Evaluation of thermophilic fungal consortium for paddy straw composting

Out of 10 thermophilic fungi isolated from wheat straw, farm yard manure, and soil, only three showed highest cellobiase, carboxymethyl cellulase, xylanase, and FPase activities. They were identified as Aspergillus nidulans (Th₄), Scytalidium thermophilum (Th₅), and Humicola sp. (Th₁₀). A fungal consortium of these three fungi was used to compost a mixture (1:1) of silica rich paddy straw and lignin rich soybean trash. The composting of paddy straw for 3 months, during summer period in North India, resulted in a product with C:N ratio 9.5:1, available phosphorus 0.042% and fungal biomass 6.512 mg of N-acetyl glucosamine/100 mg of compost. However, a C:N ratio of 10.2:1 and highest humus content of 3.3% was achieved with 1:1 mixture of paddy straw and soybean trash. The fungal consortium was effective in converting high silica paddy straw into nutritionally rich compost thereby leading to economical and environment friendly disposal of this crop residue.     

Quality evaluation of co-composted wheat straw, poultry droppings and oil seed cakes

Poultry droppings, neem cake, castor cake, jatropha cake and grass clippings were used separately as organic nitrogen additives to decrease the high C:N ratio of wheat straw. Composting was carried out aerobically in presence of fungal consortium developed by including Aspergillus awamori, Aspergillus nidulans, Trichoderma viride and Phanerochaete chrysosporium. The degraded product was characterized to assess the technical viability of organic nitrogen supplements as well as fungal consortium in improving the quality of compost and hastening the process of decomposition of high lignocellulolytic waste. Evaluation of maturity showed that mixture of wheat straw, poultry dropping and jatropha cake had the lowest C:N ratio of 10:1, the highest humic acid fraction of 3.15%, the lowest dehydrogenase activity and a germination index exceeding 80% in 60 days of decomposition. Inoculated and grass clipping amended wheat straw–poultry dropping mixture resulted in compost with highest humus content of 11.8% and C:N ratio of 13.5, humic acid fraction of 2.84% and germination index of 59.66%. Fungal consortium was effective in improving the humus content of all the composted mixtures. In some treatments, germination index could not be correlated with C:N ratio. Non edible oil seed cake supplemented substrate mixtures did not respond to fungal inoculation as far as C:N ratio was concerned.     

Effect of fungal consortium and animal manure amendments on phosphorus fractions of paddy-straw compost

The study was conducted to reveal the type of phosphorus (P) fractions present in mature compost prepared by co-composting paddy straw (P.S) with cattle manure (CM), farm yard manure (FYM) and poultry manure (PM), each added separately as nitrogen (N) and P source. A consortium of phytate mineralizing fungi developed by including Aspergillus niger ITCC 6719, Aspergillus flavus ITCC 6720 and Trichoderma harzianum ITCC 6721 was applied for recovery of P from plant and animal residues. Chemical evaluation of compost after 4 months of aerobic decomposition revealed that inoculation improved the sodium bicarbonate-extractable P content of CM and FYM supplemented P.S compost by 32.3% and 23.5% respectively compared with their respective un-inoculated control. However, the peak values for water soluble-P fractions were recorded in CM–straw compost followed by PM–straw compost. Fungal inoculation also improved the agronomic quality of PM–straw compost as the latter had the highest total P content and lowest C:N and E4/E6 ratio of 18:1 and 5.36:1 respectively. The recovery of organic P from agricultural residue has the potential to reduce the application of synthetic P fertilizer. P-enriched organic manure can offer potential environment and economic benefits to farmers under sustainable agriculture.     

葡萄籽对猪粪秸秆高温堆肥中微生物群落与碳氮含量的影响

以猪粪与秸秆(鲜质量10.5∶1)为基础,在自制的强制通风静态堆肥反应箱中进行堆肥化试验,研究添加8%葡萄籽对猪粪秸秆高温堆肥中微生物群落演替和碳氮转化的影响.在堆肥化的30 d里,分7次采集不同时期的堆肥样品,测定堆肥中微生物区系、微生物生理群的数量及堆肥碳氮含量.结果表明：添加葡萄籽使堆肥中细菌数量略高、放线菌数量显著增加、真菌数量明显降低,细菌/放线菌下降;氨化细菌和反硝化细菌数量降低;而硝化细菌、固氮菌和纤维素分解菌数量增多;铵态氮和有机碳含量下降,而硝态氮含量明显提高.堆肥中硝态氮含量与放线菌数量呈极显著正相关关系.添加葡萄籽使堆体升温快且高温期稳定,堆肥含水率波动较小,从而使堆肥高温期放线菌和亚硝化细菌的波动较小,数量较高,有利于堆肥中硝态氮含量的增加.     

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。     

Co-composting of PAH-contaminated soil with poultry manure

AIMS: To investigate the effects of co-composting poultry manure with soil contaminated with different concentrations of polycyclic aromatic hydrocarbons (PAHs), on the degradation of selected PAHs in a static-pile compost system. METHODS: Mispah form (Food & Agricultural Organisation, FAO : lithosol) soil contaminated with PAHs was co-composted with poultry manure for 19 months. The soil was mixed with wood chips in a ratio of 1:1 to improve aeration and then mixed with poultry manure in a ratio of 4:1. A data logger measured temperature monthly. Residual concentrations of selected PAHs in the compost were determined monthly by gas chromatography/flame ionisation detection (GC/FID). Moisture, pH, ash content and C:N ratios were also monitored monthly. Microbial activity was measured by measuring CO(2) evolution. CONCLUSIONS: The results obtained in this experiment have shown that co-composting poultry manure with PAH-contaminated soil is capable of removing large concentrations of high molecular weight PAH from contaminated soil to levels below 1 mg kg(-1) in 19 months. SIGNIFICANCE AND IMPACT OF THE STUDY: The paper adds to the body of knowledge necessary for the development of a cost effective technology for the remediation of soil contaminated with high molecular weight PAHs by providing information on the behaviour of selected PAHs and factors such as nutrient ratio, temperature and pH during composting.     

Influence of straw types and nitrogen sources on mushroom composting emissions and compost productivity

The effects of different straw types and organic and inorganic nitrogen (N) sources on the chemical composition and odor concentration (OC) of mushroom composting emissions, compost parameters, and mushroom yield were examined using bench-scale and large-scale (windrows and aerated tunnels) composting systems. There were close correlations between the butanol or combined H₂S+dimethyl sulfide (DMS) concentration and OC of air samples taken from different composting ingredients (r=0.83 and 0.76–0.87, P<0.01, for log_e-transformed data). Differences in N availability, in terms of NH₃ and N losses during composting, were found between different N sources. Materials in which the N was less available (chipboard and digester wastes, cocoa shells, ammonium sulfate) produced lower mushroom yields than materials in which the N was more readily available (poultry manure, urea, brewers' grains, hop and molasses wastes, cocoa meal). Replacement of poultry manure with the other N sources at 50–100% or wheat straw with rape, bean, or linseed straw in aerated tunnel or windrow composts reduced the OC and emissions of odorous sulfur-containing compounds, but also reduced yield. Urea and cocoa meal may be suitable for “low odor” prewetting of straw, with addition of poultry manure immediately before aerated tunnel composting. Rape straw in compost reduces the formation of anaerobic zones and resulting odorous emissions, since it maintains its structure and porosity better than wheat straw. Journal of Industrial Microbiology & Biotechnology (2002) 29, 99–110 doi:10.1038/sj.jim.7000292 Received 08 January 2002/ Accepted in revised form 20 June 2002     

Chemical transformation,phytotoxicity and nutrient availability in progressive composting stages of wheat straw

Chemical maturity parameters in addition to plant growth limiting factors have been monitored in the course of a 2-month composting experiment. Wheat straw with 5% dry w horse manure was adjusted to C/N= 45 with urea. The pile was rotated and homogeneous samples were taken every four days. The most intense changes in straw fractions occurred in the first 20 days of composting, as suggested by wet chemical analyses, thermogravimetry and ¹³C NMR spectrometry. Nevertheless, plant response to compost application gave significant changes at between 20–60 days that were not clearly reflected by the above techniques. Glasshouse experiments with a soil treated with compost samples taken at the successive transformation stages suggested no linear correlation between composting time and the potential of compost in improving plant yield. In the samples taken after 20 days in the conditions studied, referred to as postmature composts, the ryegrass yield did not depend on most of the organic matter characteristics, but closely paralleled the concentration of available nitrogen and – to lesser extent – phosphorous in the compost. The probable immobilization of these elements in the course of composting was also suggested by plant response experiments with different doses of compost and the addition or not of mineral solution.     

Stimulation of environmentally controlled mushroom composting by polysaccharidases

Polysaccharidases adsorbed on commercial amylodextrins were added to environmentally controlled composts of straw plus poultry manure. After 5 days of composting at 48°C, microbial enzyme activities and numbers of bacteria were higher in the treated compost than in the control. During the next phase at 80°C, between days 5 and 6, more C and N were solubilized in the treated compost. After introducing a microbial inoculum on day 6, and maintaining the substrate at 48°C, colonization by bacteria was faster in the treated compost and consequently, more fibre was degraded. Differences between composts in yields of Agaricus bisporus after 5 weeks of cropping were not significant (P=0.05).The authors are with INRA, Station de Recherches sur les Champignons, BP 81, 33883 Villenave d'Ornon, France     

Factors influencing chemical quality of composted poultry waste

The need for organic recycling is justified in the case of poultry waste because after ensuring hygienization there is a chance of obtaining a compost with substantial fertilizer value. Organic recycling of slaughter waste has its justification in sustainable development and retardation of resources. In the research being described, composting of hydrated poultry slaughterhouse waste with maize straw was carried out. Combinations with fodder yeast and postcellulose lime were also introduced in order to modify chemical and physicochemical properties of the mixtures. The experiment was carried out within 110 days in 1.2 × 1.0 × 0.8 m laboratory reactors. Temperature of the biomass was recorded during composting, and the biomass was actively aerated through a perforated bottom.Composting of substrates selected in such a way caused losses of some elements in gaseous form, an increase in concentration of other elements, and changes in relationships between elements. The ability to select substrates influences compost quality. This ability is determined by chemical indicators. Among other things, compost evaluation based on carbon to nitrogen ratio shows the intensity of the composting process and possible nitrogen losses. The addition of slaughter waste to maize straw reduced the content of individual fractions of carbon in the composts, whereas the addition of postcellulose lime intensified that process. The addition of fodder yeast significantly increased the phosphorus content in the compost. Since iron compounds were used in the processing of poultry carcasses, composts that were based on this material had an elevated iron content. The applied postcellulose lime significantly increased the copper, zinc, chromium, nickel, and lead contents. Proper selection of substrates for composting of hydrated poultry slaughterhouse waste allows to obtain a compost with chemical properties that create favorable conditions for natural application of that compost. Addition of large quantities of postcellulose lime to the composting process leads to obtaining an organic-mineral substratum for cultivation or to obtaining an agent that improves soil properties.     

Chemical and biological changes during composting of different organic wastes and assessment of compost maturity

Changes in organic C, total N, C:N ratio, activities of cellulase, xylanase and protease, and microbial population were determined during composting of different organic wastes such as mixture of sugarcane trash and cattle dung, press mud, poultry waste and water hyacinth biomass. There were losses of N in poultry waste and water hyacinth with the effect an initial increase in C:N ratio was observed which decreased later on due to decomposition. The activities of cellulase, xylanase and protease were maximum between 30 and 60 days of composting in various wastes. Similar trend was observed with respect to mesophilic bacterial and fungal population. Various quality parameters like C:N ratio, water soluble C (WSC), CO(2) evolution and level of humic substances were compared after 90 day composting. There was statistically significant correlation between C:N ratio and CO(2) evolution, WSC and humic substances. Significant correlation between CO(2) evolved and level of humic substances was also observed. The study shows that no single parameter can be taken as an index of compost maturity. However, C:N ratio and CO(2) evolved from finished compost can be taken as the most reliable indices of compost maturity.     

Composting of de-inking paper sludge with poultry manure at three nitrogen levels using mechanical turning: behavior of physico-chemical parameters.

De-inking paper sludge (DPS) is rich in carbon (C) but poor in nitrogen (N). Thus, it has a high C:N ratio which limits the composting process. Accordingly, the goal of this study was to investigate the effect of three N treatments on DPS composting. Compost piles of 100 m3 were formed by mixing raw DPS with poultry manure and chicken broiler floor litter, giving on average 0.6%, 0.7% and 0.9% total N. The changes in physico-chemical parameters, total weight and fiber losses, and maturity of composting piles of DPS were monitored during 24 weeks. The compost piles had a neutral to alkaline pH throughout the study. Inorganic N decreased whereas organic N increased over time for all treatments. These changes in magnitude were different among N treatments resulting in a final total N content of 0.9% for the 0.6% N treatment whereas final total N contents of 0.7% and 0.9% N were measured for the 0.7% and 0.9% N treatments. The total weight, cellulose and hemicellulose losses were higher in 0.6% N treatment giving the lowest C:N ratio after 24 weeks of composting. However, none of the 24 week-old composts of DPS were mature based on their final C:N ratio and colorimetric test of maturity. Except for copper, their final total trace element contents meet most known standards or guidelines for organic soil conditioners. Overall, 0.6% N treatment was the best to enhance DPS composting using mechanical turning, but a period of more than 24 weeks was required to reach compost maturity.     

Effect of low initial C/N ratio on aerobic composting of swine manure with rice straw

Two pilot composting experiments were conducted to investigate the effect of low initial C/N ratio on the composting of swine manure with rice straw by measuring physical and chemical parameters. The results showed that the thermophilic duration of bin 1 and bin 2 was long enough to satisfy the sanitary standard, and swine manure could reach maturity. Bin 1 containing larger amount of swine manure and less amount of rice straw showed a higher nitrogen loss (8%), shorter thermophilic phase, and longer maturity time (about 2 weeks) than bin 2. However, economical analysis showed a lower initial C/N ratio (20) could reduce 172 kg rice straw per ton fresh swine manure than a higher C/N ratio (25), and more swine manure could also be treated. Therefore, a low initial C/N ratio (20) could be suggested in the composting of swine manure with rice straw.     

Composting of poultry manure and wheat straw in a closed reactor: optimum mixture ratio and evolution of parameters

The main objectives of this work were to investigate the evolution of some principal physico-chemical properties (temperature, carbon dioxide, oxygen, ammonia, pH, electrical conductivity, organic matter) and microbial population (mesophilic and thermophilic bacteria and fungi) during composting poultry manure with wheat straw in a reactor system, and to evaluate the optimum mixture ratio for organic substrate production. The experiments were carried out in four small laboratory reactors (1 l) and one large reactor (32 l) under adiabatic conditions over 14 days. During the process the highest temperature was 64.6°C, pH varied between 7.40 and 8.85, electrical conductivity varied between 3.50 and 4.31 dS m⁻¹ and the highest value of organic matter (dry weight) degradation was 47.6%. Mesophilic bacteria and fungi predominated in the beginning, and started the degradation with generation of metabolic heat. By increasing the temperature in reactors, the number of thermophilic microorganisms also increased, which resulted in faster degradation of substrate. The application of a closed reactor showed a rapid degradation of manure/straw mixture as well as a good control of the emissions of air polluting gases into atmosphere. The results showed that the ratio of manure to straw 5.25:1 (dry weight) was better for composting process than the other mixture ratios.     

微生物菌剂对猪粪堆肥中细菌群落结构的影响

以猪粪和小麦秸秆做堆肥试验,处理组添加外源微生物菌剂,利用常规方法对堆肥样品进行理化性状测定,采用高通量测序技术分析堆肥过程中细菌群落特征。理化性状测定结果表明: 添加外源菌剂可延长堆肥高温时间,降低堆肥发酵末期的pH,增加全氮含量,加快C/N的下降。主成分分析表明: 外源菌剂影响堆肥样品细菌群落的稳定性。门分类水平上,厚壁菌门、变形菌门和绿弯菌门的相对丰度在处理组中较高;纲分类水平上,梭状芽孢杆菌纲、α-变形菌纲和γ-变形菌纲在处理组的升温期和高温期相对丰度增加;科分类水平上,小单孢菌科和梭状芽孢杆菌纲的消化链球菌科、梭菌科以及盐厌氧菌科的相对丰度在处理组的升温期和高温期均呈上升趋势。Pearson相关性分析表明,盐胞菌属与外源菌剂呈显著正相关,而氨苄芽孢杆菌属与外源菌剂呈显著负相关。研究表明,猪粪堆肥中添加外源菌剂可使堆肥的理化性质和细菌群落结构均发生显著变化。     

Co-composting of oil exhausted olive-cake, poultry manure and industrial residues of agro-food activity for soil amendment

The co-composting of exhausted olive-cake with poultry manure and sesame shells was investigated. These organic solid wastes were watered by the confectionary wastewater which is characterized by its high content of residual sugars raising its COD. Four aerated windrows were performed to establish the effects of confectionary by-products on the compost process. Different mixtures of the agro-industrial wastes were used. During the composting process, physico-chemical parameters (temperature, moisture, pH, electrical conductivity, total carbon and total nitrogen) were studied. The stability of the biological system was noticed after 70 days. The final products were characterized by their relatively high organic matter content, and low C/N ratio of 14-17. The humidification of the windrows with the wastewater seemed to have accelerated the composting process in comparison to a windrow humidified with water. In addition, the organic matter degradation was enhanced to reach 55-70%. The application of the obtained composts to soil appeared to significantly improve the soil fertility. Indeed, field experiments showed an increase in potato yield; the production was 30.5-37.5 tons ha(-1), compared to 30.5 tons ha(-1) with farm manure.     

畜禽粪便堆肥过程中各种氮化合物的动态变化及腐熟度评价指标

对不同畜禽粪便在堆肥过程中各种含氮化合物的动态变化进行了研究,结合综合性腐熟度评价指标——种子发芽指数（GI）,探讨了畜禽粪便堆肥过程中与氮有关的腐熟度评价指标.结果表明：随着堆肥的进行,除奶牛粪外,其它畜禽粪便的全氮（TN）含量均呈先下降而后平稳变化趋势,奶牛粪则呈先增加而后平稳变化趋势;各种畜禽粪便中,碱解性氮（HN）含量先增后降;NH₄⁺-N含量先下降而后保持平稳;NO₃^- -N含量则持续增加;NH₄⁺ -N/NO₃^- -N迅速降低.堆肥腐熟度指标中,除综合性评价指标GI值外,HN/TN和NH₄⁺ -N/TN也可作为评价畜禽粪便腐熟程度的优选指标,而NO₃^- -N/TN只能作为一般性评价指标.根据综合性评价指标GI值达到腐熟要求的标准（GI>0.50）,除仔猪粪外,其它畜禽粪便在HN/TN<20.77％、NH₄⁺ -N/TN<10.06％及NO₃^- -N/TN>0.38％时基本达到腐熟要求.     

Validation of thermal composting process using olive mill solid waste for industrial scale cultivation of Agaricus bisporus

The production of a substrate containing destoned olive mill solid waste for the cultivation of Agaricus bisporus (Lange) Imbach on an industrial scale was studied. A standard mushroom compost (C) mainly made from straw and poultry manure was compared with the experimental compost (EC) containing the same ingredients as (C) but with added olive mill solid waste (10.6% w/w). Microbial indicators such as counts of heterotrophic microbes and actinomycetes were higher in EC than in C. In addition, compost selectivity as indicated by higher mushroom yield and biological efficiency of EC was higher than that of C. Market quality of the mushrooms produced in both C and EC were comparable. These findings support our work that olive mill solid waste can be used safely in thermal composting process to produce a selective substrate for industrial-scale cultivation of A. bisporus. This study also demonstrates an environmentally sustainable system to manage solid waste from olive oil extraction processes thus overcoming environmental pollution brought about by irrational disposal of the waste on farm lands.     

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.     

猪粪和稻草对镉污染黄泥土生物活性的影响

通过培养试验研究了猪粪和稻草对Cd污染黄泥土生物活性的影响,结果表明,Cd污染土壤的生物活性下降,施用有机肥料后,土壤有效态Cd含量降低,降幅约为40％;微生物量C、N、P和脱氢酶、过氧化氢酶的活性增高,增幅为30％～100％,其中微生物量C、N与土壤有效态Cd之间有显著的负相关关系,可作为污染土壤的生物指标。