N+注入选育白腐菌及其降解油菜秸秆木质纤维素的研究

以白腐菌WY01为出发菌,利用N＋注入技术选育出一株遗传性状稳定的漆酶高产诱变菌株WY02,经过60 d的发酵培养,其产酶量由出发菌的13.75 U/g增加到52.5 U/g,即产酶量提高了2.82倍;诱变菌株WY02对油菜秸秆中的木质素、半纤维素和纤维素的降解率分别为54.1%,39.1%,32.8%,用红外光谱法（IR）分析经诱变菌株降解后的油菜秸秆中木质素官能团的变化,用于阐明诱变菌株对油菜秸秆中木质素的生物降解机制。结果表明：油菜秸秆经白腐菌诱变菌株降解后,其木质素含量明显降低。木质素与苯环相连的C=O键、木质素侧链上CH2结构以及木质素单体（紫丁香基和愈创木基）被部分降解,木质素的苯环结构遭到一定程度的破坏。     

枯草芽胞杆菌降解木质纤维素能力及产酶研究

从农林废物堆肥中分离得到1株细菌经鉴定为枯草芽胞杆菌,将该细菌用于木质素类化合物利用.固态培养条件下考察其对木质纤维素的降解能力及产酶特性,另外对发酵前后的稻草结构进行了红外光谱分析.结果表明,枯草芽胞杆菌具有木质素降解能力,兼具低分子量木质素酚型、非酚型类物质的降解能力.其对木质素降解是木质素过氧化物酶、锰过氧化物酶、漆酶、纤维素酶和半纤维素酶共同作用的结果.在实验条件下,培养30 d使木质素降解率达9.47%,同时对纤维素、半纤维素也有较高程度的降解;降解率分别为38.8%、41.84%.红外光谱分析结果表明,稻草木质素结构被破坏,枯草芽胞杆菌对木质素各官能团的降解作用有所不同.     

Comamonas serinivorans C35木质素降解性能

【目的】探讨菌株Comamonas serinivorans C35降解木质素的能力。【方法】测定Comamonas serinivorans C35在木质素培养基中的生长趋势、化学需氧量的去除、木质素降解率、脱色率和相关酶的分泌。分别采用扫描电子显微镜和傅里叶变换红外光谱分析仪检测木质素降解前后的外观结构和化学键的变化。【结果】Comamonas serinivorans C35能够在木质素培养基上生长,在培养7 d后,化学需氧量去除率为44.4%,木质素降解率和脱色率分别为43.57%和42.26%。Comamonas serinivorans C35能够分泌木质素过氧化物酶、锰过氧化物酶和漆酶,粗酶液酶活分别能达到648.4、177.8和70.1 U/L。Comamonas serinivorans C35可以使木质素解聚且对其苯环结构、醚键以及C=O键等具有明显的破坏作用。【结论】Comamonas serinivorans C35可以降解木质素,在木质素的生物转化中具有潜在的应用价值。     

解淀粉芽孢杆菌MN-8对玉米秸秆木质纤维素的降解

微生物降解木质纤维素既是生物质资源化利用中的关键问题,也是亟需解决的难点问题.本文在前期获得木质素降解菌——解淀粉芽孢杆菌MN-8菌株的基础上,进一步研究该菌株对玉米秸秆木质纤维素的降解作用.研究利用玉米秸秆粉-MSM培养基对MN-8菌株进行固态发酵,监测发酵过程中木质纤维素酶活力和木质纤维素含量变化情况,并通过傅立叶红外光谱(FTIR)和气质联用色谱(GC/MS)对木质纤维素的降解情况及产物进行分析.结果表明:解淀粉芽孢杆菌MN-8菌株可产生木质素过氧化物酶、锰过氧化物酶、纤维素酶和半纤维素酶等木质纤维素降解酶,在发酵10～16 d陆续达到酶活力峰值,最高酶活力分别为55.0、16.7、45.4和60.5 U·g-1.发酵24 d后,玉米秸秆中木质素、纤维素和半纤维素的降解率可分别达到42.9％、40.6％和27.1％.FTIR光谱数据表明,玉米秸秆发酵后木质素、纤维素和半纤维素的特征吸收峰强度均有一定程度的下降,表明木质纤维素被部分降解.GC/MS分析结果也证实,解淀粉芽孢杆菌MN-8能有效降解秸秆木质纤维素.MN-8菌株可断裂玉米秸秆木质素单体之间的连接键β-O-4,将秸秆木质素解聚为苯丙胺、苯丙酮和苯丙酸等保留木质素苯丙烷结构的单体化合物,并将部分单体化合物进一步氧化为Cα羰基化合物,如2-氨基-1-苯丙酮和紫丁香基苯乙酮等.在对纤维素和半纤维素降解产物的GC/MS分析中发现,降解产物包含葡萄糖、甘露糖和半乳糖等多种单糖化合物以及甲酸、乙酸、丙酸、1,1-乙二醇和3-羟基丁酸等代谢产物.表明解淀粉芽孢杆菌MN-8对秸秆木质纤维素表现出强降解作用,且该作用依赖于菌株产木质纤维素降解酶的能力.     

温和酸催化解聚木质素磺酸盐产物的分离与分析北大核心CSCD

木质素解聚产物是异常复杂的混合物体系,本文以温和酸催化条件下的木质素磺酸盐解聚产物为研究对象,建立分离和分析测试木质素磺酸盐解聚产物和解聚效率的有效方法。采用超高效凝胶渗透色谱对解聚产物实现了高效分离,结果表明木质素磺酸盐高分子获得了高效解聚,解聚获得的产物分子量组成主要分布在三个低聚物区间;采用GC-MS鉴定了主要的木质素基单酚和双酚类官能团化合物9种,约占解聚液的30 wt%,表明解聚产物中含有大量的单体化合物;采用SEM和EDS分析测试木质素解聚后残渣,其结果也进一步证实了在温和酸催化条件下,木质素磺酸盐在解聚过程中还原位脱除了磺酸盐。木质素磺酸盐由于具有特有的Cα-SO3M基团,在酸催化条件下β-O-4键易于断裂,促进了木质素磺酸盐快速解聚,获得了解聚效率达95 wt%以上的解聚产物。     

温和酸催化解聚木质素磺酸盐产物的分离与分析

木质素解聚产物是异常复杂的混合物体系,本文以温和酸催化条件下的木质素磺酸盐解聚产物为研究对象,建立分离和分析测试木质素磺酸盐解聚产物和解聚效率的有效方法。采用超高效凝胶渗透色谱对解聚产物实现了高效分离,结果表明木质素磺酸盐高分子获得了高效解聚,解聚获得的产物分子量组成主要分布在三个低聚物区间;采用GC-MS鉴定了主要的木质素基单酚和双酚类官能团化合物9种,约占解聚液的30 wt%,表明解聚产物中含有大量的单体化合物;采用SEM和EDS分析测试木质素解聚后残渣,其结果也进一步证实了在温和酸催化条件下,木质素磺酸盐在解聚过程中还原位脱除了磺酸盐。木质素磺酸盐由于具有特有的Cα-SO3M基团,在酸催化条件下β-O-4键易于断裂,促进了木质素磺酸盐快速解聚,获得了解聚效率达95 wt%以上的解聚产物。     

白腐菌及黑曲霉所产的纤维素复合酶对稻草秸秆的生物降解

研究了白腐菌及纤维素复合酶对稻草秸秆的协同生物降解。结果表明,利用黄孢原毛平革菌固态发酵稻草秸秆的过程中,LiP和MnP的最大活力可以达到28.3U/g和12.6U/g,同时,秸秆中的木质素能被有效降解,但纤维素、半纤维素降解率较低。添加黑曲霉所产的纤维素复合酶能有效地促进秸秆腐熟程度。在接入白腐菌培养10天后,每克稻草添加3 IU纤维素酶液并酶解48h可以使稻草秸秆中纤维素降解53.8%,半纤维素降解57.8%,木质素降解44.5%,干物质损失46.3%。此时细胞壁出现大范围破损,整个组织变得松散,秸秆完全腐熟。     

白腐菌选择性降解竹基质中木质纤维素的研究

对竹基质白腐菌选择性降解进行了初步研究。结果表明,菌株B1对竹基质中木质素和半纤维素有明显的降解选择性。降解55 d木质素和半纤维素降解率分别达44.4%和47.1%;降解20 d降解选择性最好,木质素和半纤维素降解率选择系数分别是2.08和1.98。从FTIR图谱中木质纤维素相关谱峰(2 924、1 6351、6011、5101、165、1 045、666/cm等)的明显变化也可以得出相同结论。     

微生物处理对秸秆结构的影响

使用红外光谱、X射线衍射及扫描电镜对4种经固态培养的微生物降解稻草秸秆的效果进行了研究,并与原稻草粉进行结构对比分析。结果表明：经过高碳低氮培养,秸秆木质素均有明显降解,其中黄孢原毛平革菌达到37.17%。扫描电镜发现秸秆的表面形态和内部结构发生了明显改变,红外光谱中芳香环与醚键吸收明显减少,X射线衍射得到的结晶度最大下降了5.60%。     

木质素降解菌的筛选及混合菌发酵降解秸秆的研究

农作物秸秆是农业生产的副产品,也是一项重要的生物资源。由于其成分结构的特殊性所导致的难降解问题,一直成为了转化利用秸秆的难题。目前,利用混合菌将秸秆纤维素转化为蛋白质、乙醇、乙酸、乳酸等研究已逐渐为人们所重视。本文通过马铃薯琼脂平板培养、马铃薯液体摇瓶培养和稻草秸秆固态发酵,从6株常见的食用白腐菌中筛选出了生长优势较强、产漆酶酶活高的平菇HF。为了让秸秆得到更好的降解和利用,采用平菇和康氏木霉二步混合发酵法;通过不同的组合方式,发现H6-T10组合得出的降解效果最好,其木质素降解率达到44.77%,纤维素降解率达到41.48%。     

Infra-red spectroscopic analyses of banana waste degraded by oyster mushroom

Carbon, hydrogen and nitrogen analyses of banana leaf and pseudostem biomass revealed their potentiality as substrates for microorganisms. Infra-red (IR) spectra of both biomass show presence of cellulose, xylan and lignin. IR spectra of leaf and pseudostem biomass degraded in solid state fermentation (SSF) by two Pleurotus species (P. sajor-caju and P. ostreatus) for 40 days showed the utilization of cellulose, xylan and lignin by these microbes. Dynamics of various lignocellulolytic enzymes of Pleurotus species and analyses of carbon, hydrogen and nitrogen contents of degraded biomass supported the same. Both the Pleurotus species exhibited lignin consumption ability on both the substrates.     

Fungal biodegradation of lignopolystyrene graft copolymers.

White rot basidiomycetes were able to biodegrade styrene (1-phenylethene) graft copolymers of lignin containing different proportions of lignin and polystyrene [poly(1-phenylethylene)]. The biodegradation tests were run on lignin-styrene copolymerization products which contained 10.3, 32.2, and 50.4% (wt/wt) lignin. The polymer samples were incubated with the white rot fungi Pleurotus ostreatus, Phanerochaete chrysosporium, and Trametes versicolor and the brown rot fungus Gloeophyllum trabeum. White rot fungi degraded the plastic samples at a rate which increased with increasing lignin content in the copolymer sample. Both polystyrene and lignin components of the copolymer were readily degraded. Polystyrene pellets were not degradable in these tests. Degradation was verified for both incubated and control samples by weight loss, quantitative UV spectrophotometric analysis of both lignin and styrene residues, scanning electron microscopy of the plastic surface, and the presence of enzymes active in degradation during incubation. Brown rot fungus did not affect any of the plastics. White rot fungi produced and secreted oxidative enzymes associated with lignin degradation in liquid media during incubation with lignin-polystyrene copolymer.     

Fungal biodegradation of lignopolystyrene graft copolymers.

White rot basidiomycetes were able to biodegrade styrene (1-phenylethene) graft copolymers of lignin containing different proportions of lignin and polystyrene [poly(1-phenylethylene)]. The biodegradation tests were run on lignin-styrene copolymerization products which contained 10.3, 32.2, and 50.4% (wt/wt) lignin. The polymer samples were incubated with the white rot fungi Pleurotus ostreatus, Phanerochaete chrysosporium, and Trametes versicolor and the brown rot fungus Gloeophyllum trabeum. White rot fungi degraded the plastic samples at a rate which increased with increasing lignin content in the copolymer sample. Both polystyrene and lignin components of the copolymer were readily degraded. Polystyrene pellets were not degradable in these tests. Degradation was verified for both incubated and control samples by weight loss, quantitative UV spectrophotometric analysis of both lignin and styrene residues, scanning electron microscopy of the plastic surface, and the presence of enzymes active in degradation during incubation. Brown rot fungus did not affect any of the plastics. White rot fungi produced and secreted oxidative enzymes associated with lignin degradation in liquid media during incubation with lignin-polystyrene copolymer.     

Bioremediation of oil-polluted soil with an association including the fungus Pleurotus ostreatus and soil microflora

The possibility of application of the Pleurotus ostreatus D1-soil microflora to bioremediation of oil-polluted soils was studied. The fungus degraded mainly the aromatic fraction, whereas soil microflora intensely degraded paraffin and naphthene oil fractions. Introduction of the fungus Pleurotus ostreatus D to soil induces degradation of a wider range of oil hydrocarbons. It is reasonable to further investigate the discovered phenomenon in order to improve procedures of remediation of oil-polluted soils.     

三种白腐菌及其组合菌种木质素降解酶比较研究

朱红栓菌Trametes cinnabarina、糙皮侧耳Pleurotus ostreatus、黄孢原毛平革菌Phanerochaete chrysosporium是产生木质素降解酶能力强的菌株。对三种白腐菌及其组合菌种产生木质素降解酶能力和行为进行了比较分析和研究。结果表明,最佳培养方式为液体振荡培养;最佳培养基为酵母膏液体培养基。在产漆酶(laccases,lacs)方面,Pleurotus ostreatus和Phanerochaete chrysosporium的组合菌种的酶活最强,在第6天出现峰值,酶活达到450U/L;在产锰过氧化物酶(manganese peroxidases,mnps)方面,Trametes cinnabarina和Pleurotus ostreatus的组合菌种的酶活最强,在第10天出现峰值,酶活达到1050U/L;在产木质素过氧化物酶(lignin peroxidases,lips)方面,Trametes cinnabarina和Phanerochaete chrysosporium的组合菌种的酶活最强,在第8天出现产酶峰值,酶活达到2990U/L。筛选结果表明,组合菌种比单菌种产生的三种主要木质素降解酶的活性强,这为白腐菌高效产酶提供了一条新的途径,并为白腐菌研究领域的后续工作奠定基础。     

Degradation of anthracene by selected white rot fungi

Abstract Approximately 60% of the originally supplied anthracene (AC) was degraded in ligninolytic stationary cultures of selected white rot fungi within 21 days. All the white rot fungi tested oxidized AC to anthraquinone (AQ). Unlike Phanerochaete chrysosporium and strain Px, with Pleurotus ostreatus, Coriolopsis polyzona and Trametes versicolor , AQ did not accumulate in the cultures, indicating that AQ was degraded further and its degradation did not appear to be a rate-limiting step. However, P. ostreatus and C. polyzona failed to degrade AQ in the absence of AC. P. ostreatus, T. versicolor and strain Px did not produce lignin peroxidase (ligninase) (LIP) under the test conditions but oxidized AC to AQ suggesting that white rot fungi produce enzyme(s) other than LIP capable of oxidizing compounds with high ionization potential like AC. Moreover, in the case of Ph. chrysosporium and C. polyzona , AC degradation started earlier than the production of LIP. Veratryl alcohol (VA) seemed to be playing a role in AC oxidation catalyzed by LIP in Ph. chrysosporium .     

Ultrastructure of wheat straw cell wall delignified by Pleurotus ostreatus

Abstract Transmission electron microscopy of wheat straw cell wall incubated with Pleurotus ostreatus in the presence of glucose or sunflower oil reveals different degradation patterns. Lower lignin content and increased polyphenol-oxidase activity correspond to peculiar features of the substrate at ultrastructural level. Differentiation between cellulose and lignin degradation by electron microscopy might represent a valuable tool to monitor biological delignification during industrial hydrolysis of ligno-cellulose.     

Degradation of lignin in pulp mill wastewaters by white-rot fungi on biofilm

An investigation was conducted to explore the lignin-degrading capacity of attached-growth white-rot fungi. Five white-rot fungi, Phanerochaete chrysosporium, Pleurotus ostreatus, Lentinus edodes, Trametes versicolor and S22, grown on a porous plastic media, were individually used to treat black liquor from a pulp and paper mill. Over 71% of lignin and 48% of chemical oxygen demand (COD) were removed from the wastewater. Several factors, including pH, concentrations of carbon, nitrogen and trace elements in wastewater, all had significant effects on the degradation of lignin and the removal of COD. Three white-rot fungi, P. chrysosporium, P. ostreatus and S22, showed high capacity for lignin degradation at pH 9.0-11.0. The addition of 1 g l-1 glucose and 0.2 g l-1 ammonium tartrate was beneficial for the degradation of lignin by the white-rot fungi studied.     

Degradation of 14C-labelled poplar wood lignin by selected white-rot fungi

Summary Of eight white-rot fungi examined, seven fungi grew on nitrogen-limited poplar wood meal medium and degraded ¹⁴C-lignin in wood meal to ¹⁴CO₂. Increased oxygen enhanced both the rate and extent of degradation. However, whereas Pleurotus ostreatus, Pycnoporus cinnabarinus 115 and Pycnoporus cinnabarinus A-360 degraded 12–17% of ¹⁴C-(U)-lignin of poplar wood to ¹⁴CO₂ also in an air atmosphere, Sporotrichum pulverulentum, Phlebia radiata 79 and Phanerochaete sordida 37 degraded only 1–5% under these conditions. Addition of cellulose and glucose to the poplar wood medium stimulated degradation of ¹⁴C-(RING)-lignin of poplar wood by Phlebia radiata 79 but repressed degradation by Polyporus versicolor and Pleurotus ostreatus. Cellulose added to the wood meal medium had no effect on the degradation of lignin by Phanerochaete sordida 37 and Sporotrichum pulverulentum but glucose slightly repressed lignin degradation by these fungi. Those white-rot fungi which were considered as preferentially lignin attacking fungi could degrade ¹⁴C-(RING)-lignin of poplar wood efficiently under 100% oxygen. They did not require an extra energy source in addition to wood meal polysaccharides for rapid ring cleavage and they degraded up to 50–60% of the ¹⁴C-lignin to ¹⁴CO₂ in 6–7 weeks at a maximum rate of 3–4% per day.These results were reported in part at the Journées Internationales d'Etudes du Groupe Polyphenols, 29. 9.–1. 10. 1982, Université Paul Sabatier, Toulouse, France     

Influence of Pleurotus ostreatus inoculation on wood degradation and fungal colonization

The influence of Pleurotus ostreatus inoculation on wood degradation and on fungal community structure was studied. The experiments were performed on an organically poor fly ash deposit covered with a 10 cm layer of beech wood chips inoculated with P. ostreatus isolate ZIM76. Compared to non-inoculated wood chips, inoculation increased the temperatures and relative humidities and, in the first 6 months, accelerated Klason lignin degradation by 9% and also, after 17 months, increased iron translocation into wood chips by 30%. After 6 months, PCR-DGGE showed 22-28 and 13-21 fungal taxa in non-inoculated and P. ostreatus-inoculated beech chips, respectively. The differences in number of taxa and in the fungal community structure (based on Dice coefficient) between non-inoculated and inoculated wood chips diminished with time. The results indicate that the naturally occurring processes of wood degradation are as efficient as those occurring in sites inoculated with P. ostreatus.