scholarly journals The Effectiveness of Heterotrophic Bacteria Isolated from Dumai Marine Waters of Riau, Used as Antibacterial against Pathogens in Fish Culture

Author(s):  
F Feliatra ◽  
Nursyirwani ◽  
A Tanjung ◽  
DS Adithiya ◽  
M Susanna ◽  
...  
2012 ◽  
Vol 5 (3) ◽  
pp. 241-249 ◽  
Author(s):  
A. I. Kopylov ◽  
D. B. Kosolapov ◽  
E. A. Zabotkina ◽  
P. V. Boyarskii ◽  
V. N. Shumilkin ◽  
...  

2020 ◽  
Author(s):  
Subhendu Chakraborty ◽  
Ken Andersen ◽  
Andre Visser ◽  
Keisuke Inomura ◽  
Michael J. Follows ◽  
...  

Abstract Nitrogen (N2) fixation by heterotrophic bacteria associated with sinking particles contributes to marine N cycling, but a mechanistic understanding of its regulation and significance are not available. Here we develop a mathematical model for unicellular heterotrophic bacteria growing on sinking marine particles and can fix N2 under suitable environmental conditions. We find that the interactive effects of polysaccharide and polypeptide concentrations, sinking speed of particles, and surrounding O2 and NO3- concentrations determine the N2 fixation rate inside particles. N2 fixation inside sinking particles is mainly fueled by SO42- respiration rather than NO3- respiration. Our model suggests that anaerobic processes, including heterotrophic N2 fixation, can take place in anoxic microenvironments inside sinking particles even in fully oxygenated marine waters. The modelled rates are similar to bulk rates measured in the aphotic ocean, and our study consequently suggests that particle-associated heterotrophic N2 fixation contributes significantly to oceanic N2 fixation.


1969 ◽  
Vol 26 (10) ◽  
pp. 2760-2764 ◽  
Author(s):  
Robert A. Murchelano ◽  
Carolyn Brown

The heterotrophic bacteria present in 15 mass cultures of six different genera of algae used for feeding larvae of the Atlantic oyster, Crassostrea virginica, and the hard clam, Mercenaria mercenaria, were isolated, identified, and their physiology studied. Of the 120 isolates obtained, 118 (98.3%) were asporogenous, gram-negative rods — types commonly found in marine waters. The majority of the isolates, 98 (81.6%), belonged to the genus Pseudomonas.


2013 ◽  
Vol 40 (1) ◽  
pp. 45-51 ◽  
Author(s):  
P. G. Moore

The Lochbuie Marine Institute on the Isle of Mull (Inner Hebrides), established in 1886, had links with the short-lived National Fish Culture Association of Great Britain and Ireland (inaugurated 1882). Its amalgamation with the Scottish Marine Station at Granton (Edinburgh) was informally suggested in 1887, but it ceased to exist about this time.


2013 ◽  
Vol 26 (2 (special Issue)) ◽  
pp. 55-71
Author(s):  
A. R. M. Mohamed ◽  
A. K. T. Yesser ◽  
A. H. J. Abdullah

2020 ◽  
Vol 82 (6) ◽  
pp. 54-63
Author(s):  
M.Ya. Vortman ◽  
◽  
Yu.B. Pysmenna ◽  
A.I. Chuenko ◽  
D.R. Abdulina ◽  
...  

Biocides are widely used in medicine and various industries to protect against a number of harmful microorganisms. Organic quaternary ammonium and guanidine-containing compounds, the biological action of which is based on membrane-toxic properties, are used as bactericidal preparations. The aim of this work was to study the bactericidal and fungicidal activities of the synthesized oligomeric alkylsubstituted guanidinium bromides with different radicals -C3H7, -C7H15, -C10H21, against different isolates of heterotrophic bacteria and microscopic fungi. Methods. The synthesis of alkyl-substituted guanidiniumcontaining oligomers was performed in two stages. In the first stage, alkyl-substituted guanidine was obtained by the reaction of guanidine, previously converted by alkali from the salt form to the base form by the base and alkyl bromides (Alk=-C3H7 (propyl), -C7H15 (heptyl), -C10H21 (decyl)) in methanol at a temperature of 50°C and a molar ratio of 1:1. The second carried out the reaction between aromatic oligoepoxide DER-331 and alkyl-substituted guanidine in methanol at a temperature of 50°C for 2–3 hours and a molar ratio of 1:2. Bacteria were grown on meat-peptone agar for 48 hours at a temperature of 28±2°С. Test cultures of micromycetes were cultured on agar beer wort (6°B), incubated for 14 days in a thermostat at a temperature of 28±2°C. Antimicrobial activity of newly synthesized alkyl-substituted guanidinium-containing oligomers was determined by standard disco-diffusion method (method of disks on agar) and fungicidal activity was determined by the method of holes in agar. Results. Oligomeric alkylsubstituted guanidinium bromides with different radicals composed -C3H7, -C7H15, -C10H21- synthesized by the reaction of guanidine alkyl bromides with aromatic oligoepoxydes. It was found that alkyl-substituted guanidinium-containing oligomers at a concentration of 1–3% inhibited the growth of Escherichia coli 475, Pseudomonas aeruginosa 465, Klebsiella pneumonia 479, Pseudomonas pseudoalcaligenes 109, Staphylococcus aureus 451, E. faecalis 422, Rhodococcus erythropolis 102, Bacillus subtilis 138 and most of the studied micromycetes – Aureobasidium pullulans F-41430, Paecilomyces variotii F-41432, Penicillium funiculosum F-41435, Penicillium ochrochloron F-41431, Scopulariopsis brevicaulis F-41434, Trichoderma viride F-41437, Candida albicans F-41441, Aspergillus flavus F-41442, Aspergillus niger F-41448, Penicillium sp. F-41447. Conclusions. Antimicrobial and fungicidal properties significantly depend on the length of the alkyl radical, with increasing of its length the diameter of the zone of bacterial and micromycetes growth retardation increases.10.15407/microbiolj82.06.054


2019 ◽  
Vol 19 (4A) ◽  
pp. 167-174
Author(s):  
Do Huu Hoang

In the last three decades aquaculture is a rapidly developing sector worldwide and antibiotics are used popularly as growth promoter. Antibiotic use was banned because research proved that antibiotic has caused many effects on environment and human health. Therefore, finding antibiotic alternatives is the first priority. The most prospect products today are probiotic and prebiotic. β-glucan is one of the immunostimulants which showed a variety of benefits to the health of many aquaculture species. In this paper only the results of β-glucan, a kind of prebiotic supplied in aquaculture, were summarized. The major benefit of β-glucan are to boost growth, to reduce mortality, to enhance tolerance or stress resistance to environmental or pathogen challenges. Although the applications of β-glucan are popular worldwide, its use in aquaculture in Vietnam is still limited. This paper provides an important reference for β-glucan utilisation which may help to develop a sustainable aquaculture in Vietnam.


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