DETECTION OF NEW PIGMENTS FROM EMILIANIA HUXLEYI (PRYMNESIOPHYCEAE) BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY, LIQUID CHROMATOGRAPHY–MASS SPECTROMETRY, VISIBLE SPECTROSCOPY, AND FAST ATOM BOMBARDMENT MASS SPECTROMETRY

Pigment extracts from Emiliania huxleyi (Lohm.) Hay et Mohler (strains CCMP 370, CCMP 373, and NIOZ CH 24) were analyzed using high-performance liquid chromatography (HPLC) on highly efficient monomeric and polymeric octadecylsilica columns using either ammonium acetate or pyridine containing mobile phases. Both systems showed chromatographic profiles with peaks corresponding to pigments of uncertain structure: those of the polar and nonpolar chlorophyll c forms and one peak whose on-line diode array spectrum resembled that of the fucoxanthin acyloxy derivatives. Liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry gave a molecular mass of 786 units for the unknown carotenoid. The pigments corresponding to each of these fractions were isolated and their visible spectra recorded in various solvents. Samples of the isolated pigments were subjected to analysis by fast atom bombardment mass spectrometry that confirmed a molecular mass of 786 for the unknown carotenoid and gave a mass of 654 units for the polar chlorophyll c ₃, compatible with the monovinylic structure previously suggested. The detection of these new pigments calls for attention on the use of correct methodologies when HPLC pigment signatures are used to study the taxonomic composition of natural phytoplankton populations.     

Evidence for the Existence of Differential O-Glycosylated α5-Subunits of the γ-Aminobutyric AcidA Receptor in the Rat Brain

Abstract: Polyclonal antibodies were raised to synthetic peptides having amino acid sequences corresponding with the N- or C-terminal part of the γ-aminobutyric acid_A (GABA_A) receptor α₅-subunit. These anti-peptide α₅(2–10) or anti-peptide α₅(427–433) antibodies reacted specifically with GABA_A receptors purified from the brains of 5–10-day-old rats in an enzyme-linked immunosorbent assay and were able to dose-dependently immunoprecipitate up to 6.3 or 13.1% of the GABA_A receptors present in the incubation, respectively. In immunoblots, each of these antibodies reacted with the same two protein bands with apparent molecular mass of 53 or 57 kDa. After exhaustive treatment of purified GABA_A receptors with N -Glycanase, each of these antibodies identified two proteins with apparent molecular masses of 46 and 48 kDa. Additional treatment of GABA_A receptors with neuraminidase and O -Glycanase resulted in an apparently single protein with molecular mass of 47 kDa, which again was identified by both the anti-peptide α₅(2–10) and the anti-peptide α₅(427–433) antibody. These results indicate the existence of at least two different α₅-sub-units of the GABA_A receptor that differ in their carbohydrate content. In contrast to other α- or β-subunits of GABA_A receptors so far investigated, at least one of these two α₅-subunits contains O-linked carbohydrates.     

Rod visual pigment changes in the elver of the eel Anguilla anguilla L. measured by microspectrophotometry

The visual pigments in the retinal rods of elvers ( Anguilla anguilla L.) were examined by microspectrophotometry and high performance liquid chromatography. The glass elver stage had a mixture of rhodopsin P501₁ and porphyropsin P523₂ with the former predominating (P501₁:P523₂= c. 60:40). More mature pigmented elvers had a predominance of the porphyropsin P523₂ (P501₁:P523₂= c. 10:90). The shift between the proportions of each pigment was monitored over a 7-month period and was shown to occur in individual retinal rods. This shift is a reverse of the pigment shift that occurs in adult eels during their downstream migration.     

Differential Coupling of μ-, δ-, and κ-Opioid Receptors to Gα16-Mediated Stimulation of Phospholipase C

Abstract: The μ-opioid receptor has recently been shown to stimulate phosphoinositide-specific phospholipase C via the pertussis toxin-sensitive G₁₆ protein. Given the promiscuous nature of G₁₆ and the high degree of resemblance of signaling properties of the three opioid receptors, both δ- and κ-opioid receptors are likely to activate G₁₆. Interactions of δ- and κ-opioid receptors with G₁₆ were examined by coexpressing the opioid receptors and Gα₁₆ in COS-7 cells. The δ-selective agonist [ d -Pen², d -Pen⁵]enkephalin potently stimulated the formation of inositol phosphates in cells coexpressing the δ-opioid receptor and Gα₁₆. The δ-opioid receptor-mediated stimulation of phospholipase C was absolutely dependent on the coexpression of simeter for quality control of blood units and irradiators. 13.   Transfusion 1993 ; 33 : 898 – 901 . [PubMed link] 14.   Butson MJ , Yu PK , Cheung T , et al . Dosimetry of blood irradiation with radiochromic film. Transfus Med 1999 ; 9 : 205 – 8 . [PubMed link] 15.   Nath R , Biggs PJ , Ling CC , et al . AAPM code of practice for radiotherapy accelerators: Report of AAPM Radiation Therapy Task Group No. 45. Med Phys     

Inheritance of Anthracnose Resistance in the Common Bean Differential Cultivar G 2333 and Identification of a New Molecular Marker Linked to the Co-42 gene

The inheritance of anthracnose resistance of the common bean ( Phaseolus vulgaris L.) differential cultivar G 2333 to Colletotrichum lindemuthianum races 73 and 89 was studied in crosses with the susceptible cultivar Rudá. The segregation ratios of 15 : 1 in the F₂ and 3 : 1 in the backcrosses to Rudá indicate that for each of the races tested there are two independent resistance loci in G 2333. A random amplified polymorphic DNA (RAPD) molecular marker (OPH18_1200C) linked in resistance to race 73 was identified in a BC₃F_2:3 population derived from crosses between Rudá and G 2333. A RAPD molecular marker OPAS13_950C, previously identified as linked to gene Co-4² , was also amplified in this population. Co-segregation analyses showed that these two markers are located at 5.6 (OPH18_1200C) and 11.2 (OPAS13_950C) cM of the Co-4² gene. These markers were not present in BC₁F_2:3 plants resistant to race 89 indicating that this population carries a different resistance gene. DNA amplification of BC₁F_2:3 plants with RAPD molecular marker OPAB_450C, previously identified as linked to gene Co-5 , indicated that this gene is present in this population.     

Zn(II)- and Cu(II)-induced non-fibrillar aggregates of amyloid-β (1–42) peptide are transformed to amyloid fibrils, both spontaneously and under the influence of metal chelators

Aggregation of amyloid-β (Aβ) peptides is a central phenomenon in Alzheimer's disease. Zn(II) and Cu(II) have profound effects on Aβ aggregation; however, their impact on amyloidogenesis is unclear. Here we show that Zn(II) and Cu(II) inhibit Aβ₄₂ fibrillization and initiate formation of non-fibrillar Aβ₄₂ aggregates, and that the inhibitory effect of Zn(II) (IC₅₀ = 1.8 μmol/L) is three times stronger than that of Cu(II). Medium and high-affinity metal chelators including metallothioneins prevented metal-induced Aβ₄₂ aggregation. Moreover, their addition to preformed aggregates initiated fast Aβ₄₂ fibrillization. Upon prolonged incubation the metal-induced aggregates also transformed spontaneously into fibrils, that appear to represent the most stable state of Aβ₄₂. H13A and H14A mutations in Aβ₄₂ reduced the inhibitory effect of metal ions, whereas an H6A mutation had no significant impact. We suggest that metal binding by H13 and H14 prevents the formation of a cross-β core structure within region 10–23 of the amyloid fibril. Cu(II)-Aβ₄₂ aggregates were neurotoxic to neurons in vitro only in the presence of ascorbate, whereas monomers and Zn(II)-Aβ₄₂ aggregates were non-toxic. Disturbed metal homeostasis in the vicinity of zinc-enriched neurons might pre-dispose formation of metal-induced Aβ aggregates, subsequent fibrillization of which can lead to amyloid formation. The molecular background underlying metal-chelating therapies for Alzheimer's disease is discussed in this light.     

Non-destructive optical detection of pigment changes during leaf senescence and fruit ripening

Reflectance spectra in the visible and near infra-red range of the spectrum, acquired for maple ( Acer platanoides L.), chestnut ( Aesculus hippocastanum L.), potato ( Solanum tuberosum L.), coleus ( Coleus blumei Benth.), leaves and lemon (Citrus limon L.) and apple ( Malus domestica Borkh.) fruits were studied. An increase of reflectance between 550 and 740 nm accompanied senescence-induced degradation of chlorophyll (Chl), whereas in the range 400–500 nm it remained low, due to retention of carotenoids (Car). It was found that both leaf senescence and fruit ripening affect the difference between reflectance ( R ) near 670 and 500 nm ( R ₆₇₈− R ₅₀₀), depending on pigment composition. The plant senescing reflectance index in the form ( R ₆₇₈− R ₅₀₀)/ R ₇₅₀ was found to be sensitive to the Car/Chl ratio, and was used as a quantitative measure of leaf senescence and fruit ripening. The changes in the index were followed during leaf senescence, and natural and ethylene-induced fruit ripening. This novel index can be used for estimating the onset, the stage, relative rates and kinetics of senescence/ripening processes.     

Expression of Bradyrhizobium japonicum cbb3 terminal oxidase under denitrifying conditions is subjected to redox control

Bradyrhizobium japonicum utilizes cytochrome cbb ₃ oxidase encoded by the fixNOQP operon to support microaerobic respiration under free-living and symbiotic conditions. It has been previously shown that, under denitrifying conditions, inactivation of the cycA gene encoding cytochrome c ₅₅₀, the electron donor to the Cu-containing nitrite reductase, reduces cbb ₃ expression. In order to establish the role of c ₅₅₀ in electron transport to the cbb ₃ oxidase, in this work, we have analyzed cbb ₃ expression and activity in the cycA mutant grown under microaerobic or denitrifying conditions. Under denitrifying conditions, mutation of cycA had a negative effect on cytochrome c oxidase activity, heme c (FixP and FixO) and heme b cytochromes as well as expression of a fixP '–' lacZ fusion. Similarly, cbb ₃ oxidase was expressed very weakly in a napC mutant lacking the c -type cytochrome, which transfers electrons to the NapAB structural subunit of the periplasmic nitrate reductase. These results suggest that a change in the electron flow through the denitrification pathway may affect the cellular redox state, leading to alterations in cbb ₃ expression. In fact, levels of fixP '–' lacZ expression were largely dependent on the oxidized or reduced nature of the carbon source in the medium. Maximal expression observed in cells grown under denitrifying conditions with an oxidized carbon source required the regulatory protein RegR.     

Effects of temperature, body size and feeding on rates of metabolism in young‐of‐the‐year haddock

The mean rate of oxygen consumption (routine respiration rate, R _R, mg O₂ fish⁻¹ h⁻¹), measured for individual or small groups of haddock Melanogrammus aeglefinus (3–12 cm standard length, L _S) maintained for 5 days within flow‐through respiratory chambers at four different temperatures, increased with increasing dry mass ( M _D). The relationship between R _R and M _D was allometric ( R _R = α  M ^b ) with b values of 0·631, 0·606, 0·655 and 0·650 at 5·0, 8·0, 12·0 and 15·0° C, respectively. The effect of temperature ( T ) and M _D on mean R _R was described by     indicating a Q ₁₀ of 2·27 between 5 and 15° C. Juvenile haddock routine metabolic scope, calculated as the ratio of the mean of highest and lowest deciles of R _R measured in each chamber, significantly decreased with temperature such that the routine scope at 15° C was half that at 5° C. The cost of feeding ( R _SDA) was c . 3% of consumed food energy, a value half that found for larger gadoid juveniles and adults.     

Shiga toxin-producing Escherichia coli and atypical enteropathogenic Escherichia coli strains isolated from healthy sheep of different populations in São Paulo, Brazil

Aims:  Sheep are important carriers of Shiga toxin-producing Escherichia coli (STEC) in several countries. However, there are a few reports about ovine STEC in American continent.
Methods and Results:  About 86 E. coli strains previously isolated from 172 healthy sheep from different farms were studied. PCR was used for detection of stx ₁, stx ₂, eae, ehxA and saa genes and for the identification of intimin subtypes. Restriction fragment length polymorphism (RFLP)–PCR was performed to investigate the variants of stx ₁ and stx ₂, and the flagellar antigen ( fli C) genes in nonmotile isolates. Five isolates were eae ⁺ and stx ⁻, and belonged to serotypes O128:H2/β-intimin (2), O145:H2/γ, O153:H7/β and O178:H7/ε. Eighty-one STEC isolates were recovered, and the stx genotypes identified were stx _1c stx _2d-O118 (46·9%), stx _1c (27·2%), stx _2d-O118 (23·4%), and stx _1c stx _2dOX3a (2·5%). Pulsed-field gel electrophoresis (PFGE) revealed 27 profiles among 53 STEC and atypical enteropathogenic Escherichia coli (EPEC) isolates.
Conclusions:  This study demonstrated that healthy sheep in São Paulo, Brazil, can be carriers of potential human pathogenic STEC and atypical EPEC.
Significance and Impact of the Study:  As some of the STEC serotypes presently found have been involved with haemolytic uraemic syndrome (HUS) in other countries, the important role of sheep as sources of STEC infection in our settings should not be disregarded.     

Assessing mortality changes from size‐frequency curves

The relationship between the instantaneous mortality rate ( Z ) and the instantaneous change in length‐frequency distribution of organisms per unit of animal size (μ _L ) takes the following form: Z  = μ _L k ( L _∞ −  L ) +  k , where k and L _∞ are coefficients of the von Bertalanffy equation, and L is organism size (length). Z and μ_L change coherently when they are measured for a specific size or age class. Therefore, observations of μ _L can provide information on the relative changes in mortality. This is useful when no precise information about animal growth is available and growth curve is assumed to be invariable. This method was tested on a heavily exploited population of St Peter's fish (mango tilapia) Sarotherodon galilaeus in Lake Kinneret, Israel, where large fluctuations in the size structure of the catch have occurred over the past few years. Analysis of the changes in the length‐frequency distributions showed that the changes in μ _L over multiple years estimated for fully exploited fish reflected the respective changes in Z .     

Molecular Determinants of General Anesthetic Action: Role of GABAA Receptor Structure

Abstract: Using receptors expressed from mouse brain mRNA in Xenopus oocytes, we found that enhancement of type A γ-aminobutyric acid (GABA_A) receptor-gated Cl⁻ channel response is a common action of structurally diverse anesthetics, suggesting that the GABA_A receptor plays an important role in anesthesia. To determine if GABA_A receptor subunit composition influences actions of anesthetics, we expressed subunit cRNAs in Xenopus oocytes and measured effects of enflurane on GABA-activated Cl⁻ currents. Potentiation of GABA-activated currents by enflurane was dependent on the composition of GABA_A receptor protein subunits; the order of sensitivity was α₁β₁ > α₁β₁γ_2s=α₁β₁γ_2L > total mRNA. The results suggest that anesthetics with simple structures may act on the GABA_A receptor protein complex to modulate the Cl⁻ channel activity and provide a molecular explanation for the synergistic clinical interactions between benzodiazepines and general anesthetics.     

Development of a sequence-characterized amplified region marker for diagnosis of dwarf bunt of wheat and detection of Tilletia controversa Kühn

Aims:  Dwarf bunt of wheat, caused by Tilletia controversa Kühn, is a destructive disease on wheat as well as an important international quarantined disease in many countries. The objective of this investigation was to develop a diagnostic molecular marker generated from amplified fragment length polymorphism (AFLP) for rapid identification of T . controversa .
Methods and Results:  A total of 30 primer combinations were tested by AFLP to detect DNA polymorphisms between T. controversa and related species. The primer combination E08/M02 generated a polymorphic pattern displaying a 451-bp DNA fragment specific for T. controversa . The marker was converted into a sequence-characterized amplified region (SCAR), and specific primers (SC-01₄₉/SC-02₄₁₅), designed for use in PCR detection assays, amplified a unique DNA fragment in all isolates of T. controversa , but not in the related pathogens. The detection limit with the primer set SC-01₄₉/SC-02₄₁₅ was 10 ng of DNA which could be obtained from 11  μ g of teliospores in a 25- μ l PCR reaction.
Conclusions:  An approach to distinguish T. controversa from similar pathogenic fungi has been developed based on the use of a SCAR marker.
Significance and Impact of the Study:  Development of the simple, high throughput assay kit for the rapid diagnosis of dwarf bunt of wheat and detection of T. controversa is anticipated in further studies.     

Two tertiary branched tetraamines, N4-aminopropylnorspermidine and N4-aminopropylsperimidine, are the major polyamines in thermophilic eubacteria, Thermoleophilum

Abstract Two novel polyamines were found as major polyamines of Thermoleophilum album and Thermoleophilum minutum , which are Gram-negative eubacteria obligate for thermophily and n -alkane substrates. They were identified as tertiary branched tetraamines, N⁴-aminopropylnorspermidine ( tris (3-aminopropyl)amine) [NH₂(CH₂)₃N-((CH₂)₃NH₂)(CH₂)₃NH₂ or N(CH₂CH₂CH₂NH₂)₃] and N⁴-aminopropylspermidine [NH₂(CH₂)₃N((CH₂)₃NH₂)(CH₂)₄NH₂] by high-performance liquid chromatography and gas chromatography-mass spectrometry.     

Compensatory growth of juvenile brown flounder Paralichthys olivaceus (Temminck & Schlegel) following thermal manipulation

The compensatory growth of juvenile brown flounder Paralichthys olivaceus (body mass c. 12 g) following different thermal exposure was investigated. Fish were exposed to one of the five temperatures: 8·5 ( T _8·5), 13·0 ( T _13·0), 17·5 ( T _17·5), 22·0 ( T _22·0) and 26·5° C ( T _26·5) for 10 days and fish grew best at 22·0° C. Then the water temperature in all treatments was equably adjusted to 22·0° C over 3 days. At the end of the following 30 days after temperature adjustment, there were no significant differences between body masses of fish in the different treatments (wet body mass at the end of the experiment ranged from 22·13 to 24·56 g). Results indicated that the juvenile P. olivaceus achieved complete compensatory growth. Analysis of the dynamics of the feeding rates and feed conversion efficiencies indicated that compensatory growth of the fish experienced low temperature ( T _8·5, T _13·5 and T _17·5) or high temperature ( T _26·5) exposure was mainly dependent on increasing feed intake (hyperphagia) and possibly by improvement in feed conversion efficiency. The moisture content was not affected by different temperature exposure significantly. The lipid and energy content of juvenile P. olivaceus in T _8·5, however, were significantly lower than other treatment. Results of the current study indicate that a short period of low or high temperature exposure may not affect annual growth, but may affect lipid and energy deposition.     

CaMKII associates with CaV1.2 L-type calcium channels via selected β subunits to enhance regulatory phosphorylation

Calcium/calmodulin-dependent kinase II (CaMKII) facilitates L-type calcium channel (LTCC) activity physiologically, but may exacerbate LTCC-dependent pathophysiology. We previously showed that CaMKII forms stable complexes with voltage-gated calcium channel (VGCC) β_1b or β_2a subunits, but not with the β₃ or β₄ subunits ( Grueter et al. 2008 ). CaMKII-dependent facilitation of Ca_V1.2 LTCCs requires Thr498 phosphorylation in the β_2a subunit ( Grueter et al. 2006 ), but the relationship of this modulation to CaMKII interactions with LTCC subunits is unknown. Here we show that CaMKII co-immunoprecipitates with forebrain LTCCs that contain Ca_V1.2α₁ and β₁ or β₂ subunits, but is not detected in LTCC complexes containing β₄ subunits. CaMKIIα can be specifically tethered to the I/II linker of Ca_V1.2 α₁ subunits in vitro by the β_1b or β_2a subunits. Efficient targeting of CaMKIIα to the full-length Ca_V1.2α₁ subunit in transfected HEK293 cells requires CaMKII binding to the β_2a subunit. Moreover, disruption of CaMKII binding substantially reduced phosphorylation of β_2a at Thr498 within the LTCC complex, without altering overall phosphorylation of Ca_V1.2α₁ and β subunits. These findings demonstrate a biochemical mechanism underlying LTCC facilitation by CaMKII.     

Mechanism of docosahexaenoic acid-induced inhibition of in vitro Aβ1–42 fibrillation and Aβ1–42-induced toxicity in SH-S5Y5 cells

The mechanism of the effect of docosahexaenoic acid (DHA; C22:6, n -3), one of the essential brain nutrients, on in vitro fibrillation of amyloid β (Aβ_1–42), Aβ_1–42-oligomers and its toxicity imparted to SH-S5Y5 cells was studied with the use of thioflavin T fluorospectroscopy, laser confocal microfluorescence, and transmission electron microscopy. The results clearly indicated that DHA inhibited Aβ_1–42-fibrill formation with a concomitant reduction in the levels of soluble Aβ_1–42 oligomers. The polymerization (into fibrils) of preformed oligomers treated with DHA was inhibited, indicating that DHA not only obstructs their formation but also inhibits their transformation into fibrils. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (12.5%), Tris–Tricine gradient(4–20%) gel electrophoresis and western blot analyses revealed that DHA inhibited at least 2 species of Aβ_1–42 oligomers of 15–20 kDa, indicating that it hinders these on-pathway tri/tetrameric intermediates during fibrillation. DHA also reduced the levels of dityrosine and tyrosine intrinsic fluorescence intensity, indicating DHA interrupts the microenvironment of tyrosine in the Aβ_1–42 backbone. Furthermore, DHA protected the tyrosine from acrylamide collisional quenching, as indicated by decreases in Stern–Volmer constants. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide-reduction efficiency and immunohistochemical examination suggested that DHA inhibits Aβ_1–42-induced toxicity in SH-S5Y5 cells. Taken together, these data suggest that by restraining Aβ_1–42 toxic tri/tetrameric oligomers, DHA may limit amyloidogenic neurodegenerative diseases, Alzheimer's disease.     

Plant response to destruxins visualized by imaging of chlorophyll fluorescence

Kinetic fluorescence imaging was used to set a new detection limit for plant exposure to low levels of destruxins – phytotoxins of Alternaria brassicae . A general experimental algorithm is presented that can be used to identify the combination of fluorescence parameters providing the highest contrast between the affected and unaffected plants or plant segments. Leaves of canola ( Brassica napus ) and white mustard ( Sinapis alba ) were exposed to various concentrations of destruxins and images of key fluorescence signals ( F ₀, F _M, F _P, and of F _S) were captured in a single kinetic experiment. Contrast was quantified within these images between the leaf areas exposed to destruxins and the untreated areas. The highest contrast was found in the image constructed by pixel-to-pixel division of images F ₀ by F _P and F ₀ by F _M. Using the F ₀/ F _M ratio image, we were able to detect exposure to destruxin concentration as low as approximately 0.05 mg l⁻¹ applied to canola leaf and approximately 10 mg l⁻¹ when applied to mustard. The detection limits were significantly lower than those obtained by optical microscopy indicating that kinetic chlorophyll fluorescence imaging can be used as a diagnostic tool in screening for varieties with an enhanced resistance to destruxins of Alternaria brassicae .     

A comparative study of blood oxygen transport in turbot and sea bass: effect of chronic hypoxia

A comparative study of blood oxygen binding and carrying capacities of turbot Scophthalmus maximus and sea bass Dicentrarchus labrax , two fish species differing in their demand for oxygen, was carried out under three levels of chronic hypoxia ( P o ₂ = 93, 65 and 40 mmHg) for 40 days. Blood O₂ affinity in normoxia was moderately high in both species ( P ₅₀ was c . 12–13 mmHg at pH 7·7). The Bohr factor was significantly lower in turbot (−0·52) than in sea bass (−0·85). In both species, blood O₂ affinity was not significantly affected by oxygen depletion whatever its level and duration. In turbot, however, P ₅₀ appeared to slightly decrease at the two more severe levels of hypoxia. In both species, blood O₂ carrying capacity was not affected by hypoxia and remained twice as high in sea bass than in turbot.     

Response of plankton communities to whole-lake Ca(OH)2 and CaCO3 additions in eutrophic hardwater lakes

1. The impact of whole-lake lime (slaked lime, Ca(OH)₂, and/or calcite, CaCO₃) addition on plankton communities was evaluated in eutrophic hardwater lakes on the North American Boreal Plain.
2. Two lakes received a single treatment of lime (Ca(OH)₂ at 74 or 107 mg L^–1), two lakes received multiple treatments with Ca(OH)₂ and/or CaCO₃ (5–78 mg L^–1), and four lakes were untreated and served as reference systems.
3. Over the long-term (> 1 year), phytoplankton biomass was reduced in multiple-dose lakes, but not in single-dose lakes. Cyanobacteria typically dominated the algal community in the years before, during and after lime treatment in both single- and multiple-dose lakes.
4. In the single-dose lakes, randomized intervention analysis showed no significant change in the biomass of zooplankton after lime addition.