Biohydrogen production from cattle wastewater by enriched anaerobic mixed consortia: influence of fermentation temperature and pH

Experiments were conducted to select a natural mixed microflora seed source and investigate the effect of temperature and pH on fermentative hydrogen (H2) production from cattle wastewater by sewage sludge. Sewage sludge was shown to have higher cumulative H2 production than other inoculum collected from cow dung compost, chicken manure compost, and river sludge. Experimental results show that H2 production from cattle wastewater was significantly affected by both pH and temperature of the culture. The maximum H2 yield was obtained at pH 5.5. H2 yield and the ratio of butyrate/acetate (Bu/Ac) followed a similar production trend, suggesting that butyrate formation might favor H2 production. The optimal temperature for H2 production from cattle wastewater was 45 degrees C with peak values of H2 production (368 ml), hydrogen yield of 319 ml H2/g chemical oxygen demand (COD) consumed, and butyrate/acetate ratio of 1.43. Presence of ethanol and propionic acid indicated decreased hydrogen production; their concentrations were also affected by pH and temperature. A modified Gompertz model adequately described H2 production and bacterial growth.     

Emission factors of carbon monoxide and size-resolved aerosols from biofuel combustion

This study reports emission factors of carbon monoxide and size-resolved aerosols from combustion of wood, dung cake, and biofuel briquette in traditional and improved stoves in India. Wood was the cleanest burning fuel, with higher emissions of CO from dung cake and particulate matter from both dung cake and briquette fuels. Combustion of dung cake, especially in an improved metal stove, resulted in extremely high pollutant emissions. Instead, biogas from anaerobic dung digestion should be promoted as a cooking fuel for public health protection. Pollutant emissions increased with increasing stove thermal efficiency, implying that thermal efficiency enhancement in the improved stoves was mainly from design features leading to increased heat transfer but not combustion efficiency. Compared to the traditional stove, the improved stoves resulted in the lower pollutant emissions on a kW h-1 basis from wood combustion but in similar emissions from briquette and dung cake. Stove designs are needed with good emissions performance across multiple fuels. Unimodal aerosol size distributions were measured from biofuel combustion with mass median aerodynamic diameters of 0.5-0.8 micron, about a factor of 10 larger than those from fossil fuel combustion (e.g. diesel), with potential implications for lung deposition and health risk.     

Forms of sulphur in sheep excreta and their fate after application on to pasture soil

Sheep were fed ³⁵S-labelled grass/clover herbage and the excreta was collected. About 74% of excretal S was in the form of urine and the remainder was in dung. Sulphate-S accounted for 74% of the urine S and the remainder was in Hi-reducible form. In dung, 80% of the S was C-bonded organic S and 20% was present as sulphate-S. ³⁵S-labelled dung was applied to undisturbed pasture microplots and the degradation and S release followed over a 9 month period under glasshouse conditions. During the first 34 days about 24% of ³⁵S was leached from the dung, mainly as sulphate-S and possibly some labile organic S. The C-bonded S in the dung was notably resistant to mineralisation. Only 14% of the applied ³⁵S was recovered by pasture plants. ³⁵S-labelled urine with either a high (1130 mg S litre^?1) or a low S concentration (280 mg S litre^?1) was applied in the field and its fate followed over a 10 month period. During the experiment 57 and 79% of the applied ³⁵S was recovered in pasture herbage in the high and low urine treatments, respectively. ³⁵S was also incorporated into soil organic matter and this reached a peak about 120 days after urine application when 52 and 30% of applied S had been incorporated in the high and low urine S treatments, respectively. With time, these levels declined as about 50% of the organic ³⁵S was mineralised and subsequently absorbed by the pasture plants. The results demonstrate that excreted S is recycled rapidly in pasture soils when it originates from urine. However, the bulk of S in dung appears to be relatively inert at least over a 9 month period.     

Evaluation of the hygienic quality of raw milk based on the presence of bifidobacteria: the cow as a source of faecal contamination

Fifty-eight samples of raw milk from three different farms were examined for the presence of bifidobacteria. Isolates were identified and compared with bifidobacteria isolated from dung of the cows that provided the milk. Of the raw milk samples, 88% harboured Bifidobacterium pseudolongum subsp. globosum, as did 95% of the dung samples.     

A screening level index for assessing the impacts of veterinary medicines on dung flies

Veterinary parasiticides are administered to livestock to control a wide range of parasites. Following excretion, these substances may persist in the environment and impact nontarget organisms. This paper describes a simple screening-based index for predicting the effects of veterinary parasiticides on dung flies using data on parasiticide toxicity, animal husbandry, and parasiticide use. The utility of the index has been assessed, at the farm scale for a number of dipteran species, using data from a survey of farms in England and insect ecology and ecotoxicological data. The results indicate that a large proportion (35%) of parasiticide treatments in England will have no impact on dung fly populations. In terms of individual parasiticides, the macrocyclic lactone doramectin was predicted to have the highest impact on English dipteran populations with a maximum reduction in the population of horn flies on one farm of 28%. Ivermectin pour-on had the next highest impact (6.8%), followed by eprinomectin (6.4%), and ivermectin injection (4.1%). Due to a lack of data, it was not possible to assess the effects of the benzimidazole parasiticides (oxfendazole and fenbendazole), morantel and permethrin. The approach is simple, nondata-intensive and has the potential to be a valuable tool for use in environmental risk assessment or management of new and existing veterinary parasiticides.     

Fatty acids and proximate composition of eight Thai edible terricolous insects

Fatty acid composition and proximate analysis of eight terricolous insects namely dung beetle (Copris nevinsoni Waterhouse), short tailed cricket (Brachytrupes portentosus Lichtenstein), june beetle (Holotrichia sp.), queen caste (Oecophylla smaragdina Fabricius), weaver ant (Oecophylla smaragdina Fabricius), termite (Termes sp.), longan stink bug (Tessaratoma papillosa), cicada (Meimuna opalifera Walker) were determined. Polyunsaturated fatty acid (PUFA) was the most predominant fatty acid found in all analyzed insects, followed by saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA). The concentration of total PUFA ranged from 213 in cicada to 1514 mg/100 g in dung beetle. There were five PUFAs; 18:3n ? 3, 20:3n ? 6, 20:4n ? 6, 20:5n ? 3 and 22:6n ? 3 detected in the insect samples. Two fatty acids, 20:3n ? 6, and 20:4n ? 6 were found in all analyzed insects, while, 20:5n ? 3 was only detected in dung beetle which lives in herbivore faeces, at concentration of 300 mg/100 g accounted for 13% of total fatty acid. The SFA content in ranged from 234 in termite to 733 mg/100 g in dung beetle. Only one MUFA, 18:1 was detected in the all analyzed insects. The protein content of insects ranged from 37% in queen caste to 54% in dung beetle. The highest amount of carbohydrate (16%) was found in cicada. Lipid contents ranged from 5% in june beetle to 37% in queen caste, while ash contents of edible insects ranged from 2% in queen caste to 12% in june beetle. We suggest that the insect could be considered as a good nutritional food source especially for fat and protein.     

粘细菌发酵生产新型微生物药物的初步研究

通过在家兔粪粒上诱导出子实体,转接到固体培养基中,使之发展为菌落,再挑取菌落边缘的培养物来分离纯化粘细菌。在利用纤维堆囊菌发酵生产埃坡霉素(Epothilone)的工艺中,添加环式糊精到发酵培养基中,并在获得的发酵液中添加吸附树脂,简化了产物的提取工艺。     

有机肥在红地球葡萄上的肥效对比试验

2003年和2004年连续两年在济南平阴绿色园艺场以‘绿源'生物有机肥、‘杨康'微生物有机肥和羊粪对红地球葡萄(Vitis vinifera cv.Red Globe)进行了施肥对比试验,结果表明:与不施有机肥的对照相比,三种肥料均不同程度地改善了红地球葡萄的营养生长和果实品质,但肥效作用特点不同,施用‘杨康'微生物有机肥明显提高了盛花期叶柄含氮量,提高了单穗重和产量;施用羊粪显著提高了转色期叶柄磷的含量,采收后叶片光合能力亦较强,表现了肥效的滞后性;施用‘绿源'生物有机肥的叶片光合能力最高,能维持较高的叶柄钾含量,果实糖度提高,转色、成熟期明显提前.     

Nutritional requirements of Volvariella speciosa (Fr. Ex. Fr.) Singer,a Nigerian edible mushroom

Nutritional requirement studies were carried out on synthetic and semi-synthetic media, as well as different agro-industrial wastes, to evaluate vegetative growth of Volvariella speciosa (Fr. Ex. Fr.) Singer, a Nigerian edible mushroom. The optimum temperature that supported the best growth of this fungus was 30 °C while the optimum pH was 6.0. The moisture contents were observed to vary with different substrates. The best vegetative growth was obtained at 40% moisture content, on sawdust, while it was 80% on Andropogon gianus straw. Among the different media used, the best mycelial extension (92.0 mm) was observed on semi-synthetic, potato dextrose agar while the least growth (74.0 mm) was recorded on laboratory formulated sorghum agar. Maize and A. gianus straw stimulated the best mycelial extension (92.0 mm) while fresh and fermented horse dung supported moderate growths of 70.0 and 67.0 mm, respectively. The least growth (36.0 mm) was observed on fresh cow dung. These findings are discussed in relation to the cultivation of V. speciosa in Nigeria.     

斑蝥黄质分子在大鼠体内代谢中的几何异构体组成变化

目的:观察斑蝥黄质分子在雄性大鼠体内代谢过程中的几何异构体组成变化。方法:选择体重250g±10g的雄性SD大鼠,一次灌胃1mL斑蝥黄质与豆油混合物(1.75mg斑蝥黄质/mL),4h后收集其血清、肝脏及粪便,萃取其中的斑蝥黄质组分,在酸性乙腈-水(流动相A)和MTBE(流动相B)流动相梯度洗脱中,用C30-HPLC-PDA对萃取物进行分离,检测其几何异构体的组成。结果:斑蝥黄质分子几何异构体在本项研究中所采用的C30-HPLC条件下可以获得良好的分离。检测结果表明:在大鼠体内的消化、吸收、血液运输和肝脏代谢中,未发现斑蝥黄质分子几何异构体比例的明显变化。     

重离子诱变对木聚糖酶产生菌产酶的影响

以1株由青藏高原牦牛粪中分离出的链霉菌为出发菌株,该菌株在发酵培养基中能产生胞外木聚糖酶(3 227.346 U/mL)。以此菌株为出发菌株,对其进行重离子辐照诱变处理,从大量突变株中筛选出木聚糖酶高产菌株SZ10-7,其酶活力达到5 338.42 U/mL,与出发菌株相比较,突变株SZ10-7的酶活力提高了1.65倍。对突变株SZ10-7的发酵条件进行了优化研究,结果表明,该菌株的木聚糖酶活力得到进一步提高,达到5 850.20U/mL,其最适发酵条件为:培养基(g/100 mL)为玉米芯∶麸皮(体积比1∶1)5,酵母膏0.8,K2 HPO4.3H2 O 0.1,MgSO4.7H20 0.5,NaCl 0.3,pH 7.0,培养温度25℃振荡培养时间96 h,实验结果表明,重离子辐照诱变技术是一种有效的微生物诱变育种新技术。     

不同原料堆制有机肥腐殖酸的化学组成与结构特征

采用元素分析、傅立叶变换红外光谱（FT-IR）、固体¹³C核磁共振（NMR）以及电镜扫描技术,对3种不同物料堆积的有机肥（T1,玉米杆：牛粪：菜籽饼=60：50：30;T2,玉米杆：废次烟草：牛粪：菜籽饼=35：25：40：30;T3,烟秆：废次烟叶：猪粪：菜籽饼=30：30：40：30）中腐殖酸的化学组成与结构特征进行了初步研究。结果显示：（1）不同有机肥中腐殖酸的C、H、N、O的含量均表现为T3 > T2 > T1;（2）FT-IR分析显示,T3样品中腐殖酸的双键H和苯环H较T1、T2样品多;T2样品在1050 cm^-1处的吸收强度相对较强;1710 cm^-1处的吸收峰T3样品最明显,含有羧基和羰基官能团最多,T1样品中最少。（3）固体¹³C-NMR分析结果显示,脂肪碳（δ0~50）含量T3样品最高,含氧脂肪碳（δ50~110）含量T1样品最高,芳香碳（δ110~160）含量T2样品最高,δ160~230的羧基碳和羰基碳含量表现为T2=T3 > T1;（4）电镜扫描结果显示,3种腐殖酸颗粒的表面具有维管状结构和孔隙,维管结构数量表现为T3 > T2 > T1,孔隙数量则表现为T1 > T2 > T3。以上结果表明,3种腐殖酸的化学组成与结构特征有着明显差异。     

基质对葡萄胚培苗移栽成活率的影响

研究了不同杂交组合在不同基质条件下的胚培苗移栽成活率。结果表明:在草炭:蛭石:园土:马粪(5:1:1:1),附加200g蔬菜壮苗母剂的母质中成活率达到了84%以上。并分析了影响成活率的原因。     

Process for recycling waste aluminum with generation of high-pressure hydrogen

An innovative environmently friendly hydrolysis process for recycling waste aluminum with the generation of high-pressure hydrogen has been proposed and experimentally validated. The effect of the concentration of sodium hydroxide solution on hydrogen generation rate was the main focus of the study. In the experiments, distilled water and aluminum powder were placed in the pressure-resistance reactor made of Hastelloy, and was compressed to a desired constant water pressure using a liquid pump. The sodium hydroxide solution was supplied by liquid pump with different concentrations (from 1.0 to 5.0 mol/dm3) at a constant flow rate into the reactor by replacing the distilled water, and the rate of hydrogen generated was measured simultaneously. The liquid temperature in the reactor increased due to the exothermic reaction given by Al + OH(-) + 3H2O = 1.5H2 + Al(OH)4(-) + 415.6 kJ. Therefore, a high-pressure hydrogen was generated at room temperature by mixing waste aluminum and sodium hydroxide solution. As the hydrogen compressor used in this process consumes less energy than the conventional one, the generation of hydrogen having a pressure of almost 30 MPa was experimentally validated together with Al(OH)3, a useful byproduct.     

Removal of headspace CO2 increases biological hydrogen production

For biological hydrogen production by fermentation to be a useful method of hydrogen generation, molar yields of hydrogen must be increased. While heat treatment of a soil inoculum increases hydrogen yields by preventing loss of hydrogen to methanogenesis, hydrogen is still lost to acetic acid generation from hydrogen and CO2. To reduce hydrogen losses via acetogenesis, CO2 concentrations in the headspace were substantially reduced during hydrogen production using a chemical scavenger (KOH). CO2 in the headspace was decreased from 24.5% (control) to a maximum of 5.2% during the highest gas production phase, resulting in a hydrogen partial pressure of 87.4%. This reduction in CO2 increased the hydrogen yield by 43% (from 1.4 to 2.0 mol of H2/mol of glucose). The soluble byproducts in all tests consisted primarily of acetate and ethanol. Higher concentrations of ethanol (10.9 mM) remained in solution from bottles with CO2 removal than in the control (1.2 mM), likely as a result of hydrogen inhibition of biological ethanol conversion to acetic acid. These results show that hydrogen production can be increased by removing CO2 in the reactor vessel, likely as a result of suppression of acetogenesis.     

Fermentation patterns of whole banana waste liquor with four inocula

Fermentation of whole banana waste liquor was carried out under controlled microbial conditions. Four different inocula, two axenic, one mixed, and one mixed heterogeneous inoculum (cow dung) at two different ratios, 1 : 1 and 4: 1 of banana-liquor culture medium were studied in non-aseptic conditions. The fermentation process was evaluated by measuring sugar consumption, lactic acid, ethanol and volatile fatty acids production. The ratio 1 : 1 in two of the axenic cultures showed homolactic fermentation while the ratio 4: 1 in the axenic inocula resulted in heterolactic fermentation. In the mixed inoculum for both ratios the fermentation was heterolactic. The fermentation was homolactic for both ratios with the mixed heterogeneous inoculum. Fermentation of sugar in whole banana waste using the mixed heterogeneous inoculum appeared to be better than with either the axenic or mixed inocula because lactic acid was the main product of fermentation.     

Hydrogen Peroxide Production by Lactobacillus delbrueckii Subsp. Lactis I at 5°C

Cells of Lactobacillus delbrueckii subsp. lactis I produced hydrogen peroxide at 5°C in sodium phosphate buffer (0.2M, pH 6.5) with or without glucose. However, if the cells were starved by preincubation in buffer alone, glucose or sodium lactate were necessary to cause hydrogen peroxide production at 5°C. Hydrogen peroxide production by nonstarved cells was confirmed to be in part due to a NADH oxidase. The production of hydrogen peroxide by starved cells in buffer plus glucose in the early stage of incubation was associated with the production of a small portion of lactic acid which disappeared upon further incubation. Additional experiments revealed that hydrogen peroxide was produced in buffer containing sodium lactate added in place of glucose. Results suggested the presence of a lactate oxidase in the organism which used D-lactate to produce hydrogen peroxide.     

西藏牦牛粪和乳源中益生菌的筛选与鉴定

采用钙透明圈法从西藏地区牦牛粪和乳源中分离、筛选益生菌，通过形态观察及分子生物学技术进行菌种鉴定，并对其生长特性、产酸能力、耐胆盐、酸、人工胃液能力及抑制大肠杆菌能力进行分析。结果表明，共分离、筛选出25株乳酸菌，经鉴定7株为益生菌，分别为1株植物乳杆菌（Lactobacillus plantarum），2株鼠李糖乳杆菌（Lactobacillus rhamnosus）和4株副干酪乳杆菌（Lactobacillus paracaseium）。其中植物乳杆菌B2具有良好的生长优势、产酸能力（发酵终pH值在4左右）、耐酸（pH值为4）、耐胆盐（0.6%）、耐人工胃液能力（存活率为57.4%），且抑制大肠杆菌效果较好（抑菌圈直径为22.0 mm）。     

过氧化物-氨溶液对松木的脱木素作用

介绍了用过氧化物-氨溶液对松木进行氧化脱木素,研制出的一种新型生产纸浆和含氮有机肥料方法,用过氧化氢(H2O2)-氨(NH3)溶液对松木进行脱木素,3%~9%H2O2和10%NH3溶液蒸煮松木,结果纸浆得率54.6%,纸浆中残留木素含量1.1%。通过动力学一级反应方程式讨论了H2O2-氨溶液对松木的脱木素作用是令人满意的。     

Dung treated by high-temperature composting is an optimal bedding material for suckling calves according to analyses of microbial composition,growth performance,health status,and behavior

Bedding materials are important for suckling buffalo calves. Treated dung has been used as a bedding material for dairy cows but the lack of an appropriate safety assessment limits its application. In this study, we evaluated the feasibility of treated dung (TD) as a bedding material for suckling calves by comparing TD with rice husk (RH) and rice straw (RS) bedding materials. The TD was prepared through high-temperature composting by Bacillus subtilis. Thirty-three newborn suckling buffalo calves (Bubalus bubalis, 40.06 ± 5.79 kg) were randomly divided into 3 bedding material groups (TD, RH, and RS) and bedded with 1 of the 3 bedding materials for 60 d. We compared cost, moisture content, bacterial counts, and microbial composition of the 3 bedding materials, and investigated growth performance, health status, behavior, rumen fermentation, and blood parameters of bedded calves. The results showed that TD contained the fewest gram-negative bacteria and coliforms on d 1 and 30 and the lowest relative abundance of Staphylococcus throughout the experiment. The RH and TD bedding materials had the lowest cost. Calves in the TD and RS groups showed a higher dry matter intake, and final body weight and average daily gain in the TD and RS groups tended to be higher than in the RH group. Calves in the TD and RS groups had a lower disease incidence (diarrhea and fever), fewer antibiotic treatments, and lower fecal score than calves in the RH group. Higher contents of IgG, IgA, and IgM were observed in calves of the TD and RS groups than in calves of the RH group on d 10, indicating higher immune ability in TD and RS groups. Furthermore, TD bedding increased the butyric acid content in the calf's rumen, whereas RS bedding increased the acetate content, which might be attributed to the longer time and higher frequency of eating bedding material in the RS group. Considering all of the above indicators, we concluded that TD is the optimal bedding material for calves based on economics, bacterial count, microbial diversity, growth performance, and health status. Our findings provide a valuable reference for bedding material choice and calf farming.