Investigations into the taxonomy, toxicity and ecology of benthic cyanobacterial accumulations in Myall Lake, Australia

2005 ◽  
Vol 56 (1) ◽  
pp. 45 ◽  
Author(s):  
Matthew Dasey ◽  
Natasha Ryan ◽  
Joanne Wilson ◽  
Glenn McGregor ◽  
Larelle Fabbro ◽  
...  

Large benthic accumulations of cyanobacteria occur in sheltered embayments within Myall Lake, New South Wales, Australia. The lake is shallow, with the entire bottom within the euphotic zone, and it is generally considered pristine, having low nutrient concentrations. The accumulations are highly organic and contain a mix of species mainly from the order Chroococcales, with two forms of Aphanothece being dominant. However polymerase chain reaction (PCR) analysis indicates a close similarity to Microcystis flos-aquae. The cells appear to lack aerotopes and form sticky mucilaginous amalgamations, which may enhance their benthic habit. Although Chroococcales also dominate the planktonic cyanobacterial community, the benthic species are seldom, if ever, found entrained within the water column. Some hepatotoxicity was indicated by mouse bioassay, protein phosphatase inhibition assay, enzyme-linked immuno-sorbent assay (ELISA) for microcystins, PCR and by chromatographic evidence for a microcystin. Ecological aspects of the distribution, gross morphology of the organisms and management implications for recreational water-users are discussed.

1996 ◽  
Vol 47 (4) ◽  
pp. 643 ◽  
Author(s):  
LC Bowling ◽  
PD Baker

The occurrence of a severe cyanobacterial bloom is described. This bloom affected almost 1000 km of the Barwon-Darling River, New South Wales, Australia, in November and December 1991 and was dominated by Anabaena circinalis Rabenhorst. This cyanobacterium was present in concentrations of around half a million cells per millilitre at some localities during its peak in mid November. Moderate to very high toxicity was demonstrated by mouse bioassay at many localities during this time. The bloom was attributed to very low flow conditions and high nutrient concentrations, especially of total phosphorus. However, warm water temperatures, elevated pH, reduced turbidity, and improved water transparency would also have been contributing factors. Very high ammonia concentrations were also observed during the bloom. The bloom declined during December and was eventually flushed from the river by increased flows following heavy catchment rainfall between mid December and early January.


LWT ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 714-719 ◽  
Author(s):  
Sahilah Abd Mutalib ◽  
Nursheila Mustafa Muin ◽  
Aminah Abdullah ◽  
Osman Hassan ◽  
Wan Aida Wan Mustapha ◽  
...  

Soil Research ◽  
2009 ◽  
Vol 47 (6) ◽  
pp. 555 ◽  
Author(s):  
Michael G. Jones ◽  
R. Willem Vervoort ◽  
Julie Cattle

Understanding the process by which nutrients and solids enter waterways from pastures in the Great Lakes district, New South Wales, Australia, may assist in maintaining water quality to ensure ongoing environmental and economic sustainability of the region. Rainfall simulations, using a 100-year return storm event, were conducted to determine nutrient and suspended solid concentrations in the runoff of 8 pasture sites in 3 of the catchments in the district. On 5 of the 8 sites, considerable concentrations of N or P were mobilised during the simulated rainfall event, but average nutrient concentrations and total loads across all sites were relatively low and similar to other studies of nutrient runoff from pastures. In addition, low runoff coefficients indicated that runoff is probably not the major pathway for nutrient losses from pasture in this area. Overall, rainfall runoff responses at the sites were similar in the 3 catchments. In contrast, the results suggest that, despite generating more runoff, the sites in the Wang Wauk catchment generated less nutrients in runoff than the sites in the Wallamba and Myall catchments. There was no difference in total suspended solids loads for the sites analysed by catchment. Relationships between soil physical and chemical characteristics and total nutrients loads or cumulative runoff were not strong.


Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 46
Author(s):  
Mariem Souissi ◽  
Amel Ben Lagha ◽  
Kamel Chaieb ◽  
Daniel Grenier

The ability of Streptococcus mutans to adhere to oral surfaces and form biofilm is a key step in the tooth decay process. The aim of this study was to investigate a berry (wild blueberry, cranberry, and strawberry) polyphenolic fraction, commercialized as Orophenol®, for its antibacterial, anti-biofilm, and anti-adhesion properties on S. mutans. Moreover, the biocompatibility of the fraction with human oral epithelial cells was assessed. Phenolic acids, flavonoids (flavonols, anthocyanins, flavan-3-ols), and procyanidins made up 10.71%, 19.76%, and 5.29% of the berry polyphenolic fraction, respectively, as determined by chromatography and mass spectrometry. The berry polyphenolic preparation dose-dependently inhibited S. mutans biofilm formation while not reducing bacterial growth. At concentrations ranging from 250 to 1000 µg/mL, the fraction inhibited the adhesion of S. mutans to both saliva-coated hydroxyapatite and saliva-coated nickel–chrome alloy. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis showed that incubating S. mutans with the berry polyphenolic fraction was associated with a reduced expression of luxS gene, which regulates quorum sensing in S. mutans. The berry fraction did not show any significant cytotoxicity in an oral epithelial cell model. In conclusion, Orophenol®, which is a mixture of polyphenols from wild blueberry, cranberry and strawberry, possesses interesting anti-caries properties while being compatible with oral epithelial cells.


Author(s):  
Jun-Hyung Lim ◽  
Sang Hwan Nam ◽  
Jongwoo Kim ◽  
Nam Hoon Kim ◽  
Gun-Soo Park ◽  
...  

Abstract In this study, a three-stage bioaerosol sampler with a sampling flow rate of 170 L/min was designed and fabricated for sampling the bioaerosols released during human breathing and coughing, and its performance was evaluated. The sampler was constructed using a cyclone separator with a cutoff size of 2.5 µm as a preseparator, a multi-nozzle virtual impactor with a cutoff size of 0.34 µm as an aerosol concentrator, and a BioSampler, which is a commercial product, for collecting bioaerosols in a collection fluid. The collection efficiency of the sampler was evaluated through simulations and experiments. Only particles with sizes of 0.1-4 µm were selectively collected in the collection fluid. Bacteriophage bioaerosols were sampled using the developed sampler and ACD-200 Bobcat sampler, which is a commercial product. The amounts of collected bacteriophages were compared using the polymerase chain reaction (PCR) technique. The sampling performance of the developed sampler was similar to that of the ACD-200 Bobcat sampler. Moreover, the developed sampler showed its ability to sample bioaerosols of a specific size-range and collect them directly in a collection fluid for the PCR analysis. Therefore, the developed sampler is expected to be useful for indoor environmental monitoring by effectively sampling the bioaerosols released indoors during human breathing and coughing.


1993 ◽  
Vol 265 (5) ◽  
pp. H1501-H1509 ◽  
Author(s):  
P. Ping ◽  
J. E. Faber

Six genes coding for three unique alpha 1- (1A, 1B, 1C) and three unique alpha 2- (2A, 2B, 2C) adrenergic receptor (AR) subtypes have been cloned. Ligand binding and contractile studies have demonstrated that both alpha 1- and alpha 2-ARs can exist on vascular smooth muscle (VSM) cells, although less is known about the relative distribution and specific subtypes in different vascular segments. In the present study polymerase chain reaction (PCR) analysis was used to characterize the species of alpha-AR messenger RNA (mRNA) present in freshly isolated rat thoracic aortic media and vena cava and in cultured VSM cells (passage 2) derived from both sources. To prevent possible contamination of VSM mRNA, aortic media was separated from adventitia, and vessels were denuded of endothelial cells. Oligonucleotide primers specific for each of the six adrenergic genes were synthesized and used to probe for the presence of alpha-AR mRNA species after reverse transcription of total cellular RNA to cDNA. PCR-amplified AR transcripts were distinguished by the size of amplified DNA fragments and unique restriction endonuclease cleavage. Expression of alpha 1C- or alpha 2C-mRNA was not detected in vascular tissues or cultured VSM cells, although the alpha 2C-primers detected the expected alpha 2C expression in cerebral cortex. Only alpha 1A-mRNA was detected in aortic adventitia. VSM from aorta expressed alpha 1A-, alpha 1B-, and alpha 2A-mRNA, and this pattern was preserved in cultured aortic VSM. Vena cava also expressed both alpha 1A and alpha 1B; however only alpha 2B-mRNA was detected.(ABSTRACT TRUNCATED AT 250 WORDS)


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Lijuan Hu ◽  
Jian Chen ◽  
Fan Zhang ◽  
Junjun Wang ◽  
Jingye Pan ◽  
...  

Background. Long noncoding RNAs (lncRNAs) have been shown to be involved in the mechanism of cisplatin resistance in lung adenocarcinoma (LAD). However, the roles of lncRNAs in cisplatin resistance in LAD are not well understood. Methods. We used a high-throughput microarray to compare the lncRNA and mRNA expression profiles in cisplatin resistance cell A549/DDP and cisplatin sensitive cell A549. Several candidate cisplatin resistance-associated lncRNAs were verified by real-time quantitative reverse transcription polymerase chain reaction (PCR) analysis. Results. We found that 1,543 lncRNAs and 1,713 mRNAs were differentially expressed in A549/DDP cell and A549 cell, hinting that many lncRNAs were irregular from cisplatin resistance in LAD. We also obtain the fact that 12 lncRNAs were aberrantly expressed in A549/DDP cell compared with A549 cell by quantitative PCR. Among these, UCA1 was the aberrantly expressed lncRNA and can significantly reduce the IC50 of cisplatin in A549/DDP cell after knockdown, while it can increase the IC50 of cisplatin after UCA1 was overexpressed in NCI-H1299. Conclusions. We obtained patterns of irregular lncRNAs and they may play a key role in cisplatin resistance of LAD.


2012 ◽  
Vol 49 (2) ◽  
pp. 67-70 ◽  
Author(s):  
M. Kolesárová ◽  
R. Herich ◽  
M. Levkut ◽  
J. Čurlík ◽  
M. Levkut

AbstractPCR amplification of specific DNA regions is a powerful tool for retrospective studies, but not all preservation or fixation methods render DNA that is suitable for subsequent amplification. Several factors affect sensitivity of polymerase chain reaction (PCR) amplification. There were reported the effects of commonly used fixation solutions — 10 % neutral buffered formalin, 20 % neutral buffered formalin and Carnoy’s solution and the efficiency of PCR amplification in fresh tissue and paraffin (or wax) embedded samples of Cysticercus ovis. DNA from samples was isolated and PCR product of 1300 bp was amplified. Results indicated that the samples fixed in Carnoy’s solution produced reliable amplification of desired fragments. The samples that were fixed in 10 % and 20 % neutral buffered formalin brought negative results.


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