracted and analyzed for their content in polycyclic aromatic hydrocarbons (PAHs). Total amounts of PAHs varying between 0.96 and 15.1 ng/g of wood were found, with medium to low MW compounds being mainly present. Carcinogenic benzo[a]pyrene was found in such a value, however, not alarming if maximum mandatory levels in food are considered.PAHs content in chips was unaffected by wood origin, size or toasting level while further investigations dealing with phenomena occurring during the wood seasoning could be necessary.     

Volatile composition of Bobal red wines subjected to alcoholic/malolactic fermentation with oak chips

The effect of wood, in the form of oak chips, on the volatile composition of Bobal red wines caused by adding oak chips at different stages of the fermentation process has been studied. Aroma compounds were isolated by solid phase extraction (SPE) for subsequent analysis by gas chromatography–mass spectrometry (GC/MS). Bobal control wine was produced according to traditional winemaking processes, without oak chips. Oak chips were added to the rest of the wines at two dose levels (3 and 6 g/L) at different stages of the winemaking process: at one week during alcoholic fermentation (AF), during malolactic fermentation (MLF) and in young, red Bobal wine. Wines fermented with oak chips during AF showed higher concentrations of the ethyl esters of straight-chain fatty acids and ethyl, hexyl and isoamyl acetates than the control wine. A similar, trend was observed for higher alcohols. Higher concentrations of benzene compounds, oak lactones and furanic compounds were found in wines in contact with oak chips during MLF followed by young Bobal oak wines. These results reveal that the point of addition during the winemaking process and the dose level of oak chips used have a significant effect on the volatile composition of Bobal red wines.     

制浆过程中木片浸渍机理及改善措施

从木片浸渍的基本原理、评价手段和影响木片浸渍效果的因素等方面对木片的浸渍进行了阐述,并重点讨论了加强木片浸渍的措施。     

国产大型木片洗涤系统的配套设计与生产运行

国内某厂的木片杂质含量较高,并由于贮存时间过长,木片部分纤维腐烂变质。通过配套国产木片洗涤系统,在设计能力2100t/d下砂石的洗涤去除率达80%左右;在1200t/d的生产能力下沙石的洗涤去除率达90%左右,使木片含砂率降低到0.03%左右,且去除了部分腐朽变质的纤维。经洗涤水槽沉淀后洗涤水的循环利用率为60%左右。