Mattesia bombi n. sp. (Neogregarinida: Ophrocystidae), a parasite of Bombus (Hymenoptera: Apidae)

The fat bodies of queen, male, and worker bumble bees were found to harbor a parasite, Mattesia bombi n. sp. (Neogregarinida: Ophrocystidae). The life cycle of this protozoan includes micronuclear and macronuclear schizogonies, gametogony, and sporogony. Sporocysts are predominantly oval in shape and measured 27 × 5.4 μm when mature. The life cycle of the parasite is described and the mode of infection discussed.     

Myxosporida (Protozoa): The determination and maintenance of spore size and shape

Data are presented which suggest that the size of fish myxosporidan spores is primarily determined by the parasite's development in the tissues or organ's cavities and the spore's shape is determined by the presence of physiologically and behaviorally suitable fish.     

Effect of desiccation level and storage temperature on green spore viability of Osmunda japonica

In order to effectively preserve green spores, which have relatively higher water content and lose viability more quickly than non-green spores, we studied the effect of desiccation level and storage temperature on Osmunda japonica spores. The water content of fresh spores was 11.20%. After 12 h desiccation by silica gel, the water content decreased to 6% but spore viability did not change significantly. As the desiccation continued, the decrease in water content slowed, but spore viability dropped. For almost all storage periods, the effects of storage temperature, desiccation level, and temperature × desiccation level were significantly different. After seven days of storage, spores at any desiccation level stored at 4 °C obtained high germination rates. After more than seven days storage, liquid nitrogen (LN) storage obtained the best results. Storage at −18 °C led to the lowest germination rates. Spores stored at room temperature and −18 °C all died within three months. For storage at 4 °C and in LN, spores desiccated 12 and 36 h obtained better results. Spores without desiccation had the highest germination rates after being stored at room temperature, but suffered the greatest loss after storage at −18 °C. These results suggest that LN storage is the best method of long-term storage of O. japonica spores. The critical water content of O. japonica spores is about 6% and reduction of the water content to this level improves outcome after LN storage greatly. The reason for various responses of O. japonica spores to desiccation and storage temperatures are discussed.     

Mattesia geminata sp. n. (Neogregarinida: Ophrocystidae) a Parasite of the Tropical Fire Ant,Solenopsis geminata (Fabricius)*

SYNOPSIS. A new species of neogregarine, Mattesia geminata sp. n., that infects immature stages of the tropical fire ant, Solenopsis geminata (Fabricius), is described. The parasite, which develops in the hypodermis, causes disruption of the developing eyes, melanization of the cuticle, and death of pupae. lntracolonial infection rates are usually less than 2±, but may exceed 90±. Attempts to transmit the infection were unsuccessful.     

Effect of storage temperature and duration on viability of eggs of Helicoverpa armigera (Lepidoptera: Noctuidae)

The ability to store different insect stadia for prolonged periods provides considerable flexibility and ability to conduct experiments properly. Therefore, studies were undertaken to determine the effect of storage temperature and duration on viability of eggs of Helicoverpa armigera (Hübner). The percentage egg hatch and incubation period were significantly (P=0.01) influenced by egg age, storage temperature, and storage duration. Egg hatch ranged from 0.0 to 96.8% across temperatures and storage durations. None of the eggs hatched when stored at -20 and 0 degrees C. The regression model with the optimum Mallow Cp statistic for any of the identified linear and quadratic terms did not improve the precision of prediction in egg hatch beyond 67.0%. Forecasting of incubation period based on egg age, storage duration, and durationxtemperature was quite effective (R2=84.2%). Day degrees required for egg hatching decreased with an increase in temperature from 10 to 27 degrees C, and egg age from 0 to 3 days. The day degree requirements were highest for 0-day-old eggs at 10 degrees C, and lowest at 27 degrees C. Although the incubation period was higher, the hatchability was lower for 0- and 1-day-old eggs stored at constant 10 degrees C, these eggs can be stored for 10 days at 10 degrees C, with a hatchability of >75.0%. It was safer to store the H. armigera eggs for 10 days at 10 degrees C, which will hatch within 1.6 to 2.0 days after restoration at 27 degrees C with a hatchability of >75.0%. This information will be useful in planning and execution of experiments involving H. armigera on various aspects of research in entomology.     

Effect of storage method on spore viability in five globally threatened fern species

Spore germination of five globally threatened fern species [Culcita macrocarpa C. Presl, Dryopteris aemula (Aiton) O. Kuntze, D. corleyi Fraser-Jenkins, D. guanchica Gibby and Jermy and Woodwardia radicans (L.) Sm.] was determined after 1, 6 or 12 months of storage in glass vials (dry storage) or on agar (wet storage) at -20, 5 or 20 degrees C. In all species, storage technique, storage temperature and the technique-temperature interaction all had a significant effect on germination percentage. In most cases, the germination percentage was best maintained by wet storage at 5 or 20 degrees C. In the case of the hygrophilous species C. macrocarpa and W. radicans, 6 or 12 months' dry storage killed most spores. Only Woodwardia radicans germinated in the dark during wet storage at 20 degrees C. Wet storage at 5 degrees C prevented dark germination, and reduced bacterial and fungal contamination. Wet storage at -20 degrees C killed all or most spores in all species. In the three Dryopteris species, the differences among the storage conditions tested were smaller than in C. macrocarpa and W. radicans, and the decline in spore viability during storage was less marked, with high germination percentages being observed after 12 months of dry storage at all three temperatures. Dry storage, which has lower preparation time and space requirements than wet storage, was generally more effective at the lower temperatures (-20 or 5 degrees C).     

The influence of various storage conditions on cell viability in amniotic membrane

Up to now freeze-dried, gamma-sterilised or glycerol-preserved amniotic membranes (AMs) have widely been used in the field of ophthalmology and wound care (e.g. leg ulcers, burns). After some preservation processes in use, like freeze-drying or glycerol-preserving, the cells in the AM are no longer viable. Within this study we evaluated the influence of different short-term and long-term storage conditions on cell viability in AM. Therefore AMs from cesarean section placentae were washed and biopsied to evaluate the microbiological status and to determine the viability of the tissue. Additionally, viability under various storage conditions was examined by assessment of mitochondrial activity. Preservation included temperatures above and below 0°C as well as various media compositions. As expected, cell viability in amnion decreases during storage, in fact the effect was more pronounced when stored frozen, but the higher viability of amnion obtained by storage above 0°C with medium is associated with the limitation to a short period of storage of about 28 days. The evaluated preservation methods are the basis for future non-clinical in-vivo studies in which the possible benefit of amnion as a viable biomaterial in wound healing will be investigated. A part of this work was presented at the World Congress on Tissue Banking in Rio in May 2005 and was honoured by the Poster Award Commission.     

The Fine Structure of Some Developmental Stages of Mattesia grandis McLaughlin (Sporozoa, Neogregarinida), a Parasite of the Boll Weevil Anthonomus grandis Boheman

SYNOPSIS Sporozoites, macronuclear schizonts, merozoites and gamonts of Mattesia grandis were examined by electron microscopy. A conoidal complex, consisting of conoid, polar rings and subpellicular microtubules was present in all of these stages. The conoidal complex was similar in structure to the same organelle of other Sporozoa. The conoidal complex in mono- to quadrinucleate macronuclear schizonts is transformed into an organelle similar to the mucron of some eugregarines.
This mucron consists of a specialized area of the cell membrane from which fine fibers extend into a large vacuole situated directly beneath the cell membrane. The top part of the vacuole is encircled by 2 ring-like structures formed by the dilatation of the original apical rings. The vacuole of the mucron contains many anastomosing protrusions of the cytoplasm, suggesting a nutritional role. The mucron disappears when the schizont reaches the multinucleate state. Later the merozoites bud from the surface of the schizont as in the coccidia. Each merozoite again has a conoidal complex, which persists thru the gamont stage and usually serves as the point of contact between 2 gamonts during their pairing.
The presence of a conoidal complex thru a major portion of the life cycle, its transformation into a mucron and the mode of formation of merozoites indicate that the Neogregarinida combine the fine structure characters of both the Eugregarinida and the Eucoccida, thereby suggesting a phylogenetic relationship between these sporozoans, with the neogregarines as a link between eugregarines and coccidia.     

Long-term storage and viability of Ochlerotatus albifasciatus (Diptera: Culicidae)

The viability of Ochlerotatus albifasciatus (Macquart) eggs stored at room temperature and at 5 degrees C was studied over 31 months. After 12, 18 and 31 months of storage, eggs were acclimatized at 22 degrees C for ten days, and then inundated twice every seven days. The effect of the storage period on the percentage of hatching was analyzed by one way ANOVA. Differences on the hatching response between the first and second flooding were analyzed by paired t-test. Differences on the hatching response between the two storage conditions were analyzed by Mann-Whitney rank test. Results showed that (1) Oc. albifasciatus eggs were able to survive and hatch over 31 months; (2) the percent hatching of eggs stored at 5 degrees C was higher than that of eggs stored at room temperature; and (3) low temperatures and long periods without water favor installment hatching.     

Effects of superheated steam on Geobacillus stearothermophilus spore viability

Aims: To examine the effect of processing with superheated steam (SS) on Geobacillus stearothermophilus ATCC 10149 spores. Methods and Results: Two inoculum levels of spores of G. stearothermophilus were mixed with sterile sand and exposed to SS at 105–175°C. The decimal reduction time (D‐value) and the thermal resistance constant (z‐value) were calculated. The effect of cooling of spores between periods of exposure to SS was also examined. A mean z‐value of 25·4°C was calculated for both inoculum levels for SS processing temperatures between 130°C and 175°C. Conclusions: Spore response to SS treatment depends on inoculum size. SS treatment may be effective for reduction in viability of thermally resistant bacterial spores provided treatments are separated by intermittent cooling periods. Significance and Impact of the Study: There is a need for technologies that require short thermal processing times to eliminate bacterial spores in foods. The SS processing technique has the potential to reduce microbial load and to modify food texture with less energy in comparison to commonly used hot air treatment. This work provides information on the effect of SS processing parameters on the viability of G. stearothermophilus spores.     

The effects of some storage conditions on viability of Lecanicillium lecanii conidia to whitefly (Homoptera: Trialeurodes vaporariorum)

A study on the survival of Lecanicillium lecanii conidia in storage at room temperature was carried out. Firstly, drying methods of conidia powder were compared. Vacuum-freeze drying (VFD) was more suitable for drying conidia as compared to vacuum drying (VD) at room temperature. Vacuum-freeze drying for 24-h resulted in a water content of 5.4%, and a viability, determined as germination of conidia in 2% glucose solution after16 h, was 90.3% and the infection in greenhouse whitefly, Trialeurodes vaporariorum was about 94.7% at a dose of 1×10⁸ conidia/mL. Secondly, the factors influencing viability of conidia stored at room temperature were evaluated in the laboratory. Temperature was the most critical factor influencing conidial storage stability, among the tested factors affecting survival of conidia stored at room temperature for 6 months. Both conidial germination and infection of hosts decreased with storage temperature increasing from 15 to 35°C, and at 35°C the survival of stored conidia for 6 months was near zero. The moisture content of the conidial powder was another major factor influencing viability of stored conidia at room temperature. Conidial powder dried to about 5% moisture content showed higher viability than non-dried conidial powder. For the carriers, clay and charcoal were more suitable for storage of L. lecanii conidia at room temperature. At a room temperature of 25°C, L. lecanii conidia which were dried to 5% water content and mixed with clay or charcoal could retain about 50% survival after 6 months' storage.     

The storage of infective spores of Vairimorpha necatrix (Protozoa: Microsporida) in antibiotic solution at 4 degrees C.

The interactions between the Diacrisia virginica granulosis virus (DGV) and the Hyphantria cunea baculovirus isolates were determined, utilizing defined differences between the time-mortality responses of these viruses fed to H. cunea larvae. The DGV, having a prolonged incubation period, when given an advantage in time or in the number of capsules, was able to prevent the expression of the more lethal H. cunea granulosis virus (HcGV) isolate. The time-mortality response of test larvae simultaneously fed equivalent dosages of HcGV and DGV was intermediate to that achieved with HcGV alone or DGV alone. Larvae infected with the DGV isolate were still susceptible to double infection by the nucleopolyhedrosis virus. The time-mortality response demonstrated that the development of nucleopolyhedrosis was only partly inhibited by preinfecting the test larvae with the DGV isolate.     

The effect of solid medium composition on growth and sporulation ofStreptomyces clavuligerus; spore viability during storage at +4°C

Summary The effect of solid medium composition and pH on growth and sporulation ofStreptomyces clavuligerus was studied in Petri dish and slant cultures at 30 °C. The extent of sporulation was observed under the microscope and the number of viable spores per slant was counted by serial dilution. Abundant aerial mycelium and sporulation were achieved with some of the media tested in this work. In Tris/HCl buffer (0.05 M, pH 7.2), containing 0.1% Tween 80, spores retained 28%, 17% and 2% viability at +4 °C after 1,9 and 17.5 weeks, respectively.     

The ecological energetics of Amoeba proteus (Protozoa)

The consumption, production and respiration of Amoeba proteus were measured in the laboratory for cells cultured over a range of Tetrahymena pyriformis concentrations (125–4 000 cells/0.5 ml) at 10, 15 and 20 °C. Differences were attributed to both temperature and prey availability. A series of generation energy budgets were constructed for amoebae grown under the above conditions. The biological efficiencies linking the parameters of the budget equation were calculated. Assimilation efficiencies ranged from 22–59% regardless of temperature. Net production efficiencies were high at 15 and 20 °C (65–82%) but low at 10 °C (11–49%). Gross production efficiencies were also higher at 15 and 20 °C (16–47%) than at 10 °C (4–29%). The ecological implications of this investigation are discussed.     

The storage of green coffee (Coffea arabica): decrease of viability and changes of potential aroma precursors

BACKGROUND AND AIMS: When green coffee is stored for a prolonged time the coffee quality decreases distinctively. Apart from well-known 'off-notes' that arise from undesired oxidations of lipids, a typical 'flattening' of the cup quality is detectable. In order to elucidate the biological causes for this phenomenon, differentially processed coffees (wet, dry, semi-dry processing), were stored under standard conditions for 2 years and analysed comprehensively. METHODS: Wet-processed coffee was stored either as parchment coffee, where the endocarp remained around the beans or as hulled beans. Viability of coffee seeds was estimated using the tetrazolium-test of seed viability. Changes in concentration of free amino acids and soluble carbohydrates were analysed by HPLC. KEY RESULTS: Whereas all other coffees lost viability within the first 6 months of storage, coffee beans stored within the parchment remained viable for >1 year. Glucose and fructose decreased slightly in the course of storage and glutamine content declined significantly. However, the changes observed in sugar and amino acid content were not correlated with the viability of the coffee beans. Consequently, neither typical metabolic reactions occurring within living cells nor characteristic post-mortem reactions could be responsible for the observed changes. As a result of post-mortem reactions in re-imbibed seeds, a characteristic bluish-green colour developed, putatively due to the oxidation of chlorogenic acids and subsequent reactions with primary amino compounds. This coloration might be an appropriate marker to substantiate if coffee seeds had been stored for an expanded time and putative quality losses were not relevant so far. CONCLUSIONS: It is suggested that loss of viability is relevant for the aroma flattening. As neither metabolic nor post-mortem reactions were responsible for the observed changes, it is concluded that Maillard reactions that occur during storage might be the cause of the decrease in potential aroma precursors.     

The influence of cumin seed exudates on fungal spore germination

Summary Effect of cumin seed exudates on spore germination of Curvularia lunata, Alternaria solani and Colletotrichum capsici was studied in the laboratory. Three-hour exudate obtained for first 3-hour favoured initial protrusion but inhibited subsequent growth of the germ tubes. Two-hour exudate obtained between 5 and 7 hours after soaking was suggested to have no effect on initial protrusion but was found to have promotive effect on subsequent growth of germ tube. Short treatment with inhibitor for 45 minutes followed by a treatment with promotor ensured high germination and uniform germ tube growth. Modifying effects on the spermatosphere and adaptive significance of sequential exudation are discussed. re]19730125     

Effect of storage time and temperature and the variation among replicate tests (on different days) on the performance of spore disks and strips.

Laboratory-prepared spore disks were stored for 96 weeks at 22 degrees C with 50% relative humidity (RH) and at 4 degrees C with less than 1% RH. At the same time commercial spore strips were stored for 64 weeks at 22 degrees C with 50% RH. The spore count per unit and the heat resistance were measured at the beginning of the experiment and after 16, 32, 48, 64, 80, and 96 weeks of storage. The laboratory-prepared spore disks stored at 4 degrees C with less than 1% RH showed less change in numbers of spores per disks and decrease in the survival time than did the disks stored at 22 degrees C with 50% RH. Both the laboratory-prepared spore disks and the commercial spore strips stored at 22 degrees C with 50% RH decreased in survival times with increased storage time. The relative change in the survival times with storage was less for the commercial spore strips than for the laboratory-prepared spore disks.