Colourimetric analysis and antimicrobial study of natural dyes and dyed silk

Colourimetric and antimicrobial activities of natural colourants and dyed silk have been studied. The colour strength (K/S) values were increased with increase in dye absorbance. The absorption of dyes on silk yarns was obtained from 10.56 to 39.48% at 5% concentration of dye from different plant extracts. The colourimetric parameters L¹, a¹, b¹, C, and H were measured for depth of the colour. The dyed silk with natural colourants displayed excellent antimicrobial activity (reduction rate: 25–65%) against the bacteria Escherichia coli and (reduction rate: 3–68%) against the fungal strain Aspergillus niger. The dyed silk exhibited good and durable fastness properties.     

Differential fate of metabolism of a disperse dye by microorganisms Galactomyces geotrichum and Brevibacillus laterosporus and their consortium GG-BL

The present work aims to evaluate Brown 3 REL degrading potential of developed microbial consortium GG-BL using two microbial cultures, Galactomyces geotrichum MTCC 1360 (GG) and Brevibacillus laterosporus MTCC 2298 (BL). Microbial consortium GG-BL showed 100% decolorization of a dye Brown 3 REL, while individually G. geotrichum MTCC 1360 and B. laterosporus MTCC 2298 showed 26% and 86% decolorization under aerobic condition (shaking) respectively. Measurements of biochemical oxygen demand (BOD) (76%) and chemical oxygen demand (COD) (68%) were done after decolorization by consortium GG-BL. No induction in activities of oxidoreductive enzymes found in G. geotrichum while B. laterosporus showed induction of veratryl alcohol oxidase, Nicotineamide adenine dinucleotide-dichlorophenol indophenol (NADH-DCIP) reductase and riboflavin reductase indicating their role in dye metabolism. Consortium GG-BL showed induction in the activities of laccase, veratryl alcohol oxidase, tyrosinase, NADH-DCIP reductase and riboflavin reductase. Two different sets of induced enzymes from G. geotrichum and B. laterosporus work together in consortium GG-BL resulting in faster degradation of dye. The degradation of Brown 3 REL was analyzed using high performance thin layer chromatography (HPTLC), high performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FT-IR) and gas chromatography mass spectroscopy (GC-MS). Phytotoxicity study revealed that metabolites formed after degradation was significantly less toxic in nature.     

铜绿假单胞菌对白腐菌产木质纤维素降解酶的影响

采用固态发酵的方法,考察了两株不同型号的铜绿假单胞菌（AB93066和ATCC9027）对白腐菌（黄孢原毛平革菌）产木质纤维素降解酶（木素过氧化物酶LiP、锰过氧化物酶MnP和羧甲基纤维素酶CMCase）的影响,并对酶提取液的pH值、表面张力及稻草降解残渣中挥发性有机质含量的变化进行了分析.结果表明,添加5.72%的A...     

提高平菇深层培养木质素降解酶活性和对直接湖蓝5B脱色率的探索性研究

以稻草为主要营养基质对平菇进行深层培养,研究了不同浓度(100、200、400、600、800 mg·L-1)直接湖蓝5B对平菇菌丝体产量的影响,以及平菇对不同浓度(100、150、200、250、300、400 mg·L-1)直接湖蓝5B的脱色率.此外,还研究了平菇分别与3种酵母菌(酿酒酵母、产朊假丝酵母和热带假丝酵母)混菌培养及用不同浓度(50、100、200、300、400 mg·L-1)直接湖蓝5B预适应培养的平菇菌种对木质素降解酶活性和直接湖蓝5B脱色率的影响.结果表明:100~400 mg·L-1的直接湖蓝5B均可显著提高了平菇菌丝体产量,而800 mg·L-1的染料对菌丝体的生长有显著抑制作用;染料浓度越高,平菇对其的脱色率越低,发酵时间越长,脱色效果越好.与平菇单菌发酵相比,平菇分别与酿酒酵母和产朊假丝酵母混菌培养可显著提高发酵体系漆酶的活性,平菇分别与所试3种酵母菌混菌培养时锰过氧化物酶活性均有显著增加,与产朊假丝酵母混菌培养时两种酶活性的增加量最大;用50、100、200 mg·L-1直接湖蓝5B预适应培养的菌种接种可显著提高平菇分泌的漆酶的活性,而50mg·L-1和100 mg·L-1的则显著提高锰过氧化物酶的活性.平菇分别与所试3种酵母混菌培养,以及用50 mg·L-1和100 mg·L-1直接湖蓝5B预培养的平菇菌种接种,发酵体系对直接湖蓝5B的脱色效果有显著促进作用,其中,平菇与产朊假丝酵母混菌培养时脱色率最高,达96.3%.通过比较直接湖蓝5B脱色率与漆酶、锰过氧化物酶活性之间的关系可以看出,漆酶、锰过氧化物酶活性与脱色率间基本呈正相关关系.     

Using supercritical carbon dioxide as solvent to replace water in polyethylene terephthalate (PET) fabric dyeing procedures

Dyeing fabrics in supercritical carbon dioxide (SCD) instead of water can save energy, reduce water use and prevent pollution. The special pilot plant was designed to test dyeing procedures in supercritical carbon dioxide and the analyses of the results indicate major benefits as compared to water based procedures. The dyeing of polyethylene terephthalate (PET) fabric in supercritical carbon dioxide using special pilot plant was investigated. Disperse dye, C.I. (color index) Disperse Blue 79, was used in this study. After dyeing, rinsing in supercritical carbon dioxide, which removes the excess dyes, was also discussed. At the same dyeing conditions, K/S (color yield) of dyed fabric significantly increased with increasing the dye concentration from 1% o.w.f. (on weight of fabric) to 5% o.w.f. Dyeing temperature and pressure had a strong influence on the color yield. When the temperature rose above 110 °C, the increase in color yield was obvious. At 20 MPa, 120–130 °C, dyeing reached equilibrium after 60 min. The excess dye of the dyed PET fabric was small. The suitable condition in supercritical carbon dioxide for removal of excess dye from the dyed fabric was 70 °C, 20 MPa. The PET fabric dyed in supercritical carbon dioxide had good fastness and physical properties.     

一组可抗抗生素干扰的木质纤维素分解菌复合系ADC-6的筛选

以高温期堆肥样为菌源,在含0.025 mg·mL-1四环素的培养基内以秸秆作为唯一碳源,经多代驯化筛选到一组能够分解木质纤维素和抗生素的ADC-6复合系.该复合系能够在6 d内分解四环素0.0194 mg,在14 d内使稻秆减重32%.ADC-6纤维素内切酶酶活、半纤维素酶活、总纤维素酶活在第4 d、2 d和2 d达到最大值分别为15.85 U·mL-1、62.97 U·mL-1和15.56 U·mL-1.用变性梯度凝胶电泳检测驯化过程中菌种的动态变化,并用克隆文库对稳定阶段的菌种多样性分析,发现该菌群中含Bacteroidetes、Sphingobacteriales、Bacillaceae、Clostridiales和Proteobacteria等5个属的微生物,其中,Clostridiales对木质纤维素的转化能力较强,很可能是菌群中分解木质纤维素的关键菌,而Bacteroidetes很可能是分解抗生素的关键菌.     

西南喀斯特山区寿竹林地土壤微生物量与酶活性在不同坡位和剖面层次的分布特征

以重庆市梁平县城东乡云佛村寿竹(Dip)林地为研究对象,分析了不同坡位[上坡(US)、中坡(MS)、下坡(BS)]和剖面[表层(0~15 cm),底层(15~30 cm)]土壤微生物量碳、氮(SMBC、SMBN)、微生物碳熵、氮熵(qMBC、qMBN)、土壤过氧化氢酶(CAT)、碱性磷酸酶(ALK)、脲酶(URE)、蔗糖酶(INV)之间的关系.结果表明,在不同坡位下,表层土壤SMBC、SMBN、qMBC、qMBN、CAT和INV表现为BS>MS>US,ALK呈BS>US>MS,URE呈MS>US>BS;底层土壤SMBC和qMBC呈MS>BS>US,SMBN、qMBN、CAT、ALK、URE和INV呈BS>MS>US.在不同土壤层次下,SMBC、SMBN、CAT、ALK、URE和INV均表现为表层>底层;qMBC和qMBN表现为底层>表层.相关分析表明,不同坡位和剖面层次土壤微生物碳氮与土壤酶活性、含水率之间均存在显著(P<0.05)或极显著(P<0.01)相关.从回归分析得出的2个方程可知,SMBC随着土壤CAT和ALK的增加而增加,随着pH的增大而减小;SMBN则随着INV和ALK的增加而增加.     

Construction and application of the Synechocystis sp. PCC6803-ftnA in microbial contamination control in a coupled cultivation and wastewater treatment

Inspired by iron fertilization experiments in HNLC (high-nitrate, low-chlorophyll) sea areas, we proposed the use of iron-rich engineered microalgae for microbial contaminant control in iron-free culture media. Based on the genome sequence and natural transformation system of Synechocystis sp. PCC6803, ftnA (encoding ferritin) was selected as our target gene and was cloned into wild-type Synechocystis sp. PCC6803. Tests at the molecular level confirmed the successful construction of the engineered Synechocystis sp. PCC6803-ftnA. After Fe^3 +-EDTA pulsing, the intracellular iron content of Synechocystis sp. PCC6803-ftnA was significantly enhanced, and the algae was used in the microbial contamination control system. In the coupled Synechocystis sp. PCC6803-ftnA production and municipal wastewater (MW, including Scenedesmus obliquus and Bacillus) treatment, Synechocystis sp. PCC6803-ftnA accounted for all of the microbial activity and significantly increased from 70% of the microbial community to 95%. These results revealed that while the stored iron in the Synechocystis sp. PCC6803-ftnA cells was used for growth and reproduction of this microalga in the MW, the growth of other microbes was inhibited because of the iron limitation, and these results provide a new method for microbial contamination control during a coupling process.     

硫酸盐还原反应器污泥驯化过程中微生物群落变化分析

采用PCR-DGGE技术,对硫酸盐还原反应器UASB污泥驯化过程中微生物群落的变化进行了分析.结果表明,污泥驯化过程中,微生物群落生物多样性与反应器硫酸盐及COD去除率呈明显的正相关,微生物群落Shannon指数大于3.45时,反应器硫酸盐去除率稳定在95%左右;对DGGE图谱中优势条带进行回收克隆并测序表明,污泥中微生物群落主要包含Firmicutes、Proteobacteria、Deinococcus-Thermus和Chloroflexi这4大类群,分别占总数的50.0%、28.6%、14.3%和7.1%;其中厌氧发酵细菌Clostridium sp.在驯化全过程中均占优势,但优势菌群的种类发生变化;厌氧细菌Chloroflexi sp.、Geopsychrobacter sp.等在污泥驯化过程中曾成为优势菌群但之后消亡;厌氧细菌Geobacter sp.则在污泥驯化过程中逐渐成为优势菌群;Desulfovibrio sp.在污泥驯化的最后2个阶段成为优势菌.     

Polypropylene/poly (butylene terephthalate) melt spun alloy fibers dyeable with carrier-free exhaust dyeing as an environmentally friendlier process

Carrier agent as one of the synthetic persistent molecules present in textile effluents considered as one of the most highly toxic, carcinogenic and serious inhibitor of the microbial respirometric activity. This chemical is used as accelerants in the dyeing or printing the hydrophobic fibers by dispersed dyes. Hydrophobic polypropylene (PP) fibers cannot be dyed by conventional dyeing process due to the absence of dye sites in the molecular chain and their high crystallinity. This study presents a carrier-free exhaust dyeing as an environmentally friendlier and cleaner process. In order to produce dyeable PP fibers, the PP was blended and melt spun with poly(butylene terephthalate) (PBT) at various ratios. First PP and PBT granules at blend ratios of 5, 10, 20, 30, 40 percent of PBT dispersed phase were physically mixed then the melt spinning of blended samples was carried out by a Maddock mixing zone extruder. The results showed that suitable exhaust dyeing process without using any carrier agents was possible for all PP/PBT alloy fiber samples. The dye uptake of samples significantly increased by increasing the PBT dispersed phase content. By increasing the PBT dispersed phase content decrease in the crystallinity percent resulting in significant enhancement in dye uptake of the alloy fiber samples was observed. A degree of four polynomial equation for dye uptake against blend ratio was obtained by which the optimum blend ratio was 72/28 percent of PP/PBT alloy fiber composition. In all alloy fiber dyed samples uniform coloration was observed. No considerable changes in the mechanical properties for dyed samples against undyed samples were observed. Interestingly, the best mechanical property among alloy fiber samples was observed in the sample containing 30 percent PBT dispersed phase which approximately corresponds to optimum blend ratio gained from mathematical calculations. In all PP/PBT alloy fiber samples strong fastness to soaping and very good to excellent fastness to light were achieved.     

Comparison the effects of bioaugmentation versus biostimulation on marine microbial community by PCR–DGGE: A mesocosm scale

In order to better understand the effects of biostimulation and bioaugmentation processes on a marine microbial community, three different mesocosm experiments were planned. Natural seawater(10.000 L) was artificially polluted with crude oil(1 L) and(1) inorganic nutrients(Biostimulating Mesocosm, BM),(2) inorganic nutrients and an inoculum of Alcanivorax borkumensis SK2(Single Bioaugmentation Mesocosm, SBM),(3) inorganic nutrients and inoculums of A. borkumensis SK2 and Thalassolituus oleivorans MIL-1(Consortium Bioaugmentation Mesocosm, CBM). During the experimental period(20 days), samples were taken from each mesocosm and the community structure was analyzed by PCR–DGGE. The 16 S r RNA gene DGGE banding patterns and sequence analysis demonstrated that biostimulation had the lowest effect on microbial biodiversity in the mesocosms; however, the biodiversity of the marine microbial community dramatically decreased in the CBM(Shannon index was 0.6 in T3). The community structures among the three mesocosms were also markedly different,and major bacteria derived from DGGE bands were related to uncultured Gamma Proteobacteria. The biodegradation results show that the Single Bioaugmentation Mesocosm(SBM) system had the highest percentage of degradation(95%) in comparison to the BM mesocosm(80%) and CBM(70%).     

不同基质条件下透性处理对脱硫弧菌硫酸盐还原活性的影响

乙醇透性处理1株普通脱硫弧菌Desulfovibrio vulgaris Hildenborough(DvH)强化硫酸盐生物还原活性,研究不同基质条件下透性处理程度对其硫酸盐还原活性影响.当以H2为电子供体时,10%乙醇处理的DvH硫酸盐还原活性最强,其次为15%;当乙醇浓度>15%时,DvH硫酸盐还原活性显著降低.当以乳酸为电子供体时,最佳乙醇浓度为20%,其次为15%和10%,乙醇浓度达到25%时,DvH仍保持一定的还原活性.不同供体条件下DvH对透性处理程度的响应不同,是因为H2与乳酸在细胞内发生氧化的位置不同,从而胞内电子传递途径不同.确保供体与受体之间电子传递链的完整性是合理确定透性处理程度及透性技术应用的关键.     

Dye reduction-based electron-transfer activity monitoring assay for assessing microbial electron transfer activity of microbial fuel cell inocula

Microbial fuel cells (MFC) utilize microbes as catalysts to convert chemical energy to electricity. Inocula used for MFC operation must therefore contain active microbial population. The dye reduction-based electron-transfer activity monitoring (DREAM) assay was employed to evaluate different inocula used in MFCs for their microbial bioelectrical activity. The assay utilizes the redox property of Methylene Blue to undergo color change from blue to colorless state upon microbial reduction. The extent of Methylene Blue reduction was denoted as the DREAM assay coefficient. DREAM assay was initially performed on a microbial culture along with the growth curve and estimation of colony forming units (CFUs). DREAM coefficient correlated to the CFU/mL obtained over time as growth progressed. The assay was then extended to water samples (domestic sewage, lake and a man-made pond) serving as inocula in MFCs. Domestic wastewater gave the highest DREAM coefficient (0.300 ± 0.05), followed by pond (0.224 ± 0.07) and lake (0.157 ± 0.04) water samples. Power density obtained conformed to the DREAM coefficient values, with the three samples generating power densities of 46.45 ± 5.1, 36.12 ± 3.2 and 25.08 ± 4.3 mW/m² respectively. We have also studied the role of addition of various carbon sources and their concentrations towards improving the sensitivity of the assay. The DREAM assay is a rapid, easy-to-perform and cost-effective method to assess inocula for their suitability as anolytes in terms of electron transfer potential in MFCs.     

基于PCR-DGGE和拟杆菌(Bacteroides)16S rRNA的岩溶地下水粪便污染来源示踪研究:以重庆南山老龙洞地下河系统为例

岩溶地下水的微生物污染日益严重,其来源的研究得到国际学术界的广泛关注.本研究以重庆南山老龙洞岩溶地下河系统为对象,采用滤膜法监测地下水中的总细菌、大肠杆菌、粪大肠菌及粪链球菌等微生物指标,以拟杆菌(Bacteriodes)为指示细菌,采用PCR-DGGE示踪地下水中大肠杆菌/粪大肠杆菌的来源.结果表明,老龙洞地下河流域各类细菌含量严重超标,总细菌数为10~2.9×10~7CFU·m L~(-1),大肠菌群总数达4.3~4.0×10~5CFU·m L~(-1),其中粪大肠菌群(FC)和粪链球菌(FS)分别最高达到1.1×10~6CFU·(100 m L)~(-1)、1.1×10~5CFU·(100 m L)~(-1);FC/FS多数为2以上,暗示流域地下水受人类粪便影响为主.地下水样和粪便样品的拟杆菌群落的PCR-DGGE比对分析表明地下水与人粪之间相似性为7.1%~69.1%,其中地下河出口处达到69.1%.地下水与猪粪之间相似性为1.1%~53.4%,地下河出口处仅为1.5%.因此,人类粪便为地下河污染的主要来源,猪粪污染为动物粪便污染的一部分,还存在其他动物粪便污染来源.此外,PCR-DGGE产物切胶测序发现大部分Bacteroides为人类肠道或粪便来源的细菌.     

Micelle dyeing with low liquor ratio for reactive dyes using dialkyl maleic acid ester surfactants

Micelle dyeing with low liquor ratio is novel fabric dyeing method for cleaner production. Preparation and interaction of dye-surfactant micelles using dibutyl maleic acid ester sodium sulfate surfactant were investigated by UV-Vis spectra. Dyeing properties of cellulose fabrics using micelle dyeing with low liquor ratio were discussed by color yields (K/S), color differences (ΔE), exhaustion (E), fixation (F) and reactivity (R) of three reactive dyes. The results show that reactive dye molecules could be solved in surfactant micelles and form stable dye-surfactant micelles. Micelles formed by dibutyl maleic acid ester sodium sulfate had good anti-agglomeration effect on dye solutions. Liquor ratio of micelle dyeing for cellulose fabrics could be reduced from 1:15 to 1:5. Leveling properties of three reactive dyes using micelle dyeing were good. The exhaustion, fixation and reactivity of all three dyes using micelle dyeing were similar with the conventional dyeing technology. Wet rubbing, washing and perspiration fastnesses of dyed samples using micelle dyeing were also good. Micelle dyeing with low liquor ratio can save a large amount of water and energy.     

牵牛花对石油污染盐碱土壤微生物群落与石油烃降解的影响

利用磷脂脂肪酸（PLFAs）生物标记法分析野生型牵牛花（Pharbitis nil （Linn.） Choisy）根际土壤微生物群落结构,探讨牵牛花生长对石油烃污染土壤微生物群落与石油烃降解的影响.结果表明,供试土壤微生物群落中,先后出现了24种PLFAs,包括标记细菌的饱和脂肪酸（SAT）、革兰氏阳性菌（G⁺）的末端支链饱和脂肪酸（TBSAT）、革兰氏阴性菌（G^-）的单不饱和脂肪酸（MONO）和环丙脂肪酸（CYCLO）、真菌的多不饱和脂肪酸（PUFA）和放线菌的中间型支链饱和脂肪酸（MBSAT）等六大类型.PLFAs的主成分分析（PCA）表明,牵牛花根际与对照组（未种牵牛花,CK）土壤微生物群落具有明显的差异,微生物多样性在春季增加83%、夏季增加140%、秋季增加50%;微生物的生物量在春季增加97.6%,夏季增加116.3%,秋季增加60.3%.牵牛花根际与对照组相比土壤中石油烃降解率明显提高,在春、夏、秋季分别提高了7.5%、34.2%和19.7%;并且,在牵牛花生长的不同季节石油烃的降解率有明显的差异,春季为22.3%,夏季为51.8%,秋季为38.0%.相关性分析表明,石油烃降解与土壤微生物总生物量具有中等程度的相关性（|r|=0.75）;与G⁺细菌、甲烷氧化菌的生物量具有高度相关性,相关系数|r|>0.8;与G^-的生物量具有中度相关性,相关系数为|r|=0.74;与真菌的生物量具有低度相关性,相关系数为|r|=0.36,与放线菌没有相关性,相关系数为|r|<0.30.     

宁南山区林地土壤原位矿化过程中碳氮转化耦合特征

为了解宁南山区典型植被恢复模式之一——人工林地土壤碳氮转化的特征以及二者的关系,运用PVC顶盖埋管法进行1 a的原位矿化培养实验,每隔2个月采样,研究柠条、山桃、山杏林地中土壤有机碳、可溶性有机碳和微生物量碳与土壤有机氮、无机氮以及净氨化速率、净硝化速率、净矿化速率和微生物固定速率在一年中的变化特征以及碳氮耦合关系.结果表明在原位培养过程中,61~120 d碳氮的变化最明显,主要受到土壤水分的影响;土壤有机碳和全氮极显著正相关,土壤微生物量碳氮、可溶性有机碳氮显著正相关;土壤有机碳转化速率显著影响净氨化速率、净硝化速率和MBN转化速率,且符合一元线性回归方程;柠条地培养一年后土壤微生物商(MBC/SOC)、MBN/SON显著升高,而且净硝化速率、净矿化速率显著大于山桃和山杏.     

Enhanced methane production in an anaerobic digestion and microbial electrolysis cell coupled system with co-cultivation of Geobacter and Methanosarcina

The anaerobic digestion(AD)and microbial electrolysis cell(MEC)coupled system has been proved to be a promising process for biomethane production.In this paper,it was found that by co-cultivating Geobacter with Methanosarcina in an AD–MEC coupled system,methane yield was further increased by 24.1%,achieving to 360.2 m L/g-COD,which was comparable to the theoretical methane yield of an anaerobic digester.With the presence of Geobacter,the maximum chemical oxygen demand(COD)removal rate(216.8 mg COD/(L·hr))and current density(304.3 A/m_3)were both increased by 1.3 and 1.8 fold compared to the previous study without Geobacter,resulting in overall energy efficiency reaching up to 74.6%.Community analysis demonstrated that Geobacter and Methanosarcina could coexist together in the biofilm,and the electrochemical activities of both were confirmed by cyclic voltammetry.Our study observed that the carbon dioxide content in total gas generated from the AD reactor with Geobacter was only half of that generated from the same reactor without Geobacter,suggesting that Methanosarcina may obtain the electron transferred from Geobacter for the reduction of carbon dioxide to methane.Taken together,Geobacter not only can improve the performance of the MEC system,but also can enhance methane production.     

固定化白地霉处理高硬度及高矿化度岩溶水的研究

为了使白地霉固定化小球处理太原市地下岩溶水达到最佳絮凝效果,分别研究了白地霉菌体的最佳扩大培养条件.同时,分别选用海藻酸钠(SA)、聚乙烯醇-海藻酸钠(PVA-SA)及聚乙烯醇-海藻酸钠-明胶(PVA-SA-明胶)作为固定化剂,固定化白地霉菌体,进行絮凝性能分析.最后,确定了固定化小球处理岩溶水的最佳搅拌时间及投加量,并与六水合氯化铝、自制三元复合吸附剂及壳聚糖的5%冰醋酸溶液的絮凝效果进行了比较.结果表明,将白地霉种子培养基按3%的接种量接入白地霉扩大培养基3中进行扩大培养,可在第2d获取活性较好的大量白地霉菌体进行固定化.处理岩溶水时应选用PVA-SA-明胶固定化的白地霉小球,并在其投加量为4g·L-1、搅拌时间为60min时,对岩溶水矿化度、硬度的最大絮凝率分别为96.88%、50.00%.经与化学混凝剂絮凝性能对比发现,微生物絮凝剂具有操作简便、无二次污染、絮凝效果较好的优点.     

不同温度下的土壤微生物呼吸及其与水溶性有机碳和转化酶的关系

为研究不同温度下的土壤微生物呼吸及其与水溶性有机碳(DOC)和转化酶的关系,设置了室内培养实验.采集南京市周边老山、紫金山、宝华山的土壤,研究不同土壤的微生物呼吸对温度升高的响应规律,并分析土壤DOC含量及转化酶活性.结果表明,不同土壤的累积微生物呼吸与土壤温度之间的关系均可用指数方程描述,其P值均达到极显著水平(P0.001),不同地点土壤的微生物呼吸温度敏感系数(Q10值)在1.762~1.895之间变异.累积土壤微生物呼吸的Q10值随着土壤温度升高表现出降低的趋势.培养后27 d土壤微生物呼吸的Q10值与培养后1 d的Q10值无显著差异(P0.05),这表明难分解有机质的温度敏感性与易分解有机质的温度敏感性一致.对于所有土壤而言,累积土壤微生物呼吸与DOC含量之间存在极显著(P=0.003)的线性回归关系,DOC可以解释累积土壤微生物呼吸31.6%的变异性.无论是单独分析不同土壤还是综合所有土壤的测定结果,累积微生物呼吸与土壤转化酶活性均存在极显著(P0.01)的一元线性回归关系,由此说明转化酶活性是衡量土壤微生物呼吸大小的一个较好的指标.