Abiotic factors in colony formation: effects of nutrition and light on extracellular polysaccharide production and cell aggregates of Microcystis aeruginosa

2013 ◽  
Vol 31 (4) ◽  
pp. 796-802 ◽  
Author(s):  
Zhen Yang ◽  
Fanxiang Kong
Keyword(s):  
Microcystis Aeruginosa ◽  
Colony Formation ◽  
Abiotic Factors ◽  
Extracellular Polysaccharide ◽  
Cell Aggregates ◽  
Polysaccharide Production

Effects of toxic cyanobacterium Microcystis aeruginosa on the morphology of green alga Chlorella vulgaris

2019 ◽  
Vol 55 ◽  
pp. 7 ◽  
Author(s):  
Jing Dong ◽  
Chenlu Li ◽  
Mengyang Chang ◽  
Dujuan Dai ◽  
Shiwen Liu ◽  
...  
Keyword(s):  
Microcystis Aeruginosa ◽  
Green Alga ◽  
Chlorella Vulgaris ◽  
Colony Formation ◽  
Abiotic Factors ◽  
Defensive Strategies ◽  
Green Alga Chlorella ◽  
Continuous Induction ◽  
Active Substances ◽  
Morphology Changes

In eutrophic freshwater lakes, cyanobacteria and green algae are in succession due to abiotic factors. Allelochemical interaction also exists. In this study, we indicated that filtrates of Microcystis aeruginosa can influence the growth rate and photosynthetic pigments of the target alga named Chlorella vulgaris. We also determined the morphological appearance and colony formation of green alga C. vulgaris that were induced by chemicals associated with a competitor cyanobacterium named M. aeruginosa. However, microcystins (MCs) were not the active substances in this study. The morphology changes and growth of C. vulgaris affected by M. aeruginosa filtrates were dependent on the initial cultivation density of the target algae and the cultivation phase of M. aeruginosa. We also assumed that the morphology changes were defensive strategies utilised by C. vulgaris to resist M. aeruginosa. The temporary stress of M. aeruginosa was favourable to the growth of C. vulgaris. By contrast, the continuous induction of colony formation by M. aeruginosa in the field inhibited the growth of C. vulgaris. The present results provided new insights into the interaction between algae and theoretical basis for algae succession in the field.

Effects of lead(II) on the extracellular polysaccharide (EPS) production and colony formation of cultured Microcystis aeruginosa

2013 ◽  
Vol 67 (4) ◽  
pp. 803-809 ◽  
Author(s):  
Xiang-dong Bi ◽  
Shu-lin Zhang ◽  
Wei Dai ◽  
Ke-zhing Xing ◽  
Fan Yang
Keyword(s):  
Heavy Metals ◽  
Microcystis Aeruginosa ◽  
Colony Formation ◽  
Extracellular Polysaccharide ◽  
Extracellular Polysaccharides ◽  
Control Group ◽  
Natural Conditions ◽  
Laboratory Conditions ◽  
Large Colony ◽  
Middle Colonies

To investigate the effects of lead(II) on the production of extracellular polysaccharides (EPS), including bound extracellular polysaccharides (bEPS) and soluble extracellular polysaccharides (sEPS), and the colony formation of Microcystis aeruginosa, cultures of M. aeruginosa were exposed to four concentrations (5.0, 10.0, 20.0 and 40.0 mg/L) of lead(II) for 10 d under controlled laboratory conditions. The results showed that 5.0 and 10.0 mg/L lead(II) stimulated M. aeruginosa growth throughout the experiment while 20.0 and 40.0 mg/L lead(II) inhibited M. aeruginosa growth in the first 2 d exposure and then stimulated it. As compared to the control group, significant increases in the bEPS and sEPS production were observed in 20.0 and 40.0 mg/L lead(II) treatments (P < 0.05). Large colony formations were not observed throughout the experiment. However, four tested concentrations of lead(II) could significantly promote the formation of small and middle colonies after 10 d exposure (P < 0.05), and 40.0 mg/L lead(II) had the best stimulatory effect. Lead(II) could stimulate bEPS production, which conversely promoted colony formation, suggesting that heavy metals might be contributing to the bloom-forming of M. aeruginosa in natural conditions.

scholarly journals Effect of medium pH and cultivation period on mycelial biomass, polysaccharide, and ligninolytic enzyme production by Ganoderma lucidum from Montenegro

2006 ◽  
Vol 58 (3) ◽  
pp. 179-182 ◽  
Author(s):  
Jelena Vukojevic ◽  
Mirjana Stajic ◽  
Sonja Duletic-Lausevic ◽  
Jasmina Simonic
Keyword(s):  
Ganoderma Lucidum ◽  
Enzyme Production ◽  
Ligninolytic Enzymes ◽  
Extracellular Polysaccharide ◽  
Ligninolytic Enzyme ◽  
Extracellular Polysaccharides ◽  
Medium Ph ◽  
Polysaccharide Production ◽  
Intracellular Polysaccharide ◽  
Maximal Production

The effect of initial medium pH on biomass, extracellular and intracellular polysaccharide, and ligninolytic enzyme production by Ganoderma lucidum was investigated at different pH values after 7 and 14 days of cultivation. Maximal production of biomass was recorded at pH 4.5 and 5.0; maximal production of extracellular polysaccharides at pH 7.0 and 3.0; and maximal production of intracellular polysaccharides at pH 7.0 and 5.5. Ligninolytic enzymes were not produced at any pH of the medium. Maximal biomass production was obtained on the 11th day of cultivation; maximal extracellular polysaccharide production on the 7th day; and maximal intracellular polysaccharide production on the 6th and 10th day of cultivation. .

Nodulation competitiveness of Tn5-induced mutants of Rhizobium fredii USDA208 that are altered in motility and extracellular polysaccharide production

1991 ◽  
Vol 37 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Robert E. Zdor ◽  
Steven G. Pueppke
Keyword(s):  
Parental Strain ◽  
Extracellular Polysaccharide ◽  
Triphenyltetrazolium Chloride ◽  
Polysaccharide Production ◽  
Production Type ◽  
Rhizobium Fredii ◽  
Induced Mutants ◽  
Nodulation Competitiveness

The role of motility and extracellular polysaccharide production in nodulation competitiveness of Rhizobium fredii was examined. Transposon Tn5 was used to mutagenize strain USDA208, and mutants with reduced motility on semisolid agar medium were isolated. One such mutant, 208M3, migrated to only one-seventh the distance of the parental strain. Solid medium amended with triphenyltetrazolium chloride was used to identify mutants altered in extracellular polysaccharide production. Type 1 colonies, typified by mutant 208T13, were heavily mucoid, while type 2 colonies, represented by mutant 208T3, were dry and nonmucoid. Compared with strain USDA208, these mutants produced 4- to 5-fold more extracellular polysaccharide and 20% as much extracellular polysaccharide, respectively. Marker exchange of 208T3 genomic DNA containing Tn5 into strain USDA208 resulted in a mutant, 208K1, that produced extracellular polysaccharide levels similar to mutant 208T3. Mutants 208M3, 208T3, and 208T13 contained single Tn5 insertions. All formed pink nodules on 'Peking' soybean that were structurally indistinguishable and contained proteins with similar profiles. Rates of nodulation were similar in the mutants and the parental strain. Mutants 208M3 and 208T13 were as competitive against an isolate of Bradyrhizobium japonicum serogroup 123 as was strain USDA208. In contrast, mutants 208T3 and 208K1 were competitively superior. Key words: nodulation competition, motility, extracellular polysaccharide, Rhizobium.

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