Production of hard-type cheese using free or immobilized freeze-dried kefir cells as a starter culture

This study provides a contribution to hard-type cheese starter culture production through the use of a freeze-dried culture in the ripening of hard-type cheeses. The effect of initial cell concentration, ripening temperature, and cell immobilization of kefir on the degree of openness, mold spoilage, microbial associations, physicochemical characteristics, and aroma-related compounds was studied. Use of kefir starter cultures resulted in cheese with an increased shelf life and resistance to spoilage as compared to control cheeses without kefir inoculants. Furthermore, the freeze-dried kefir culture improved aroma, taste, and texture characteristics while increasing the degree of openness in comparison to traditional hard-type cheese products. The kefir culture resulted in an increase in counts of total aerobic bacteria, yeasts and molds, lactococci, and lactobacilli until the 15th day of ripening. From then on, only lactobacilli counts increased, reaching levels up to 9.17 log CFU/g in cheeses ripened at 5 degrees C using freeze-dried kefir cells immobilized on casein. SPME-GC/MS analysis revealed major differences in volatile composition, especially with regard to alcohols (up to 75%), carbonyl compounds (up to 75%), and esters (up to 64%) between cheeses made with kefir cells and cheeses made without kefir inoculants.     

Isolation and characterization of three novel peptides from casein hydrolysates that stimulate the growth of mixed cultures of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus

In this study, sodium caseinate hydrolysates produced by papain with strong growth-stimulating activity for Streptococcus thermophilus (St) and Lactobacillus delbrueckii subsp. bulgaricus (Lb) were obtained. A series of separation methods including ultrafiltration, macroporous adsorption resin chromatography, gel filtration chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC) were applied to isolate and purify the peptide(s), which were mainly responsible for the activity. Finally, three novel growth-stimulating peptides, H-2-A, F2-c, and F2-b, corresponding to amino acid residues 29-35 and 103-108 of bovine α(S2)-casein and 181-186 of bovine α(S1)-casein, respectively, were obtained. With supplementation of H-2-A, F2-b, or F2-c at a protein concentration of 0.3%, the biomass yield of these two lactic acid bacteria (LAB) was enhanced by 193.3, 166.7, or 151.7%, respectively. In addition, there were significant (p < 0.05) increases in viable counts of St and lactic acid production of LAB in the presence of the purified peptides.     

马链球菌兽疫亚种类M蛋白亚单位疫苗小鼠免疫效果评价

马链球菌兽疫亚种旧名马腺疫链球菌，多年来是引致我国猪链球菌病的主要病原。链球菌类M蛋白是一种二聚体丝状蛋白，C端为保守区域锚在细胞膜上并跨越整个细胞壁，与其它革兰氏阳性菌的表面蛋白有结构上的同源性。类M蛋白和荚膜多糖都有抗吞噬细胞的吞噬作用，有利于细菌在动物机体中生存和繁殖㈦。链球菌类M蛋白是一种良好的     

Evaluation of wood ash disposal on agricultural land. I. Potential as a soil additive and liming agent

Abstract

This study evaluated wood ash as an agricultural fertilizer and liming material. Winter wheat (Triticwn aestivum) and poplar (Populus sp.) were grown in a greenhouse on six different Idaho soils amended with different ash concentrations. At ash levels equal to or lower than 2%, no detrimental plant growth effects were observed. In fact, the biomass of the wheat and the caliper and height of the poplar cuttings increased more at 2% ash (40 mt/ha) than with the control soil. These results suggest that wood ash could be used in agricultural applications as a low analysis fertilizer containing K and/or a liming agent. Land application of wood ash could be less expensive and more environmentally sound than present landfilling practices.     

Evaluation of fly ash as a soil amendment for the Atlantic Coastal Plain: II. Soil chemical properties and crop growth

Crop yields in the Atlantic Coastal Plain of the U.S.A. are limited by the low moisture-holding capacities of the sandy soils common to the region. Corn was grown in a Hammonton loamy sand soil amended with fly ash (0, 5, 10, 20, 30, and 40%) to determine if the ash rates required to improve soil moisture holding capacity would adversely affect plant growth, or soil and plant levels of nutrients and heavy metals. Fly ash increased soil test levels of P, K, Ca, Mg, Mn, Cu, Zn, B, Cd, Cr, Ni, and Pb. Nutrient concentrations in plants grown in the ash-amended soils, except P, Mn, and B, remained within established sufficiency ranges. The 20 and 40% ash rates increased soil soluble salt (EC) levels from 0.2 to 1.1–1.5 and 1.7–2.1 mmho cm^?1, soil pH from 5.6 to 6.0–6.4 or 6.3–6.9, and extractable B from 0.2 to 2.2–5.9 and 2.2–9.0 mg kg^?1. Fly ash reduced corn germination, delayed seedling emergence, and reduced root and shoot dry weights. Plant B concentrations at the 40% ash rate were in the phytotoxic range (136–189 mg kg^?1). Management practices that allow for pre-leaching of B and soluble salts will likely be required to attain satisfactory corn growth in ash-amended soils.     

Evaluation of fly ash as a soil amendment for the Atlantic Coastal Plain: I. Soil hydraulic properties and elemental leaching

A major limitation to crop yields in the Atlantic Coastal Plain is drought stress caused by the low moisture-holding capacities of the coarse-textured soils common to the area. Because coal fly ash is comprised primarily of silt and clay-sized particles, it has the potential, if applied at high enough rates, to permanently change soil texture and increase moisture holding capacity. A series of soil column studies were conducted to evaluate the effects of high rates of fly ash on soil hydraulic properties and elemental leaching of trace metals and boron. Fly ash from two Delaware power plants (EM=Edgemoor and IR=Indian River) was incorporated in a Hammonton loamy sand (fine-loamy, siliceous, mesic, Typic Hapludults) at six rates (0, 5, 10, 20, 30, and 40%, by weight). The effect of fly ash on soil moisture holding capacity, hydraulic conductivity, and wetting front velocity was determined. Leachates from columns amended with 30% fly ash were analyzed for B, Cd, Ni, Pb, Cu, and Zn. Soil moisture holding capacity was increased from 12% in the soil alone to 25% in the soil amended with 30% fly ash. Boron and soluble salts leached rapidly from ash amended soils while only trace quantities of Cd, Ni, Pb, Cu, and Zn were detected in column leachates.     

Enzyme-linked immunosorbent assay based on a polyclonal antibody for the detection of the insecticide fenitrothion. Evaluation of antiserum and application to the analysis of water samples.

For development of an indirect competitive enzyme-linked immunosorbent assay (ELISA) for the organophosphorus insecticide fenitrothion, the specificity of the antiserum R-3 generated with the bifunctional hapten, LysMNPA (2-[[[(3-methyl-4-nitrophenyl)oxy]methylcarbonyl]amino]-6-(2,4-dinitrophenyl)aminohexanoic acid) and the application to the residual analysis of some water samples were evaluated. At optimized ELISA conditions, the quantitative working range was from 1 to 39 ng/mL with a limit of detection of 0.3 ng/mL and an IC(50) value of 6 ng/mL. Cross-reactivity to structurally similar organophosphorus compounds and related chemicals was determined. The antiserum R-3 showed significant cross-reactivity with fenitrooxon and 3-methyl-4-nitrophenol, which have a 3-methyl-4-nitrophenoxy group as common structures, but showed relatively low cross-reactivity with other compounds. Each water sample (river water, tap water, purified water, and bottled water) had a matrix effect and was investigated by adding Tween 20 in the assay buffer. These four kinds of water samples were fortified with fenitrothion at several concentration levels and were directly analyzed with only dilution with an equal volume of antiserum solution. The mean recovery was 105.9%, and the mean coefficient of variation was 10.9%. The results suggested that the developed ELISA would be very suitable for a preliminary screening for fenitrothion in water samples at such low levels.     

Effects of conventional and organic (manure) fertilization on soil,plant tissue nutrients and berry yields in vineyards. The use of the original native soil as a control

The effects of conventional and organic (manure) fertilization on soils of vineyards were examined in the area of Nemea in southern Greece. The soil properties of the adjacent natural environment (maquis), which served as a control (considering the land use changes as treatments), were also examined and compared with those of the vineyards. The null hypothesis was that there was no difference among them. The results rejected the null hypothesis. It was found that the maquis top soil had the highest C concentration than both types of vineyards and the organic vineyard had significantly higher C concentration than the conventional one. The organic soil N followed the same pattern. The vine leaves (blades) in the conventional vineyards had significantly higher concentrations of Ca, Mg, Mn, and Zn. The average values of Mg and Zn concentrations in leaves in the organic vineyards were below the suggested ranges for nutrient sufficiency in vines and for this reason a foliar application of Mg and Zn is recommended for the organic vineyards. The average berry yield was significantly higher in the conventional vineyards.