Intrinsic Biodegradation of Heavy Oil from Nakhodka and the Effect of Exogenous Fertilization at a Coastal Area of the Sea of Japan

We performed a field experiment in thebiodegradation of heavy oil spilled from the Russian tankerNakhodka on a beach in the Sea of Japan. We collectedoil-contaminated cobbles and treated half with nitrogen andphosphorus slow-release fertilizers to stimulate microbialdegradation of the oil; the other half acted as unfertilizedcontrols. The cobbles were placed in porous acrylic vessels andsubmerged. We monitored changes in the oils, macronutrients,microbial community structure and amount of chlorophyll a. There were no significant differences in these criteriabetween the fertilized and unfertilized vessels, apart from anincrease in chlorophyll a in the fertilized vessels.However, there was a major intrinsic degradation of semi-volatile oil compounds in the unfertilized vessels; this occurred at a rate similar to that in the fertilized vessels, despite the low concentration of macronutrients in the seawater at the site.     

Decontamination of aflatoxin-forming fungus and elimination of aflatoxin mutagenicity with electrolyzed NaCl anode solution.

Electrolysis of a 0.1% (17.1 mM) solution of NaCl using separate anode and cathode compartments gives rise to solutions containing active chemical species. The strongly acidic "anode solution" (EW+) has high levels of dissolved oxygen and available chlorine in a form of hypochlorous acid (HOCl) with a strong potential for sterilization, which we have investigated here. Exposing Aspergillus parasiticus at an initial density of 10(3)spores in 10 microL to a 50-fold volume (500 microL) of EW+ containing ca. 390 micromol HOCl for 15 min at room temperature resulted in a complete inhibition of fungal growth, whereas the cathode solution (EW-) had negligible inhibitory effects. Moreover, the mutagenicity of aflatoxin B(1) (AFB(1)) for Salmonella typhimurium TA-98 and TA-100 strains was strongly reduced after AFB(1) exposure to the EW+ but not with the EW-. In high-performance liquid chromatography analysis, the peak corresponding to AFB(1) disappeared after treatment with the EW+, indicating decomposition of the aflatoxin. In contrast, the routinely used disinfectant sodium hypochlorite, NaOCl, of the same available chlorine content as that of EW+ but in a different chemical form, hypochlorite (OCl-) ion, did not decompose AFB(1) at pH 11. However, NaOCl did decompose AFB(1) at pH 3, which indicated that the principle chemical formula to participate in the decomposition of AFB(1) is not the OCl- ion but HOCl. Furthermore, because the decomposition of AFB(1) was suppressed by pretreating the EW+ with the OH radical scavenger thiourea, the chemical species responsible for the AFB(1)-decomposing property of the EW+ should be at least due to the OH radical originated from HOCl. The OH in EW+ was proved by electron spin resonance analysis.     

The fate of markerAzospirillum lipoferum inoculated into rice and its effect on growth,yield and N2 fixation of plants studied by acetylene reduction,15N2 feeding and15N dilution techniques

Summary A spontaneous mutant ofAzospirillum lipoferum, resistant to streptomycin and rifampicin, was inoculated into the soil immediately before and 10 days after transplanting of rice (Oryza sativa L.). Two rice varieties with high and low nitrogen-fixing supporting traits, Hua-chou-chi-mo-mor (Hua) and OS4, were used for the plant bacterial interaction study. The effect of inoculation on growth and grain and dry matter yields was evaluated in relation to nitrogen fixation, by in situ acetylene reduction assay,¹⁵N₂ feeding and¹⁵N dilution techniques. A survey of the population of marker bacteria at maximum tillering, booting and heading revealed poor effectivety. The population of nativeAzospirillum followed no definite pattern. Acetylene-reducing activity (ARA) did not differ due to inoculation at two early stages but decreased in the inoculated plants at heading. In contrast, inoculation increased tiller number, plant height of Hua and early reproductive growth of both varieties. Grain yield of both varieties significantly increased along with the dry matter. Total N also increased in inoculated plants, which was less compared with dry matter increase.¹⁵N₂ feeding of OS4 at heading showed more¹⁵N₂ incorporation in the control than in the inoculated plants. The ARA,¹⁵N and N balance studies did not provide clear evidence that the promotion of growth and nitrogen uptake was due to higher N₂ fixation.     

Molecular typing of Staphylococcus aureus isolated from bovine mastitic milk on the basis of toxin genes and coagulase gene polymorphisms

A total of 270 strains of Staphylococcus aureus, isolated from mastitic milk, were investigated by the polymerase chain reaction for the presence of genes encoding enterotoxins (sea to sej) and a toxic shock syndrome toxin (tst). One hundred eighty three (67.8%) bovine isolates possessed either one or more toxin genes and the most common pattern that coexisted in S. aureus was tst, sec, seg, and sei. Coagulase genotyping revealed 15 patterns, and 161 of the 270 isolates (59.6%) belonged to the coagulase genotype B1. Further, these 161 isolates possessed at least two enterotoxin genes. However, the role of these toxins in udder pathogenicity remains unclear. Moreover, the predominant isolate possessed the enterotoxin genes supporting the theory that superantigenic toxins are important for the udder pathogenesis.     

Chemical composition of cultures and natural samples of N2-fixing blue-green algae from rice fields

Summary Laboratory cultures, soil cultures, and natural samples of N₂-fixing blue-green algae (BGA) from rice fields were analyzed for dry matter, ash, N, C, P, and a few other constituents.Results show a very large variability of the composition. Dry matter contents ranged from 0.28% to 13.6% (average 3.3%). Ash contents ranged from 15.6% to 71.3%. Nitrogen contents ranged from 1.9% to 11.8% on an ash-free basis (average 6%). Carbon content was less variable, ranging from 37% to 72% and averaging 43.7%.A decrease in N and pigment contents, and an increase in reducing sugars, was observed in aging laboratory cultures.Large differences in composition were observed between field samples and material grown in artificial medium. Soil-grown BGA and field samples were characterized by very high ash contents, N contents lower than those in laboratory cultures, and P deficiency.Extrapolation from (1) average dry matter, ash, and N contents and (2) records of BGA biomass in rice fields indicates that an algal bloom has a potentiality of about 15–25 kg N per hectare and that a BGA biomass of agronomic significance is visible to the naked eye.     

The effects of acute exposure to deoxynivalenol on some inflammatory parameters in miniature pigs

Seven miniature pigs were injected intravenously with deoxynivalenol (DON) at 1 mg/kg body weight; afterward, the number of leukocytes in peripheral blood, the luminol-dependent chemiluminescence of neutrophils, the serum or plasma concentration of cytokines and acute-phase proteins were evaluated to determine the effects of acute exposure to DON on inflammatory responses. White blood cell counts were transiently increased at 3, 6, and 12 hr post-injection (PI) due to the increased number of neutrophils. The luminol-dependent chemiluminescence value of neutrophils was significantly elevated at 24 hr PI, indicating the activation of the bactericidal function of neutrophils. Significant increases of interleukin (IL)-8 and tumor necrosis factor-α at 3 hr PI and IL-6 at 6 hr PI were detected in the serum. The concentration of haptoglobin and serum amyloid A was significantly increased at 24 hr PI. These results suggest that acute exposure to DON induced a temporary recruitment of neutrophils in the peripheral blood by IL-8 and subsequent activation of the bactericidal function, and a transient increase of proinflammatory cytokines and acute-phase proteins, indicating the immunomodulatory effects of DON in pigs.     

Citronella as an insect repellent in food packaging

Of five commercial plant extracts (citronella, garlic oil, neem extract, pine oil, and pyrethrum), citronella was found to be effective in deterring the infestation of cartons containing muesli and wheat germ by red flour beetles. The chemical components were applied as part of a coating on the carton board. In an experimental set up that accelerates infestation over a 2 week period, citronella-treated cartons (0.2 g/m2 of carton board) reduced beetle infestation to approximately 50% of the level observed in control cartons. Evidence was provided to indicate that an insect repellent effect persists for at least 16 weeks. Additional work on the controlled release of the insect repellent would be required to prolong the effect.     

Microsatellite mapping of the genes for sham ramification and extra glume in spikelets of tetraploid wheat

The loci for expression of prolonged spikelet rachilla named ‘sham ramification’ in three tetraploid wheat accessions, two accessions of Triticum jakubzineri Udacz. et Schachm. (2n = 4× = 28, genome BBAA) ‘PI 585014’ and ‘R-101-03’ and one sample of Triticum turgidum L. (2n = 4× = 28, genome BBAA) ‘PI 67339’, were mapped by genotyping F₂ populations using microsatellite markers. The segregation analysis confirmed that sham ramification was controlled by recessive, epistatic genes, shr1 (sham ramification 1) and shr2 (sham ramification 2). The genotypes of ‘sham ramification’ were shr1shr1Shr2Shr2 for T. jakubzineri and Shr1Shr1shr2shr2 for T. turgidum (PI 67339). Normal rachilla was determined by Shr1Shr1Shr2Shr2. The shr1 gene and the gene for extra glume (exg) were completely linked; and, the shr1/exg gene complex was bracketed by the markers Xbarc319 and Xbarc232 on the long arm of chromosome 5A. In the F₂ of PI 67339/LD222 the gene shr2 was bracketed by Xwmc819 and Xwmc794 on the long arm of chromosome 2A.     

Field measurement of carbon dioxide evolution from soil by a flow-through chamber method using a portable photosynthesis meter

Extract

Since a rise in atmospheric carbon dioxide (CO₂) concentration is expected to lead to global warming, it is important to quantify the global carbon circulation. The CO₂ evolution rate from soil has usually been measured by one of three methods: 1) CO₂ absorption (Anderson 1982), where the evolved CO₂ is absorbed in an alkali solution and the content subsequently determined, 2) closed chamber (Rolston 1986) in which the CO₂ evolution rate is calculated from the increase of the CO₂ concentration in a closed chamber covering the soil surface, and 3) flow-through chamber (Rolston 1986) in which a fixed rate of ambient air is pumped through an open chamber and the difference in the. CO₂ concentration between the inlet and the outlet is measured. Although the CO₂ absorption method is very simple in terms of apparatus and procedure, the determined CO₂ evolution rate tends to be underestimated in cases where the evolved CO₂ is not fully absorbed in the alkali solution (Ewel et al. 1987; Sakamoto and Yoshida 1988), or overestimated in cases where the CO₂ concentration in the chamber is too low to stimulate microbial activity (Koizumi et al. 1991; Nakadai et al. 1993), In the closed chamber method, when the gas concentration in the chamber is higher than that of the ambient air, gas diffusion from the soil to the atmosphere is restricted (Denmead 1978). At this point, the flow-through chamber method seems to be most suitable for measuring the CO₂ evolution rate, because the rate is determined under nearly natural conditions. However, this method has a disadvantage in that the apparatus is composed of an infra-red CO₂ analyzer, air pumps, mass flow meters, a recorder, and other items, which are too large, heavy, and complex to use in the field (Freijer and Bouten 1991). Hence, in spite of the above limitations, most of the studies on CO₂ evolution in situ have been carried out using the CO₂ absorption method (Kowalenko et al. 1978; Seto et al. 1978a, b; Ewel et al 1981, 1987; Gupta and Singh 1981; Reinke et al. 1981; Edwards and Ros-Todd 1983; Grahammer et al. 1991) or the closed chamber method (Naganawa et al. 1989; Mariko et al. 1994). The flow-through chamber method has been used only at sites where electric power supply and other types of equipment were available (Mathes and Schriefer 1985; Ewel et al. 1987; Nakadai et al. 1993). In the present report a flow-through chamber method using a portable CO₂ analyzer system was examined, for the determination of CO₂ evolution from soil without an electric power supply or other special equipment.