Kinetics of particulate organic matter removal as a response to bioflocculation in aerobic biofilm reactors.

Recent research has identified that the major fraction of chemical oxygen demand in domestic wastewaters is in particulate form. The research presented herein develops the kinetics of particle removal as a response to bioflocculation at the surface of aerobic biofilms. This study focuses on the removal of particles that are maintained in aqueous suspension after 30 minutes of gravity settling. It is helpful to consider the particulate organics removal process in biofilms as the sum of four steps, namely (1) external transport of the particles to the biofilm surface, (2) bioflocculation, (3) organic particulate hydrolysis, and (4) diffusion and reaction of the solubilized organics by the bacterial cells comprising the biofilm. Organic (native corn starch) and inorganic particle (Min-U-Sil 10 [U.S. Silica Company, Berkeley Springs, West Virginia]) suspensions, with micronutrients, were continuously fed to a rotating disc biofilm reactor to verify a first-order kinetic expression that has been used to describe bioflocculation and to demonstrate that bioflocculation is the primary particle removal mechanism. Extracellular polymeric substances were extracted and quantified to describe the role they play in the bioflocculation process.     

Removal of nitric oxide in a biotrickling filter under thermophilic condition using Chelatococcus daeguensis

The development of a thermophilic biotrickling filter (BTF) system to inoculate a newly isolated strain of Chelatococcus daeguensis TAD1 for the effective treatment of nitric oxide (NO) is described. A bench-scale BTF was run under high concentrations of NO and 8% O2 in thermophilic aerobic environment. A novel aerobic denitrifier Chelatococcus daeguensis TAD1 was isolated from the biofilm of an on-site biotrickling filter and it showed a denitrifying capability of 96.1% nitrate removal rate in a 24 h period in aerobic environment at 50 degrees C, with no nitrite accumulation. The inlet NO concentration fluctuated between approximately 133.9 and 669.6 mg m-3 and kept on a steady NOx removal rate above 80% in an oxygen stream of 8%. The BTF system was able to consistently remove 80-93.7% NO when the inlet NO was 535.7 mg m-3 in an oxygen stream of 2-20%. The biological removal efficiency of NO at 50 degrees C is higher than that at 25 degrees C, suggesting that the aerobic denitrifier TAD1 display well denitrification performance under thermophilic condition. Starvation for 2, 4 and 8 days resulted in the re-acclimation times of Chelatococcus daeguensis TAD1 ranging between 4 and 16 hours. A longer recovery time than that for weekend shutdown will be required when a longer starvation occurs. The results presented here demonstrate the feasibility of biotrickling filter for the thermophilic removal of NOx from gas streams. Implications: A novel denitrifier Chelatococcus daeguensis TAD1 was isolated from an on-site biotrickling filter in aerobic environment at 50 degrees C. To date, C. daeguensis has not been previously reported to be an aerobic denitrifier. In this study, a thermophilic biotrickling filter system inoculated with Chelatococcus daeguensis TADI for treatment of nitric oxide is developed. In coal-fired power plants, influent flue gas stream for nitrogen oxides (NOx) removal typically exhibit temperatures between 50 and 60 degrees C. Traditionally, cooling gases to below 40 degrees C prior to biological treatment is inevitable, which is costly. Therefore, the application ofthermophilic microorganisms for the removal of nitric oxide (NO) at this temperature range would offer great savings and would greatly extend the applicability ofbiofilters and biotrickling filters. Until now there has not been any study published about thermophilic biological treatment of NO under aerobic condition.     

Comparison of two biological treatment processes using attached-growth biomass for sanitary landfill leachate treatment

The objective of this investigation was to compare two biological systems using attached-growth biomass, for treatment of leachates generated in a typical municipal solid waste sanitary landfill. A moving-bed biofilm process, which is a relatively new type of biological treatment system, has been examined. It is based on the use of small, free-floating polymeric (polyurethane) elements, while biomass is being grown and attached as biofilm on the surface of these porous carriers. A granular activated carbon (GAC) moving-bed biofilm process was also tested. This method combines both physico-chemical and biological removal mechanisms for the removal of pollutants. The presence of GAC offers a suitable porous media, which is able to adsorb both organic matter and ammonia, as well as to provide an appropriate surface onto which biomass can be attached and grown. A laboratory-scale sequencing batch reactor (SBR) was used for the examination of both carriers. The effects of different operation strategies on the efficiency of these biological treatment processes were studied in order to optimize their performance, especially for the removal of nitrogen compounds and of biodegradable organic matter. It has been found that these processes were able to remove nitrogen content almost completely and simultaneously, the removal of organic matter (expressed as BOD5 and COD), color and turbidity were sufficiently achieved.     

Removal of nitric oxide in a biotrickling filter under thermophilic condition using Chelatococcus daeguensis

The development of a thermophilic biotrickling ?lter (BTF) system to inoculate a newly isolated strain of Chelatococcus daeguensis TAD1 for the effective treatment of nitric oxide (NO) is described. A bench-scale BTF was run under high concentrations of NO and 8% O₂ in thermophilic aerobic environment. A novel aerobic denitrifier Chelatococcus daeguensis TAD1 was isolated from the biofilm of an on-site biotrickling filter and it showed a denitrifying capability of 96.1% nitrate removal rate in a 24 h period in aerobic environment at 50 °C, with no nitrite accumulation. The inlet NO concentration fluctuated between approximately 133.9 and 669.6 mg m-3 and kept on a steady NOx removal rate above 80% in an oxygen stream of 8%. The BTF system was able to consistently remove 80–93.7% NO when the inlet NO was 535.7 mg m-3 in an oxygen stream of 2–20%. The biological removal efficiency of NO at 50 °C is higher than that at 25 °C, suggesting that the aerobic denitri?er TAD1 display well denitrification performance under thermophilic condition. Starvation for 2, 4 and 8 days resulted in the re-acclimation times of Chelatococcus daeguensis TAD1 ranging between 4 and 16 hours. A longer recovery time than that for weekend shutdown will be required when a longer starvation occurs. The results presented here demonstrate the feasibility of biotrickling ?lter for the thermophilic removal of NOx from gas streams.

Implications A novel denitrifier Chelatococcus daeguensis TAD1 was isolated from an on-site biotrickling filter in aerobic environment at 50 °C. To date, C. daeguensis has not been previously reported to be an aerobic denitrifier. In this study, a thermophilic biotrickling ?lter system inoculated with Chelatococcus daeguensis TAD1 for treatment of nitric oxide is developed. In coal-fired power plants, influent flue gas stream for nitrogen oxides (NO_x) removal typically exhibit temperatures between 50 and 60 °C. Traditionally, cooling gases to below 40 °C prior to biological treatment is inevitable, which is costly. Therefore, the application of thermophilic microorganisms for the removal of nitric oxide (NO) at this temperature range would offer great savings and would greatly extend the applicability of biofilters and biotrickling filters. Until now there has not been any study published about thermophilic biological treatment of NO under aerobic condition.     

Evaluation of Acinetobacter sp. B9 for Cr (VI) resistance and detoxification with potential application in bioremediation of heavy-metals-rich industrial wastewater

Present work demonstrates Cr (VI) detoxification and resistance mechanism of a newly isolated strain (B9) of Acinetobacter sp. Bioremediation potential of the strain B9 is shown by simultaneous removal of major heavy metals including chromium from heavy-metals-rich metal finishing industrial wastewater. Strain B9 tolerate up to 350 mg L^?1 of Cr (VI) and also shows level of tolerance to Ni (II), Zn (II), Pb (II), and Cd (II). The strain was capable of reducing 67 % of initial 7.0 mg L^?1 of Cr (VI) within 24 h of incubation, while in presence of Cu ions 100 % removal of initial 7.0 and 10 mg L^?1 of Cr (VI) was observed with in 24 h. pH in the range of 6.0–8.0 and inoculum size of 2 % (v/v) were determined to be optimum for dichromate reduction. Fourier transform infrared spectroscopy and transmission electron microscopy studies suggested absorption or intracellular accumulation and that might be one of the major mechanisms behind the chromium resistance by strain B9. Scanning electron microscopy showed morphological changes in the strain due to chromium stress. Relevance of the strain for treatment of heavy-metals-rich industrial wastewater resulted in 93.7, 55.4, and 68.94 % removal of initial 30 mg L^?1 Cr (VI), 246 mg L^?1 total Cr, and 51 mg L^?1 Ni, respectively, after 144 h of treatment in a batch mode.     

Degradation of microcystins using immobilized microorganism isolated in an eutrophic lake

The final purpose of our series of studies is to establish a biological removal method of cyanobacteria and their toxic products using immobilized microorganisms that can lyse cyanobacteria and decompose microcystins. To establish the biological removal method in non-point areas and water purification plants, as the first step, we explored bacteria active against the cyanobacterial hepatotoxin microcystin in the present study. Eleven active bacteria were isolated from samples taken from Lakes Tsukui and Sagami, Japan. Among 3 strains (B-9 to B-11) with degradative activity, strain B-9 exhibited the strongest activity. The 16S rDNA sequence of the strain B-9 showed the highest similarity to that of Sphingomonas sp. Y2 (AB084247, 99% similarity). Microcystins-RR and -LR were completely degraded by strain B-9 (SC16) within 1d, which led to an immobilized microorganism with a polyester resin. The degradation of microcystin-RR in a bioreactor using the immobilized strain B-9 was observed and microcystin-RR (> 90%) was completely degraded after 24 h. Microcystin-RR was added to the lake water at regular intervals and the degradation after 24 h was observed in the bioreactor over a 72-d period. An over 80% removal efficiency continued for 2 months, showing that the life of the immobilized B-9 in terms of activity was at least 2 months under the optimized conditions. From these results, this immobilized B-9 is feasible for the practical treatment of microcystins in non-point areas and water purification plants.     

Biodegradation of 2,4,6-trichlorophenol in the presence of primary substrate by immobilized pure culture bacteria

In this study, pure strains that are capable of utilizing 2,4,6-trichlorophenol have been isolated from the mixed culture grown on substrates containing chlorophenolic compounds. Studies have been carried out on the capability of these isolated pure strains in suspended and immobilized forms to decompose 2,4,6-trichlorophenol. Additionally, the influence of primary substrates (e.g., phenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol) on the decomposition of 2,4,6-trichlorophenol by the isolated pure strains grown in immobilized form is also investigated. The results are: Through bacterial isolation and identification, three pure strains have been obtained: Pseudomonas spp. strain 01, Pseudomonas spp. strain 02 and Agrobacterium spp. Whether in suspended or immobilized forms, all strains have poor removal efficiencies of 2,4,6-trichlorophenol. However, addition of 200 mg/l phenol will enable the immobilized Pseudomonas spp. strain 01, and Pseudomonas spp. strain 02 to achieve 65% and 48% removal of 2,4,6-trichlorophenol, respectively. Addition of phenol will assist the immobilized Pseudomonas spp. strain 02 in achieving removal of 2,4,6-trichlorophenol but the removal efficiency is not good if the phenol concentration is too low. The optimum phenol concentration should be between 200 and 400 mg/l.     

The removal of phosphorus during wastewater treatment: a review

Phosphorus removal from wastewater can be achieved either through chemical removal, advanced biological treatment or a combination of both. The chemical removal of phosphorus involves the addition of calcium, iron and aluminium salts to achieve phosphorus precipitation by various mechanisms which are discussed. In addition, the effects of operating conditions, especially wastewater characteristics; sludge production in terms of quality and quantity; optimisation of chemical use and re-use; points of chemical addition combined with biological treatment; alternative chemical/physical treatments and examples of full-scale applications are also reviewed. Biological phosphorus removal is dependent upon the uptake of phosphorus in excess of normal bacterial metabolic requirements and is proposed as an alternative to chemical treatment. Early developments and the postulated removal mechanisms are reviewed; these include either natural chemical precipitation, enhanced biological removal, or a combination of both. The nature of excess biological phosphorus removal in activated sludge wastewater treatment plants is evaluated, considering various operating parameters, bacteriology and process designs.     

1,1-二氯乙烯降解菌的分离鉴定及降解特性

从好氧活性污泥中分离得到一株能以1,1-二氯乙烯(1,1-DCE)作为惟一碳源和能源生长的革兰氏阴性菌株D-B,经鉴定属于产碱杆菌属(Alcaligenessp.)。当维持菌株D-B浓度一定时,1,1-DCE的去除率随着1,1-DCE浓度的增大先增加后降低,且降解过程主要发生在加入1,1-DCE后的3~5 h内。当1,1-DCE的初始浓度为300μg/L时去除率达到最大值85.32%。菌株D-B对1,1-DCE的降解符合Monod方程,饱和常数Ks=21.96 mg/L,1,1-DCE的最大比基质降解速率Vmax=50.76 mg/(L.h)。     

2-Chlorobenzoate biodegradation by recombinant Burkholderia cepacia under hypoxic conditions in a membrane bioreactor.

The feasibility of applying bacterial hemoglobin technology to degrade 2-chlorobenzoate (2-CBA) through co-metabolism under hypoxic conditions in a membrane bioreactor (MBR) process has been studied in the laboratory. 2-chlorobenzoate removal and chloride release rates in the MBR system varied from 99 to 78% and 98 to 73%, respectively, depending on the operation conditions. Chemical oxygen demand (COD) removal efficiencies were more than 90% at food-to-microorganism ratios ranging from 0.32 to 0.62 g/g/d, and the observed yield was 0.13 to 0.20 g biomass/g COD. The bacterial cell-floc size-distribution analysis showed that there is a significant change in bacterial floc size due to high shear stress during operation of the MBR. To characterize growth kinetics of Burkholderia cepacia strain dinitrotoluene, a mathematical model that describes co-metabolic oxidation of 2-CBA in an MBR has been developed.     

CAS-BT复合反应器同步脱氮除磷试验研究

在CAST反应器中引入自制悬浮填料,构成了CAS-BT复合反应器,采用人工配制废水,对其同步脱氮除磷效果进行了试验研究.试验结果表明,当TN为178.05 mg/L、TP为28.32 mg/L时,CAS-BT工艺取得了很好的同步脱氮除磷效果,TN和TP的去除率分别达到97.55%和98.10%.进行同步脱氮除磷时,CAS-BT比其他的水处理工艺更具优势.     

降解SO_2功能菌的16S rRAN基因测序及降解特性

用低浓度SO2诱导驯化方法获得高效脱硫菌群,并用分离培养与16S rRNA基因测序技术相结合的方法鉴定菌群种属,分析驯化过程中种群结构的动态变化,同时研究分离纯菌种的脱硫性能。结果表明,从诱导驯化7 d和14 d菌液中分别分离出23株菌和22株菌,16S rRNA序列分析发现这些菌归属于13个种,其中有6个种（Rhodococcus erythropolis、Pseudomonas putida、Microbacterium oxydans、Sphingomonas koreensis、Acinetobacter junii、Acinetobacter johnsonii）对SO2-3有较强的降解能力,并在持续驯化过程中稳定的生长传代,降解产物以硫酸根为主,还有极少量的单质硫。与含混合菌的驯化菌液降解SO2-3的能力相比,单一脱硫菌的脱硫性能较弱。脱硫功能菌株及其基本特性的研究为微生物处理SO2烟气提供了丰富的菌源信息和理论基础。     

Ozone oxidation and aerobic biodegradation with spent mushroom compost for detoxification and benzo(a)pyrene removal from contaminated soil

The combination of ozonation and spent mushroom compost (SMC)-mediated aerobic biological treatment was investigated in the removal of benzo(a)pyrene from contaminated soil. The performances of the process alone and combined were evaluated in terms of benzo(a)pyrene removal efficiency, mineralization efficiency (as total organic carbon removal), and soil residual toxicity (phytotoxicity to Lepidium Sativum and toxicity to Vibrio fischeri). In spite of the removal efficiency (35%) obtained by SMC-mediated biological process as a stand-alone treatment, the combined process showed a benzo(a)pyrene concentration reduction higher than 75%; the best removal (82%) was observed after 10 min pre-ozonation treatment. In particular, ozonation improved the biodegradability of the contaminant, as confirmed by the increase of CO(2) production (close to 70% compared to the control), mineralization (greater than 60%) and bacterial density (which increased by two orders of magnitude). Moreover, according to phytotoxicity tests on L. Sativum, the aerobic biological process of pre-ozonated soil decreased toxicity. According to the results achieved in the present study, ozonation pre-treatment showed an high potential to overcome the limitation of bioremediation of recalcitrant compound, but it should be carefully operated in order to maximize PAH removal efficiency as well as to minimize soil residual toxicity which can result from the formation of the oxidation intermediates.     

沸石滤料曝气生物滤池启动性能研究

沸石滤料曝气生物滤池 (ZBAF)对氨氮的去除包括生物硝化和离子交换两种作用。中试装置启动试验表明 ,初期对氨氮的去除以离子交换作用为主 ,末期以硝化作用为主 ,不能以氨氮总去除率达到稳定作为启动过程结束的标志 ,而应以氨氮硝化去除率达到稳定作为标志。沿程试验表明 ,硝化细菌对沸石的“生物再生功能” ,实质是已被沸石交换的氨氮被水中浓度较大的其他阳离子交换下来后 ,被硝化菌所利用的现象 ;沸石表面有生物膜时 ,仍具有交换氨氮能力     

采油废水厌氧处理系统的微生物群落特征

为了深入认识石油烃的厌氧降解过程,利用分子生物学技术分析了大庆油田采油废水处理系统厌氧池和进水中的微生物群落特征。基于DGGE和克隆文库的分析结果均表明,厌氧生物膜中存在的古菌源自于采油废水。厌氧生物膜和采油废水中的古菌主要是产甲烷菌,包括嗜甲基的Methanomethylovorans thermophila和利用氢和甲酸的Methanolinea tarda。值得注意的是,氢营养型的M.tarda在厌氧生物膜中得到了富集。进水和厌氧生物膜中的细菌群落结构明显不同。进水中的主要细菌类群为Epsilonproteobacteria,而生物膜中的主要类群为Nitrospira和Deltaproteobacteria。在厌氧生物膜中发现许多与产甲烷古菌(尤其是氢营养型产甲烷菌)协同降解石油烃类物质的细菌相关克隆:其中一个克隆与Syntrophus具有较高的同源性,该类菌是产甲烷菌介导的厌氧烃降解微生物区系中的关键细菌;许多Deltaproteobacteria克隆属于group TA类群,该类群细菌主要参与芳香族化合物产甲烷菌介导的厌氧降解过程。这些结果表明,在大庆油田采油废水厌氧处理系统中已经建立起由产甲烷菌所介导的厌氧石油烃降解的微生物区系。     

Cr(VI) sorption by free and immobilised chromate-reducing bacterial cells in PVA–alginate matrix: equilibrium isotherms and kinetic studies

Chromate-resistant bacterial strain isolated from the soil of tannery was studied for Cr(VI) bioaccumulation in free and immobilised cells to evaluate its applicability in chromium removal from aqueous solution. Based on the comparative analysis of the 16S rRNA gene, and phenotypic and biochemical characterization, this strain was identified as Paenibacillus xylanilyticus MR12. Mechanism of Cr adsorption was also ascertained by chemical modifications of the bacterial biomass followed by Fourier transform infrared spectroscopy analysis of the cell wall constituents. The equilibrium biosorption analysed using isotherms (Langmuir, Freundlich and Dubinin–Redushkevich) and kinetics models (pseudo-first-order, second-order and Weber–Morris) revealed that the Langmuir model best correlated to experimental data, and Weber–Morris equation well described Cr(VI) biosorption kinetics. Polyvinyl alcohol alginate immobilised cells had the highest Cr(VI) removal efficiency than that of free cells and could also be reused four times for Cr(VI) removal. Complete reduction of chromate in simulated effluent containing Cu²⁺, Mg²⁺, Mn²⁺ and Zn²⁺ by immobilised cells, demonstrated potential applications of a novel immobilised bacterial strain MR12, as a vital bioresource in Cr(VI) bioremediation technology.     

Identification and molecular characterization of a Bacillus subtilis IS13 strain involved in the biodegradation of 4,5,6-trichloroguaiacol

4,5,6-Trichloroguaiacol (4,5,6-TCG) is a recalcitrant organochlorine compound produced during pulp bleaching and a potential environmental hazard in paper mill effluents. We report here the identification by biochemical tests and molecular biological analysis, using 16S ribotyping, of a 4,5,6-TCG-degrading bacterium, identified as a strain of Bacillus subtilis that is most closely related according to the phylogenetic analysis to B. subtilis strain Lactipan (alignment score 99%). Biodegradation of 4,5,6-TCG by this organism in a mineral salts medium was shown to occur only when the inoculum was composed of cells in the stationary phase of growth and to be accelerated by an additional carbon source, such as glucose, sucrose, glycerol or molasses. An additional nitrogen source (as ammonium sulfate) did not affect the rate of 4,5,6-TGC removal. No plasmids were detected in the bacterial cells. This is the first strain of B. subtilis which degrades chlorophenols and shows that 4,5,6-TCG is not degraded by cometabolism and that the gene encoding this characteristic is probably located on the chromosome. The lack of requirement for additional nitrogen source, the ability to enhance biodegradation by adding cheap carbon sources such as molasses, and the fact the trait is likely to be stable since it is encoded on the cell chromosome, are all characteristics that make the organism an attractive possibility for treatment of wastes and environments polluted with organochlorine compounds.     

Effects of oxalic acid on the regrowth of heterotrophic bacteria in the distributed drinking water

Three laboratory-scale water pipe systems were set up to study the effects of adding oxalic acid on the bacterial regrowth and biofilm formation in the distributed drinking water. The results of water pipe experiment displayed that around 38% carbon in the oxalic acid could be converted to bacterial biomass. The maximum HPCs in biofilm were equal to 3.5x10(4), 3.38x10(5) and 2.8x10(6) CFUcm(-2) while the maximum HPCs of free bacteria were equal to 1.2x10(3), 2.54x10(3) and 3.78x10(4) CFUml(-1) for the blank and with addition of 10 and 50 micrograms OA eq-Cl(-1), respectively. These results imply that the addition of oxalic acid to distributed water has positive effect on the assimilable organic carbon content of drinking water and bacterial regrowth in water pipe. This effect is enhanced with addition of high-level oxalic acid. Batch tests were also conducted using water samples collected from a Taiwanese drinking water distribution system. The bacterial regrowth potentials (BRPs) of the blank were equal to 4.25x10(3), 1.46x10(4), 4.9x10(4) and 7.54x10(4) CFUml(-1) for water samples collected from treatment plant effluent, commercial area, mixed area, and residential area, respectively. These results show that the biological stability of distributed drinking water is the highest in treatment plant effluent, the moderate in the commercial area and mixed area, and the lowest in the residential area.     

从矿区土壤中筛选微生物对Pb^2＋、Zn^2＋吸附的研究

从铅锌矿区土壤中分离到12株细菌和10株真菌,通过其干菌体对Pb^2＋和Zn^2＋的吸附试验,筛选出具有较强生物吸附能力的细菌菌株B6和真菌菌株F1。探讨了pH值、吸附时间、菌量和Pb^2＋、Zn^2＋的初始浓度对B6和F1菌株的吸附影响,结果表明：2株菌对Pb^2＋、Zn^2＋吸附是一个快速的过程,pH值为5.0-6.0是菌体吸附的较适范围。Pb^2＋、Zn^2＋初始浓度在150-300 mg/L内,B6和F1菌株吸附效果明显。当B6菌株的菌量超过0.1 g,F1菌株的菌量超过0.2 g后吸附率趋于平缓。应用Langmuir和Freundlich吸附等温线研究,Langmuir吸附等温线更为适合模拟B6和F1菌株的吸附过程。B6和F1菌株吸附Pb^2＋、Zn^2＋的动力学过程都可以用准二级动力学方程进行描述。16S rDNA基因序列分析表明,B6菌株属于里拉微球菌（Micrococcus lylae）。用形态及理化特征鉴定,F1菌株属于镰刀霉菌属（Fusarium sp.）。     

Evaluation of Saccharomyces cerevisiae strains as probiotic agent with aflatoxin B(1) adsorption ability for use in poultry feedstuffs

In this study the aflatoxin B(1) (AFB(1)) removal capacity, the tolerance to salivary and gastrointestinal conditions, autoaggregation and coaggregation with pathogenic bacteria of Saccharomyces cerevisiae strains isolated from broiler feces, were evaluated. Only four of twelve isolated strains were identified as Saccharomyces cerevisiae using molecular techniques. The results obtained in AFB(1) binding studies indicated that the amount of AFB(1) removed was both strain and mycotoxin-concentration dependent. Therefore, a theoretical model was applied in order to select the most efficient strain to remove AFB(1) in a wide range of mycotoxin concentration. The results indicated that S. cerevisiae 08 and S. cerevisiae 01 strains were the most efficient microorganisms in the mycotoxin removal. Viability on simulated salivary and gastrointestinal conditions was investigated and S. cerevisiae 08 strain showed the best results, achieving 98% of total survival whereas S. cerevisiae 01 reached only 75%. Autoaggregation and coaggregation assays showed S. cerevisiae 08 as the most appropriate strain, mainly because it was the unique strain able to coaggregate with the four bacterial pathogens assayed. Consequently, S. cerevisiae 08 is the best candidate for future in vivo studies useful to prevent aflatoxicosis. Further quantitative in vitro and in vivo studies are required to evaluate the real impact of yeast-binding activity on the bioavailability of AFB(1) in poultry. However, this study could be useful in selecting efficient strains in terms of AFB(1) binding and provide an important contribution to research into microorganisms with potential probiotic effects on the host.