Autotrophic nitrification in acid tea soils

Hayatsu, Masahito; Kosuge, Nobuo

doi:10.1080/00380768.1993.10416992

Cited by 50 publications

(30 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This similarity strongly supports our hypothesis that pH, within wide limits, does not primarily control growth and activity of nitrifiers. Our findings are in line with the observation that the increased addition of calcium carbonate to acidic tea soils does not affect nitrification rate (30).…”

supporting

confidence: 82%

Nitrification in a Biofilm at Low pH Values: Role of In Situ Microenvironments and Acid Tolerance

Gieseke

Tarre

Green

et al. 2006

Appl Environ Microbiol

View full text Add to dashboard Cite

The sensitivity of nitrifying bacteria to acidic conditions is a well-known phenomenon and generally attributed to the lack and/or toxicity of substrates (NH 3 and HNO 2 ) with decreasing pHs. In contrast, we observed strong nitrification at a pH around 4 in biofilms grown on chalk particles and investigated the following hypotheses: the presence of less acidic microenvironments and/or the existence of acid-tolerant nitrifiers. Microelectrode measurements (in situ and under various experimental conditions) showed no evidence of a neutral microenvironment, either within the highly active biofilm colonizing the chalk surface or within a control biofilm grown on a nonbuffering (i.e., sintered glass) surface under acidic pH. A 16S rRNA approach (clone libraries and fluorescence in situ hybridizations) did not reveal uncommon nitrifying (potentially acid-tolerant) strains. Instead, we found a strongly acidic microenvironment, evidence for a clear adaptation to the low pH in situ, and the presence of nitrifying populations related to subgroups with low K m s for ammonia (Nitrosopira spp., Nitrosomonas oligotropha, and Nitrospira spp.). Acid-consuming (chalk dissolution) and acid-producing (ammonia oxidation) processes are equilibrated on a low-pH steady state that is controlled by mass transfer limitation through the biofilm. Strong affinity to ammonia and possibly the expression of additional functions, e.g., ammonium transporters, are adaptations that allow nitrifiers to cope with acidic conditions in biofilms and other habitats.Chemolithoautotrophic nitrifying bacteria, i.e., ammoniaoxidizing bacteria (AOB), catalyzing the first oxidation step of ammonia to nitrite and nitrite-oxidizing bacteria (NOB) completing the oxidation of the intermediate nitrite to nitrate are known to be sensitive to low pHs. Optimum growth occurs under neutral to moderately alkaline conditions (pH 7.5 to 8.0). In liquid pure culture, growth is usually restricted to a lower pH of 5.8 (AOB) or 6.5 (NOB) (62) and activity ceases typically below pH 5.5 (28, 31). The failure of AOB to cope with acidic conditions is thought to be primarily based on the unavailability of a substrate: with decreasing pHs, ammonia, the substrate of AOB (58), is increasingly protonated. Nitrite, the substrate of NOB, undergoes protonation to nitric acid, which disproportionates to nitrate and gaseous nitric oxide at low pHs (6). Furthermore, when present at elevated concentrations under low pHs, free nitric acid negatively affects the growth and activity of nitrifying bacteria (4).Despite these limitations, autotrophic nitrifying bacteria have been isolated from, or nitrifying activity has been demonstrated in, acidic environments, such as soils, activated sludge, and biofilms. Numerous nitrifying isolates have been obtained from soils with pHs around 4 (for a review, see reference 18 and references therein) to even as low as 2.5 (45). However, the majority of such isolates do not show nitrifying activity in acidic mineral medium (18). In contrast, autotrophic nitr...

show abstract

supporting

confidence: 82%

Nitrification in a Biofilm at Low pH Values: Role of In Situ Microenvironments and Acid Tolerance

Gieseke

Tarre

Green

et al. 2006

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Though the pH of the surface tea soils used ranged from 3.2 to 3.8, the concentration of N0 3 --N in soils was high ( Table 1). This finding is in agreement with the report that nitrification can occur in tea soils despite the low pH of about 3.5 (Hayatsu and Kosuge 1993). Hayatsu (1993) was able to isolate acidophilic NH4 + oxidizers from tea soils.…”

Section: Bacteriasupporting

confidence: 83%

“…Hayatsu (1993) was able to isolate acidophilic NH4 + oxidizers from tea soils. Hayatsu and Kosuge (1993) reported that nitrification was completely inhibited in the tea soils treated with nitrapyrin or acetylene, suggesting that nitrification in the strongly acid tea soils was caused by autotrophic NH4 + -oxidizing bacteria. However, lower numbers of autotrophic NH4 + oxidizers than autotrophic NO z -oxidizers especially in the Kuroniga, Taisekigan, and Anzangan soils were observed (Fig.…”

Section: Bacteriamentioning

confidence: 99%

Microbial ecology in tea soils

Pansombat

Kanazawa

Horiguchi

1997

Soil Science and Plant Nutrition

View full text Add to dashboard Cite

“…Pommerening-Roser et al recently described six lineages in the genus Nitrosomonas based on 165 rRNA sequence and DNA-DNA hybridization analyses, and showed that the existence of lineages of the species in the genus Nitrosomonas was consistent with ecophysiological distinctions among the species (Pommerening-Roser et al, 1996). Further delineation of the phylogenetic relationships among beta-subdivision ammonia oxidizers will continue for additional isolates obtained from diverse environments (deBoer and Laanbroek, 1989;Hayatsu and Kosuge, 1993;Jones et al, 1988;Koops et al, 1991;Stehr et al, 1995;Suwa et al, 1994;Utaker et al, 1995).…”

mentioning

confidence: 99%