Effect of additions of liquid poultry manure on excretion of degradative enzymes by bacteria in forest soil and litter

Liquid poultry manure was applied to three forest sites at 35, 70, and 225 metric tonnes (1 tonne = 1000 kg) per hectare (1 ha = 10 000 m2) for 1 to 3 years. Two of the sites were white pine plantations, one dry, one moist, and the third site was mixed hardwoods. Over a period of 35 months the total bacterial population in litter and in soil, in both control and manure plots, was studied as well as the ability of the population to produce extracellular proteases, cellulases, lipases, pectinases, and amylases. Total bacterial counts in litter tended to be higher in the autumn and lower in the spring. Litter always contained about 10-fold more bacteria than soil and the number of bacteria in soil fluctuated little with season or treatment. In white pine litter, bacteria able to excrete protease were more numerous than other enzyme-producing bacteria. More bacteria able to excrete lipases were found on moist than on dry sites, especially on manured plots. At the end of the 35-month test period, all bacterial counts in manured plots had returned nearly to the original level of the control. Statistical analysis revealed significant differences in total bacterial count and counts of specific enzyme producers between manured and control plots. Little difference was seen among rates of manure application. Adding large amounts of poultry manure to these forest plots did not greatly change the bacterial ecology of the soil or litter.

An examination of enzyme production of Phytophthora spp. on solid and liquid media

Solid media were used to determine which extracellular hydrolytic enzymes are produced by Phytophthora parasitica; P. parasitica var. nicotianae, races 0, 1, and 3; and several other Phytophthora spp. Most isolates produced RNase, DNase, phosphatase, lipase, and cellulase uniformly. All race 3 isolates of P. parasitica var. nicotianae exhibited protease activity on a medium containing gelatin, while only 33 and 60% of the race 0 and 1 isolates, respectively, and 14% of the P. parasitica isolates did so. Addition of sorbose to this medium enabled the detection of protease activity by most of the isolates. Amylase activity, measured in the culture fluid, was higher in race 3 than in races 0 or 1 of P. parasitica var. nicotianae and P. parasitica.

Production of Kestoses (Fructosylsucroses) by Phytophthora parasitica var. nicotianae

The synthesis of kestoses (trisaccharides composed of two fructose units and one glucose unit) by races 0 and 1 of Phytophthora parasitica var. nicotianae is shown. The trisaccharide is found in culture filtrates of isolates grown in liquid media containing 3% sucrose. The utilization of sucrose and trisaccharide formation by the organisms over a 16-day period is described. The kestoses were identified by chemical and enzymatic analysis, and two of three possible isomers were found.

Solid media containing carboxymethylcellulose to detect CX cellulose activity of micro-organisms

Solid media containing carboxymethyl cellulose (CMC) were developed to detect CX cellulose-producing micro-organisms. Hydrolysis of CMC was seen as a clear zone around colonies after flooding plates with 1% aqueous hexadecyltrimethyl-ammonium bromide. Tests with ten bacterial and four fungal species showed that the degree of substitution (DS) of the CMC affects both growth and enzyme production. Most of the organisms produced more CX cellulase on CMC with a DS of 0-9, but CMC with a DS of 0-4 was better for one fungus. A qualitative measure of cellulase production may be obtained by calculating the ratio of zone size to colony diameter. Solid media containing CMC provided a more rapid assay of CX cellulose production than a medium containing native cellulose.

Lead on painted handles of kitchen utensils

The lead content of paint on wooden handles of kitchen utensils ranged from 0 to 9.7 per cent (97,000 ppm). Yellow paint showed the highest concentration of lead followed by green and red colors. The values of lead often exceeded the legal limit on toys and paint for use indoors.

Microorganisms from composting leaves: Ability to produce extracellular degradative enzymes

Mixed populations of bacteria, fungi, and actinomycetes in a leaf compost pile were examined over a 100-day test period for their ability to produce extracellular proteolytic, lipolytic, amylolytic, cellulolytic, pectolytic, and ureolytic enzymes and ability to utilize alkanes. Urea was added to the leaves to adjust the carbon to nitrogen ratio but was of little value in maintaining the proper ratio since it was degraded within the first few days. The degradative enzymes excreted by microorganisms was dependent on the temperature of the pile. In many cases organisms able to produce specific extracellular enzymes at medium temperatures were able to grow at high temperatures, but either did not excrete the specific enzymes or the enzymes were inactivated by the high temperature.

Bacteria in enucleated prostate

The controversial nature of prostatitis is compounded by questions concerning the incidence and significance of bacteria within the prostate. Criticism of bacteriologic studies of expressed prostatic secretion, ejaculate, needle biopsy, and transurethral chips led us to culture the core of enucleated prostates. Of 65 prostates, 26 (40 per cent) were positive: 15 pathogens (23 per cent) and 11 nonpathogens (17 per cent). This was correlated with preoperative urinary infections, anterior urethral infection, and postoperative infectious complications. Prostatic pathogens were usually found when the urine and anterior urethra were infected.

Selecting lysine-excreting mutants of lactobacilli for use in food and feed enrichment

Lysine analogues are used to select for lysine-excreting mutants of Lactobacillus plantarum. The use of lactobacilli that excrete lysine for the enrichment of foods and feedstuffs by fermentation is discussed. The increase in lysine content of soybean milk by a mutant of L. bulgaricus and in silage by L. plantarum is shown.

Inducible pectate lyase synthesis and phytopathogenicity of Pseudomonas fluorescens

A strain of Pseudomonas fluorescein which synthesizes large quantities of an inducible extracellular pectate lyase proved to act as a virulent soft rot organism on potatoes, whereas a parent strain that synthesized no lyase showed little pathogenicity. The procedure for inducing lyase synthesis involves culture of P. fluorescens for at least five generations on a combined carbon source of pectin plus a factor extracted from acetone powders of potatoes. The extracted factor is dialyzable and heat-labile but can be sterilized by Millipore filtration. When soil was inoculated into the induction medium, microorganisms present synthesized pectate lyase.Less than half of the single colony isolates obtained by plating out induced cultures of P. fluorescens synthesized pectate lyase when reinoculated into induction medium. Serial reisolation and reinoculation of induced cultures failed to increase the proportion of induced cells. This failure suggests that inducibility is lost during growth of cells on induction medium and (or) on solid agar used for plating. Under similar conditions, cultures of Erwinia carotovora contained induced cells only. The apparent loss of inducibility that occurs in P. fluorescens may account for its generally saprophytic behavior in nature.

Simplified method for mass screening for lead poisoning based on delta-aminolevulinic acid in urine

This new dipstick test offers a practical way to screen children repeatedly for possible lead ingestion. Children with positive results by this screening method may be followed up with more specific diagnostic and laboratory approaches.

Regulation of pectate lyase synthesis in Pseudomonas fluorescens and Erwinia carotovora

Inducible synthesis of extracellular pectate lyase occurs in Erwinia carotovora, a bacterial soft-rot pathogen of plants, and, to a lesser extent, in a nonpathogenic isolate of Pseudomonas fluorescens. A combination of pectin and a heat-labile factor in fresh potato tissue or acetone powders of the tissue provided the best carbon source for induction. Yields of inducible pectate lyase were much greater than those usually reported. The pathogen, but not the saprophyte, produced a small amount of constitutive enzyme when grown on glucose. The relatively low level or absence of constitutive synthesis in these bacteria did not result from catabolite repression. Attempts were made to relieve any existing catabolite repression by restricting growth through slow feeding of glucose or by growing the organisms on glycerol. These conditions did not significantly alter the differential rate of lyase synthesis compared with changes observed in the presence of inducers. Previous growth history did not affect induction in the pathogen. However, P. fluorescens previously cultured on glucose required 10 to 20 generations of growth on inducing medium before appreciable lyase synthesis occurred. Differences between the pathogen and nonpathogen suggest that regulation of pectate lyase synthesis is related to pathogenicity of soft-rot bacteria.