降解棉秆纤维素分解菌的筛选及其降解特性研究

从土壤中筛选到两株能降解棉秆的纤维素分解菌M59、F115,通过构建酶活曲线确定了发酵周期,并进一步检测了不同氮源、不同浓度对菌株降解棉秆酶活的影响。结果表明,M59和F115均能有效降解纤维素,在刚果红纤维素平板上形成的水解圈直径〉0.5cm,降解滤纸的CMC酶活〉7.8 U.ml-1,FPA酶活〉3.9 U.ml-1;两菌株均能降解棉秆且维持较高的酶活（CMC酶活〉7.0 U.ml-1,FPA酶活〉2.5 U.ml-1）,发酵周期均确定为10d;氮源及其浓度对两菌株降解棉秆的CMC酶活和FPA酶活影响显著,以0.5%的酵母粉、蛋白胨作氮源,菌株M59的CMC酶活和FPA酶活、F115的CMC酶活均最高,可确定0.5%酵母粉、蛋白胨为两株纤维素分解菌较适宜的氮源。     

纤维素分解菌的分离筛选

[目的]为获得纤维素分解菌,以研究其在有机物质资源的利用上的应用。[方法]通过固体培养初筛和摇瓶发酵复筛从腐烂的含菌秸秆、腐叶、朽木和土壤中筛选出纤维素酶活较高的菌株,并对它们对不同碳源的利用进行了初步研究。[结果]通过初筛和复筛获得了内切酶活力和滤纸酶活力均较高的3株细菌和4株真菌。将7个菌株分别接种到不同碳源的液体培养基中,经3d培养后测定其CMC酶活,可发现不同菌株对同一碳源产生的酶活不同,同一菌株对不同来源纤维素的利用能力也不同。[结论]测定各菌株在不同纤维素碳源中的纤维素酶活力并将其应用于相应行业,这在生产上具有重大意义。     

多功能纤维素降解菌的分离及对水稻秸秆降解能力的初步研究

从采集的土壤样品中筛选出纤维素分解高活性菌株3株,分别编号为M2、M19和DZ,其中2株为木霉,1株为青霉,并对滤纸和水稻秸秆降解率进行初步的测定,结果表明M2和土3菌株在酶反应24h后,滤纸均成糊状,两株菌在37℃下降解率分别为53.22%和27.41%。     

复合菌系发酵条件及其牛粪堆肥纤维素降解的影响

[目的]为快速降解堆肥中的纤维素提供理论依据。[方法]从碳源、氮源、固液比、接种量、培养基初始pH值等方面,研究复合菌系产酶条件,及其对牛粪堆肥纤维素降解的影响。[结果]酶活力最高培养基配方为稻草粉∶麸皮=6∶4,豆饼粉2%,固液比1.0∶2.5,接种量10%;最佳培养条件：pH值为7.5,装料量50g,培养温度32℃,培养时间6d。在该条件下,CMC、FPA酶活力分别达到4564.86、624.13IU/g,堆肥结束时,纤维素降解率为74.24%。[结论]复合菌系能有效促进堆肥纤维素降解,加快堆肥腐熟速度。     

纤维素分解菌的筛选及玉米秸秆降解

从不同来源的土样中分离出降解纤维素能力强的5株霉菌及5株放线菌,测定了这10株菌在玉米秸秆发酵中的CMC酶及木聚糖酶的动态酶活。结果表明,霉菌菌株F6在整个培养过程中CMC酶及木聚糖酶的活性最高,分别为14.57和25.69 U/g,其次为放线菌A4,CMC酶及木聚糖酶酶活分别为8.62、27.07U/g。采用F6,A4处理玉米秸秆15 d,降解率分别达44.80%和41.12%。进一步研究表明,接种不同菌株后的玉米秸秆降解率与降解过程中菌株产CMC酶及木聚糖酶最大酶活呈显著的正相关关系。     

纤维素降解菌系的筛选及降解稻草条件研究

以已分离的11株纤维素降解菌为材料,采用滤纸崩解法和透明圈法,初步筛选出4株纤维素降解能力较强的菌株.将这4株单菌进行两两组合.研究混合菌系在9d内的CMC酶活和FPA酶活与单菌发酵之间的异同.结果表明,混合菌发酵CMC酶活和FPA酶活均优于单一菌株;同时筛选出一组具有高降解能力的混合菌体系;并对该混合菌系降解稻草的最...     

几种纤维素分解菌在有机质转化中的作用

采用培养实验,研究了在添加有机物料的条件下几种纤维素分解菌在土壤有机质转化中的作用.目的在于探讨黑土有机质变化的微生物机理,并从中筛选出活性较高的菌株及其组合,以期将之用于秸秆还田,提高土壤肥力,充分发挥微生物在生态系统中的作用.结果表明,在添加有机物料培养条件下土壤有机质的转化与纤维素分解菌的种类与数量有一定的相关性,不同的纤维素分解菌在有机质转化中的作用不同,多种菌株联合接种比单一接种对有机质转化的作用要强.所选择的4株菌株中哈茨木霉(Trichoderma harziamum Rifai,Mycol)比绿色木霉(Trichoderma atroviride P.karsten,Finl.)、桔青霉(Penicillium citrinum Thom.)和黑曲霉(Aspergillus niger v.Tiegh.)在有机质转化中的作用大.     

复合纤维素降解菌对城市落叶的降解研究

[目的]研究了纤维素降解菌处理落叶的方法,以解决目前城市落叶难于处理的问题。[方法]以落叶为发酵过程中唯一的碳源,研究不同起始pH值对降解过程中的pH值和酶活的影响,确定发酵最佳起始pH值;比较不同培养方式对降解效果的影响;测定发酵过程中产酶、产还原糖的变化;通过干物质的变化及其分解率来确定降解效果。[结果]试验得出,发酵的最佳起始pH值为6.0。静瓶培养比摇瓶培养降解效果更明显。在发酵第5天出现最高CMC酶活,达到9.012 U;第7天滤纸酶活最高,达到14.806 U。发酵结束后,干物质的分解率最高可达到43.42%。复合菌系对发酵液的pH值有良好的调节作用。[结论]纤维素降解落叶的方法不仅能够产还原糖还能够有效减少干物质量,对实际应用有积极的意义。     

一株纤维素降解菌的筛选与鉴定

从落叶覆盖的腐殖层土壤中富集、分离得到12株纤维素降解菌,从中筛选出一株高效降解菌(X10),研究其最适宜的培养条件为:配制以葡萄糖+微晶纤维素(1∶1)为碳源、以蛋白胨+牛肉膏(1∶1)为氮源的培养基,pH值7.5,30℃下培养40 h,测得纤维素降解酶酶活可达到67.44 U。通过对其16s rRNA测序鉴定,该菌与氧化微杆菌(Microbacterium oxydans)有99%的同源性。纤维素降解菌的选育可为高效生产纤维素酶提供新的菌种来源。     

发酵床垫料中高效纤维素降解菌的分离与筛选

为获得高效纤维素降解菌,从发酵床垫料中分离出5 株能降解纤维素的微生物菌株,对5株菌进行了透明圈和纤维素酶活性测定。结果表明:5 株菌株均可在纤维素-刚果红平板上快速形成透明圈,其中菌株A3 产酶活性最强,在接种后72 h 达到125.47U·mL^-1。对其16SrDNA 序列进行分析,结合形态学观察和生理生化特征,将该菌鉴定为地衣芽孢杆菌 (Bacillus licheniformis) 。培养时间和温度对菌株的酶活力影响较大,各菌株的产酶最适温度为30~40℃。该芽孢杆菌分解纤维素能力强、适应能力高,在发酵床垫料堆肥中具有潜在的应用前景。     

纤维素分解菌的分离筛选研究

从土壤、马粪、牛粪等材料中分离出分解纤维素能力较强的3个微生物菌群,其中高温细菌1株(a1),中温分解菌2株(b3,c1)。在稻草培养基中,a1菌群的纤维素酶活力为5.33 mg/(g.h),b3菌群的纤维素酶活力为6.43 mg/(g.h),c1菌株的纤维素酶活力为4.42 mg/(g.h),稻草经a1,b3,c1分解后,其中的粗纤维含量分别降至6.87%,6.47%和8.51%。     

Soil Organic Carbon,Black Carbon,and Enzyme Activity Under Long-Term Fertilization

The present study aims to understand the effects of long-term fertilization on soil organic carbon (SOC), black carbon (BC), enzyme activity, and the relationships among these parameters. Paddy field was continuously fertilized over 30 yr with nine different fertilizer treatments including N, P, K, NP, NK, NPK, 2NPK (two-fold NPK), NPK+manure (NPKM), and CK (no fertilization), N, 90 kg urea-N ha⁻¹ yr⁻¹; P, 45 kg triple superphosphate-P₂O₅ ha⁻¹ yr⁻¹; K, 75 kg potassium chloride-K₂O ha⁻¹ yr⁻¹; and pig manure, 22 500 kg ha⁻¹ yr⁻¹. Soil samples were collected and determined for SOC, BC content, and enzyme activity. The results showed that the SOC in the NPKM treatment was significantly higher than those in the K, P, and CK treatments. The lowest SOC content was found in the CK treatment. SOC content was similar in the N, NP, NK, NPK, 2NPK, and NPKM treatments. There was no significant difference in BC content among different treatments. The BC-to-SOC ratios (BC/SOC) ranged from 0.50 to 0.63, suggesting that BC might originate from the same source. Regarding enzyme activity, NPK treatment had higher urease activity than NPKM treatment. The urease activity of NPKM treatment was significantly higher than that of 2NPK, NP, N, P, K, CK, and NPKM treatment which produced higher activities of acid phosphatase, catalase, and invertase than all other treatments. Our results indicated that long-term fertilization did not significantly affect BC content. Concurrent application of manure and mineral fertilizers increased SOC content and significantly enhanced soil enzyme activities. Correlation analysis showed that catalase activity was significantly associated with invertase activity, but SOC, BC, and enzyme activity levels were not significantly correlated with one another. No significant correlations were observed between BC and soil enzymes. It is unknown whether soil enzymes play a role in the decomposition of BC.     

Soil Organic Carbon,Black Carbon,and Enzyme Activity Under Long- Term Fertilization

The present study aims to understand the effects of long-term fertilization on soil organic carbon （SOC）, black carbon （BC）, enzyme activity, and the relationships among these parameters. Paddy field was continuously fertilized over 30 yr with nine different fertilizer treatments including N, P, K, NP, NK, NPK, 2NPK （two-fold NPK）, NPK＋manure （NPKM）, and CK （no fertilization）, N, 90 kg urea-N ha^-1 yr^-1; P, 45 kg triple superphosphate-P205 ha^-1 yr^-1; K, 75 kg potassium chloride-K20 ha^-1 yr^-1; and pig manure, 22 500 kg ha^-1 yr^-1. Soil samples were collected and determined for SOC, BC content, and enzyme activity. The results showed that the SOC in the NPKM treatment was significantly higher than those in the K, P, and CK treatments. The lowest SOC content was found in the CK treatment. SOC content was similar in the N, NP, NK, NPK, 2NPK, and NPKM treatments. There was no significant difference in BC content among different treatments. The BC-to-SOC ratios （BC/SOC） ranged from 0.50 to 0.63, suggesting that BC might originate from the same source. Regarding enzyme activity, NPK treatment had higher urease activity than NPKM treatment. The urease activity of NPKM treatment was significantly higher than that of 2NPK, NP, N, P, K, CK, and NPKM treatment which produced higher activities of acid phosphatase, catalase, and invertase than all other treatments. Our results indicated that long-term fertilization did not significantly affect BC content. Concurrent application of manure and mineral fertilizers increased SOC content and significantly enhanced soil enzyme activities. Correlation analysis showed that catalase activity was significantly associated with invertase activity, but SOC, BC, and enzyme activity levels were not significantly correlated with one another. No significant correlations were observed between BC and soil enzymes. It is unknown whether soil enzymes play a role in the decomposition of BC.     

羔羊精饲料在瘤胃中有机物降解率预测模型的建立

[目的]测定不同饲料在瘤胃中有机物降解率,并建立其预测模型。[方法]通过尼龙袋法测定不同饲料厂生产的羔羊早期育肥精饲料的瘤胃有机物降解率,分析瘤胃有机物降解率与其饲料化学成分的相关性,并提出通过饲料营养成分预测有机物动态降解率的预测模型。[结果]各饲料在瘤胃有机物动态降解率的高低顺序为C1羔羊料E1羔羊料F1羔羊料I1羔羊料A1羔羊料D1羔羊料H1羔羊料G1羔羊料。瘤胃有机物动态降解率与羔羊料的常规营养成分的回归方程为ED=145.387-0.606DM-2.364CP-4.041EE-1.857NDF+2.271ADF+7.573ASH(r=0.926)。预测ED与实测ED的相关系数为0.88。[结论]该研究可为快速评定精饲料的瘤胃有效动态降解率提供了预测模型。     

雾灵山地区土壤有机质全氮及碱解氮的关系

通过对海拔1 050~1 950 m处土壤样点中有机质、全氮和碱解氮的测定,发现河北省雾灵山地区土壤中有机质、碱解氮和全氮含量垂直变化明显。在1 050~1 200 m处,各项含量均随高度的增加而减少,于1 200 m处达到最低值,在1 200~1 950 m处各项含量又随高度的增加而增加。在同一土壤剖面中,有机质、全氮和碱解氮含量又随着发生层的降低逐渐减少,表层明显高于其他各层。利用回归分析方法将三者的关系一一建立了回归模型,结果表明各回归方程均达到了极显著水平,用该方程描述该地区三者含量之间的关系,具有较高的可信度,模拟效果较好。     

外源有机碳对植烟土壤活性有机碳及酶活性的影响

试验设置2%木本泥炭(M1)、2%草本泥炭(M2)和2%褐煤(M3)3个处理,对植烟土壤的活性有机碳、碳库管理指数和酶活性进行了考察。结果表明:施用外源有机碳可以提高土壤活性有机碳(LOC)、高活性有机碳(HLOC)和碳库管理指数(CMI),提升幅度为木本泥炭褐煤草木泥炭;施用外源有机碳后,植烟土壤的过氧化氢酶活性均无显著变化,施用木本泥炭12个月后,土壤蔗糖酶活性降低了54.6%,脲酶活性升高了25.9%,而草本泥炭和褐煤处理的土壤蔗糖酶和脲酶活性变化不大。     

纳帕海湿地退化对碳氮积累影响的研究

以纳帕海原生沼泽湿地作为参照,选择人为干扰下的草甸作为研究对象,研究人为干扰对纳帕海湿地土壤碳氮积累的影响。结果表明,原生沼泽演化为草甸后,土壤容重增加,土壤含水量降低;原生沼泽的C／N值较大;纳帕海湿地土壤的有机碳和氮含量在空间分布上是不平衡的,且土壤全氮空间分布呈现与有机碳相同的趋势,在垂直空间分布上,土壤有机碳0～20cm表层与20～40cm下层相差15倍,土壤全氮0～20cm表层与20～40cm下层相差8倍;在水平空间分布上,0～20cm表层的有机碳相差7倍,20～40cm下层的有机碳相差15倍;0～20cm表层的全氮相差5倍,20～40cm下层的全氮相差8倍,并经估算,表明纳帕海湿地退化为草甸后,导致有机碳的损失约为4．44×10^9t,损失率为89．4％,氮的损失约为2．43×10^8t,损失率为79．67％,损失的碳氮以CO2、C地和NO2等温室气体的形式释放到大气中,加重温室气体对全球气候的影响。     

马尾松天然林土壤碳氮磷含量与碳密度的关系

基于江西中部马尾松天然林不同生长阶段土壤性质测定,探讨其不同林龄土壤碳密度及其垂直分布规律,分析不同土层土壤有机碳密度与土壤碳氮磷含量之间的关系。结果表明:各龄组土壤有机碳和全氮含量均随土层的加深而降低,且表层（0~10 cm）含量显著高于其他各层,各土层间全磷含量无显著性差异;土壤有机碳密度整体上呈随土层深度的增加而降低的趋势,平均有机碳密度为10.09 kg·m^-2,主要分布在0~50 cm;土壤有机碳密度与土壤碳氮磷含量之间相关性在表层均达显著水平（p<0.05）。