Eimeria saudiensis N. Sp. (Apicomplexa: Eimeriidae) from the Arabian Oryx (Oryx leucoryx) in Saudi Arabia

Oocysts of Eimeria saudiensis n. sp. (Apicomplexa: Eimeriidae) are described from the feces of the Arabian oryx, Oryx leucoryx , from the Riyadh Zoo, Saudi Arabia. The oocysts were ellipsoidal or slightly ovoid, 31.2 times 24.5 (24.3–36.5 times 20.0–27.6) μm with a bilayered wall about 1.7 μm thick. The micropyle was covered by a dome-shaped cap. The oocyst residuum was absent, but tiny polar granules were present. The sporocysts were elongate ovoid, 14.3 times 7.2 (11.5–18.5 times 6.0–9.0) μm, had a Stieda body, but lacked a substiedal body. The sporocyst residuum was present, composed of numerous small granules. The sporozoites were elongate club-shaped, and contained two prominent refractile bodies.     

EARLY STARVATION1 specifically affects the phosphorylation action of starch‐related dikinases

Starch phosphorylation by starch‐related dikinases glucan, water dikinase (GWD) and phosphoglucan, water dikinase (PWD) is a key step in starch degradation. Little information is known about the precise structure of the glucan substrate utilized by the dikinases and about the mechanisms by which these structures may be influenced. A 50‐kDa starch‐binding protein named EARLY STARVATION1 (ESV1) was analyzed regarding its impact on starch phosphorylation. In various in vitro assays, the influences of the recombinant protein ESV1 on the actions of GWD and PWD on the surfaces of native starch granules were analyzed. In addition, we included starches from various sources as well as truncated forms of GWD. ESV1 preferentially binds to highly ordered, α‐glucans, such as starch and crystalline maltodextrins. Furthermore, ESV1 specifically influences the action of GWD and PWD at the starch granule surface. Starch phosphorylation by GWD is decreased in the presence of ESV1, whereas the action of PWD increases in the presence of ESV1. The unique alterations observed in starch phosphorylation by the two dikinases are discussed in regard to altered glucan structures at the starch granule surface.     

Nutrient Leaching and End Product Accumulation in Plastic Composite Supports for L-(+)-Lactic Acid Biofilm Fermentation

Investigations on the leachate bioavailability, leaching rate, and lactic acid accumulation properties of plastic composite supports (PCS) were essential for large-scale or long-term lactic acid fermentation. Leachates from PCS and polypropylene discs (controls) were analyzed by the micro-Kjeldahl method; by absorbances at 260, 275, and 280 nm; and by bioassays with Lactobacillus casei subsp. rhamnosus (ATCC 11443). The amount of leached nitrogen in a 20-ml initial soaking solution had a high correlation with the soaking solution's cell density (r = 0.87) and absorbance at 260 nm (r = 0.95). Leaching rates of various PCS were evaluated by 20 20-ml simulated repeated-batch fermentations (RBF). PCS with only yeast extract as the minor agricultural ingredient had a high leaching rate and leached out 51 to 60% of the total nitrogen during the first RBF. PCS blended with dried bovine albumin, dried bovine erythrocytes, and/or soybean flour had slowed nutrient leaching (20 to 30% of the initial leached nitrogen). Hence, they could still maintain 1 g of lactic acid per liter and measurable cell density (absorbance at 620 nm, 0.4 to 0.6) at the 20th 20-ml RBF. Lactic acid accumulation properties of PCS were evaluated by soaking the supports in a 30% lactic acid solution for 72 h at 45(deg)C. The lactic acid-soaked supports were rinsed three times and then heat treated (121(deg)C, 15 min) in 15 ml of deionized water. The results showed that lactic acid accumulation in PCS was mainly due to absorption and had no correlation with lactic acid production or biofilm formation.     

Investigation of the potential for microbial contamination of deep granitic aquifers during drilling using 16S rRNA gene sequencing and culturing methods

Total number of bacteria, viable counts of aerobic and anaerobic heterotrophic bacteria and 16S rRNA gene diversity were investigated during drilling of three boreholes in the walls of the Äspö hard rock laboratory tunnel, at depths ranging from 380 to 446 m below sea level. Water samples were taken from the drill water source, the drilling equipment and from the drilled boreholes. The drill water was kept under nitrogen atmosphere and all equipment was steam cleaned before the start of a new drilling. Total and viable counts of bacteria in the drilled boreholes were several orders of magnitude lower than in the samples from the drilling equipment, except for sulphate reducing bacteria. A total of 158 16S rRNA genes that were cloned from the drill water source, the drilling equipment and the drilled boreholes were partially sequenced. The drilled boreholes generally had a 16S rRNA diversity that differed from what was found in samples from the drilling equipment. Several of the sequences obtained could be identified on genus level as one of the genera Acinetobacter, Methylophilus, Pseudomonas and Shewanella. In conclusion, the tubing used for drill water supply constituted a source of bacterial contamination to the rest of the drilling equipment and the boreholes. The results show, using molecular and culturing methods, that although large numbers of contaminating bacteria were introduced to the boreholes during drilling, they did not establish in the borehole groundwater at detectable levels.     

Characterization of Plant Alcohol Dehydrogenase

The final activity of the alcohol dehydrogenase (E.C.1.1.1.1, abbreviated ADH) from germinating pea, isolated by fractionating with ammonium sulphate, chromatography on DEAE cellulose and gel filtration, was 80,000, from bean 25,000 and from lentil 13,500 units per mg protein. Molecular weights of the ADHs are close to each other: pea and bean ADH 60,000, lentil ADH 70,000. The K_m values are mutually similar with three enzymes, i.e. of the order of 10⁻⁴M for NAD and 10⁻²M for ethanol. The pH optima lie in the alkaline region. These enzymes catalyse oxidation of a number of monovalent alcohols. At temperatures above 60°C the enzymes are thermally unstable. Stability is enhanced slowly by ethanol but not by NAD. Pyrazol, imidazol and pyridine inhibit plant ADH similarly to the enzyme from horse liver. There is a similarity between plant alcohol dehydrogenases and animal and yeast enzymes.     

Culture-dependent comparison of microbial diversity in deep granitic groundwater from two sites considered for a Swedish final repository of spent nuclear fuel

Site selection for a spent nuclear fuel (SNF) repository required analysis of microbial abundance and diversity at two Swedish sites, Forsmark and Laxemar-Simpevarp. Information about sulphate-reducing bacteria (SRB) was required, as sulphide could corrode copper SNF canisters. Total number of cells (TNC) and ATP were analysed, and plate counts and most probable number (MPN) analyses were conducted using eight media based on different electron donors and acceptors for specific microorganism physiological groups. Groundwater chemical composition and E(h) were analysed; sampling depths were 112-978 m below sea level. TNC was 5.5 × 10(3) to 4.7 × 10(5) cells mL(-1), correlating with ATP concentrations. Culturability in TNC percentage was 0.01-35.9, averaging 5.12. Culturable numbers varied greatly between sample positions and uncorrelated with depth. SRB were found in 29 samples and were below detection in three; the MPN of SRB correlated negatively with E(h), as did the MPN of acetogens. Data indicated that microbial sulphate reduction was ongoing in many sampled aquifers; published stable isotope data and modelling results supported this observation. The sites did not differ significantly, but the large data range suggested that analysis of more samples would enable detailed evaluation of microbial processes and their relationship with geochemical information.