Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
18,261
result(s) for
"Aquatic microorganisms"
Sort by:
Secrets of the sea
Traveling from the rock pools of the shoreline to the deepest depths of the ocean, a blending of illustrations and facts about marine animals provides an introduction to some of the ocean's rarely seen creatures.
BOOK
Antimicrobial activity, antibiotic susceptibility and virulence factors of Lactic Acid Bacteria of aquatic origin intended for use as probiotics in aquaculture
Background
The microorganisms intended for use as probiotics in aquaculture should exert antimicrobial activity and be regarded as safe not only for the aquatic hosts but also for their surrounding environments and humans. The objective of this work was to investigate the antimicrobial/bacteriocin activity against fish pathogens, the antibiotic susceptibility, and the prevalence of virulence factors and detrimental enzymatic activities in 99 Lactic Acid Bacteria (LAB) (59 enterococci and 40 non-enterococci) isolated from aquatic animals regarded as human food.
Results
These LAB displayed a broad antimicrobial/bacteriocin activity against the main Gram-positive and Gram-negative fish pathogens. However, particular safety concerns based on antibiotic resistance and virulence factors were identified in the genus
Enterococcus
(86%) (
Enterococcus faecalis
, 100%;
E. faecium,
79%). Antibiotic resistance was also found in the genera
Weissella
(60%),
Pediococcus
(44%),
Lactobacillus
(33%), but not in leuconostocs and lactococci. Antibiotic resistance genes were found in 7.5% of the non-enterococci, including the genera
Pediococcus
(12.5%) and
Weissella
(6.7%). One strain of both
Pediococcus pentosaceus
and
Weissella cibaria
carried the erythromycin resistance gene
mef
(A/E), and another two
P. pentosaceus
strains harboured
lnu
(A) conferring resistance to lincosamides. Gelatinase activity was found in
E. faecalis
and
E. faecium
(71 and 11%, respectively), while a low number of
E. faecalis
(5%) and none
E. faecium
exerted hemolytic activity. None enterococci and non-enterococci showed bile deconjugation and mucin degradation abilities, or other detrimental enzymatic activities.
Conclusions
To our knowledge, this is the first description of
mef
(A/E) in the genera
Pediococcus
and
Weissella
, and
lnu
(A) in the genus
Pediococcus
. The
in vitro
subtractive screening presented in this work constitutes a valuable strategy for the large-scale preliminary selection of putatively safe LAB intended for use as probiotics in aquaculture.
Journal Article
Pesticides have negative effects on non-target organisms
Pesticides affect a diverse range of non-target species and may be linked to global biodiversity loss. The magnitude of this hazard remains only partially understood. We present a synthesis of pesticide (insecticide, herbicide and fungicide) impacts on multiple non-target organisms across trophic levels based on 20,212 effect sizes from 1,705 studies. For non-target plants, animals (invertebrate and vertebrates) and microorganisms (bacteria and fungi), we show negative responses of the growth, reproduction, behaviour and other physiological biomarkers within terrestrial and aquatic systems. Pesticides formulated for specific taxa negatively affected non-target groups, e.g. insecticidal neonicotinoids affecting amphibians. Negative effects were more pronounced in temperate than tropical regions but were consistent between aquatic and terrestrial environments, even after correcting for field-realistic terrestrial and environmentally relevant exposure scenarios. Our results question the sustainability of current pesticide use and support the need for enhanced risk assessments to reduce risks to biodiversity and ecosystems.
Journal Article
Hypes, hopes, and the way forward for microalgal biotechnology
Microalgae can contribute to food security through the sustainable production of proteins and lipids, which are required to meet population growth and address environmental challenges.Cellular agriculture is developing with emerging bioprocesses based on solar energy, photovoltaics, H2, C1 carbon sources, and sugar as feedstocks.Different trophic modes – autotrophy, heterotrophy, and mixotrophy – have been successfully explored for microalgae.The production of microalgae has tripled in the last 5 years.The genetic toolbox for industrially relevant phototrophic strains expanded tremendously in the last 5 years.
The urge for food security and sustainability has advanced the field of microalgal biotechnology. Microalgae are microorganisms able to grow using (sun)light, fertilizers, sugars, CO2, and seawater. They have high potential as a feedstock for food, feed, energy, and chemicals. Microalgae grow faster and have higher areal productivity than plant crops, without competing for agricultural land and with 100% efficiency uptake of fertilizers. In comparison with bacterial, fungal, and yeast single-cell protein production, based on hydrogen or sugar, microalgae show higher land-use efficiency. New insights are provided regarding the potential of microalgae replacing soy protein, fish oil, and palm oil and being used as cell factories in modern industrial biotechnology to produce designer feed, recombinant proteins, biopharmaceuticals, and vaccines.
Journal Article
Overview and Challenges of Large-Scale Cultivation of Photosynthetic Microalgae and Cyanobacteria
Microalgae and cyanobacteria are diverse groups of organisms with great potential to benefit societies across the world. These organisms are currently used in food, feed, pharmaceutical and cosmetic industries. In addition, a variety of novel compounds are being isolated. Commercial production of photosynthetic microalgae and cyanobacteria requires cultivation on a large scale with high throughput. However, scaling up production from lab-based systems to large-scale systems is a complex and potentially costly endeavor. In this review, we summarise all aspects of large-scale cultivation, including aims of cultivation, species selection, types of cultivation (ponds, photobioreactors, and biofilms), water and nutrient sources, temperature, light and mixing, monitoring, contamination, harvesting strategies, and potential environmental risks. Importantly, we also present practical recommendations and discuss challenges of profitable large-scale systems associated with economical design, effective operation and maintenance, automation, and shortage of experienced phycologists.
Journal Article
Impacts of neonicotinoids on biodiversity: a critical review
Neonicotinoids are the most widely used class of insecticides in the world but they have raised numerous concerns regarding their effects on biodiversity. Thus, the objective of this work was to do a critical review of the contamination of the environment (soil, water, air, biota) by neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid, thiamethoxam) and of their impacts on terrestrial and aquatic biodiversity. Neonicotinoids are very frequently detected in soils and in freshwater, and they are also found in the air. They have only been recently monitored in coastal and marine environments, but some studies already reported the presence of imidacloprid and thiamethoxam in transitional or semi-enclosed ecosystems (lagoons, bays and estuaries). The contamination of the environment leads to the exposure and to the contamination of non-target organisms, and to negative effects on biodiversity. Direct impacts of neonicotinoids are mainly reported on terrestrial invertebrates (e.g., pollinators, natural enemies, earthworms) and vertebrates (e.g., birds), and on aquatic invertebrates (e.g., arthropods). Impacts on aquatic vertebrate populations and communities, as well as on microorganisms, are less documented. In addition to their toxicity to directly exposed organisms, neonicotinoid induce indirect effects via trophic cascades as demonstrated in several species (terrestrial and aquatic invertebrates). However, more data are needed to reach firmer conclusions and to get a clearer picture of such indirect effects. Finally, we identified specific knowledge gaps that need to be filled to better understand the effects of neonicotinoids on terrestrial, freshwater and marine organisms, as well as on ecosystem services associated with these biotas.
Journal Article
Bioremediation of hazardous heavy metals by marine microorganisms: a recent review
Heavy metals (HMs) like Zn, Cu, Pb, Ni, Cd, and Hg, among others, play a role in several environmental problems. The marine environment is polluted by several contaminants, such as HMs. A variety of physico-chemical methods usually available for sanitation HMs remediation suffer from either limitation. Bioremediation is a promising way of dealing with HMs pollution. Microbes have the ability with various potencies to resist HMs tension. The current review discusses the main sources and influences of HMs, the role of marine microorganisms in HMs bioremediation, as well as the microbial mechanisms for HMs detoxification and transformation. This review paper aims to provide an overview of the bioremediation technologies that are currently available for the removal of HMs ions from industrial and urban effluent by aquatic organisms such as bacteria, fungi, and microalgae, particularly those that are isolated from marine areas. The primary goals are to outline various studies and offer helpful information about the most important aspects of the bioelimination techniques. The biotreatment practices have been primarily divided into three techniques based on this topic. They are biosorption, bioaccumulation, bioleaching, and biotransformation. This article gives the brief view on the research studies about bioremediation of HMs using marine microorganisms. The current review also deals with the critical issues and recent studies based on the HMs biodetoxification using aquatic microorganisms.
Journal Article
Current status of microplastics pollution in the aquatic environment, interaction with other pollutants, and effects on aquatic organisms
Microplastics, as emerging pollutants, have received great attention in the past few decades due to its adverse effects on the environment. Microplastics are ubiquitous in the atmosphere, soil, and water bodies, and mostly reported in aqueous environment. This paper summarizes the abundance and types of microplastics in different aqueous environments and discusses the interactions of microplastics with other contaminants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), antibiotics, and heavy metals. The toxicity of microplastics to aquatic organisms and microorganisms is addressed. Particularly, the combined toxic effects of microplastics and other pollutants are discussed, demonstrating either synergetic or antagonistic effects. Future prospectives should be focused on the characterization of different types and shapes of microplastics, the standardization of microplastic units, exploring the interaction and toxicity of microplastics with other pollutants, and the degradation of microplastics, for a better understanding of the ecological risks of microplastics.
Journal Article
Using Microbial Aggregates to Entrap Aqueous Phosphorus
The increasing use and associated loss of phosphorus to the environment pose risks to aquatic ecosystems. Technology for phosphorus removal based on microbial aggregates is a natural, ecologically widespread, and sustainable reclamation strategy. Two main processes dominate phosphorus removal by microbial aggregates: extra- and intra-cellular entrapment. Extracellular phosphorus entrapment relies on extracellular polymeric substances, while intracellular entrapment uses a wider variety of phosphorus-entrapping mechanisms. In microbial aggregates, microalgae–bacteria interactions, quorum sensing, and acclimation can enhance phosphorus removal. Based on these insights, we propose novel avenues for entrapping phosphorus using ecological and genetic engineering, manipulated interactions, and integrated processes to create phosphorus removal technology mediated by microbial aggregates.
Phosphorus (P) entrapment by microbial aggregates is a natural process that requires relatively small amounts of operational inputs and is eco-friendly; it offers an effective means to remove P from eutrophic surface waters.Extracellular polymeric substances in microbial aggregates play an important role in extracellular P entrapment due to their inherent characteristics, chemical composition, and role in aggregation.Multiple mechanisms allow intracellular P entrapment by microalgae and polyphosphate-accumulating microorganisms in microbial aggregates.In microbial aggregates, microalgae–bacteria interactions, quorum sensing, and adaption can enhance the community’s ability to remove P.Ecological and genetic engineering, regulation of interactions, and integrated processes (microbial aggregates with enhanced biological P removal and bioelectrochemical system), can help to design P removal technology based on microbial aggregates.
Journal Article
Toxicokinetics and metabolism of deoxynivalenol in animals and humans
Deoxynivalenol (DON) is the most widespread mycotoxin in food and feedstuffs, posing a persistent health threat to humans and farm animals. The susceptibilities of DON vary significantly among animals, following the order of pigs, mice/rats and poultry from the most to least susceptible. However, no study comprehensively disentangles factors shaping species-specific sensitivity. In this review, the toxicokinetics and metabolism of DON are summarized in animals and humans. Generally, DON is fast-absorbed and widely distributed in multiple organs. DON is first enriched in the plasma, liver and kidney and subsequently accumulates in the intestine. There are also key variations among animals. Pigs and humans are highly sensitive to DON, and they have similar absorption rates (1 h <
t
max
< 4 h), high bioavailability (> 55%) and long clearance time (2 h <
t
1/2
< 4 h). Also, both species lack detoxification microorganisms and mainly depend on liver glucuronidation and urine excretion. Mice and rats have similar toxicokinetics (
t
max
< 0.5 h,
t
1/2
< 1 h). However, a higher proportion of DON is excreted by feces as DOM-1 in rats than in mice, suggesting an important role of gut microbiota in rats. Poultry is least sensitive to DON due to their fast absorption rate (
t
max
< 1 h), low oral bioavailability (5–30%), broadly available detoxification gut microorganisms and short clearance time (
t
1/2
< 1 h). Aquatic animals have significantly slower plasma clearance of DON than land animals. Overall, studies on toxicokinetics provide valuable information for risk assessment, prevention and control of DON contamination.
Journal Article