高寒森林不同生境凋落叶分解过程中水溶性组分动态特征

凋落叶分解所产生的水溶性组分(water soluble matter)是森林水陆不同生境碳和养分迁移的重要载体。本研究通过布设高寒森林4种代表物种凋落叶分解袋,即康定柳(Salix paraplesia)、高山杜鹃(Rhododendron lapponicum)、方枝柏(Sabina saltuaria)和四川红杉(Larix mastersiana),探讨其在林下地表、溪流和河岸带3种生境下不同分解时期(冻结初期、冻结期、融化期、生长季节、生长季节后期)的水溶性组分及水溶性碳含量动态及其影响因素。结果表明:经两年的分解,发现溪流显著促进了凋落叶中水溶性组分和水溶性碳的释放;同一物种凋落叶在不同生境下水溶性组分和水溶性碳损失差异显著(P<0.05),整体表现为溪流>河岸带>林下;在分解初期水溶性组分含量有明显的降低;在整个分解过程中,水溶性组分(-70.43%)和水溶性碳(-84.31%)含量变化基本一致且呈明显降低趋势。此外,凋落叶中水溶性组分和水溶性碳的释放速率受时间、物种以及区域环境因子(温度、p H值、营养成分)的调控。这些结果表明,高寒森林凋落叶中水溶性组分和水溶性碳在分解过程中易随水体的流动而转移至下游生态系统,并且区域环境因子在凋落叶水溶性组分和水溶性碳释放过程中具有重要的作用,这为深入理解高寒森林以凋落物为载体的物质迁移过程提供了科学依据。     

高寒森林不同生境凋落叶分解过程中水溶性组分动态特征

凋落叶分解所产生的水溶性组分(water soluble matter)是森林水陆不同生境碳和养分迁移的重要载体。本研究通过布设高寒森林4种代表物种凋落叶分解袋,即康定柳(Salix paraplesia)、高山杜鹃(Rhododendron lapponicum)、方枝柏(Sabina saltuaria)和四川红杉(Larix mastersiana),探讨其在林下地表、溪流和河岸带3种生境下不同分解时期(冻结初期、冻结期、融化期、生长季节、生长季节后期)的水溶性组分及水溶性碳含量动态及其影响因素。结果表明:经两年的分解,发现溪流显著促进了凋落叶中水溶性组分和水溶性碳的释放;同一物种凋落叶在不同生境下水溶性组分和水溶性碳损失差异显著(P0.05),整体表现为溪流河岸带林下;在分解初期水溶性组分含量有明显的降低;在整个分解过程中,水溶性组分(-70.43%)和水溶性碳(-84.31%)含量变化基本一致且呈明显降低趋势。此外,凋落叶中水溶性组分和水溶性碳的释放速率受时间、物种以及区域环境因子(温度、p H值、营养成分)的调控。这些结果表明,高寒森林凋落叶中水溶性组分和水溶性碳在分解过程中易随水体的流动而转移至下游生态系统,并且区域环境因子在凋落叶水溶性组分和水溶性碳释放过程中具有重要的作用,这为深入理解高寒森林以凋落物为载体的物质迁移过程提供了科学依据。     

雪被覆盖对高山森林凋落物分解过程中水溶性和有机溶性组分含量的影响

季节性雪被可能通过冻结、淋溶以及冻融循环等对高山森林凋落物水溶性和有机溶性组分含量产生影响.本文采用凋落物分解袋法,以川西高山森林典型乔木（四川红杉、岷江冷杉、红桦、方枝柏）和灌木（高山杜鹃、康定柳）凋落物为研究对象,研究了雪被覆盖不同时期（雪被形成期、雪被覆盖期和雪被融化期）和雪被厚度（厚型雪被、中型雪被、薄型雪被和无雪被）下凋落物水溶性和有机溶性组分含量的动态变化特征.结果表明： 在一个冬季的分解过程中,6种凋落物水溶性组分含量在雪被形成期和融化期降低而雪被覆盖期增加,但除高山杜鹃凋落物有机溶性组分含量在雪被覆盖期增加外,其他5种凋落物有机溶性组分含量在整个冬季呈降低趋势.相对于凋落物有机溶性组分含量,不同厚度雪被斑块对凋落物水溶性组分含量变化的影响更大,且主要表现在雪被形成期和雪被覆盖期.相对于其他雪被斑块,薄型雪被斑块更加显著地促进了高山柳和高山杜鹃凋落物水溶性组分含量降低,但显著抑制了方枝柏凋落物水溶性组分含量降低,而其他凋落物水溶性组分含量变化在不同斑块间无显著差异.冬季高山森林雪被对凋落物水溶性和有机溶性组分含量的影响主要受控于凋落物质量.     

高寒森林溪流对凋落叶分解过程中木质素降解的影响

溪流广泛分布于高寒森林地表,凋落于其中的林木凋落物的分解是整个森林生态系统物质循环的重要环节,水体流动过程中的冲刷和淋洗作用及其他独特的环境条件可能显著影响凋落物中木质素的降解。该研究采用凋落袋法对比研究了岷江上游高寒森林4种典型且初始质量差异显著的凋落叶,即康定柳(Salix paraplesia)、高山杜鹃(Rhododendron lapponicum)、方枝柏(Sabina saltuaria)和四川红杉(Larix mastersiana),在不同生境(林下、溪流和河岸带)下分解过程中木质素残留质量和浓度(质量百分率)的动态变化特征。经过两年的分解,发现溪流显著促进了凋落叶中木质素的降解;同一物种凋落叶在不同生境下木质素残留质量差异显著(p0.05),整体表现为溪流河岸带林下;在凋落叶分解的初期木质素有明显的降解,其浓度表现为先降低后升高,但不同物种之间存在显著(p0.05)的差异;在整个分解过程中,木质素残留质量总体呈现出了降低的趋势。此外,生境类型、分解时期和区域性环境因子(温度、p H值和营养元素的有效性)能显著影响木质素的降解率。这些结果表明,传统上认为木质素在凋落叶分解初期相对稳定的观点可能并不准确,其浓度很可能是先下降后升高,这也与有关木质素动态的最新研究结果相一致。另一方面,在不同分解时期和不同生境下,凋落叶木质素降解率表现出了显著差异,表明区域性环境因子在凋落叶分解和木质素降解过程中具有重要的作用。     

高寒森林不同生境对凋落叶分解灰分动态的影响

灰分是凋落叶的重要组成部分,其浓度直接关系到凋落叶的分解过程及有机组分的动态特征,且可能受生境和分解时期的影响,然而有关凋落叶分解过程中灰分动态的研究鲜有报道。采用凋落袋法,以岷江上游高寒森林4种代表性植物康定柳(Salix paraplesia)、高山杜鹃(Rhododendron lapponicum)、方枝柏(Sabina saltuaria)和四川红杉(Larix mastersiana)凋落叶为研究对象,研究了高寒森林凋落叶在3种不同环境条件下(林下、溪流、河岸带)分解过程中灰分的动态特征。结果表明,灰分量随凋落叶的分解整体呈现降低的趋势,且不同环境条件和不同物种之间存在明显的差异。与之相反,经过两年的分解,除溪流中康定柳凋落叶灰分浓度略有下降外(-0.99%),林下和河岸带中康定柳凋落叶及其它物种凋落叶中灰分浓度在所有环境条件下均表现出了增加的趋势(5.86%—72.15%)。凋落叶分解过程中灰分浓度变异量在不同分解时期存在明显或显著的差异,且受物种和环境因子的调控。这些结果表明,传统上认为凋落叶分解过程中灰分浓度比较稳定的观点是不准确的,且以凋落叶分解过程中灰分浓度不变的前提下采用无灰分质量损失(ash free mass loss)而计算凋落叶质量损失的方法存在一定的不准确性。研究为认识凋落叶分解过程中灰分的动态特征及凋落叶质量损失的测定方法提供了一定的参考。     

雪被斑块对高山森林两种灌木凋落叶质量损失的影响

高山/亚高山森林灌木层植物凋落物的分解对于系统物质循环等过程具有重要意义,并可能受到冬季不同厚度雪被斑块下冻融格局的影响.该文采用凋落物分解袋法,研究了高山森林典型灌层植物华西箭竹(Fargesia nitida)和康定柳(Salix paraplesia)凋落物在沿林窗-林下形成的冬季雪被厚度梯度(厚型雪被斑块、较厚型雪被斑块、中型雪被斑块、薄型雪被斑块、无雪被斑块)上在第一年不同关键时期(冻结初期、冻结期、融化期、生长季节初期和生长季节后期)的质量损失特征.在整个冻融季节,华西箭竹和康定柳凋落叶的平均质量损失分别占全年的(48.78±2.35)％和(46.60±5.02)％.冻融季节雪被覆盖斑块下凋落叶的失重率表现出厚型雪被斑块大于薄型雪被斑块的趋势,而生长季节无雪被斑块的失重率明显较高.尽管如此,华西箭竹凋落物第一年分解表现出随冬季雪被厚度增加而增加的趋势,但康定柳凋落物第一年失重率以薄型雪被斑块最高,而无雪被斑块最低.同时,相关分析表明冻融季节凋落叶的失重率与平均温度和负积温呈极显著正相关,生长季节凋落叶的失重率与所调查的温度因子并无显著相关关系,但全年凋落物失重率与平均温度和正、负积温均显著相关.这些结果清晰地表明,未来冬季变暖情境下高山森林冬季雪被格局的改变将显著影响灌层植物凋落物分解,影响趋势随着物种的差异具有明显差异.     

间歇性溪流米槠凋落叶分解过程胞外酶活性动态

以米槠(Castanopsis carlesii)凋落叶为研究对象,于2021年4—7月,对照森林地表和持续流水的溪流,研究间歇性溪流凋落叶分解过程中胞外酶活性变化规律。结果表明：(1)间歇性溪流凋落叶分解过程中酸性磷酸酶、β-葡萄糖苷酶、β-N-乙酰氨基葡萄糖苷酶和脲酶活性总体高于地表,低于溪流。(2)通过分析胞外酶化学计量比和矢量特征,发现三种生境凋落叶分解过程中微生物群落受碳和磷的共同限制。分解初期,间歇性溪流凋落叶分解过程中微生物群落相对碳限制程度高于其他两个生境,但相对磷限制低于地表,高于溪流;随着分解的进行,间歇性溪流凋落叶分解过程中微生物群落相对磷限制程度逐渐减弱,相对碳限制程度逐渐加强。(3)统计分析表明,间歇性溪流中大气温度是凋落叶分解过程中胞外酶活性的主控因子,而地表凋落叶分解过程中胞外酶活性与大气温度、地表温度和土壤含水量关系更为密切,溪流凋落叶分解过程中胞外酶活性主要受水体温度、溪流深度和气温等因子的影响。研究结果为全面认识亚热带森林生态系统物质迁移与循环过程提供了新思路和科学依据。     

退化红壤丘陵区森林凋落物初始化学组成与分解速率的关系

通过小盆+凋落袋控制试验,研究了我国南方退化红壤丘陵区8种森林凋落物和4种混合凋落物初始化学组成与分解速率的关系.结果表明:阔叶凋落物中的氮、磷、钾、镁含量显著高于针叶凋落物,木质素、碳含量显著低于针叶凋落物;凋落物分解速率与凋落物初始氮、磷、钾、镁含量呈显著正相关,与凋落物初始碳、木质素含量以及木质素/氮、木质素/磷和碳/磷值呈显著负相关;木质素含量解释了凋落物分解速率变异的54.3%,是影响分解速率的最关键因子,凋落物碳、氮、磷含量也与分解速率密切相关,它们与木质素含量一起可解释分解速率变异的81.4%.在退化红壤丘陵区植被恢复过程中,低木质素含量、高氮磷含量的阔叶物种的引入有利于加速凋落物的分解速率和土壤肥力的恢复进程.     

中亚热带次生林和人工林凋落枝水溶性碳氮磷动态特征

凋落枝是森林地上部分凋落物的重要组分,揭示其水溶性碳氮磷的动态规律对于认识森林物质循环过程具有重要意义,但目前研究集中于凋落叶,而对凋落枝缺乏必要关注。因此,以中亚热带典型马尾松（Pinus massoniana）人工林、杉木（Cunninghamia lanceolata）人工林和米槠（Castanopsis carlesii）次生林为研究对象,在一个自然年内调查了凋落枝水溶性碳、氮、磷含量及其芳香化指数以及化学计量比的动态变化过程。结果显示：（1）米槠次生林凋落枝水溶性碳、氮、磷含量及芳香化指数明显大于马尾松和杉木人工林;（2）水溶性碳和磷、水溶性碳比磷、水溶性氮比磷和芳香化指数有明显的季节变化;（3）水溶性碳、水溶性磷、水溶性氮比磷和芳香化指数在不同林分和季节间有交互作用。（4）马尾松和杉木人工林、米槠次生林凋落枝水溶性物质含量的季节变化多数与气温和降水呈显著负相关。这些结果表明亚热带次生林可能相对于人工林具有更为高效的以凋落枝为载体的物质循环过程,在未来气候变暖背景下亚热带森林由凋落枝归还给土壤的养分浓度可能降低。     

雪被期川西高山林线交错带凋落物可溶性有机碳的淋失特征

凋落物可溶性有机碳(dissolved organic carbon,DOC)是土壤DOC的主要来源之一,同时,凋落物DOC的淋失过程是生态系统碳循环的重要环节。本文采用凋落物分解袋法,于2012年10月—2013年5月,以川西高山林线交错带12种代表性植物的凋落物为材料,研究了冬季雪被期凋落物DOC在暗针叶林森林、高山林线和高山草甸3种分解生境中的淋失特征。结果表明:1)凋落物初始DOC含量为22.78~178.8 g·kg-1,物种间差异显著;2)经过一个雪被期(182 d),凋落物DOC淋失率为18.92%~62.33%,各物种DOC的淋失率对分解生境的响应差异较大;3)分解生境差异对凋落物DOC的淋失产生了显著影响,暗针叶林生境中凋落物DOC的淋失率显著高于林线和高山草甸生境;4)雪被是影响冬季高山林线交错带凋落物DOC淋失的主要环境因素。因此,高山林线交错上雪被期DOC淋失的空间变异性主要是景观尺度分布的雪被差异造成的,分解生境中较厚的雪被更利于凋落物DOC的淋失。     

Root Growth Effects on Soluble C and P in Manured and Non-manured Soils

There is limited research on relationships between root characteristics and soil chemical properties and processes. Because previous studies have shown specific C compounds may release previously sorbed P and make P more plant-available, crops which contribute to high soil C levels could play an important role in soil P cycling. The objectives of this study were to determine (1) whether rotation crops had different amounts of root growth, (2) whether different amounts of root growth among the crop species could be related to different levels of soluble soil C and (3) whether there were differences in P concentration among the soils under different crops that could be related to soluble C soil concentration. Roots and soil from potato (Solanum tuberosum L.), barley (Hordeum vulgare L.), soybean (Glycine max (L.) Merr.), and a forage consisting of alfalfa (Medicago sativa L.) and timothy (Phleum pretense L.) were sampled from the Aroostook Research Farm in Presque Isle, Maine, during the summers of 2003 and 2004 to determine root length density (RLD) and soluble C and P concentrations. Half of the sampled plots were amended with beef manure and half were not amended. Barley and forage consistently had higher RLD than potato or soybean crops. Barley and forage typically had higher concentrations of soluble soil C than potato or soybean, but the differences were significant at only three of the five sampling dates. RLD was significantly correlated to soluble C (r=0.56) only for amended soils on the August 2003 sampling date. For other dates r values were non-significant and ranged from 0.32 to 0.49. As with soil C, soluble soil P levels were typically higher in barley and forage than in potato or soybean crops. Significant differences were detected at four of the five sampling dates. Correlations between soluble C and soluble P were significant at two of the five sampling dates (r = 0.58 and 0.62) in amended soils and one of five sampling dates (r = 0.80) in unamended soils. Although the correlations between RLD and soluble C were not significant at every sampling date, the August 2003 data do suggest a possible effect of roots on soluble C. In addition, significant correlations between soluble C and soluble P at several sampling dates suggest a relationship between these parameters. Therefore cropping systems that include crops with higher amounts of root growth may promote increased soluble soil C levels and enhance P bioavailability.     

Elevated Concentrations of Circulating Intercellular Adhesion Molecule 1 (ICAM-1) and of Vascular Cell Adhesion Molecule 1 (VCAM-1) in HIV-1 Infection

The aim of this study was to determine whether elevated levels of circulating forms of the soluble adhesion molecules, Intercellular Adhesion Molecule-1 (cICAM-1), Vascular Cell Adhesion Molecule-1 (cVCAM-1) and E-Selectin (cE-Selectin) are observed in the sera of HIV-1 infected individuals as compared to healthy HIV seronegative adults and whether these elevated levels can be correlated with disease progression. Significantly elevated levels of cICAM-1—ranging from 184 to 1116 ng/ml with a mean of 617 ng/ml—and cVCAM-1—ranging from 653 to 3456 ng/ml with a mean of 1500 ng/ml—were observed in the sera of 29 HIV-1 infected individuals as compared to controls-ranging from 152 to 354 ng/ml with a mean of 248 ng/ml for cICAM-1 and from 328 to 792 ng/ml with a mean of 560 ng/ml for cVCAM-1 (P < 0.001). The serum concentrations of cE-Selectin of the HIV-1 infected individuals did not differ from those of the healthy controls. The elevated levels of cICAM-1, cVCAM-1 did not correlate with the CD4 count or the serum concentration of C-reactive protein. However, a significant correlation was observed between the serum concentrations of cVCAM-1 and those of neopterin. Since cICAM-1 as well as cV-CAM-1 can interfere with adhesion events leading to immunological functions, it can be suggested that the high amounts of these circulating forms of adhesion molecules, when present in the sera of HIV-1 positive individuals, can further disturb the immune system of these patients. In addition, the present study also suggests that the seric concentrations of cVCAM-1 can be used as pronostic indicators.     

Partitioning of phosphorus between particles and water in a river outflow

The mixing zone between Cayuga Lake, N.Y. and one of its tributaries, Salmon Creek, was studied to determine effects of physical processes such as adsorption, precipitation or sedimentation on phosphorus discharged by the Creek. A high sodium concentration in the lake served as a natural tracer, by which proportions of Creek and Lake water were determined at any point in the mixing zone. Proportions of Creek and Lake water were used to predict amounts of P that would be expected on the basis of mixing alone. Differences between predicted and observed concentrations were attributed to local physical processes. This analysis showed that, in several of the six plumes surveyed, there was substantial loss of P due to sedimentation. The P-distribution in all plumes showed evidence of exchanges between particles and the medium, as a result of which soluble reactive-P usually decreased and soluble unreactive-P usually increased. The nature and magnitude of these local processes were such that they could have significant effects on the fate of stream-P discharged into the lake.Supported in part by Office and Technology, U.S. Department Interior and by Hatch Funds from U.S. Department of Agriculture.     

脂联素及其球状区在大肠杆菌中的可溶性表达

目的:克隆表达有生物学活性的脂联素及其球状区蛋白,并制备抗体。方法:以pQE30-adiponectin质粒为模板,PCR扩增脂联素及其球状区蛋白基因片段,插入pGEX-4T-2载体,转化大肠杆菌BL21后获得表达,用GSTrap柱亲和纯化可溶性表达的蛋白。用纯化的蛋白免疫家兔制备多抗,Westernblot鉴定抗体与人血清中脂联素的反应性。结果:PCR扩增脂联素基因片段长约710bp,脂联素球状区基因片段长约430bp。表达的GST-脂联素融合蛋白表观Mr约51000,GST-脂联素球状区融合蛋白表观Mr约42000,纯化后纯度高于90%。免疫产生的抗体与人血清中的脂联素能特异性结合。结论:表达获得的脂联素蛋白和制备的抗体为脂联素的检测及对其功能的研究奠定了基础。     

The mechanism of boron tolerance for maintenance of root growth in barley (Hordeum vulgare L.)

Cultivar differences in root elongation under B toxic conditions were observed in barley (Hordeum vulgare L.). A significant increase in the length and width of the root meristematic zone (RMZ) was observed in Sahara 3771 (B tolerant) when it was grown under excessive B concentration, compared to when grown at adequate B supply. This coincided with an increase in cell width and cell numbers in the meristematic zone (MZ), whereas a significant decrease in the length and no significant effect on the width of the MZ was observed in Clipper (B intolerant) when it was grown under excessive B supply. This was accompanied by a decrease in cell numbers, but an increase in the length and width of individual cells present along the MZ. Excessive B concentrations led to a significantly lower osmotic potential within the cell sap of the root tip in SloopVic (B tolerant) and Sahara 3771, while the opposite was observed in Clipper. Enhanced sugar levels in the root tips of SloopVic were observed between 48 and 96 h after excess B was applied. This coincided with an increase in the root elongation rate and with a 2.7-fold increase in sucrose level within mature leaf tissue. A significant decrease in reducing sugar levels was observed in the root tips of Clipper under excessive B concentrations. This coincided with significantly lower root elongation rates and lower sucrose levels in leaf tissues. Results indicate a B tolerance mechanism associated with a complex control of sucrose levels between leaf and root tip that assist in maintaining root growth under B toxicity.     

原核系统可溶性表达策略

获得大量目的蛋白的最简单最经济的方法是利用原核表达系统表达外源基因.但由于原核系统的自身特点,使所表达的蛋白常常形成无活性的包涵体.多年来世界各国的研究为解决这一问题尝试了多种方法.本简单介绍原核表达系统的特点及提高蛋白可溶性表达的常用方法.     

低温处理对牡丹春节催花及营养类物质变化的影响

连续观察、测定了牡丹春节催花进程中不同低温天数处理对温室外自然低温解除休眠及温室内培养过程中形态及某些生理生化变化的影响,结果显示：低温处理34d后的11月28日温室外牡丹花芽形态及可溶性糖、淀粉、可溶性蛋白、游离氨基酸含量变化显著,11月28日左右是低温处理期间牡丹花芽代谢变化剧烈的时期;处理41d后的12月5口及以后移入温室的植株能够正常开花。以上结果从形态与营养物质变化的角度说明了11月28日左右牡丹花芽开始逐步解除休眠,12月5日花芽已彻底解除休眠,不同低温对牡丹春节催花过程中花芽的发育有着质的作用。     

3种进化类型大豆叶片的某些生理特性比较

半野生、半栽培和栽培大豆叶片可溶性糖和可溶性蛋白含量以及过氧化物酶（POD）和超氧化物歧化酶（SOD）活性均表现为随品种的进化而增加的变化趋势。POD活性在生育期中呈上升变化,SOD活性则随着生育进程逐渐下降。栽培大豆的可溶性糖含量和POD活性以上部叶片最高,半栽培大豆与栽培大豆类似,半野生大豆的变化则不明显。     

有机肥中可溶性有机碳、氮含量及其特性

测定了7种不同种类、不同腐熟程度有机肥中可溶性有机氮（SON）和可溶性有机碳（SOC）的含量,结果表明：有机肥的水和0．01mol／LCaCl2溶液提取液中SON含量分别平均为105．2mg／L和91．6mg／L;每千克干样平均含SON分别为1188mg和1037mg;SON占可溶性总氮（TSN）和全氮（TN）的比例分别在70．5％～74．7％和4．3％～4．9％之间。水和0．01mol／LCaCl2溶液提取液中SOC含量分别平均为695mg／L和622mg／L;每千克干样平均含SOC分别为7873mg和7054mg;SOC占有机肥有机碳（TOC）比例分别平均为2．1％和1．9％;SOC／SON平均分别为6．7和6．9。SON与SOC间的相关性较高,SON与NO3^--N含量呈现负相关关系。有机肥料中的可溶性氮素绝大部分以SON形式存在,如此高的SON和SOC含量可能会成为氮、碳养分流失和环境污染的潜在来源。     

Effect of NaCl salinity in vivo and in vitro on ribonuclease activity in the halophyte Suaeda maritima

Ribonuclease (EC 2.7.7.17) activity in the obligate halophyte Suaeda maritima (L.) Dum. var. macrocarpa Moq. was studied in relation to salinity (increasing concentrations of NaCl) of incubation and growth media. In vitro, the addition of 50 to 400 m M NaCl did not affect ribonuclease activity. This result, which was also found for Phaseolus vulgaris , indicates that the hydrolase is insensitive to high saline concentrations. The subcellular distribution of RNase activity did not change significantly with the salinity of the medium or with the age of the plant. The microsomal ribonuclease activity expressed on a fresh weight basis represented in every case less than 6% of the total activity. After 23 days of culture, the absence of salt stimulated the activity of soluble ribonuclease in aerial parts of Suaeda ; inversely, the capacity of the enzyme was lower under optimal saline conditions (130 m M NaCl). This was also evidenced by transfer of whole plants from a non-saline to a saline medium. Such a saline shock caused a decrease followed by a stabilization of the capacity of ribonuclease from Suaeda . The influx of NaCl in the tissues lowered the activity of the hydrolase.