Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Abstracted in Dissertation abstracts, v. 19 (1959) no. 11, p. 2779. Includes Gas chromatographic separation of some permanent gases on silica gel at reduced temperatures, by D.H. Szulczewski and T. Higuchi, reprinted from Analytical chemistry, vol. 29 (1957) p. 1541-[1543]. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

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1) Nitrapyrin was less inhibitory to Nitrosomonas europaea in soil culture than in liquid batch culture.2) In the course of liquid batch culture studies, 3 strains of N. europaea were isolated which exhibited differing responses to nitrapyrin. All 3 strains however, were inhibited by 0.5 ppm nitrapyrin and stationary phase cells were found to be less sensitive than exponentially growing cells. 3) 6-chloropicoline, a hydrolysis product of nitrapyrin, was found to inhibit exponentially growing but not stationary phase cells. 4) Cells of N. europaea adhered to glass slides and during the initial stages of colonisation cells were not protected from the inhibitory effect of nitrapyrin. Once cells had become established at the solid/liquid interface there was a significant reduction in the specific growth rate compared with freely suspended cells and 0.5 ppm nitrapyrin no longer inhibited growth. 5) The specific growth rate of cells detached from the surface of a glass slide was not significantly different from that of cells adhered to the surface but significantly less than the specific growth rate of freely suspended cells. Detached cells were not significantly inhibited by 0.5 ppm nitrapyrin. 6) In the presence of montmorillonite, vermiculite and ammonia-treated vermiculite (ATV), growth of N. europaea occurred in two distinct growth phases. All three clay types reduced the inhibitory effect of nitrapyrin and inhibition was only observed during the second growth phase. In the presence of a fourth clay type, illite, growth occurred in one phase only and there was no significant reduction in inhibition by nitrapyrin. 7) Addition of Cu2+ and A13+ enhanced inhibition of N. europaea by nitrapyrin in liquid batch culture. 8) Growth of N. europaea at sub-optimal rates in chemostat culture reduced the sensitivity of cells to nitrapyrin. Productivity increased with increasing nitrapyrin concentrations and ammonia oxidizing activity per cell increased following addition of 0.5 ppm and 1.5 ppm nitrapyrin to steady state cultures. 9) Therefore the clay content of soils and the physiological state of N. europaea may reduce the effectiveness of nitrapyrin when applied in the field.

This study used Vanadium (III) reduction- chemiluminescence method to measure the very low concentration of nitrite plus nitrate (N+N) in oligotrophic seawaters with a detection limit of 0.7nM. In addition, the high temperature catalytic oxidation (HTCO) ¡V chemiluminescence method was applied to determine the concentration of total dissolved nitrogen (TDN) with a detection limit of 0.5£gM based on a volume of 150£gL seawater. Both methods have high degree of precision and accuracy. Furthermore, the Magic method and persulfate oxidation method were conducted to measure the concentrations of soluble reactive phosphorus (SRP) and total dissolved phosphorus (TDP) with detection limits about 10 nM (original seawater) and 100 nM, respectively. All these analytical methods meet the ranges of parameters in most oligotrophic oceans. According to the hydrology data, the Kuroshio of east Taiwan may be classified into four types: 1. Kuroshio Waters affected by the East China Seawater (ECS-KW)¡F2. typical Kuroshio Waters (KW)¡F3. Kuroshio Waters affected by the South China Seawater (SCS- KW) and 4.Kuroshio waters affected by riverplume (plume- KW). In the euphotic zone, the concentrations of N+N, SRP, DON and DOP in the plume-KW are about 0.6 ~ 4 £gM, 0.03 ~ 0.4 £gM, 2 ~ 6 £gM, and 0.05 ~ 0.2 £gM, respectively, higher than those in other type waters. The plume-KW is apparently influenced by the input of freshwater. Besides, the nitrogen and phosphorus species in the SCS-KW and ECS-KW are higher than those in the KW. Positive correlations are significant between Ch1 a and DON and DOP, indicating that biological activity controls primarily on the distributions of DON and DOP in the euphotic zone. KW has oligotrophic characteristics, and in the euphotic zone, the concentrations of N+N and SRP are generally lower than those in other water types. The Chl a has positive correlations with DON and N+N, resulted likely from their same features of subsurface maxima. The ratio between N+N and SRP in the euphotic zone is about 0.02~0.15, and the value increases gradually in deep water, and eventually close the Redfield ratio. Judging from the distribution of the nitrate anomaly (2.5~ 1.5£gM), nitrogen fixation may prevail in the KW. The N+N and SRP values in the euphotic zone in the SCS-KW near the southeastern coast of Taiwan are about 0.02£gM higher in spring than in summer. DON and DOP are also about 1~2.5£gM and 0.02~0.2£gM higher, respectively, in spring than in summer. This feature may be caused from getting stratification torward the summer season in the SCS-KW.

Extraction of bitumen from oil sands by surface mining and alkaline hot water process has generated large amount of oil sand process water (OSPW) which are contaminated by naphthenic acids (NAs). Due to the toxic and harmful nature of NAs, OSPW have been stored on-site in extremely large tailing ponds. With the understanding that the OSPW must be treated before their release into the natural water bodies and the need for reuse of the water, there is an urgent need in finding ways to treat these OSPWs effectively and economically. Numerous works on different treatment methods including photocatalysis, ozonation, adsorption, phytoremediation, simulated wetlands and bioremediation have been conducted and bioremediation has been proved as one of the most feasible ways among these methods. Research works on biodegradation of NAs, both aerobically and anoxically, have been conducted intensively in our research group in the past several years. Using surrogate NAs, specially trans-4-methyl-1-cyclohexane carboxylic acid (trans-4MCHCA), aerobic (Paslawski et al., 2009a,b,c, Huang et al., 2012; D’Souza et al., 2013) and anoxic (Gunawan et al., 2014) biodegradations of NA have been studied in batch, CSTR, biofilm system and circulating packed-bed bioreactor. Effects of naphthenic acid concentration, temperature, and naphthenic acid loading rate on the biodegradation process have been investigated. The results of the anoxic biodegradation of trans-4MCHCA in the presence of nitrate as an electron acceptor revealed that its performance was similar or better than the aerobic biodegradation. The results of that study also indicated the production of nitrite during the denitrification of nitrate and its subsequent consumption as part of biodegradation process. Given the importance of denitritation (nitrite reduction) as an essential step in anoxic biodegradation in the presence of nitrate, and the potential inhibitory effect of nitrite, the current research was conducted with the aim of investigating the performance of the anoxic biodegradation of trans-4MCHCA in the presence of nitrite as an electron acceptor, using batch, CSTR and biofilm reactors. The results of batch studies showed that nitrite at concentration up to 690 mg L-1 did not have a marked inhibitory effect but concentrations above 920 mg L-1 imposed a strong inhibitory effect. The optimum temperature was found to be in the range 24 C to 30°C. Continuous anoxic biodegradation of trans-4MCHCA with nitrite in CSTR achieved the maximum trans-4MCHCA biodegradation rate of 14.4 mg L-1 h-1 at a trans-4MCHCA loading rate of 22.9 mg L-1 h-1, which was about seven fold lower than the maximum trans-4MCHCA biodegradation rate observed with nitrate as an electron acceptor (105.4 mg L-1 h-1; Gunawan 2013). Both the trans-4MCHCA and nitrite degradation rates decreased with further increase of trans-4MCHCA loading rate. Using the experimental data the biokinetic coefficients Y (biomass yield), Ke (endogenous rate constant), μm (maximum specific growth rate) and Ks (saturation constant) were determined as 0.3 mg cell mg substrate-1, ~0 h-1, 0.4 h-1 and 20.9 mg substrate L-1, respectively. Similar pattern was observed in the biofilm system whereby the maximum trans-4MCHCA biodegradation rate was 82.2 mg L-1 h-1 at a trans-4MCHCA loading rate of 171.8 mg L-1 h-1, was about five folder lower than the maximum trans-4MCHCA biodegradation rate observed when nitrate was used as an electron acceptor (435.8 mg L-1 h-1; Gunawan 2013). The findings of current study suggested that the anoxic NA biodegradation in the presence of nitrite occurred at rates which were lower than those observed in the presence of nitrate, as well as those obtained under aerobic conditions with oxygen as the electron acceptor.

Membrane inlet mass spectrometry was used to observe nitric oxide in the well-studied reaction of nitrite with hemoglobin. The membrane inlet was submerged in the reaction solutions and measured NO in solution via its flux across a semipermeable membrane leading to the mass spectrometer detecting the mass-to-charge ratio m/z 30. This method measures NO directly in solution and is an alternate approach compared with methods that purge solutions to measure NO. Addition to deoxy-Hb(FeII) (near 38 μM heme concentration) of nitrite in a range of 80 μM to16 mM showed no accumulation of either NO or N2O3 on a physiologically relevant time scale with a sensitivity near 1 nM. The addition of nitrite to oxy-Hb(FeII) and met-Hb(FeIII) did not accumulate free NO to appreciable extents. These observations show that for several minutes after mixing nitrite with hemoglogin, free NO does not accumulate to levels exceeding the equilibrium level of NO. The presence of cyanide ions did not alter the appearance of the data; however, the presence of 2 mM mercuric ions at the beginning of the experiment with deoxy-Hb(FeII) shortened the initial phase of NO accumulation and increased the maximal level of free, unbound NO by about twofold. These experiments appear consistent with no role of met-Hb(FeIII) in the generation of NO and an increase in nitrite reductase activity caused by the presumed binding of mercuric to cysteine residues. These results raise questions about the ability of reduction of nitrite mediated by deoxy-Hb(FeII) to play a role in vasodilation.

It is usually assumed that the reduction of nitrite by nitrite reductase results in the formation of ammonia. The purpose of this investigation was to enquire whether more than one nitrite reductase activity is responsible for in vivo nitrite reduction. An assay system which measures the production of ammonia, as a result of nitrite reductase is described. The. reduction of nitrite by nitrite reductase did not result in the formation of stoichiometric amounts of ammonia. Nitrite non-utilizing mutants showed that nitrite reduction could occur in vitro with no subsequent formation of ammonia or could result in the formation of essentially stoichiometric amounts of ammonia. Sedimentation velocity gradient centrifugation resulted in the separation of at least two peaks of nitrite reductase activity. A model is described which accounts for the results in terms of two nitrite reductase activities, necessary for in vivo nitrite reduction. / Thesis / Master of Science (MSc)

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