Fertilization and Bioaugmentation for Oil Biodegradation in Salt Marsh Mesocosms

Biodegradation of crude oil is often dependent on the population sizes and metabolic activity of hydrocarbon-degrading microorganisms in addition to nutrient supply. Fertilization with N and P and bioaugmentation of oil-contaminated soil with hydrocarbon-degrading microorganisms may serve to enhance oil biodegradation rates. Glasshouse experiments were conducted to determine the impacts of fertilization and commercial bioremediation products on crude oil biodegradation and on changes in nutrient concentrations and populations of hydrocarbon-degrading microorganisms in salt marsh mesocosms growing Spartina alterniflora. Experiments were conducted under continuously-flooded and alternately-flooded/drained conditions with and without N and P fertilization. MaxBac, a slow-release fertilizer, was applied at a rate of 100 kg N ha^-1 and 20 kg P ha^-1, while additional P was applied at 20 kg P ha^-1. Commercial products failed to enhance total oil or total petroleum hydrocarbon (TPH) degradation under either continuously or alternately-flooded conditions. An average of 62% of TPH was degraded by 33 d under continuously-flooded conditions, while 59% was degraded by 41 d after oil application under alternately-flooded conditions. Products generally did not increase population sizes of heterotrophs orhydrocarbon-degrading microorganisms. Concentrations of NH₄ ⁺ and P decreased during experimentation, and fertilization with N and P stimulated total oil and TPH degradation under continuously-flooded, but not under alternately-flooded conditions.     

Controlling microbial contamination on beef and lamb meat during processing

SUMMARY The microbiological quality of carcases, meat and environmental surfaces was evaluated in commercial boning rooms processing beef and lamb. There was considerable variation in the level of microbial contamination on both carcases and meat, with counts ranging from less than 20 to 10⁸/cm² on carcases and to 2 times 10⁷/cm² on meat. The level of microbial contamination on meat was influenced by the level of carcase contamination at boning and by the boning process itself. Carcase contamination was the major determinant of microbiological quality, as more than 70% of carcases had microbial counts greater than 10³/cm². Cutting boards were a major source for microbial dissemination during boning, particularly when carcase counts were less than 10³/cm². If carcases were heavily contaminated, the contamination of processing surfaces was irrelevant in determining microbial loads on meat. Where carcase contamination was at low to moderate levels, the contribution of the boning process to the contamination on meat assumed increased significance. Under these conditions, improved sanitation of cutting surfaces in the boning room resulted in a significant reduction in microbial contamination on the surface of meat. These results can form the basis for ensuring that improvements made in carcase management before boning, to improve microbiological quality, will be preserved through attention to cutting board hygiene during boning.     

Effectiveness of passive gas-scavenging canisters attached to isoflurane anesthesia systems under standard-use conditions in a laboratory animal facility

Chronic exposure to trace levels of waste anesthetic gases has been linked to higher incidences of neurologic and reproductive dysfunction, hepatic and renal toxicity, and neoplasia in health care professionals. We have shown that low levels of isoflurane emissions are likely in conventional laboratory animal treatment rooms during the use of standard anesthesia delivery systems equipped with activated charcoal canisters for passive gas scavenging. In the present study, we surveyed the effectiveness of canisters (attached to well‐maintained precision isoflurane vaporizers) in current use throughout our AAALAC‐accredited laboratory animal facility. Canisters (Omnicon f/air) had been weighed prior to use and then attached to dual‐loop systems (face mask and induction box circuits) from 1 week to 6 months of service. Isoflurane emissions were measured using a pre‐calibrated, portable infrared spectrophotometer by attaching each canister to the face‐mask circuit, occluding the face mask and closing the stopcock to the induction circuit, and running the system at uniform isoflurane concentration (2%) and oxygen flow rate (1 L minute^?1). Samples were taken in animal procedure rooms (size range, 45–80 m³) in which the air turnover rate ranged between 20 and 30 nonrecirculating changes per hour. Nine of the 60 canisters (15%) in current use were found to have exceeded the manufacturer's recommended use‐life (defined as a weight increase of 50 g). Of these nine, seven canisters did not scavenge isoflurane at all (indicated by emissions greatly exceeding 100 ppm). Isoflurane was not detected in the operator's breathing zone under normal use conditions (i.e. gas directed to both circuits at once). Of the 51 canisters that had not exceeded their rated use‐life, 12 (23.5%) exhausted isoflurane at >2 ppm. Our data show that (i) the potential for exposure to waste isoflurane emissions will depend on the configuration of the delivery system and that (ii) enhanced attention to canister surveillance may be warranted even in well‐run facilities.     

The isolation of salmonella from kangaroos and feral pigs processed for human consumption

A total of 154 feral pig carcases and 81 kangaroo carcases were examined for the presence of Salmonella, coliforms and total aerobic counts. Approximately 34% of pig carcases yielded one or more serotypes of Salmonella, while about 11% of kangaroo carcases were contaminated with salmonella. The results differed widely between sampling occasions. A total of 13 serotypes were isolated from feral pigs with S. anatum (31 isolates) and S. typhimurium (9 isolates) being the predominant serotypes. Coliforms were isolated from approximately 90% of carcases. The mean log10 coliform count on feral pigs was 4.39 +/- 1.45/g and the mean log10 total count was 6.15 +/- 1.15/g. About 21% of carcases were contaminated with more than 100,000 coliforms/g. A total 3 serotypes were isolated from kangaroos (S. bahrenfeld, S. binza, and S. onderstepoort). The mean log10 coliform count on kangaroos was 3.54 +/- 1.04. More than 50% of kangaroo carcases were contaminated with less than 100 coliforms/g. About 15% of carcases were contaminated with more than 10,000 coliforms/g. The mean log10 total count was 5.2 +/- 1.01/g.     

Demographic studies on final year veterinary students of nine European schools

In 1975 a survey of some aspects of veterinary student selection, background and education as well as intended employment after qualification was conducted in the veterinary schools at Bristol, Glasgow, Liverpool, Helsinki, Stockholm, Hannover, Ghent, Toulouse and Vienna. In all schools student selection was primarily based on academic ability. A numerus clausus existed in six of the nine schools. No sex discrimination in student selection was practised in seven of the nine schools. The proportion of male students in the final year of 1975 ranged from 57 per cent in Glasgow to 97 per cent in Ghent. The parents of the students were predominantly of socioeconomic classes 1 (28 per cent), 2 (38 per cent) or 3 non manual (20 per cent), and no significant differences were found between the UK and the continental schools. Six per cent of the parents were veterinarians while 15 per cent were farmers. The financing by students of their veterinary studies varied markedly between schools. Over 80 per cent of the students wished to go first into general practice, with little tendency, except among UK students, to go into employment abroad first.     

Sulfur influences on rumen microorganisms in vitro and in sheep and calves

When continuously cultured ruminal microbes were given orchardgrass hay and sufficient sulfuric acid or hydrochloric acid to maintain a pH of 5.5, fermentation and numbers of protozoa were reduced compared with cultures whose pH was controlled with phosphoric acid. Likewise, when sulfur-deficient, purified diets were supplied to cultures, less methane (mmol X liter-1 X d-1), 3.2 vs 32.6, was produced and fewer cellulolytic bacteria (log10/ml), 5.8 vs 7.2 were present than when cultures were given the same diet supplemented with .3% elemental sulfur. The rumen of sheep fed the .04% sulfur diet had reduced digesta weights (1.69 vs 3.2 kg) compared with sheep fed the diet with .34% sulfur at the same intake. There also was reduced methanogenesis 12.3 vs 25.8 mmol X liter-1 X d-1) and reduced numbers of cellulolytic bacteria (7.4 vs 8.4 log10/ml) in sulfur-deficient sheep in comparison to sulfur-supplemented sheep. In growing calves, the same types of bacteria predominated in the rumen, but more facultative anaerobic bacteria were isolated from calves fed .04% sulfur than from calves fed diets with .34 to 1.72% sulfur. None of the dietary levels of sulfur appeared toxic. Regardless of treatment, volatile fatty acids were more predominant than lactic acid as end-products of fermentation of ruminal microbes in fermenters, sheep and calves. The greater methanogenesis and the greater cellulolytic bacterial numbers of sulfur-supplemented sheep compared with sulfur-deficient in vitro cultures, is interpreted to be the result of recycling of sulfur to the rumen in sheep where it is efficiently scavengered by ruminal bacteria.     

Transperineal punch biopsy of the canine prostate gland

Transperineal punch biopsy using an obturator-canula assembly ('Tru-cut') was performed successfully under general anaesthesia in twenty-three dogs suspected of having prostatic disease. Diagnostic portions of tissue were obtained in all cases. One dog developed transient post-operative orchitis and scrotal oedema.