The Manufacture of Cheddar Cheese Using Vacuum Concentrated Milks

The United States (US) cheese industry has grown rapidly in the past decade. From 1971 to 1981, milk fat utilization for cheese manufacture increased from 17.7 to 27.6% of the total US milk fat supply, accompanied by a 49% increase in sales of cheese per capita (34). Offsetting substantial increases in sales and prices for cheeses, there have been marked increases in the cost of labor, energy, waste treatment, raw materials, and equipment. Hence, the manufacturers are realizing narrower profit margins. As a survival mechanism, cheesemakers have sought to maximize cheese yields per unit of milk, since increases in cheese yields logically would lead to increased profits. Actually, however, cheesemakers have observed decreases in product yields during the past 20 to 30 yr. This decrease is primarily due to milk producers breeding and feeding for higher milk production, as there is an inverse relationship between volume of milk produced and solids content (60). From 1971 to 1981, annual milk production per cow in the US increased from 4423 to 5510 kg (9,751 to 12,147 lb), accompanied by a decrease in solids. It follows that solids content will continue to decrease as milk production per cow increases (16). Obviously, there is a direct relationship between milk solids content and cheese yields per 100 kg of milk. Research abroad has indicated cheese yields can be increased by vacuum concentrating milk prior to cheesemaking (26). Vacuum concentration is the process by which milk is heated to boiling under a vacuum and water removed as water vapor. Boiling is .achieved at a lower temperature due to the reduced pressure on the milk under vacuum. This lower temperature treatment causes less protein degradation than would occur by boiling off the water at normal atmospheric pressure and resultant higher temperature. Other researchers have found vacuum concentration resulted in greater retention of milk fat in cheese (25). The process can also lead to increased productivity, since more cheese can be produced in the same equipment without an increase in labor. Whey processing costs are also decreased, as there is less whey volume from concentrated milks that are made into cheese compared to the whey from unconcentrated milk made into cheese. Increasingly important, with motor fuel prices on the increase, is the economic advantage of concentrating milk before shipping over long distances (5). Hauling costs are reduced since a tanker carries more solids per load, with less money spent to transport water. Although there are reports (11, 21) of preconcentration of milk by ultrafiltration for cheesemaking in the US, few research reports were found on vacuum concentration for this purpose. Ultrafiltration equipment tends to be large, requiring more floor space than vacuum concentration equipment. Ultrafiltration equipment is also limited in its capacity, in relation to that of vacuum concentration. Moreover, many dairy plants already have vacuum concentration equipment. Too, although ultrafiltration is legal for the manufacture of processed cheese, it is currently not legal for cheddar cheese manufacture. Hence, with indications of increased cheese yields and greater productivity, it seemed practical to investigate the potentials of vacuum concentration of milk for cheesemaking, primarily cheddar cheese manufacture, while also determining whether the resultant cheese was comparable or superior to cheese as normally made from fluid milk

1,3,4,6-Tetramethyl-1,4-dihydro-1,2,4,5-tetrazine, C_6H_(12)N_4

M_r =140∙19, monoclinic, P2_1/n, a = 10∙612(3), b=6∙820(1), c= 10∙975 (2) Å, β=95∙31(2)°, V=790.9(5) Å^3, Z=4, D_m=1.13(5) (flotation), D_x = 1∙177 g cm^(-3), Mo Kα, λ = 0.71073 Å, μ= 0.848 cm^(-1), F(000) = 304, T= 295 K, R = 0∙077 for 704 observed reflections. This potentially antiaromatic or homoaromatic ring system has a flattened boat conformation with both N-methyls in equatorial positions. Bond angles and distances (excluding H's) predicted to be symmetry equivalent exhibit variations of 0.002-0.014 Å and 0.0-2.0°. Substantial delocalization of the electron lone pairs of N(1) and N(4) is found

Identification, cloning and characterization of SpEX exotoxin produced by Staphylococcus pseudintermedius

Staphylococci have evolved numerous strategies to evade their hosts’ immune systems. Some staphylococcal toxins target essential components of host innate immunity, one of the two main branches of the immune system. Analysis of the Staphylococcus pseudintermedius secretome using liquid chromatography mass spectrometry guided by genomic data, was used to identify an S. pseudintermedius exotoxin provisionally named SpEX. This exoprotein has low overall amino acid identity with the Staphylococcus aureus group of proteins named staphylococcal superantigen like proteins (SSLs) and staphylococcal enterotoxin- like toxin X (SEIX), but predictive modeling showed that it shares similar folds and domain architecture to these important virulence factors. In this study, we found SpEX binds to complement component C5, prevents complement mediated lysis of sensitized bovine red blood cells, kills polymorphonuclear leukocytes and monocytes and inhibits neutrophil migration at sub-lethal concentrations. A mutant version of SpEX, produced through amino acid substitution at selected positions, had diminished cytotoxicity. Anti-SpEX produced in dogs reduced the inhibitory effect of native SpEX on canine neutrophil migration and protected immune cells from the toxic effects of the native recombinant protein. These results suggest that SpEX likely plays an important role in S. pseudintermedius virulence and that attenuated SpEX may be an important candidate for inclusion in a vaccine against S. pseudintermedius infections

Characterization of a leukocidin identified in Staphylococcus pseudintermedius

Bacterial infections from Staphylococcus pseudintermedius are the most common cause of skin infections (pyoderma) affecting dogs. Two component pore-forming leukocidins are a family of potent toxins secreted by staphylococci and consist of S (slow) and F (fast) components. They impair the innate immune system, the first line of defense against these pathogens. Seven different leukocidins have been characterized in Staphylococcus aureus, some of which are host and cell specific. Through genome sequencing and analysis of the S. pseudintermediussecretome using liquid chromatography mass spectrometry we identified two proteins, named “LukS-I” and “LukF-I”, encoded on a degenerate prophage contained in the genome of S. pseudintermedius isolates. Phylogenetic analysis of LukS-I components in comparison to the rest of the leukocidin family showed that LukS-I was most closely related to S. intermediusLukS-I, S. aureus LukE and LukP, whereas LukF-I was most similar to S. intermedius LukF-I S. aureus gamma hemolysin subunit B. The killing effect of recombinant S. pseudintermediusLukS-I and LukF-I on canine polymorphonuclear leukocytes was determined using a flow cytometry cell permeability assay. The cytotoxic effect occurred only when the two recombinant proteins were combined. Engineered mutant versions of the two-component pore-forming leukocidins, produced through amino acids substitutions at selected points, were not cytotoxic. Anti-Luk-I produced in dogs against attenuated proteins reduced the cytotoxic effect of native canine leukotoxin which highlights the importance of Luk-I as a promising component in a vaccine against canine S. pseudintermedius infections

The growth and erosion of cinder cones in Guatemala and El Salvador: Models and statistics

Morphologic data for 147 cinder cones in southern Guatemala andwestern El Salvador are comparedwith data from the San Francisco volcanic field, Arizona (USA), Cima volcanic field, California (USA), Michoácan–Guanajuato volcanic field, Mexico, and the Lamongan volcanic field, East Java. The Guatemala cones have an average height of 110+/-50 m, an average basal diameter of 660+/-230 m and an average top diameter of 180+/-150 m. The generalmorphology of these cones can be described by their average cone angle of slope (24+/-7), average heightto- radius ratio (0.33+/-0.09) and their flatness (0.24+/-0.18). Although the mean values for the Guatemalan cones are similar to those for other volcanic fields (e.g., San Francisco volcanic field, Arizona; Cima volcanic field, California; Michoácan–Guanajuato volcanic field, Mexico; and Lamongan volcanic field, East Java), the range of morphologies encompasses almost all of those observed worldwide for cinder cones. Three new 40Ar/39Ar age dates are combined with 19 previously published dates for cones in Guatemala and El Salvador. There is no indication that the morphologies of these cones have changed over the last 500–1000 ka. Furthermore, a re-analysis of published data for other volcanic fields suggests that only in the Cima volcanic field (of those studied) is there clear evidence of degradation with age. Preliminary results of a numerical model of cinder cone growth are used to show that the range of morphologies observed in the Guatemalan cinder cones could all be primary, that is, due to processes occurring at the time of eruption

Staphylococcus pseudintermedius Sbi paralogs inhibit complement and bind IgM, IgG Fc and Fab

The success of staphylococci as pathogens has been attributed, in part, to their ability to evade their hosts’ immune systems. Although the proteins involved in evasion have been extensively studied in staphylococci affecting humans little characterization has been done with Staphylococcus pseudintermedius, an important cause of pyoderma in dogs. Staphylococcus aureus binder of immunoglobulin (Sbi) interferes with innate immune recognition by interacting with multiple host proteins. In this study, a S. pseudintermedius gene that shares 38% similarity to S. aureus Sbi was cloned from S. pseudintermedius strains representative of major clonal lineages bearing two paralogs of the protein. Binding of immunoglobulins and Fab and Fc fragments as well as interaction with complement was measured. S. pseudintermedius Sbi protein bound IgG from multiple species and canine complement C3, neutralized complement activity and bound to canine IgM and B cells. Evidence from this work suggests Sbi may play an important role in S. pseudintermedius immune evasion

Complete Genome Sequence of Staphylococcus pseudintermedius Type Strain LMG 22219

We report the first complete genome sequence of LMG 22219 (=ON 86T = CCUG 49543T), the Staphylococcus pseudintermedius type strain isolated from feline lung tissue. This sequence information will facilitate phylogenetic comparisons of staphylococcal species and other bacteria at the genome level

The growth and erosion of cinder cones in Guatemala and El Salvador: Models and statistics

Morphologic data for 147 cinder cones in southern Guatemala andwestern El Salvador are comparedwith data from the San Francisco volcanic field, Arizona (USA), Cima volcanic field, California (USA), Michoácan–Guanajuato volcanic field, Mexico, and the Lamongan volcanic field, East Java. The Guatemala cones have an average height of 110+/-50 m, an average basal diameter of 660+/-230 m and an average top diameter of 180+/-150 m. The generalmorphology of these cones can be described by their average cone angle of slope (24+/-7), average heightto- radius ratio (0.33+/-0.09) and their flatness (0.24+/-0.18). Although the mean values for the Guatemalan cones are similar to those for other volcanic fields (e.g., San Francisco volcanic field, Arizona; Cima volcanic field, California; Michoácan–Guanajuato volcanic field, Mexico; and Lamongan volcanic field, East Java), the range of morphologies encompasses almost all of those observed worldwide for cinder cones. Three new 40Ar/39Ar age dates are combined with 19 previously published dates for cones in Guatemala and El Salvador. There is no indication that the morphologies of these cones have changed over the last 500–1000 ka. Furthermore, a re-analysis of published data for other volcanic fields suggests that only in the Cima volcanic field (of those studied) is there clear evidence of degradation with age. Preliminary results of a numerical model of cinder cone growth are used to show that the range of morphologies observed in the Guatemalan cinder cones could all be primary, that is, due to processes occurring at the time of eruption

Complete Genome Sequences of Three Staphylococcus pseudintermedius Strains Isolated from Botswana

We report here the first whole-genome sequences for 3 strains of Staphylococcus pseudintermedius (112N, 113N, and 114N) isolated in Africa. Samples of this opportunistic pathogen were collected from nasal swabs obtained from healthy carrier dogs in Botswana. The sequence information will facilitate spatial phylogenetic comparisons of staphylococcal species and other bacteria at the genome level