supperguppy
ZeewaterForum lid
Ik kwam nog een boeiend artikel tegen (zie de abstract hieronder)
Gezien we nitrifiecatie belangrijk vinden is dit punt ook wel belangrijk in de discussie. Blijkbaar is honing (high grade) slechter voor de nitrificerende bacteriën. Wel beter voor heterotrophic bacteriën en deze leggen ook ammoniak, nitriet en nitraat vast.
We verstoren dus het bacterieel evenwicht)(doel bewust) maar hoe erg is dat op de lange termijn. Is dan misschien een andere koolstof bron handiger? (andere bron: Regulation of nitrification in aquatic sediments by organic carbon)
Abstract—Nitrification, the microbial conversion of am-
monium to nitrate, is an important transformation in the aquat-
ic nitrogen cycle, but the factors regulating nitrification rates
in freshwater ecosystems are poorly understood. We investi-
gated the effects of organic carbon quantity and quality on
nitrification rates in stream sediments. First, we hypothesized
that when environmental C : N ratios are high, heterotrophic
bacteria are subject to N limitation and will outcompete nitri-
fying bacteria for available NH , thereby reducing nitrification 1
4
rates. In laboratory experiments, organic carbon amendments
(30 mg C L21
, as glucose) to stream sediments completely
inhibited nitrification with or without addition of NH ( 1
4 P ,
0.0001), whereas amendment with NH only (0.75 mg N L21
) 1
4
increased nitrification by 40% compared with unamended con-
trols (P ,0.0001). Carbon amendments also increased micro-
bial respiration rates over controls by 4–6 times. Therefore,
organic carbon additions significantly decreased nitrification
rates but increased total microbial activity. Second, we hy-
pothesized that carbon of high quality would have a stronger
negative effect on nitrification than would carbon of low qual-
ity. To stream sediments, we added organic carbon as either
glucose (higher quality) or sugar maple leaf extract (lower
quality). Nitrification rates were reduced by the addition of
either organic carbon source but were more severely inhibited
by glucose (P 50.001). Our results suggest that organic car-
bon is an important regulator of nitrification rates and is of
key importance in understanding N dynamics in freshwater
ecosystems.
Gezien we nitrifiecatie belangrijk vinden is dit punt ook wel belangrijk in de discussie. Blijkbaar is honing (high grade) slechter voor de nitrificerende bacteriën. Wel beter voor heterotrophic bacteriën en deze leggen ook ammoniak, nitriet en nitraat vast.
We verstoren dus het bacterieel evenwicht)(doel bewust) maar hoe erg is dat op de lange termijn. Is dan misschien een andere koolstof bron handiger? (andere bron: Regulation of nitrification in aquatic sediments by organic carbon)
Abstract—Nitrification, the microbial conversion of am-
monium to nitrate, is an important transformation in the aquat-
ic nitrogen cycle, but the factors regulating nitrification rates
in freshwater ecosystems are poorly understood. We investi-
gated the effects of organic carbon quantity and quality on
nitrification rates in stream sediments. First, we hypothesized
that when environmental C : N ratios are high, heterotrophic
bacteria are subject to N limitation and will outcompete nitri-
fying bacteria for available NH , thereby reducing nitrification 1
4
rates. In laboratory experiments, organic carbon amendments
(30 mg C L21
, as glucose) to stream sediments completely
inhibited nitrification with or without addition of NH ( 1
4 P ,
0.0001), whereas amendment with NH only (0.75 mg N L21
) 1
4
increased nitrification by 40% compared with unamended con-
trols (P ,0.0001). Carbon amendments also increased micro-
bial respiration rates over controls by 4–6 times. Therefore,
organic carbon additions significantly decreased nitrification
rates but increased total microbial activity. Second, we hy-
pothesized that carbon of high quality would have a stronger
negative effect on nitrification than would carbon of low qual-
ity. To stream sediments, we added organic carbon as either
glucose (higher quality) or sugar maple leaf extract (lower
quality). Nitrification rates were reduced by the addition of
either organic carbon source but were more severely inhibited
by glucose (P 50.001). Our results suggest that organic car-
bon is an important regulator of nitrification rates and is of
key importance in understanding N dynamics in freshwater
ecosystems.