ABSTRACT
Objective To design a device for studying the effects of shear stress on the activity of blue-green algae. Methods The device was optimized in terms of the weakness of current shear stress devices, such as small volume, unstability, inability for quantitative analysis and short working period. The effective volume of the new device was 400-700 mL, and the error was less than 13.8%. Moreover, this device could produce a quantitative and uniform shear stress field and be continued to follow observation for more than 96 hours. Results By experiment on growth of microcystis aeruginosa, the device was proved to generate shear stress that could significantly affect the activity of microcystis aeruginosa cells. Conclusions This experimental device is an effective equipment for investigating the effects of shear stress on the activity of blue-green algae.
ABSTRACT
Objective To design a device for studying the effects of shear stress on the activity of blue-green algae.Methods The device was optimized in terms of the weakness of current shear stress devices,such as small volume,unstability,inability for quantitative analysis and short working period.The effective volume of the new device was 400-700 mL,and the error was less than 13.8％.Moreover,this device could produce a quantitative and uniform shear stress field and be continued to follow observation for more than 96 hours.Results By experiment on growth of microcystis aeruginosa,the device was proved to generate shear stress that could significantly affect the activity of microcystis aeruginosa cells.Conclusions This experimental device is an effective equipment for investigating the effects of shear stress on the activity of blue-green algae.
ABSTRACT
Objective To design a device for studying the effects of shear stress on the activity of blue-green algae.Methods The device was optimized in terms of the weakness of current shear stress devices,such as small volume,unstability,inability for quantitative analysis and short working period.The effective volume of the new device was 400-700 mL,and the error was less than 13.8％.Moreover,this device could produce a quantitative and uniform shear stress field and be continued to follow observation for more than 96 hours.Results By experiment on growth of microcystis aeruginosa,the device was proved to generate shear stress that could significantly affect the activity of microcystis aeruginosa cells.Conclusions This experimental device is an effective equipment for investigating the effects of shear stress on the activity of blue-green algae.
ABSTRACT
Objective To design a device for studying the effects of shear stress on the activity of blue-green algae.Methods The device was optimized in terms of the weakness of current shear stress devices,such as small volume,unstability,inability for quantitative analysis and short working period.The effective volume of the new device was 400-700 mL,and the error was less than 13.8％.Moreover,this device could produce a quantitative and uniform shear stress field and be continued to follow observation for more than 96 hours.Results By experiment on growth of microcystis aeruginosa,the device was proved to generate shear stress that could significantly affect the activity of microcystis aeruginosa cells.Conclusions This experimental device is an effective equipment for investigating the effects of shear stress on the activity of blue-green algae.
ABSTRACT
Satara district is located in Western Ghats of Maharashtra. The district occupies 10,480 km2area. The district includes 11 administrative tahasils viz., Satara, Karad, Patan, Jaoli, Wai, Mahabaleshwar, Phaltan, Maan, Khatav, Koregaon, Khandala. Entire district falls within Deccan trap area, however the common soil types are the black, loamy and clay. Some western part of district enjoys average annual rainfall exceeding 500 mm while eastern side has the rainfall less than 300 mm. These variations in environmental condition have helped this region to be rich in floral biodiversity. Present work was carried out to explore the diversity of blue green algae from Satara district. Variety of habitats from 82 localities were screened to explore blue green algae from the district. Between June 2010 to May 2013 in all 127 species from 36 genera belonging to 4 orders were recorded. Out of these 28 species were unicellular while 99 were filamentous. Filamentous forms were found to be dominant over unicellular forms.
ABSTRACT
Na pecuária extensiva, os bebedouros naturais ou artificiais possibilitam o acesso direto dos bovinos ao seu interior e trazem como consequência a degradação da qualidade da água e o aumento dos riscos sanitários. Em tais circunstâncias ocorre a eutrofização e consequentemente a floração de algas, dentre elas cianobactérias toxigênicas. O presente estudo teve por objetivo verificar a ocorrência de cianobactérias de interesse sanitário em água de dessedentação de bovinos e descrever os seus parâmetros físico-químicos pH, temperatura e oxigênio dissolvido. Foram examinadas 19 amostras de água de cacimbas ou bebedouros naturais formados predominantemente em decorrência da precipitação pluviométrica, coletadas em seis propriedades rurais localizadas nas regiões Sudeste e Centro-Oeste, para a presença de cianobactérias e mensurados os valores de pH, temperatura e oxigênio dissolvido. Microcystis e/ou Merismopedia foram detectadas em dois bebedouros; em um dos quais havia intensa floração. Os valores de pH, temperatura e oxigênio dissolvido nas 19 coleções oscilaram entre pH 7,2-9,7, 31-34ºC e 7,8-30mg/l, respectivamente. Foram detectadas ainda algas consideradas não patogênicas de diversos gêneros, em conjunto ou não com a ocorrência das cianofíticas. Nessas condições, as práticas comuns de oferta de água de dessedentação na bovinocultura extensiva, as possibilidades de eutrofização e a contaminação por cianobactérias trazem potenciais riscos à saúde dos animais.
In extensive animal husbandry, natural or artificial ponds allow direct access of cattle to water but result in degradation of water quality and in increased health risks. Under such circumstances eutrophication occurs and consequently algal bloom, among them toxigenic cyanobacteria. The present study aimed to report the occurrence of cyanobacteria in the drinking water of cattle and to describe their physical and chemical parameters, as pH, temperature and dissolved oxygen. Nineteen samples of natural ponds or water troughs formed predominantly as result of rainfall from six farms located in the Southeast and Midwest regions of Brazil were analyzed for the presence of cyanobacteria, and pH, temperature and dissolved oxygen was measured. Microcystis and/or Merismopedia were detected in two ponds; one of them was covered with intense flowering. The values of pH, temperature and dissolved oxygen in 19 collections were pH 7.2-9.7, 31-34ºC and 7.8-30mg/l respectively. Also non-pathogenic algae of several genera were detected besides the occurrence or not of cianogenics. Under these conditions, the common practices of drinking water supply for extensively raised cattle and the possibilities of eutrophication and cyanobacterial growth bring potential risks for animal health.
Subject(s)
Animals , Cattle , Animal Husbandry , Drinking Water/analysis , Drinking Water/microbiology , Cyanobacteria/isolation & purification , Eutrophication , Harmful Algal BloomABSTRACT
Extracellular polypeptides released by both N2-grown [peptide I] and NO3-grown [peptide II] Anabaena L-31 have molecular weight of approximately 3,500 but have distinctly different amino acid composition. Acid hydrolysis of the peptide I fraction (obtained by separation on Sephadex G-25) yielded ten amino acids whereas that from peptide II fraction yielded only 3 amino acids. On addition to a freshly inoculated N2-grown culture, the peptide I fraction stimulated pro-heterocyst and to a lesser extent heterocyst differentiation, whereas the peptide II fraction strongly inhibited differentiation. The inhibitory effect of polypeptide II fraction could not be relieved by methionine sulphoximine, which by itself enhances differenttiation, but was greatly relieved by addition of the peptide I fraction. The data suggest but does not prove, that Anabaena L-31 synthesises "inducer" or " inhibitor " peptides which could possibly control pattern formation.