Aerobic decomposition of settled algae in a laboratory system: The impact of resuspension on microbial activity

Otten, Jerko H.; Gons, Herman J.

doi:10.1080/03680770.1989.11898839

Cited by 3 publications

(2 citation statements)

References 13 publications

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“…This result is consistent with those obtained from other studies [42]. According to the literature, several stages can be distinguished in the decomposition of phytoplankton [22,43]. After the death of algae, part of the biomass is released as DOM by lysis of the cells.…”

Section: Adsorbent Characteristicssupporting

confidence: 92%

Sorption of Chlorobenzenes to Mineralizing Phytoplankton

Koelmans

Jiménez

Lijklema

1993

Environ Toxicol Chem

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The influence of mineralization of phytoplankton (laboratory Scenedesmus spp.) on the desorption characteristics of 1,2,3,4-tetrachlorobenzene (TeCB) and hexachlorobenzene (HCB) was studied using a purge and trap method. For comparison several field samples, including a sediment, algae at different growth stages, and freeze-dried algae, were used. The desorption characteristics were evaluated using multiple box models similar to those generally used for desorption from sediments. It was found for all adsorbents that the desorption could adequately be described using a two-compartment nonequilibrium biosorption model. Generally, HCB was bound more strongly and released more slowly than TeCB. Aging and mineralization of unicell and coenobian forms of the algal species resulted in a significant 60 to 100% increase of OC-normalized partition coefficients. Generally, sorption affinity as quantified by the OC-normalized partition coefficient (K0J was lower, and desorption kinetics faster for algae than for soils and sediments. Evaluation of the biosorption rate parameters using a log kz vs. log K p plot showed that in contrast to sediments and soils, no clear inverse relationship between K p and k, exists. A bioconcentration experiment with four chlorobenzenes showed good agreement with the sorption parameters measured with the purge method, and showed a linear correlation of the bioconcentration factor with the octanol/water partition coefficient.

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Section: Adsorbent Characteristicssupporting

confidence: 92%

Sorption of Chlorobenzenes to Mineralizing Phytoplankton

Koelmans

Jiménez

Lijklema

1993

Environ Toxicol Chem

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“…Due to this well characterized relationship, the concentration of chl‐a in a lake can be used as an indirect measure of microbial abundance. Algae likely increases the activity of bacteria and thereby increases eDNA degradation (Otten & Gons, 1991; but see Barnes et al., 2014). For example, P‐limited algae are known to exude considerable amounts of dissolved organic carbon, which can increase bacterial biomass and microbial P‐limitation (Berman‐Frank & Dubinsky, 1999).…”

Section: Discussionmentioning

confidence: 99%

Quantifying the effect of water quality on eDNA degradation using microcosm and bioassay experiments

McKnight,

Shafer,

Frost

2024

Environmental DNA

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Environmental DNA (eDNA) is often used to determine the presence and absence of species in a specific environment, be it air, water, or soil. Numerous environmental conditions are known to directly alter the rate at which eDNA degrades, including pH, temperature, and UV‐B light exposure. Beyond these, many limnological parameters have not been thoroughly examined for their ability to modify the degradation rate of eDNA. Here we used 20 mL microcosms with water collected from 12 lakes from the Kawartha Highlands near Peterborough Ontario, Canada, to study the decay rates of dissolved Yellow perch (Perca flavescens) eDNA. We measured and related rates of eDNA loss to multiple water quality parameters: total dissolved phosphorus, total dissolved nitrogen, size‐fractionated carbon, and chlorophyll‐a levels. Bioassays were also conducted to examine the bacterial role in eDNA degradation using three treatments under natural system conditions: non‐filtered, filtered (0.22 μm), and non‐filtered with added phosphorus (50 μg/L). Each microcosm exhibited a unique rate of degradation with eDNA half‐life (C0.5) ranging from 2.5 to 12.9 h. Chlorophyll‐a levels exhibited a positive linear relationship to the rate of degradation, while all other parameters showed no effect. The bioassays showed a general trend of the filtered treatments exhibiting the lowest rate of degradation, followed by the phosphorus treatments with the non‐filtered treatment containing bacteria exhibiting the highest rate of degradation. Overall, water with an increased level of chlorophyll‐a, in conjunction with elevated bacteria (i.e. non‐filtered bioassay) will exhibit a faster overall rate of eDNA degradation. These results show the necessity to individualize eDNA survey plans to the water body of interest and to account for environmental conditions relating to the microbial processing of eDNA.

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