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Kinetic responses of activated sludge microorganisms to individual and joint copper and zinc.

The individual and joint effects of copper and zinc on the growth kinetics of activated sludge microorganisms were studied in batch reactors fed with glucose as sole carbon source. The observed specific growth rate, substrate utilization rate and removal efficiency were determined at different concentrations of individual and joint Cu and Zn. Activated sludge microorganisms showed different kinetic responses to Cu and Zn, and the Haldane model seemed applicable for the inhibitory effect of Zn, while a first-order kinetics for Cu. Compared to Zn, Cu exhibited high toxicity to activated sludge microorganisms even at a very low concentration of 1.0 mg/dm3. However, Zn concentrations less than 40 mg/dm3 would stimulate the growth of activated sludge microorganism, and Zn acted as inhibitory chemical only at concentrations above this value. The combined effect of Cu and Zn could be regarded as neither synergistic nor antagonistic action.

Bacteria↗

Systemic host responses in severe sepsis analyzed by causative microorganism and treatment effects of drotrecogin alfa (activated).

Clinical trials with novel therapeutic agents for severe sepsis have suggested that patients might respond differently depending on causative microorganism. Data from a large, placebo-controlled trial of recombinant human drotrecogin alfa (activated) (DrotAA) were analyzed by type of causative microorganism for treatment-associated differences in mortality, coagulopathy, and inflammatory response. Compared with placebo, mortality rates associated with DrotAA were consistently reduced for each microorganism group (gram-positive bacteria, gram-negative bacteria, mixed bacteria, fungi, other, and unknown microbial etiology), with a stratified relative risk (RR) of 0.80 (95% confidence interval [CI], 0.69-0.94). The greatest reduction in the mortality rate was for Streptococcus pneumoniae infection (RR, 0.56; 95% CI, 0.35-0.88). Levels of coagulation and inflammation biomarkers varied with different pathogens at study entry. Results demonstrate that DrotAA, administered as an adjunct to standard anti-infective therapy, can improve the rate of survival for patients who develop severe sepsis regardless of causative microorganism.

Anti-Bacterial Agents↗

In vitro antimicrobial activity of oxidized regenerated cellulose against antibiotic-resistant microorganisms.

BACKGROUND: The emergence of multi-drug resistant microorganisms presents a critical problem for patients undergoing surgery. Acidic pH, which is produced by oxidized regenerated cellulose (ORC), is a broad-spectrum physiological detriment to survival of microorganisms known to cause surgical infections. The purpose of this study was to examine the antimicrobial effect of ORC against antibiotic-resistant organisms. METHODS: ORC products were challenged with ATCC reference strains and clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant Enterococcus (VRE), penicillin-resistant Streptococcus pneumoniae (PRSP), and non-resistant ATCC strains of S. aureus and Pseudomonas aeruginosa. Samples of three ORC products (SURGICEL absorbable hemostat, SURGICEL Fibrillar absorbable hemostat, and SURGICEL NU-KNIT absorbable hemostat and identified, respectively, as ORC-R, ORC-F, and ORC-N for this study) were inoculated with challenge organisms in nutrient broth to produce a weight to volume ratio of 15 mg ORC/mL. Plate counts were performed at 0, 1, 6, and 24 h. RESULTS: Antimicrobial activity was seen with all three ORC products against the challenge organisms. Data indicate that antibiotic-resistant microorganisms remain susceptible to the antimicrobial activity of ORC. In testing with nine of 10 bacteria, including four antibiotic-resistant clinical isolates (VRE, MRSA, and PRSP) three-log or greater reductions were seen at 24-h exposure. One ATCC strain of VRE demonstrated some level of resistance to the acidic pH effect. ORC-N showed a three-log reduction with this organism, whereas the reductions with ORC-R and ORC-F were less than one log. CONCLUSION: Since low pH affects a relatively broad-spectrum of bacteria and does not act in a mechanism-specific manner, as do antibiotics, antibiotic-resistant strains of bacteria are unlikely to resist the ORC pH effect. Results of this in vitro assessment support the hypothesis that the antimicrobial activity of ORC is effective against antibiotic-resistant microorganisms.

Cellulose, Oxidized↗

Whole genome-based phylogenetic analysis of free-living microorganisms.

A phylogenetic 'tree of life' has been constructed based on the observed presence and absence of families of protein-encoding genes observed in 11 complete genomes of free-living microorganisms. Past attempts to reconstruct the evolutionary relation-ships of microorganisms have been limited to sets of genes rather than complete genomes. Despite apparent rampant lateral gene transfer among microorganisms, these results indicate a single robust underlying evolutionary history for these organisms. Broadly, the tree produced is very similar to the small subunit rRNA tree although several additional phylogenetic relationships appear to be resolved, including the relationship of Archaeoglobus to the methanogens studied. This result is in contrast to notions that a robust phylogenetic reconstruction of microorganisms is impossible due to their genomes being composed of an incomprehensible amalgam of genes with complicated histories and suggests that this style of genome-wide phylogenetic analysis could become an important method for studying the ancient diversification of life on Earth. Analyses using informational and operational subsets of the genes showed that this 'tree of life' is not dependent on the phylogenetically more consistent informational genes.

Computational Biology↗

The growth of microorganisms in propofol and mixtures of propofol and lidocaine.

UNLABELLED: Propofol emulsion supports bacterial growth. Extrinsic contamination of propofol has been implicated as an etiological event in postsurgical infections. When added to propofol, local anesthetics (e.g., lidocaine) alleviate the pain associated with injecting it. Because local anesthetics have antimicrobial activity, we determined whether lidocaine would inhibit microbial growth by comparing the growth of four microorganisms in propofol and in mixtures of propofol and lidocaine. Known quanta of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans were inoculated into solutions of 1% propofol, 0.2% lidocaine in propofol, 0.5% lidocaine in propofol, 0.5% lidocaine in isotonic sodium chloride solution, and 0.9% isotonic sodium chloride solution. All microorganisms were taken from stock cultures and incubated for 24 h. Growth of microorganisms in each solution was compared by counting the number of colony-forming units grown from a subculture of the solution at 0, 3, 6, 12 and 24 h. Propofol supported the growth of E. coli and C. albicans. Propofol maintained static levels of S. aureus and was bactericidal toward P. aeruginosa. The addition of 0.2% and 0.5% lidocaine to propofol failed to prevent the growth of the studied microorganisms. The effect of 0.5% lidocaine in isotonic sodium chloride solution did not differ from the effects of isotonic sodium chloride solution alone. We conclude that lidocaine, when added to propofol in clinically acceptable concentrations, does not exhibit antimicrobial properties. IMPLICATIONS: Local anesthetics such as lidocaine have antimicrobial activity. Propofol supports the growth of bacteria responsible for infection. Bacteria were added to propofol and propofol mixed with lidocaine. The addition of lidocaine to propofol in clinically relevant concentrations did not prevent the growth of bacteria. The addition of lidocaine to propofol cannot prevent infection from contaminated propofol.

Anesthetics, Intravenous↗

Cotton fleahopper and associated microorganisms as components in the production of stress ethylene by cotton.

Excised cotton terminal buds incubated with adults or nymphs of the cotton fleahopper (CFH), Pseudatomoscelis seriatus (Reuter), produced ethylene at theoretical abscission-inducing rates by 24 h after introduction of the insect. Inoculation of cotton shoot tips with three microorganisms commonly associated with CFH and cotton in all cases promoted ethylene production to theoretical abscission-inducing rates by 24 h after inoculation. CFH alone or injection of microorganisms consistently caused cotton shoot tips to darken and become soft. These changes paralleled the rise in ethylene production and did not occur in control shoot tips. Of the three microorganisms, Xanthomonas campestris pv malvacearum (Smith) Dye (XCM) produced little ethylene when grown in culture, while the two fungi, Penicillium purpurogenum Stoll and P. glabrum (Wehmer) Westling, produced higher levels. The parallel between plant response to CFH, XCM, and CFH + XCM suggests a similar mechanism of ethylene induction by these two stress agents. Since a portion of the CFH were devoid of microorganisms, yet their impact on ethylene production by cotton tissue was uniform, we propose that the primary mechanism of ethylene induction involves the insect's salivary fluids which contain cell wall hydrolyzing enzymes.

Journal Article↗

Diversity and abundance of sulfate-reducing microorganisms in the sulfate and methane zones of a marine sediment, Black Sea.

The Black Sea, with its highly sulfidic water column, is the largest anoxic basin in the world. Within its sediments, the mineralization of organic matter occurs essentially through sulfate reduction and methanogenesis. In this study, the sulfate-reducing community was investigated in order to understand how these microorganisms are distributed relative to the chemical zonation: in the upper sulfate zone, at the sulfate-methane transition zone, and deeply within the methane zone. Total bacteria were quantified by real-time PCR of 16S rRNA genes whereas sulfate-reducing microorganisms (SRM) were quantified by targeting their metabolic key gene, the dissimilatory (bi)sulfite reductase (dsrA). Sulfate-reducing microorganisms were predominant in the sulfate zone but occurred also in the methane zone, relative proportion was maximal around the sulfate-methane transition, c. 30%, and equally high in the sulfate and methane zones, 5-10%. The dsrAB clone library from the sulfate-methane transition zone, showed mostly sequences affiliated with the Desulfobacteraceae. While, the dsrAB clone libraries from the upper, sulfate-rich zone and the deep, sulfate-poor zone were dominated by similar, novel deeply branching sequences which might represent Gram-positive spore-forming sulfate- and/or sulfite-reducing microorganisms. We thus hypothesize that terminal carbon mineralization in surface sediments of the Black Sea is largely due to the sulfate reduction activity of previously hidden SRM. Although these novel SRM were also abundant in sulfate-poor, methanogenic areas of the Black Sea sediment, their activities and possibly very versatile metabolic capabilities remain subject of further study.

Colony Count, Microbial↗

Growth of phenol-mineralizing microorganisms in fresh water.

A method was developed to enumerate the procaryotic and eucaryotic phenol-mineralizing microorganisms present in samples of fresh water. Sixty-five percent or greater mineralization of [U-14C]phenol was considered a positive tube (contained phenol-mineralizing microorganisms) in the most-probable-number technique. Replicate most-probable-number tubes contained no microbial inhibitors, streptomycin and tetracycline, or cyclohexamide and nystatin plus 200 pg to 100 micrograms of phenol per ml. Phenol mineralization rates were obtained by measuring the amount of exogenous phenol that disappeared from solution over time in the presence or absence of the microbial inhibitors. Initially, less than 100 phenol-mineralizing bacteria per ml and 1 phenol-mineralizing fungus per ml were present at both 200 pg and 100 micrograms of phenol per ml. Phenol mineralization rates were 6.3 times greater for the mineralizing bacteria than for the fungi at 200 pg of phenol per ml. Phenol concentrations above 10 micrograms/ml were inhibitory to the microorganisms capable of mineralizing phenol. The phenol mineralizers grew in the water samples in the absence of phenol, indicating that there were sufficient indigenous nutrients in the lake water to support growth. There was no difference in the growth rate of these microorganisms in the presence or absence of 1 ng of phenol per ml, whereas the growth rate was more rapid at 1 microgram of phenol per ml than in its absence. There was a correlation between microbial growth and the amount of phenol mineralized at 1 microgram but not at 1 ng of phenol per ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria↗

Prediction of substrate removal rates of attached microorganisms and of relative contributions of attached and suspended communities at field sites.

A mathematical model composed of a direct proportionality relationship between bulk water velocities and field-determined second-order microbial transformation rate coefficients, and the relative rate coefficient of a benchmark chemical, was developed for estimating the substrate removal rates of rapidly degraded chemicals by attached organisms in shallow (<1 m deep) aquatic ecosystems. Data from 31 field experiments involving the addition of 2,4-dichlorophenoxyacetic acid methyl ester (2,4-DME) in nine field areas were used to determine a field-derived second-order rate coefficient for microbial transformation of the ester. By using 2,4-DME as a benchmark chemical, the model was used to predict microbial transformation rates of the butoxyethyl ester of 2,4-dichlorophenoxyacetic acid (2,4-DBE) at five other field sites. The predicted half-lives of 2,4-DBE varied 1,500-fold and were within about a threefold range or less of the measured half-lives. Under conditions of mass transport limitation, the contributions of attached microorganisms relative to total microbial activities at various field sites were related to the ratio of water velocity, U, and depth, D, showing that historical definitions of ecosystems according to flow and depth characteristics are also valid for describing the process-related structure of ecosystems. An equation was developed for predicting the relative contributions of attached and suspended communities with values of U and D for lotic and lentic ecosystems. On the basis of this equation, attached microorganisms were expected to be insignificant in deep lentic ecosystems and suspended microorganisms were expected to be insignificant in shallow lotic systems for the same process carried out by both populations. Neglecting epiphytic microorganisms, both suspended and attached organisms were expected to be significant in wetlands.

Journal Article↗

Microcosm for assessing survival of genetically engineered microorganisms in aquatic environments.

Laboratory-contained microcosms are important for studying the fate and survival of genetically engineered microorganisms. In this study, we describe a simple aquatic microcosm that utilizes survival chambers in a flowthrough or static renewal system. The model was used to study the survival of genetically engineered and wild-type strains of Escherichia coli and Pseudomonas putida in the lake water environment. Temperature-dependent studies indicated that the genetically engineered microorganisms survived better or at least as well as their wild-type counterparts at 15, 25, and 30 degrees C. The genetic determinants of the genetically engineered microorganisms also remained fairly stable within the host cell under the tested conditions. In the presence of organisms indigenous to lake water, E. coli was eliminated after 20 days, whereas P. putida showed an initial decline but was able to stabilize its population after 5 days. A herbicide, Hydrothol-191, caused a significant decline in numbers of P. putida, but no significant difference was observed between the genetically engineered microorganisms and the wild-type strain. The microcosm described is simple, can be easily adapted to study a variety of environmental variables, and has the advantage that the organisms tested are constantly exposed to test waters that are continuously renewed.

Dicarboxylic Acids↗

Dechlorination of Four Commercial Polychlorinated Biphenyl Mixtures (Aroclors) by Anaerobic Microorganisms from Sediments.

The rate, extent, and pattern of dechlorination of four Aroclors by inocula prepared from two polychlorinated biphenyl (PCB)-contaminated sediments were compared. The four mixtures used, Aroclors 1242, 1248, 1254, and 1260, average approximately three, four, five, and six chlorines, respectively, per biphenyl molecule. All four Aroclors were dechlorinated with the loss of meta plus para chlorines ranging from 15 to 85%. Microorganisms from an Aroclor 1242-contaminated site in the upper Hudson River dechlorinated Aroclor 1242 to a greater extent than did microorganisms from Aroclor 1260-contaminated sediments from Silver Lake, Mass. The Silver Lake inoculum dechlorinated Aroclor 1260 more rapidly than the Hudson River inoculum did and showed a preferential removal of meta chlorines. For each inoculum the rate and extent of dechlorination tended to decrease as the degree of chlorination of the Aroclor increased, especially for Aroclor 1260. The maximal observed dechlorination rates were 0.3, 0.3, and 0.2 mug-atoms of Cl removed per g of sediment per week for Aroclors 1242, 1248, and 1254, respectively. The maximal observed dechlorination rates for Hudson River and Silver Lake organisms for Aroclor 1260 were 0.04 and 0.21 mug-atoms of Cl removed per g of sediment per week, respectively. The dechlorination patterns obtained suggested that the Hudson River microorganisms were more capable than the Silver Lake organisms of removing the last para chlorine. These results suggest that there are different PCB-dechlorinating microorganisms at different sites, with characteristic specificities for PCB dechlorination.

Journal Article↗

Anaerobic dechlorination of polychlorobiphenyls (Aroclor 1242) by pasteurized and ethanol-treated microorganisms from sediments.

A polychlorobiphenyl (PCB)-dechlorinating inoculum eluted from upper Hudson River sediments was treated with either heat or ethanol or both. The treated cultures retained the ability to dechlorinate PCBs (Aroclor 1242) under strictly anaerobic conditions. The dechlorination activity was maintained in serial cultures inoculated with transfers of 1% inoculum when the transferred inoculum was treated each time in the same manner. No methane production was detected in any treated culture, although dechlorination of PCBs in the untreated cultures was always accompanied by methane production. All treated cultures preferentially removed meta chlorines, yielding a dechlorination pattern characterized by accumulation of certain ortho- and para-subsituted congeners such as 2-4-chlorobiphenyl (2-4-CB), 2,4-2-CB, and 2,4-4-CB. In contrast, the untreated cultures showed more extensive dechlorination activities, which almost completely removed both meta and para chlorines from Aroclor 1242. These results suggest that microorganisms responsible for the dechlorination of PCBs in the upper Hudson River sediments can be grouped into two populations according to their responses to the heat and ethanol treatments. Microorganisms surviving the heat and ethanol treatments preferentially remove meta chlorines, while microorganisms lost from the enrichment mainly contribute to the para dechlorination activity. These results indicate that anaerobic sporeformers are at least one of the physiological groups responsible for the reductive dechlorination of PCBs. The selection of a dechlorinating population by such treatments may be an important step in isolation of PCB-dechlorinating microorganisms.

Aroclors↗

Microcosm and in situ field studies of enhanced biotransformation of trichloroethylene by phenol-utilizing microorganisms.

The ability of different aerobic groundwater microorganisms to cometabolically degrade trichloroethylene (TCE), 1,2-cis-dichloroethylene (c-DCE), and 1,2-trans-dichloroethylene (t-DCE) was evaluated both in groundwater-fed microcosms and in situ in a shallow aquifer. Microcosms amended with phenol or toulene were equally effective in removing c-DCE (> 90%) followed by TCE (60 to 70%), while the microcosm fed methane was most effective in removing t-DCE (> 90%). The microcosm fed ammonia was the least effective. None of the microcosms effectively degraded 1,1,1-trichloroethane. At the Moffett Field groundwater test site, in situ removal of c-DCE and TCE coincided with biostimulation through phenol and oxygen injection and utilization, with c-DCE removed more rapidly than TCE. Greater TCE and c-DCE removal was observed when the phenol concentration was increased. Over 90% removal of c-DCE and TCE was observed in the 2-m biostimulated zone. This compares with 40 to 50% removal of c-DCE and 15 to 25% removal of TCE achieved by methane-grown microorganisms previously evaluated in an adjacent in situ test zone. The in situ removal with phenol-grown microorganisms agrees qualitatively with the microcosm studies, with the rates and extents of removal ranked as follows: c-DCE > TCE > t-DCE. These studies demonstrate the potential for in situ TCE bioremediation using microorganisms grown on phenol.

Biodegradation, Environmental↗

Transfer of microorganisms, including Listeria monocytogenes, from various materials to beef.

The quantity of microorganisms that may be transferred to a food that comes into contact with a contaminated surface depends on the density of microorganisms on the surface and on the attachment strengths of the microorganisms on the materials. We made repeated contacts between pieces of meat and various surfaces (stainless steel and conveyor belt materials [polyvinyl chloride and polyurethane]), which were conditioned with meat exudate and then were contaminated with Listeria monocytogenes, Staphylococcus sciuri, Pseudomonas putida, or Comamonas sp. Attachment strengths were assessed by the slopes of the two-phase curves obtained by plotting the logarithm of the number of microorganisms transferred against the order number of the contact. These curves were also used to estimate the microbial population on the surface by using the equation of A. Veulemans, E. Jacqmain, and D. Jacqmain (Rev. Ferment. Ind. Aliment. 25:58-65, 1970). The biofilms were characterized according to their physicochemical surface properties and structures. Their exopolysaccharide-producing capacities were assessed from biofilms grown on polystyrene. The L. monocytogenes biofilms attached more strongly to polymers than did the other strains, and attachment strength proved to be weaker on stainless steel than on the two polymers. However, in most cases, it was the population of the biofilms that had the strongest influence on the total number of CFU detached. Although attachment strengths were weaker on stainless steel, this material, carrying a smaller population of bacteria, had a weaker contaminating capacity. In most cases the equation of Veulemans et al. revealed more bacteria than did swabbing the biofilms, and it provided a better assessment of the contaminating potential of the polymeric materials studied here.

Animals↗

Unexpected thermal destruction of dried, glass bead-immobilized microorganisms as a function of water activity.

To help us understand the factors and mechanisms implicated in the death of microorganisms or their resistance to temperature in a low water activity environment, microorganisms were dried on the surface of glass beads before being subjected to high temperatures for a short period followed by rapid cooling. Two microorganisms were studied: the yeast Saccharomyces cerevisiae and the bacterium Lactobacillus plantarum. Experiments were carried out at 150, 200, and 250 degrees C, with four durations of heat treatment and seven levels of initial water activity between 0.10 and 0.70. We observed an unexpected range of water activity, between 0.30 and 0.50, at which microorganisms were more resistant to the various treatments, with maximal viability at 0.35 for L. plantarum and 0.40 for S. cerevisiae.

Food Microbiology↗

Reductive dehalogenation of brominated phenolic compounds by microorganisms associated with the marine sponge Aplysina aerophoba.

Marine sponges are natural sources of brominated organic compounds, including bromoindoles, bromophenols, and bromopyrroles, that may comprise up to 12% of the sponge dry weight. Aplysina aerophoba sponges harbor large numbers of bacteria that can amount to 40% of the biomass of the animal. We postulated that there might be mechanisms for microbially mediated degradation of these halogenated chemicals within the sponges. The capability of anaerobic microorganisms associated with the marine sponge to transform haloaromatic compounds was tested under different electron-accepting conditions (i.e., denitrifying, sulfidogenic, and methanogenic). We observed dehalogenation activity of sponge-associated microorganisms with various haloaromatics. 2-Bromo-, 3-bromo-, 4-bromo-, 2,6-dibromo-, and 2,4,6-tribromophenol, and 3,5-dibromo-4-hydroxybenzoate were reductively debrominated under methanogenic and sulfidogenic conditions with no activity observed in the presence of nitrate. Monochlorinated phenols were not transformed over a period of 1 year. Debromination of 2,4,6-tribromophenol, and 2,6-dibromophenol to 2-bromophenol was more rapid than the debromination of the monobrominated phenols. Ampicillin and chloramphenicol inhibited activity, suggesting that dehalogenation was mediated by bacteria. Characterization of the debrominating methanogenic consortia by using terminal restriction fragment length polymorphism (TRFLP) and denaturing gradient gel electrophoresis analysis indicated that different 16S ribosomal DNA (rDNA) phylotypes were enriched on the different halogenated substrates. Sponge-associated microorganisms enriched on organobromine compounds had distinct 16S rDNA TRFLP patterns and were most closely related to the delta subgroup of the proteobacteria. The presence of homologous reductive dehalogenase gene motifs in the sponge-associated microorganisms suggested that reductive dehalogenation might be coupled to dehalorespiration.

Anaerobiosis↗

Cellulase from Ruminococcus albus and mixed rumen microorganisms.

Cellulase in the cultural filtrates of Ruminococcus albus and cellulase extracted from mixed rumen microorganisms were investigated with acid-swollen cellulose and carboxymethylcellulose as substrates. Maximal activity occurred at approximately pH 5.8 and 47 C. Apparent Michaelis constants (K(m)) varied between 0.53 and 0.02% carboxymethylcellulose, depending on the level of activity and the method of assay. R. albus cellulase has a lower K(m) value than the enzyme extracted from mixed rumen microorganisms. Antisera from rabbits immunized with a cellulase preparation from R. albus inhibited the cellulolytic activity of both systems. Based on the relative degree of inhibition, approximately 20% of the cellulase of the mixed rumen microorganisms was immunologically similar to R. albus cellulase. Ratios of activity in different assay techniques showed the two sources of activity to be similar in the mechanisms of degradation. However, glucose is the main product of cellulose degradation by mixed rumen microorganisms, and cellobiose is the product of degradation by R. albus.

Animals↗

Endocarpic microorganisms of two types of windrow-dried peanut fruit (Arachis hypogaea L.).

The endocarpic microorganisms of peanut fruit dried in either a random windrow (plants left as they fell from the digger) or an inverted windrow (plants inverted to expose fruit to sunlight) were different from that of freshly dug fruit. Chaetomium, Penicillium, Trichoderma, Rhizoctonia, and Fusarium were the dominant fungi found associated with shells (pericarp) of freshly dug fruit. The dominant fungi of shells of windrowed fruit included Chaetomium, Rhizoctonia, Fusarium, Sclerotium, and Alternaria. Seeds of freshly dug fruit were dominated by Penicillium and Aspergillus. The only dominant species in seed of windrowed fruit was Penicillium. Microorganisms were isolated from shells and seed of freshly dug fruit at a frequency of 79% and 52%, respectively. The percentage of infestation was reduced by drying in the field. This was particularly true of the inverted windrow. The proportion of shells and seed infested with a microorganism was reduced 13% and 36%, respectively, after field drying for 5 to 7 days in random and inverted windrows. Microorganisms were isolated much more frequently from shell pieces (73%) than from seed (36%).

Arachis↗