Removal of Methylene Blue from an Aqueous Medium Using Atemoya Peel as a Low-cost Adsorbent

Water, Air, & Soil Pollution - The objective of the present study was the synthesis and characterization of chitosan-alginate-based cross-linked copolymer (CACC) for the effective removal of...     

Phenotypic and genotypic characterisation of Pasteurella multocida isolated from pigs at slaughter in New Zealand

AIMS: To examine pigs at slaughter in New Zealand for the presence of Pasteurella multocida, and to determine for isolates, their biochemical profiles, somatic and capsular types, and the presence or absence of the HSB and toxA genes, associated with haemorrhagic septicaemia (HS) and progressive atrophic rhinitis (PAR), respectively.

METHODS: Swabs from 173 lungs, 158 palatine tonsils and 82 nasal passages of pigs at two abattoirs in New Zealand were cultured for P. multocida using conventional techniques, and isolated colonies were subjected to biochemical tests for identification of biovars. Somatic serotyping was conducted using an agar gel immunodiffusion (AGID) test. Polymerase chain reaction (PCR) assays were used to confirm phenotypic identification of colonies using species-specific primers, capsule type using serogroup-specific primers and multiplex PCR, and to test for the presence of HSB and toxA genes.

RESULTS: Pasteurella multocida was isolated from 11/173 (6.4%) lung, 32/158 (20.2%) palatine tonsil and 5/82 (6.1 %) nasal swab samples, a total of 48 isolates from 413 samples (11.6%). Isolation rates per farm ranged from 1–53% of tissue samples collected from pigs 5–6 months of age. On phenotypic characterisation, isolates were allocated to seven main biovars, viz 1, 2, 3, 5, 9, 12, and a dulcitol-negative variant of Biovar 8, the majority (30/48) being Biovar 3. Of the 42 isolates for which somatic serotyping was conducted, 10% were Serovar 1, 79% were Serovar 3, 2% were Serovar 6,1, 2% were Serovar 12, and 7% could not be typed. All 48 isolates were confirned as P. multocida using a species-specific PCR. In the capsular multiplex PCR, 92% of isolates were Capsular (Cap) type A, 2% were Cap D, and 6% could not be typed. None of the samples were positive for the HSB or toxA genes.

CONCLUSION: Serovars or capsular types of P. multocida associated with HS or PAR in pigs were not detected. Establishment of species-specific, capsular and toxin PCR assays allowed the rapid screening of isolates of P. multocida, while serotyping provided an additional tool for epidemiological and tracing purposes.     

Detection of Mycoplasma conjunctivae in sheep affected with conjunctivitis and infectious keratoconjunctivitis

AIM: To determine the aetiolog y of a recurring and severe form of infectious keratoconjunctivitis (IKC) in sheep.

METHODS: Five sheep flocks that had experienced a severe form of IKC were examined. Clinical history, conjunctival swabs and blood samples were collected from affected animals. Culture for bacteria, and also specifically for Mycoplasma and Chlamydophila spp, and detection of Mycoplasma conjunctivae DNA by polymerase chain reaction (PCR) were attempted. Serum samples were tested for antibodies to M. agalactiae, M. capricolum, M. conjunctivae and Chlamydophila spp.

RESULTS: Mycoplasma conjunctivae DNA was detected using PCR in 3/5 flocks, and in all flocks antibodies to M. conjunctivae were detected in sera. A pure growth of Branhamella ovis was cultured from conjunctival swabs from a small proportion of sheep in two flocks. No other pathogens were detected.

CONCLUSIONS: This investigation demonstrated that M. conjunctivae was a primary pathogen causing severe IKC in sheep, and is the first report of detection of this organism in sheep in New Zealand. Introduction of clinically normal carrier sheep appeared to have caused the outbreaks.     

European pennyroyal (Mentha pulegium) from Portugal: Chemical composition of essential oil and antioxidant and antimicrobial properties of extracts and essential oil

There is a growing interest of industry to replace synthetic chemicals by natural products with bioactive properties from plant origin. The aim of this study was to determine the chemical composition of European pennyroyal (Mentha pulegium) essential oil and to characterize the in vitro antioxidant and antimicrobial activities of its water (hot and cold) and ethanolic extracts and of the essential oil. The essential oil revealed menthone, pulegone and neo-menthol as the main constituents, comprising 35.9, 23.2 and 9.2% of the essential oil, respectively. The hot water extract exhibited the highest antioxidant activity and phenol content. In contrast, the extracts were not very effective to inhibit the growth of the seven foodborne spoilage and pathogenic bacteria tested, but the essential oil showed antibacterial activity against all bacterial strains. In conclusion, extracts and essential oil of M. pulegium from Mediterranean origin have huge potential as an alternative to chemical additives for the food industry.     

Plant protein and vegetable oil‐based diets modulate gilthead seabream (Sparus aurata) muscle biochemical status and proteolytic enzymes at an early postmortem stage

A 70 days feeding trial was carried out on juvenile gilthead seabream (Sparus aurata) (mean initial body weight: 362 ± 59 g) to evaluate whether the simultaneous replacement of fishmeal and fish oil by vegetable ingredients affected the muscle's proteolytic potential. Fish were fed either a fishmeal/fish oil diet, a fishmeal/vegetable oil diet, a plant protein/fish oil or a plant protein/vegetable oil diet. The use of dietary plant proteins resulted in lower sulphated glycosaminoglycans' content and lower glycogen phosphorylase activity in the muscle, while both plant proteins and vegetable oil increased muscle pH and reduced cathepsin B activity. Our results indicate that high replacement of fish meal and/or fish oil with plant ingredients has a significant impact on early postmortem metabolic processes and proteolytic potential of seabream muscle, especially when replacing both fish meal and fish oil.     

Spineless cactus associated with Tifton hay or sugarcane bagasse may replace corn silage in sheep diets

The effect of the replacement of corn silage with spineless cactus associated with Tifton 85 hay or sugarcane bagasse was evaluated on the performance, body weight components and sheep meat quality. Twenty-one Santa Inês male sheep with initial body weight of 22.9 ± 2.9 kg were used. They were confined in individual stalls for 74 days receiving the following diets: corn silage + concentrate (CS); spineless cactus + Tifton 85 hay + concentrate (TH); spineless cactus + sugarcane bagasse + concentrate (SB). After the feedlot period, the animals were slaughtered and their body components were weighed and sampled. Data were submitted to Tukey’s test at 5% probability. The average daily gain (0.25 vs 0.14 kg), cold carcass weight (13.3 vs 13.7 kg), loin muscularity (0.6 vs 0.4 kg) and liver weight (0.7 vs. 0.5 kg) were higher (P < 0.05) for the TH diet when compared to that for the CS. The physical-chemical parameters of meat were not influenced (P > 0.05) by the treatments and presented about 20.1% of crude protein, 6.1% of crude fat and shear force of 2.0 kgf/cm². In complete diets for sheep, Tifton 85 hay associated with spineless cactus provides greater weight gain, cold carcass muscularity and organ weight when compared to those for animals fed with corn silage as exclusive roughage. Sugarcane bagasse associated with spineless cactus may replace corn silage in complete diets for sheep.     

Nondestructive evaluation of heat-treated Eucalyptus grandis Hill ex Maiden wood using stress wave method

The objectives of this study were to evaluate the effect of heat treatment of eucalypt wood (Eucalyptus grandis Hill ex Maiden) on the dynamic modulus of elasticity by using the stress wave nondestructive method and also to determine the air-dry density variation, weight loss and equilibrium moisture content following treatment. Heat treatments were performed at four different temperatures (180, 200, 215 and 230°C) and for three different durations (15?min, 2 and 4?h). The results revealed a significant reduction in air-dry density following heat treatment independent of temperature and time. A significant weight loss was observed between and within treatments. The treatment at 230°C for 2 and 4?h produced a weight loss of 20.5 and 26.5%, respectively, which was statistically different from other treatment conditions. The dynamic modulus of elasticity decreased by about 13% in the most severe treatment (230°C for 4?h). Depending on the temperature and time, the equilibrium moisture content was significantly reduced within the range of 40–74%.