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Kinetics of anaerobic ammonium oxidation (anammox) reaction in marine anammox bacterial culture was first investigated. The nitrogen removal performance of the reactor was compared with prediction of Monod model, modified Stover-Kincannon model, first-order and the Grau second-order substrate removal models. Based on calculations, Monod model, modified Stover-Kincannon model and the Grau second-order model proved to be more appropriate to describe the nitrogen removal kinetics of the reactor than first-order model with high determination coefficients of 0.993, 0.993 and 0.991, respectively. According to the modified Stover-Kincannon model, the maximal substrate removal rate (rm) and saturation rate constant (KB) were suggested as 7.37 and 6.41 g N/L/d, respectively. In addition, in light of the Monod model, the saturation concentration (Ks) and the maximal specific substrate removal rate constant (Rm) were determined to be 0.107 g/L and 0.952 g N/g MLVSS/d, respectively. Moreover, model evaluation was carried out by assessing the linear correlation between measured and predicted values. Both kinetics study and model evaluation showed that Monod model, modified Stover-Kincannon model and the Grau second-order substrate removal models could be used to describe the kinetic behavior or design of the marine anammox reactor., (Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

Anaerobic ammonium oxidation (anammox) bacteria have been detected in variety of marine environment in recent years, however, there have been only a few studies on their characteristics in the culture. The aim of this study is to reveal the effect of temperature on nitrogen removal ability and bacterial community in a culture of marine anammox bacteria (MAAOB). The MAAOB were cultured from the sediment of a sea-based waste disposal site at the North Port of Osaka Bay in Japan. The maximum nitrogen removal rate (NRR) was observed at 25°C in the MAAOB culture, and it decreased both at below 20°C and over 33°C. The activation energy of the MAAOB culture was calculated to be 54.6 kJ mol(-1) in the 5°C to 30°C range. No significant change in bacterial community according with temperature (5-37°C) was confirmed in the results of polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE). Meanwhile, a number of bacteria related to the oxidation-reduction reaction of sulfur were confirmed and it is speculated that they involved in the activity of MAAOB and nitrogen removal ability in the culture., (Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

The present study investigates the enrichment of anaerobic ammonium oxidation (anammox) bacteria in the marine environment using sediment samples obtained from a sea-based waste disposal site and discusses the construction of marine anammox bioreactor. Enrichment of bacteria related to Candidatus Scalindua wagneri along with simultaneous removal of nitrite and ammonium ions was observed in the continuous bioreactor culture under a total nitrogen loading rate of 0.4 kg-N m(-3) day(-1).

The effect of conditioning for a variety of inoculums on fermentative hydrogen production was investigated. In addition, the effects of pH condition on hydrogen fermentation and bacterial community were investigated. The effect of conditioning on hydrogen production was different depending on the inoculum types. An appreciable hydrogen production was shown with anaerobic digested sludge and lake sediment without conditioning, however, no hydrogen was produced when refuse compost and kiwi grove soil were used as inoculums without conditioning. The highest hydrogen production was obtained with heat-conditioned anaerobic digested sludge, almost the same production was also obtained with unconditioned digested sludge. The pH condition considerably affected hydrogen fermentation, hydrogen gas was efficiently produced with unconditioned anaerobic sludge when the pH was controlled at 6.0 throughout the culture period and not when only the initial pH was adjusted to 6.0 and 7.0. Hydrogen production decreased when the culture pH was only adjusted at the beginning of each batch in continuous batch culture, and additionally, bacterial community varied with the change in hydrogen production. It was suggested that Clostridium and Coprothermobacter species played important role in hydrogen fermentation, and Lactobacillus species had an adverse effect on hydrogen production.

An aryl-phosphate ester (APE)-degrading bacterium was isolated from the leachate of a sea-based waste disposal site. The isolated APE-degrading bacterial strain YS-57 grew well in a medium containing glucose and NaCl, and degraded two types of APE:tricresyl phosphate and triphenyl phosphate. The optimal temperature, pH, and NaCl concentration for the growth of strain YS-57 were 30 degrees C, 7.0, and 1.0%, respectively. Strain YS-57 grew at an APE concentration of 25 mg/l without being inhibited. APEs were degraded by the supernatant of the medium in which strain YS-57 was cultured, suggesting that the APE-degrading enzyme was released into the extracellular space in the logarithmic growth phase. The 16S rDNA sequence of strain YS-57 showed 95.6% similarity to that of Roseobacter gallaeciensis and the morphological properties were also comparable. Consequently, strain YS-57 was closely related to the genus Roseobacter.