Effects of Malachite Green on the Microbiomes of Milkfish Culture Ponds

Intensive fish farming through aquaculture is vulnerable to infectious diseases that can increase fish mortality and damage the productivity of aquaculture farms. To prevent infectious diseases, malachite green (MG) has been applied as a veterinary drug for various microbial infections in aquaculture settings worldwide. However, little is known regarding the consequences of MG and MG-degrading bacteria (MGDB) on microbial communities in milkfish culture ponds (MCPs). In this study, small MCPs were used as a model system to determine the effects of MG on the microbial communities in MCPs. The addition of MG led to cyanobacterial blooms in the small MCP. The addition of MGDB could not completely reverse the effects of MG on microbial communities. Cyanobacterial blooms were not prevented. Microbial communities analyzed by next generation sequencing revealed that cyanobacterial blooms may be due to increase of nitrogen cycle (including nitrogen fixation, nitrate reduction and anammox) associated microbial communities, which raised the levels of ammonium in the water of the small MCP. The communities of anoxygenic phototrophic bacteria (beneficial for aquaculture and aquatic ecosystems) decreased after the addition of MG. The results of this investigation provide valuable insights into the effects of MG in aquaculture and the difficulties of bioremediation for aquatic environments polluted by MG.

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Gluten-degrading bacteria: availability and applications

Applied Microbiology and Biotechnology ◽

10.1007/s00253-021-11263-5 ◽

2021 ◽

Author(s):

Viia Kõiv ◽

Tanel Tenson

Keyword(s):

Microbial Communities ◽

Digestive Tract ◽

Storage Proteins ◽

Gluten Free Diet ◽

Natural Food ◽

Gluten Free ◽

Efficient Treatment ◽

Gluten Intolerance ◽

Degrading Bacteria ◽

Human Digestive Tract

Abstract Gluten is a mixture of storage proteins in wheat and occurs in smaller amounts in other cereal grains. It provides favorable structure to bakery products but unfortunately causes disease conditions with increasing prevalence. In the human gastrointestinal tract, gluten is cleaved into proline and gluten rich peptides that are not degraded further. These peptides trigger immune responses that might lead to celiac disease, wheat allergy, and non-celiac gluten sensitivity. The main treatment option is a gluten-free diet. Alternatively, using enzymes or microorganisms with gluten-degrading properties might alleviate the disease. These components can be used during food production or could be introduced into the digestive tract as food supplements. In addition, natural food from the environment is known to enrich the microbial communities in gut and natural environmental microbial communities have high potential to degrade gluten. It remains to be investigated if food and environment-induced changes in the gut microbiome could contribute to the triggering of gluten-related diseases. Key points • Wheat proteins, gluten, are incompletely digested in human digestive tract leading to gluten intolerance. • The only efficient treatment of gluten intolerance is life-long gluten-free diet. • Environmental bacteria acquired together with food could be source of gluten-degrading bacteria detoxifying undigested gluten peptides.

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Dynamics of the prokaryotic and eukaryotic microbial community during a cyanobacterial bloom

Bioscience Biotechnology and Biochemistry ◽

10.1093/bbb/zbab179 ◽

2021 ◽

Author(s):

Yilin Qian ◽

Kunihiro Okano ◽

Miwa Kodato ◽

Michiko Arai ◽

Takeru Yanagiya ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Negative Correlation ◽

Aquatic Environment ◽

Cyanobacterial Bloom ◽

Cyanobacterial Blooms ◽

Gene Copy ◽

Degrading Bacteria ◽

Freshwater Bodies ◽

Predator Community

Abstract Toxic cyanobacterial blooms frequently develop in eutrophic freshwater bodies worldwide. Microcystis species produce microcystins (MCs) as a cyanotoxin. Certain bacteria that harbor the mlr gene cluster, especially mlrA, are capable of degrading MCs. However, MCs-degrading bacteria may possess or lack mlr genes (mlr+ and mlr− genotypes, respectively). In this study we investigated the genotype that predominantly contributes to biodegradation and cyanobacterial predator community structure with change in total MCs concentration in an aquatic environment. The two genotypes co-existed but mlr+ predominated, as indicated by the negative correlation between mlrA gene copy abundance and total MCs concentration. At the highest MCs concentrations, predation pressure by Phyllopoda, Copepoda, and Monogononta (rotifers) was reduced; thus, MCs may be toxic to cyanobacterial predators. The results suggest cooperation between MCs-degrading bacteria and predators may reduce Microcystis abundance and MCs concentration.

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Harmful phytoplankton blooms and fish mortality in a eutrophicated reservoir of northeast Brazil

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132008000400022 ◽

2008 ◽

Vol 51 (4) ◽

pp. 633-641 ◽

Cited By ~ 23

Author(s):

Naithirithi Tiruvenkatachary Chellappa ◽

Sarah Laxhmi Chellappa ◽

Sathyabama Chellappa

Keyword(s):

Cyanobacterial Bloom ◽

Hplc Method ◽

Freshwater Ecosystems ◽

Cyanobacterial Blooms ◽

Fish Mortality ◽

Cylindrospermopsis Raciborskii ◽

Northeast Brazil ◽

Cyanobacterial Toxin ◽

Bloom Formation ◽

Harmful Effects

The aim of this work was to study the eutrophication in the tropical freshwater ecosystems and the consequent cyanobacterial bloom formation and economical damage to fisheries and harmful effects to public health. Mass fish mortality due to toxin producing cyanobacterial blooms was registered during December 2003 in Marechal Dutra Reservoir, Acari/RN, Northeast Brazil. Phytoplankton and fish samplings were carried out on alternate days during the episode of fish mortality and monthly during January to June 2004. The cyanobacterial toxin was identified and quantified from the seston samples and liver of the dead fishes using the standard HPLC method. The results indicated that the toxic blooms of Cylindrospermopsis raciborskii and Microcystis aeruginosa were persistent for two weeks and represented 90% of the phytoplankton species assemblages. The lethally affected fishes were Oreochromis niloticus, Plagioscion squamosissimus, Cichla monoculus, Prochilodus brevis, Hoplias malabaricus and Leporinus friderici. The microcystin levels varied from 0.07 to 8.73µg L-1 the seston samples and from 0.01 to 2.59µg g-1in the liver samples of the fishes during the bloom period.

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Resilience of Microbial Communities after Hydrogen Peroxide Treatment of a Eutrophic Lake to Suppress Harmful Cyanobacterial Blooms

Microorganisms ◽

10.3390/microorganisms9071495 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1495

Author(s):

Tim Piel ◽

Giovanni Sandrini ◽

Gerard Muyzer ◽

Corina P. D. Brussaard ◽

Pieter C. Slot ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Microbial Community ◽

Microbial Communities ◽

Microbial Community Composition ◽

Glycoside Hydrolases ◽

Microbial Community Analysis ◽

Cyanobacterial Blooms ◽

Temporary Increase ◽

Low Concentrations ◽

Harmful Cyanobacterial Blooms

Applying low concentrations of hydrogen peroxide (H2O2) to lakes is an emerging method to mitigate harmful cyanobacterial blooms. While cyanobacteria are very sensitive to H2O2, little is known about the impacts of these H2O2 treatments on other members of the microbial community. In this study, we investigated changes in microbial community composition during two lake treatments with low H2O2 concentrations (target: 2.5 mg L−1) and in two series of controlled lake incubations. The results show that the H2O2 treatments effectively suppressed the dominant cyanobacteria Aphanizomenon klebahnii, Dolichospermum sp. and, to a lesser extent, Planktothrix agardhii. Microbial community analysis revealed that several Proteobacteria (e.g., Alteromonadales, Pseudomonadales, Rhodobacterales) profited from the treatments, whereas some bacterial taxa declined (e.g., Verrucomicrobia). In particular, the taxa known to be resistant to oxidative stress (e.g., Rheinheimera) strongly increased in relative abundance during the first 24 h after H2O2 addition, but subsequently declined again. Alpha and beta diversity showed a temporary decline but recovered within a few days, demonstrating resilience of the microbial community. The predicted functionality of the microbial community revealed a temporary increase of anti-ROS defenses and glycoside hydrolases but otherwise remained stable throughout the treatments. We conclude that the use of low concentrations of H2O2 to suppress cyanobacterial blooms provides a short-term pulse disturbance but is not detrimental to lake microbial communities and their ecosystem functioning.

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Cyanobacterial Toxin Degrading Bacteria: Who Are They?

BioMed Research International ◽

10.1155/2013/463894 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 40

Author(s):

Konstantinos Ar. Kormas ◽

Despoina S. Lymperopoulou

Keyword(s):

Meta Analysis ◽

Toxin Production ◽

Cyanobacterial Blooms ◽

Ecological Knowledge ◽

Cyanobacterial Toxin ◽

Molecular Approaches ◽

Degrading Bacteria ◽

Ecological Problems ◽

Ecosystem Level ◽

Toxin Degradation

Cyanobacteria are ubiquitous in nature and are both beneficial and detrimental to humans. Benefits include being food supplements and producing bioactive compounds, like antimicrobial and anticancer substances, while their detrimental effects are evident by toxin production, causing major ecological problems at the ecosystem level. To date, there are several ways to degrade or transform these toxins by chemical methods, while the biodegradation of these compounds is understudied. In this paper, we present a meta-analysis of the currently available 16S rRNA andmlrA(microcystinase) genes diversity of isolates known to degrade cyanobacterial toxins. The available data revealed that these bacteria belong primarily to the Proteobacteria, with several strains from the sphingomonads, and one from each of theMethylobacillusandPaucibactergenera. Other strains belonged to the generaArthrobacter, Bacillus, andLactobacillus. By combining the ecological knowledge on the distribution, abundance, and ecophysiology of the bacteria that cooccur with toxic cyanobacterial blooms and newly developed molecular approaches, it is possible not only to discover more strains with cyanobacterial toxin degradation abilities, but also to reveal the genes associated with the degradation of these toxins.

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Cave Drip Water-Related Samples as a Natural Environment for Aromatic Hydrocarbon-Degrading Bacteria

Microorganisms ◽

10.3390/microorganisms7020033 ◽

2019 ◽

Vol 7 (2) ◽

pp. 33 ◽

Cited By ~ 4

Author(s):

Eric Marques ◽

Gislaine Silva ◽

João Dias ◽

Eduardo Gross ◽

Moara Costa ◽

...

Keyword(s):

Aromatic Hydrocarbon ◽

Microbial Communities ◽

16S Rdna ◽

Aromatic Compounds ◽

Denaturing Gradient Gel Electrophoresis ◽

Amplicon Sequencing ◽

Drip Water ◽

Rdna Sequencing ◽

Degrading Bacteria ◽

Cave Drip Water

Restricted contact with the external environment has allowed the development of microbial communities adapted to the oligotrophy of caves. However, nutrients can be transported to caves by drip water and affect the microbial communities inside the cave. To evaluate the influence of aromatic compounds carried by drip water on the microbial community, two limestone caves were selected in Brazil. Drip-water-saturated and unsaturated sediment, and dripping water itself, were collected from each cave and bacterial 16S rDNA amplicon sequencing and denaturing gradient gel electrophoresis (DGGE) of naphthalene dioxygenase (ndo) genes were performed. Energy-dispersive X-ray spectroscopy (EDX) and atomic absorption spectroscopy (AAS) were performed to evaluate inorganic nutrients, and GC was performed to estimate aromatic compounds in the samples. The high frequency of Sphingomonadaceae in drip water samples indicates the presence of aromatic hydrocarbon-degrading bacteria. This finding was consistent with the detection of naphthalene and acenaphthene and the presence of ndo genes in drip-water-related samples. The aromatic compounds, aromatic hydrocarbon-degrading bacteria and 16S rDNA sequencing indicate that aromatic compounds may be one of the sources of energy and carbon to the system and the drip-water-associated bacterial community contains several potentially aromatic hydrocarbon-degrading bacteria. To the best of our knowledge, this is the first work to present compelling evidence for the presence of aromatic hydrocarbon-degrading bacteria in cave drip water.

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Anoxygenic phototrophic bacteria from microbial communities of Goryachinsk thermal spring (Baikal Area, Russia)

Microbiology ◽

10.1134/s0026261714040080 ◽

2014 ◽

Vol 83 (4) ◽

pp. 407-421 ◽

Cited By ~ 8

Author(s):

A. M. Kalashnikov ◽

V. A. Gaisin ◽

M. V. Sukhacheva ◽

B. B. Namsaraev ◽

A. N. Panteleeva ◽

...

Keyword(s):

Microbial Communities ◽

Thermal Spring ◽

Phototrophic Bacteria ◽

Anoxygenic Phototrophic Bacteria

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Quantitative Determination of Microbial Oil Degradation and Of Oil Absorption by a New Oil-Binding System in a Baltic Sea Mesocosm Experiment

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-2014.1.1059 ◽

2014 ◽

Vol 2014 (1) ◽

pp. 1059-1072 ◽

Cited By ~ 1

Author(s):

Janne Haehnel ◽

Jenny Jeschek ◽

Detlef E. Schulz-Bull

Keyword(s):

Crude Oil ◽

Baltic Sea ◽

Microbial Communities ◽

Medium Size ◽

Oil Absorption ◽

Binding System ◽

Degrading Bacteria ◽

Joint Research Project ◽

Meso Scale ◽

Oil Binding

ABSTRACT In this study, a novel oil-binding system for marine application was developed within the joint research project “BIOBIND” (“Airborne clean-up of oil pollution at sea with biogenic oil binders”). The system's components include oil-absorbing solids, made of biogenic and biodegradable wood-fiber, that can be dropped from an aircraft and subsequently recovered either at sea or along the coast. The binder-based system was tested together with oil-degrading microbial communities previously isolated from coastal water samples of the Baltic Sea. In a first attempt at a meso-scale setup, mesocosms containing different combinations of seawater, oil binders, crude oil, and oil-degrading bacteria were established. These experiments sought answers to the following questions: (1) How does the microbial community isolated from the Western Baltic Sea react to oil entries? (2) What happens to the crude oil? (3) How efficient is the oil absorption capacity of the developed binders? Microbial activity was monitored by measuring the oxygen, phosphate, and ammonia contents of the mesocosms. Weight loss of the whole crude was estimated using a gravimetric method. In one of the mesocosms, the selected inoculum degraded around 25 % of the added crude oil. In another, in which the absorption efficiency of the oil binders was examined, more than 98 % of the crude oil was absorbed. Further molecular details on the fate of the oil were obtained using gas chromatography with a flame ionization detector and mass spectrometry to quantify alkanes and polycyclic aromatic hydrocarbons, respectively; both were efficiently degraded by the selected inoculum. The oil absorption and oil-degrading capabilities of a system consisting of oil binders and oil-degrading microbial communities at the meso-scale was shown. These promising preliminary tests recommend its further development for use in responding to small- and medium-size oil spills in near-coastal shallow-water areas.

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Benzyldimethyl[3-(miristoylamino)-propyl]ammonium chloride stabilized silver nanoparticles (Argumistin™) in medicine: results of clinical trials for treatment of infectious diseases of dogs and perspectives for humans

European Journal of Nanomedicine ◽

10.1515/ejnm-2016-0018 ◽

2016 ◽

Vol 8 (4) ◽

Cited By ~ 5

Author(s):

Yurii Krutyakov ◽

Alexey Klimov ◽

Boris Violin ◽

Vladimir Kuzmin ◽

Victoria Ryzhikh ◽

...

Keyword(s):

Silver Nanoparticles ◽

Clinical Trials ◽

Infectious Diseases ◽

Ammonium Chloride ◽

Dosage Form ◽

Multiple Drug Resistance ◽

Periodontal Diseases ◽

Veterinary Drug ◽

Antibacterial Drug ◽

Eye Drops

AbstractIncreased interest in nanosilver during the last 10 years is mainly explained by the emergence and spread of pathogenic microorganisms with multiple drug resistance, including resistance to last-generation antibiotics. In this article, we for the first time, give a description of large-scale clinical trials of a new nanosilver based antibacterial drug [containing two active components: silver nanoparticles (AgNPs) (10–50 ppm) and benzyldimethyl[3-(miristoylamino)-propyl]ammonium chloride (100 ppm)] registered in Russia in 2015 as a veterinary drug under the brand name Argumistin™. This drug has been approved for application in a diluted dosage form – as eye drops, intranasal drops and orally; it has also been approved for application in a more concentrated dosage form (up to 50 ppm of nanosilver) as ear drops and as an antiseptic during demodicosis and gum disease treatment, open wound treatment, etc. We have registered the high therapeutic effectiveness of Argumistin™ during treatment of infectious conjunctivitis, gingivitis, parodontosis and enteritis of dogs. Application of this antibacterial drug gives considerable (up to 70% in case of periodontal diseases) reduction in the treatment period and prevention of complications. The results of clinical trials in the treatment of infectious diseases of dogs makes Argumistin™ a promising candidate for an effective antibacterial drug for human medicine.

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