农业有机废物与城市生活垃圾堆肥高温期微生物种群结构比较

通过PCR、克隆文库方法分析了农业有机废物和城市垃圾堆肥高温期间细菌和真菌种群的多样性.提取堆肥高温期的DNA,PCR扩增,构建各高温期的16S rDNA和18S rDNA克隆文库,结果表明:农业有机废物和城市生活垃圾16S rDNA克隆文库中分别共有18个、21个OTUs,分别属于细菌域的14个、15个不同属,其18S rDNA克隆文库中分别共有8个、9个OTUs,分别属于细菌域的8个、9个不同属,推断农业有机废物堆体的优势菌为Bacillus megaterium、Rhizobium sp.、Phanerochaete chrysosporium、Penicillium sp.同属或同种的菌株;城市生活垃圾堆体的优势菌为Bacillus megaterium、Azospirillum sp.、Phanerochaete chrysosporium同种或同属的菌株.     

双孢蘑菇培养料发酵过程中细菌群落动态变化

双孢蘑菇产量的最主要影响因素是培养料的堆肥发酵过程,而微生物是其中的主要推动力。为了揭示工厂化生产双孢蘑菇堆肥发酵过程中的微生物群落结构变化及演替规律,深入了解细菌在堆肥发酵过程中作用,文章以工厂化生产双孢蘑菇堆肥为研究对象,采用16S rRNA基因高通量测序技术分析堆肥前、一次发酵、二次发酵过程中细菌群落特征。共产生有效操作分类单元(OTUs) 854个,涵盖了19门259属的细菌。堆肥前优势类群为Proteobacteria,一次发酵优势类群为Firmicutes、Deinococcus-Thermus等,二次发酵时绿弯菌门Chloroflexi为主要类群。研究结果表明:微生物种类和数量随堆肥过程不断升高,并在二次发酵后降低,且微生物群落结构呈现连续变化的规律。高通量测序还发现了很多未分类细菌,说明双孢蘑菇培养料堆肥样品中还蕴含着大量未知的微生物种类。     

草菇培养料二次发酵过程中真菌的群落结构

【目的】明确草菇培养料二次发酵过程中真菌群落变化情况,确定发酵不同阶段的优势菌群,为能够在分子水平上准确高效监测发酵过程,解析发酵机制奠定基础。【方法】采用变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)及克隆菌株18S r DNA序列分析技术对草菇培养料二次发酵不同阶段真菌群落结构进行分析。【结果】DGGE图谱显示,不同处理真菌群落多样性存在差异,发酵高温阶段条带多样性较高,而且优势条带及相对含量也在发生动态变化。回收克隆不同发酵阶段的20个优势菌株中,9个菌株为非培养未知真核生物或真菌,其余克隆菌株为非培养散子囊菌目(Eurotiales)、烟曲霉(Aspergillus fumigatus)、曲霉菌属(Aspergillus sp.)、米曲霉(Aspergillus oryzae)、Melanocarpus albomyces、炭疽菌属(Colletotrichum sp.)、根毛霉菌属(Rhizomucor sp.)、轮枝菌属(Verticillium sp.)、普通青霉(Penicillium commune)、三角孢小囊菌(Microascus trigonosporus)和Trichosporon lactis真菌,其中14株(70%)克隆菌株为耐热真菌。【结论】草菇培养料二次发酵过程中真菌群落结构及优势菌群在发生着动态的变化。     

变性梯度凝胶电泳分析草菇培养料二次发酵过程中细菌群落演替

[目的]了解草菇以废棉为主要成分的培养料在二次发酵过程中细菌群落结构变化情况,确定发酵不同阶段的优势菌群,为能够在分子水平上快速准确地监测发酵过程中菌群动态变化奠定基础.[方法]采用变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)及克隆菌株16S rDNA序列分析技术对草菇废棉培养料二次发酵不同阶段的样品中细菌群落结构进行分析.[结果]DGGE图谱显示,细菌群落多样性较为丰富,条带多样性随着发酵进程逐渐降低,而且在不同阶段中的优势条带及相对丰度在发生着动态的变化.回收克隆的23个不同发酵阶段的优势菌株来自于变形菌门、拟杆菌门和厚壁菌门,α,β,γ-变形菌纲、鞘脂杆纲、拟杆菌纲和梭菌纲6个菌纲的11个属,其中19株克隆菌株为耐热细菌,在发酵的高温及降温阶段,丛毛单胞菌属、鞘脂杆菌属、中华根瘤菌属和寡养单胞菌属细菌为优势类群.[结论]草菇废棉培养料二次发酵过程中细菌的群落结构及优势菌群在发生着动态的变化,尤其是在进入高温期阶段,优势菌群变化显著.     

基于高通量测序分析桃蚜体内微生物群落结构及多样性

为探明桃蚜Myzus persicae体内微生物群落结构及其种类多样性,采用Illumina HiSeq二代测序技术检测桃蚜体内细菌16S rRNA基因和真菌ITS基因序列的方法,分析取食白菜Brassica pekinensis和甘蓝Brassica oleracea的无翅孤雌桃蚜成虫体内微生物群落结构及多样性。研究结果获得桃蚜体内细菌16S rDNA和真菌ITS1优质序列分别为473 750条和472 980条,并根据序列相似性对其进行聚类分析,分别获得959个和1 424个OTUs。基于OTUs分类结果,共注释鉴定细菌类群26个门、55个纲、128个目、227个科、419属、451种,真菌类群10个门、31个纲、77个目、172个科、343属、441种。其中,在门级水平上,取食白菜和甘蓝的桃蚜体内细菌类群均以变形菌门Proteobacteria内的细菌（占73.11%,80.10%）为优势菌;真菌类群均以子囊菌门Ascomycota真菌（占51.91%,50.98%）为优势菌。在属级水平上,取食白菜和甘蓝的桃蚜体内细菌均以布赫纳氏菌属Buchnera（占60.82%,56.11%）为优势属,而其次优势细菌属则分别为未培养的叶绿体菌Chloroplas（占2.84%）和立克次氏小体属Rickettsiella（占10.04%）;取食白菜的桃蚜体内真菌优势属为青霉属Penicillium（占5.15%）,次优势菌属为被孢霉属Mortierella（占3.83%）,而取食甘蓝的桃蚜体内真菌优势属为曲霉属Aspergillus（占3.93%）,次优势菌属为被孢霉属Mortierella（占3.86%）。以上研究结果表明取食不同植物的桃蚜体内微生物群落结构和种类多样性存在一定差异。α多样性指数表明桃蚜体内微生物群落结构具有较高的丰富度和多样性。研究结果为进一步挖掘桃蚜体内关键微生物,并解析其生物学功能及其利用等方面奠定了重要基础。     

新疆醉马草内生菌群落结构

【目的】揭示醉马草不同组织内生细菌和内生真菌种群组成和分布。【方法】采用液氮研磨法分别提取醉马草种子、叶、茎、根组织总DNA,采用通用引物扩增内生细菌16S rDNA和真菌ITS,通过限制性内切酶HhaⅠ和RsaⅠ对16S rDNA PCR产物酶切,HhaeⅢ和HinfⅠ对真菌rDNA ITS PCR产物酶切得到不同的TRFs片段。TRFs经T-RFLP分析程序结合基因文库比对后,分析醉马草不同组织中内生细菌和内生真菌的群落组成及内生菌群落相似性。【结果】研究表明醉马草根部内生细菌多样性最高,而种子内生真菌多样性最为丰富。醉马草各组织内生细菌优势菌属均为Bacillus(29%以上),种子、叶、茎、根内生真菌优势菌属分别为Mycosphaerella(6.5%),Teratosphaeria(4.5%),Fragum(1.1%),Sebacina(11.3%)。聚类分析表明茎和叶内生细菌群落结构相似,种子和其他组织内生细菌群落结构相似性较远,而茎和种子内生真菌群落结构相似,叶和其他组织内生真菌群落结构相似性较远。醉马草内生菌多样性丰富且存在尚未认识的新类群。     

核糖体小亚基V4和V9区引物扩增大亚湾真核浮游生物的比较研究

对大亚湾水体的环境DNA分别进行18S rDNA的V4和V9区的引物扩增,通过高通量测序技术进行测序,并比较分析二者浮游真核生物基因多样性和相对丰度。18S rDNA V4区引物扩增共检测出浮游动物56纲, 101目,浮游植物52纲, 69目; 18S rDNA V9区引物扩增共检测出浮游动物47纲, 81目,浮游植物56纲, 101目。两对引物对浮游真核生物扩增都具有较高覆盖度,在纲级别上二者的结果相近:颚足纲(Maxillopoda)是浮游动物优势类群;甲藻纲(Dinophyceae)、圆筛藻纲(Coscinodiscophyceae)、小豆藻纲(Mamiellophyceae)是浮游植物优势类群,其中甲藻纲多样性与丰度的结果相近,而18S rDNA V9区引物扩增得到的圆筛藻纲丰度高于18S rDNA V4区引物。分析结果表明, 18S rDNAV4区引物扩增的浮游动物多样性比18SrDNAV9区引物高,而18SrDNAV9区引物扩增的浮游植物多样性比18S rDNA V4区引物高。同时,通过高通量测序技术首次确定大亚湾海区大量存在着寄生型甲藻(Syndiniales),小豆藻目...     

堆肥发酵菌种的分离、鉴定及其堆肥发酵效果研究

为获得适应性良好的菌种用于猪粪的堆肥处理,从新鲜猪粪中分离出一株酵母样菌株783,并采用PCR技术扩增其18S rDNA基因,并测定其基因序列.基于18S rDNA序列同源性比对以及系统发育树的分析,发现783是解脂耶罗威亚酵母.菌株783的18S rDNA序列已经被GenBank数据库收录,其序列号为EU434621.对猪粪堆肥发酵效果表明其在提高堆肥质量方面有着较好的效果.     

不同覆土基质微生物结构特征研究及其对双孢蘑菇产量的影响

覆土是影响双孢蘑菇产量、质量和出菇整齐度的重要因子,利用现代分子生态学的方法快速、准确地对不同覆土基质微生物结构特征进行检测,以进一步了解微生物群落与双孢蘑菇相互作用关系。测定了不同覆土的理化特性,应用PCR技术对不同覆土材料提取总DNA,扩增细菌16S rDNA和真菌28S rDNA,运用变性梯度凝胶电泳技术对PCR产物进行分析,研究双孢蘑菇不同覆土基质微生物结构特征。结果表明:不同处理的覆土材料微生物群落的基因具有多样性,其中细菌群落基因多样性存在差异,使用纯泥炭与粉碎稻草处理差异最大,相似性仅为62%;通过真菌28S rDNA变性梯度凝胶电泳结果显示,粉碎稻草处理多样性指数最高,达3.576,但随着泥炭比例的提高,覆土处理中真菌群落的多样性相对减少;栽培试验发现,双孢蘑菇子实体形成量、总产量可能与覆土中的真菌群落多样性呈负相关。     

昆明盐矿古老岩盐沉积中的原核生物多样性

应用PCR-DGGE和rRNA分析法研究了昆明盐矿古老岩盐沉积中的原核生物多样性。样品的细菌DGGE分析得到27条带,古菌得到18条带。样品与纯培养得到的19个属菌株的DGGE图谱对比分析发现,细菌18个属菌株,只有1个属菌株与样品中的1条带迁移位置都不一致;古菌1个属的菌株不与样品中任何条带迁移位置一致。表明纯培养所得菌株并非该环境中的优势类群。同时,建立了样品细菌和古菌的16S rDNA克隆文库,从中分别挑取36个细菌克隆和20个古菌克隆进行ARDRA分析。细菌可分为10个OTUs,其中3个OTUs是优势类群,分别占38.9%,25.0%,16.7%,其余7个OTUs各含有1个克隆。古菌分为8个OTUs,没有明显的优势类群。每个OTU的代表克隆16S rDNA序列分析表明,细菌分属3大类群:α-Proteobacteria,γ-Proteobacteria和Actinobacteria,以Pseudomonas属菌为优势,含有其它岩盐沉积中没有发现的Actinobacteria。古菌主要是Halorubrum属、Haloterrigena属菌和未培养古菌。本研究表明,昆明盐矿古老岩盐沉积具有较丰富的原核生物多样性,含有大量未知的、未培养或不可培养的原核生物,但在原核生物物种组成和丰度上,免培养与此前的纯培养研究结果存在一定差异。因此,结合使用两类方法才能较全面地认识高盐极端环境微生物的多样性。     

Comparison of characterization and microbial communities in rice straw- and wheat straw-based compost for <Emphasis Type="Italic">Agaricus bisporus</Emphasis> production

Rice straw (RS) is an important raw material for the preparation of Agaricus bisporus compost in China. In this study, the characterization of composting process from RS and wheat straw (WS) was compared for mushroom production. The results showed that the temperature in RS compost increased rapidly compared with WS compost, and the carbon (C)/nitrogen (N) ratio decreased quickly. The microbial changes during the Phase I and Phase II composting process were monitored using denaturing gradient gel electrophoresis (DGGE) and phospholipid fatty acid (PLFA) analysis. Bacteria were the dominant species during the process of composting and the bacterial community structure dramatically changed during heap composting according to the DGGE results. The bacterial community diversity of RS compost was abundant compared with WS compost at stages 4–5, but no distinct difference was observed after the controlled tunnel Phase II process. The total amount of PLFAs of RS compost, as an indicator of microbial biomass, was higher than that of WS. Clustering by DGGE and principal component analysis of the PLFA compositions revealed that there were differences in both the microbial population and community structure between RS- and WS-based composts. Our data indicated that composting of RS resulted in improved degradation and assimilation of breakdown products by A. bisporus, and suggested that the RS compost was effective for sustaining A. bisporus mushroom growth as well as conventional WS compost.     

Dynamic Changes in Bacterial Communities During Compost and Earthworm Treatment of Low-Grade Potassium Ore

Both composting and earthworm treatment can degrade potassium rock powders and bacteria play a key role during the bio-processings. To understand the dominant bacteria and bacterial profile in biological conversion of the ore including compost and earthworm treatment, the bacterial communities in the compost were studied by using the method of denaturing gradient gel electrophoresis (DGGE) after ore powder was co-composted with organic wastes and then treated with earthworms. Results showed bacterial community structure changed very quickly during the early stages of solid-state fermentation, but relatively stable in the later stages of fermentation and during earthworm treatment. The dominant species of bacteria largely varied in the earlier stage of composting, but they were stable in the latter stage and during earthworm treatment. Two classes of bacteria, represented by band 12 (likely Alteromonas) and band 14 (likely Firmicutes) in DGGE profile, were found to be dominant species over the entire solid-state fermentation period. No special dominant bacterial species appeared during earthworm treatment. Phylogenetic studies of the bacteria based on 16S rRNA sequences indicate that major 13 bands came from phyla Proteobacteria and Firmicutes, suggesting that bacteria in these phyla played an important role during the compost treatment.     

New insights into the structure and dynamics of actinomycetal community during manure composting

Despite advancing knowledge about the functional role of actinomycetes in degrading lignocellulosic materials, definitive knowledge concerning the diversity and dynamics of the actinomycetal community in composting is still lacking. In this study, real-time polymerase chain reaction (PCR) coupled with denaturing gradient gel electrophoresis (DGGE) and clone library construction were applied to investigate actinomycetal diversity and dynamics in a pilot-scale composting. Quantitative real-time PCR data revealed that actinomycetes accounted for 18–86 % of bacteria and that the fraction peaked during the maturing phase, indicating that Actinobacteria were critical to the compost ecosystem. Qualitatively, actinomycetal communities displayed distinct temporal variations during composting. Fourteen distinct genera of actinomycetes and an unknown group were observed in manure composts. Redundancy analysis indicated that temperature exerted an influence over the actinomycetal communities. Specifically, pathogenic Corynebacterium species dominated in the initial phase, whereas the genera Saccharomonospora and Thermobifida were abundant in the thermophilic phase. In maturing composts, mesophilic Micrococcineae members were most prevalent. The dominant thermophiles along with Micrococcineae may jointly facilitate the degradation of lignocellulosic materials during composting. Together, our research revealed a more detailed ecological and potential functional role for actinomycetes in the compost ecology.     

Assessment of survival of Listeria monocytogenes,Salmonella Infantis and Enterococcus faecalis artificially inoculated into experimental waste or compost

Aims: To evaluate survival of pathogenic strains, Listeria monocytogenes and Salmonella Infantis and a sanitation indicator Enterococcus faecalis in composts at different stages of the composting process and during storage. Methods and Results: The studied pathogenic and indicator strains, originally isolated from compost, were inoculated into compost samples from the various stages of the composting process. During incubation, indigenous microflora diversity was monitored with DGGE analysis. After 90 days of incubation, strain survival was observed in compost sampled before the beginning of the cooling phase, and DGGE analysis demonstrated an increase of microbial diversity up to the cooling phase. However, inoculated strains were not detected in composts after 30, 60 or 90 days of incubation in compost sampled after the start of the cooling phase. Microbial diversity also became stable, and DGGE profiles reached a maximum number of bands at this stage. Conclusions: Strain survival was not observed in stabilized composts. The cooling phase seems to be the turning point for pathogen survival and at this stage the indigenous microflora appeared to play a significant role in suppression. Significance and Impact of the Study: The importance of indigenous microflora in the survival of pathogens in four different composts was demonstrated. Stabilized composts were recommended for spreading on land.     

Physical degradation of wheat straw by the in-vessel and windrow methods of mushroom compost production

Mushroom compost manufacturers in Ireland are moving away from the traditional outdoor phase I windrow method, favouring in-vessel production. Composters and growers have reported better quality compost with faster spawn run and higher yields produced by this process. In the present study, physical examination of samples highlighted differences when comparing the windrow and in-vessel methods of compost production. Observations using scanning electron microscopy suggest that the cuticle of wheat straw from in-vessel production is damaged during phase I, peeling away from the surface in fragments, and exposing the epidermis. Changes in silicon levels on the straw surface acted as a marker for cuticle damage when comparing both composting systems. Cuticle damage may be important during composting and afterwards, as substrate colonisation is faster, and consequently spawn run is shorter. The phase I compost microbial community is altered by the in-vessel technique, producing a predominantly thermophilic bacterial flora in contrast to the mesophilic and thermophilic bacteria and fungi found in windrow phase I compost. These differences may be significant in mushroom compost production.     

Changes in Bacterial and Fungal Communities across Compost Recipes,Preparation Methods,and Composting Times

Compost production is a critical component of organic waste handling, and compost applications to soil are increasingly important to crop production. However, we know surprisingly little about the microbial communities involved in the composting process and the factors shaping compost microbial dynamics. Here, we used high-throughput sequencing approaches to assess the diversity and composition of both bacterial and fungal communities in compost produced at a commercial-scale. Bacterial and fungal communities responded to both compost recipe and composting method. Specifically, bacterial communities in manure and hay recipes contained greater relative abundances of Firmicutes than hardwood recipes with hay recipes containing relatively more Actinobacteria and Gemmatimonadetes. In contrast, hardwood recipes contained a large relative abundance of Acidobacteria and Chloroflexi. Fungal communities of compost from a mixture of dairy manure and silage-based bedding were distinguished by a greater relative abundance of Pezizomycetes and Microascales. Hay recipes uniquely contained abundant Epicoccum, Thermomyces, Eurotium, Arthrobotrys, and Myriococcum. Hardwood recipes contained relatively abundant Sordariomycetes. Holding recipe constant, there were significantly different bacterial and fungal communities when the composting process was managed by windrow, aerated static pile, or vermicompost. Temporal dynamics of the composting process followed known patterns of degradative succession in herbivore manure. The initial community was dominated by Phycomycetes, followed by Ascomycota and finally Basidiomycota. Zygomycota were associated more with manure-silage and hay than hardwood composts. Most commercial composters focus on the thermophilic phase as an economic means to insure sanitation of compost from pathogens. However, the community succeeding the thermophilic phase begs further investigation to determine how the microbial dynamics observed here can be best managed to generate compost with the desired properties.     

不同培养料和发酵次数栽培巴氏菇比较

分别以玉米秸秆和稻草为培养料栽培巴氏菇,对菌丝生长性状进行对比;同时,在我国传统发酵栽培方法的基础上,将三次发酵法与二次发酵法进行了对比。试验结果表明:利用玉米秸秆栽培的巴氏菇在发菌速度及子实体质量和产量上均优于稻草;培养料经过3次发酵更适宜巴氏菇生长。经过3次发酵的玉米秸秆培养料栽培的巴氏菇产量和生物学效率分别为7.7 kg/m2和27.5%,子实体粗蛋白含量44.89%,可溶性糖含量44.01%,18种氨基酸总量31.70%,明显高于2次发酵的玉米秸秆培养料及2次、3次发酵的稻草培养料。     

静态好氧高温牛粪堆肥中nirK型反硝化细菌群落动态变化

【背景】堆肥过程中,不同反硝化微生物相互作用产生大量气态氮,不仅导致氮素流失使得堆肥肥效降低,而且造成环境污染。但是目前关于堆肥中反硝化细菌群落结构变化,尤其是群落结构与堆肥理化因子间相关性方面的报道较为欠缺。【目的】对堆肥中反硝化细菌进行研究,旨在揭示反硝化细菌群落动态变化,为深入理解堆肥氮循环机理提供科学数据。【方法】设计一种静态好氧高温堆肥技术处理牛粪和水稻秸秆,利用高通量测序技术研究堆肥中nirK型反硝化细菌群落组成的动态变化,并分析优势反硝化细菌菌属与理化指标之间的相关性。【结果】堆肥全程共17d,各项堆肥理化指标以及生物学指标表明堆肥已经基本腐熟。高通量测序结果表明,在堆肥的不同阶段nirK型反硝化细菌群落结构差异显著。门水平上,堆肥中反硝化细菌属于变形菌门(Proteobacteria)和一未分类门;目水平上,优势类群主要属于根瘤菌目(Rhizobiales)、红杆菌目(Rhodobacterales)和伯克氏菌目(Burkholderiales),其中根瘤菌目(Rhizobiales)的种类最多,而伯克氏菌目(Burkholderiales)的相对丰度最高。Spearman相关性分析表明未分类门的反硝化细菌和未分类科根瘤菌目的反硝化细菌与全碳、碳氮比、含水率以及pH呈显著负相关(P0.05),与凯氏氮和硝态氮呈显著正相关(P0.05);其他优势菌属与全碳、碳氮比、含水率以及pH呈显著正相关(P0.05),与凯氏氮和硝态氮呈显著负相关(P0.05);未分类科伯克氏菌目的反硝化细菌、未分类纲变形菌门的反硝化细菌、产碱杆菌科的Pusillimonas属和副球菌属(Paracoccus)与铵态氮显著相关(P0.05)。【结论】静态好氧高温堆肥技术可以缩短堆肥周期。在堆肥的不同阶段nirK型反硝化细菌群落结构差异显著,并且该菌群落结构的变化受到堆肥理化因子的显著影响。本研究有助于揭示堆肥中氮素转化规律,并为改进堆肥工艺提供理论依据。     

Variations of culturable thermophilic microbe numbers and bacterial communities during the thermophilic phase of composting

Composting is a process of stabilizing organic wastes through the degradation of biodegradable components by microbial communities under controlled conditions. In the present study, genera and species diversities, amylohydrolysis, protein and cellulose degradation abilities of culturable bacteria in the thermophilic phase of composting of cattle manure with plant ash and rice bran were investigated. The number of culturable thermophilic bacteria and actinomyces decreased with the increasing temperature. At the initiation and end of the thermophilic phase, genera and specie diversities and number of bacteria possessing degradation abilities were higher than during the middle phase. During the thermophilic composting phase, Bacillus, Geobacillus and Ureibacillus were the dominant genera, and Geobacillus thermodenitrificans was the dominant species. In later thermophilic phases, Geobacillus toebii and Ureibacillus terrenus were dominant. Bacillus, at the initiation, and Ureibacillus and Geobacillus, at the later phase, contributed the multiple degradation abilities. These data will facilitate the control of composting in the future.     

Bio-degradation of olive mill wastewater sludge by its co-composting with agricultural wastes

The use of maize straw (MS) or cotton waste (CW) as bulking agents in the composting of olive mill wastewater (OMW) sludge was compared by studying the organic matter (OM) mineralisation and humification processes during composting and the characteristics of the end products. Both composts were prepared in a pilot-plant using the Rutgers static-pile system. The use of CW instead of MS to compost OMW sludge extended both the thermophilic and bio-oxidative phases of the process, with higher degradation of polymers (mainly lignin and cellulose), a greater formation of nitrates, higher total nitrogen losses and a lower biological nitrogen fixation. The CW produced a compost with a more stabilised OM and more highly polymerised humic-like substances. In the pile with CW and OMW sludge, OM losses followed a first-order kinetic equation, due to OM degradation being greater at the beginning of the composting and remaining almost constant until the end of the process. However, in the pile with MS and OMW sludge this parameter followed a zero-order kinetic equation, since OM degraded throughout the process. The germination index indicated the reduction of phytotoxicity during composting.