Ecology of Sphaerotilus in an experimental outdoor channel

This paper describes ecological investigations performed in an outdoor experimental channel receiving Huron River water and beet sugar or crude molasses during two summers of operation (1965 and 1966).The channel was assembled in two lengths, 645 ft (1965) and 704 ft (1966), with sampling stations located one near the beginning, one in the middle and one near the end. At each station, three strands of knitting yarn were suspended and allowed to remain for 24 hr. After this time, the strands were removed, together with attached growth, and fresh strings replaced. The replicate strings were cut into 10 cm sections, with one-half of these sections used for dry weight determinations.The attached organisms were removed by violently shaking the strings suspended in a measured quantity of water. One drop was then removed and direct microscopic counts and identification made immediately. Dry weights were obtained by drying the strings in aluminum weighing pans overnight at 90[deg]C.A total of 12 experiments was run, the duration of each being in most cases five days.In the first series of experiments flow through the channel was at 100 g/min. at an essentially uniform velocity of 1 ft/sec. Nutrient concentration was varied from 1 mg/l as sucrose.In the last series of experiments, nutrient concentration was held at 5 mg/l and velocity varied at the three stations by altering the height of an overflow weir between 0.0 and 0.6 ft, and changing the flow between 25 and 200 g/min. This provided a range of velocities at the station from 0.09 to 1.49 ft/sec.The results of attached organism determinations are presented following each experiment and their response to nutrient concentration and velocity summarized in the Discussion.Sphaerotilus-dominated biological flocs were stimulated to bloom proportions within 30 hr after the addition of as little as 1 mg/l of sucrose. Maximum growth was obtained at a concentration of 5 mg/l at velocities from 0.58 to 1.49 ft/sec in the temperature range of 20-28[deg] C after around 72 hr of feeding. About this time, detaching and floating material was equivalent to new material being formed, and the term "saturation population" was proposed to describe this condition.The biological floc community was composed chiefly of Sphaerotilus natans, Melosira varians, M. granulata, Nitzschia sp., Navicula sp., Cosmarium sp., Euglena sp., and the protozoans, Bodo sp., Tetrahymena pyriformis, Colipidium colpoda, and Amoeba sp., tendipedid and simuliid larval forms also apparently found a mutualistic association within the flocs.Saturation population and classical Sphaerotilus flocs could not be obtained at temperatures below 17[deg] C. The typical form was replaced in dominance at low temperatures by an unidentified filamentous bacillus, the total mass of which never approached that of the classical growth.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33316/1/0000711.pd

Limnological investigation of Florence Lake, South Manitou Island, Michigan

http://deepblue.lib.umich.edu/bitstream/2027.42/49263/2/2207327.0005.001.pd

Water quality studies in the Sleeping Bear Dunes National Lakeshore region-the lower Platte River system, Michigan

reprinted 1978; Bibliography: p. 48-50.http://deepblue.lib.umich.edu/bitstream/2027.42/49265/4/2191362.0002.001.pd

Investigations into ecological and sociological determinants of land-use decisions: a study of inland lake watersheds in northern Michigan

reprinted June l978; Bibliography: p. 251-259.http://deepblue.lib.umich.edu/bitstream/2027.42/49266/2/2194424.0001.001.pd

Fecal coliform disappearance in a river impoundment

Fecal coliform (FC) disappearance studies were conducted in Ford Lake during the summer of 1979. Ford Lake, an artificial impoundment at the lower end of the Huron River drainage basin below Ypsilanti, Michigan, receives all upstream flow (2072 km2 of drainage). During dry weather an overall daytime FC disappearance rate of 0.4 (h-1) (K base e) was measured using dye tracer for timed collection. assuming a first order equation of the Chick type. Sedimentation was demonstrated as important in the overall FC disappearance in the upper end of the lake. Rooftop studies showed light level to affect daytime disappearance. Two types of wet weather conditions were documented: (1) where a substantial increase in flow occurred due to an isolated upriver storm; and (2) as a result of two different storm events in the Ford Lake area itself. In both cases, Ford Lake was effective in substantially reducing the large FC contribution.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25455/1/0000905.pd

The suitability of soils for on-site wastewater disposal.

pt. 1. Water quality and nutrient budget by John E. Gannon and Daniel J. Mazur--pt. 2. The suitability of soils for on-site wastewater disposal by Arthur Gold and John E. Gannon. Includes bibliographies.http://deepblue.lib.umich.edu/bitstream/2027.42/49260/2/2193573.0008.001.pd

The in vivo efficacy of two administration routes of a phage cocktail to reduce numbers of Campylobacter coli and Campylobacter jejuni in chickens

<p>Abstract</p> <p>Background</p> <p>Poultry meat is one of the most important sources of human campylobacteriosis, an acute bacterial enteritis which is a major problem worldwide. <it>Campylobacter </it><it>coli </it>and <it>Campylobacter </it><it>jejuni </it>are the most common <it>Campylobacter </it>species associated with this disease. These pathogens live in the intestinal tract of most avian species and under commercial conditions they spread rapidly to infect a high proportion of the flock, which makes their treatment and prevention very difficult. Bacteriophages (phages) are naturally occurring predators of bacteria with high specificity and also the capacity to evolve to overcome bacterial resistance. Therefore phage therapy is a promising alternative to antibiotics in animal production. This study tested the efficacy of a phage cocktail composed of three phages for the control of poultry infected with <it>C. coli </it>and <it>C. jejuni</it>. Moreover, it evaluated the effectiveness of two routes of phage administration (by oral gavage and in feed) in order to provide additional information regarding their future use in a poultry unit.</p> <p>Results</p> <p>The results indicate that experimental colonisation of chicks was successful and that the birds showed no signs of disease even at the highest dose of <it>Campylobacter </it>administered. The phage cocktail was able to reduce the titre of both <it>C. coli </it>and <it>C. jejuni </it>in faeces by approximately 2 log₁₀cfu/g when administered by oral gavage and in feed. This reduction persisted throughout the experimental period and neither pathogen regained their former numbers. The reduction in <it>Campylobacter </it>titre was achieved earlier (2 days post-phage administration) when the phage cocktail was incorporated in the birds' feed. <it>Campylobacter </it>strains resistant to phage infection were recovered from phage-treated chickens at a frequency of 13%. These resistant phenotypes did not exhibit a reduced ability to colonize the chicken guts and did not revert to sensitive types.</p> <p>Conclusions</p> <p>Our findings provide further evidence of the efficacy of phage therapy for the control of <it>Campylobacter </it>in poultry. The broad host range of the novel phage cocktail enabled it to target both <it>C. jejuni </it>and <it>C. coli </it>strains. Moreover the reduction of <it>Campylobacter </it>by approximately 2 log₁₀cfu/g, as occurred in our study, could lead to a 30-fold reduction in the incidence of campylobacteriosis associated with consumption of chicken meals (according to mathematical models). To our knowledge this is the first report of phage being administered in feed to <it>Campylobacter-</it>infected chicks and our results show that it lead to an earlier and more sustainable reduction of <it>Campylobacter </it>than administration by oral gavage. Therefore the present study is of extreme importance as it has shown that administering phages to poultry via the food could be successful on a commercial scale.</p