Evaluation of the Petrifilm Aerobic Count Plate for Enumeration of Aerobic Marine Bacteria from Seawater and Caulerpa lentillifera

The enumeration and evaluation of the activity of marine bacteria are important in the food industry. However, detection of marine bacteria in seawater or seafood has not been easy. The Petrifilm aerobic count plate (ACP) is a ready-to-use alternative to the traditional enumeration media used for bacteria associated with food. The purpose of this study was to evaluate the usefulness of a simple detection and enumeration method utilizing the Petrifilm ACP for enumeration of aerobic marine bacteria from seawater and an edible seaweed, Caulerpa lentillifera. The efficiency of enumeration of total aerobic marine bacteria on Petrifilm ACP was compared with that using the spread plate method on marine agar with 80 seawater and 64 C. lentillifera samples. With sterile seawater as the diluent, a close correlation was observed between the method utilizing Petrifilm ACP and that utilizing the conventional marine agar (r = 0.98 for seawater and 0.91 for C. lentillifera). The Petrifilm ACP method was simpler and less time-consuming than the conventional method. These results indicate that Petrifilm ACP is a suitable alternative to conventional marine agar for enumeration of marine microorganisms in seawater and C. lentillifera samples.

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Ultrastructure of two species of oil-degrading marine bacteria

Canadian Journal of Microbiology ◽

10.1139/m73-006 ◽

1973 ◽

Vol 19 (1) ◽

pp. 43-45 ◽

Cited By ~ 10

Author(s):

R. M. Atlas ◽

C. E. Heintz

Keyword(s):

Crude Oil ◽

Marine Bacteria ◽

Inclusion Bodies ◽

Marine Agar ◽

Sudan Black B ◽

Presence And Absence

Two species of marine bacteria with the ability to degrade crude oil were compared ultrastructurally after growing in the presence and absence of oil. Large electron-dense inclusions, which were located predominantly at the cell terminus, characterized species of Flavobacterium and Brevibacterium when growing on oil. Cells of Flavobacterium sp. had smaller inclusions when grown on marine agar, while inclusion bodies were not found in Brevibacterium sp. grown on marine agar. Sudan black B staining indicated the inclusions are stored lipids.

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Research Progress in Anti-Inflammatory Bioactive Substances Derived from Marine Microorganisms, Sponges, Algae, and Corals

Marine Drugs ◽

10.3390/md19100572 ◽

2021 ◽

Vol 19 (10) ◽

pp. 572

Author(s):

Chao-Qun Li ◽

Qin-Yuan Ma ◽

Xiu-Zhen Gao ◽

Xuan Wang ◽

Bei-Li Zhang

Keyword(s):

Marine Bacteria ◽

Marine Organism ◽

Research Progress ◽

Defense Reaction ◽

Marine Microorganisms ◽

Bioactive Substances ◽

Evaluation Models ◽

Inflammatory Drugs ◽

Anti Inflammatory ◽

Bacteria And Fungi

Inflammation is the body’s defense reaction in response to stimulations and is the basis of various physiological and pathological processes. However, chronic inflammation is undesirable and closely related to the occurrence and development of diseases. The ocean gives birth to unique and diverse bioactive substances, which have gained special attention and been a focus for anti-inflammatory drug development. So far, numerous promising bioactive substances have been obtained from various marine organisms such as marine bacteria and fungi, sponges, algae, and coral. This review covers 71 bioactive substances described during 2015–2020, including the structures (65 of which), species sources, evaluation models and anti-inflammatory activities of these substances. This review aims to provide some reference for the research progress of marine-organism-derived anti-inflammatory metabolites and give more research impetus for their conversion to novel anti-inflammatory drugs.

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Isolation of SAR11 Marine Bacteria from Cryopreserved Seawater

mSystems ◽

10.1128/msystems.00954-20 ◽

2020 ◽

Vol 5 (6) ◽

pp. e00954-20

Author(s):

Elizabeth A. Monaghan ◽

Kelle C. Freel ◽

Michael S. Rappé

Keyword(s):

High Throughput ◽

Marine Bacteria ◽

Mixed Cultures ◽

Rrna Gene ◽

Marine Microorganisms ◽

Culture Collections ◽

Natural Systems ◽

Wide Range ◽

Long Time ◽

Cultivation Experiment

ABSTRACTWhile marine microorganisms are frequently studied in their natural environment, isolated strains are invaluable resources that can be used in controlled experiments to expand upon direct observations from natural systems. Here, we sought a means to enhance culture collections of SAR11 marine bacteria by testing the use of seawater cryopreserved with glycerol as an inoculum. Using a raw seawater sample collected from the tropical Pacific Ocean, a subsample was diluted in seawater growth medium to create 576 2-ml dilution cultures containing 5 cells each and incubated for a high-throughput culturing (HTC) experiment, while another portion was cryopreserved in 10% glycerol. After 10 months, a cryopreserved aliquot was thawed and used to create a second cultivation experiment of 480 2-ml cultures containing 5 cells each and 470 cultures containing 105 cells each. The raw seawater cultivation experiment resulted in the successful isolation of 54 monocultures and 29 mixed cultures, while cryopreserved seawater resulted in 59 monocultures and 29 mixed cultures. Combined, the cultures included 51 SAR11 isolates spanning 11 unique 16S rRNA gene amplicon sequence variants (ASVs) from the raw seawater inoculum and 74 SAR11 isolates spanning 13 unique ASVs from cryopreserved seawater. A vast majority (92%) of SAR11 isolates from the two HTC experiments were members of SAR11 subclade Ia, though subclades IIIa and Va were also recovered from cryopreserved seawater and subclade Ib was recovered from both. The four most abundant SAR11 subclade Ia ASVs found in the initial seawater environmental sample were isolated by both approaches.IMPORTANCE High-throughput dilution culture has proved to be a successful approach to bring some difficult-to-isolate planktonic microorganisms into culture, including the highly abundant SAR11 lineage of marine bacteria. While the long-term preservation of bacterial isolates by freezing them in the presence of cryoprotectants, such as glycerol, has been shown to be an effective method of storing viable cells over long time periods (i.e., years), to our knowledge it had not previously been tested for its efficacy in preserving raw seawater for later use as an inoculum for high-throughput cultivation experiments. We found that SAR11 and other abundant marine bacteria could be isolated from seawater that was previously cryopreserved for nearly 10 months at a rate of culturability similar to that of the same seawater used fresh, immediately after collection. Our findings (i) expand the potential of high-throughput cultivation experiments to include testing when immediate isolation experiments are impractical, (ii) allow for targeted isolation experiments from specific samples based on analyses such as microbial community structure, and (iii) enable cultivation experiments across a wide range of other conditions that would benefit from having source inocula available over extended periods of time.

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Advances in cultivation, wastewater treatment application, bioactive components of Caulerpa lentillifera and their biotechnological applications

PeerJ ◽

10.7717/peerj.6118 ◽

2019 ◽

Vol 7 ◽

pp. e6118 ◽

Cited By ~ 7

Author(s):

Xiaolin Chen ◽

Yuhao Sun ◽

Hong Liu ◽

Song Liu ◽

Yukun Qin ◽

...

Keyword(s):

Fatty Acids ◽

Wastewater Treatment ◽

Unsaturated Fatty Acids ◽

Saturated Fatty Acids ◽

Algal Growth ◽

Stress Factors ◽

Nutrient Concentrations ◽

Bioactive Components ◽

Edible Seaweed ◽

Caulerpa Lentillifera

The edible seaweed Caulerpa lentillifera, a powerful natural food source that is rich in protein, minerals, dietary fibers, vitamins, saturated fatty acids and unsaturated fatty acids, has been mass cultured in some Asian countries and has been the focus of researchers in recent years. Here, the operational conditions of its culture, application in wastewater treatment, and bioactive components are summarized and comparatively analyzed. Based on previous studies, salinity, nutrient concentrations, irradiance and temperature are stress factors for algal growth. Moreover, dried Caulerpa lentillifera seaweed is efficient in the biosorption of heavy metals and cationic dyes in wastewater, and fresh seaweed can be introduced as a biofilter in aquaculture system treatment. In addition, among the rich bioactive compounds in Caulerpa lentillifera, the phenolic compounds show the potential ability for regulating glucose metabolism in vivo. Polysaccharides and oligosaccharides exhibit anticoagulant, immunomodulatory effects and cancer-preventing activity. Siphonaxanthin is a compound with attractive novel functions in cancer-preventing activity and lipogenesis-inhibiting effects. Furthermore, the antioxidant activity of siphonaxanthin extracted from Caulerpa lentillifera could be stronger than that of astaxanthin. This review offers an overview of studies of Caulerpa lentillifera addressing various aspects including cultivation, wastewater treatment and biological active components which may provide valuable information for the cultivation and utilization of this green alga.

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Effects of Gelling Agent and Extracellular Signaling Molecules on the Culturability of Marine Bacteria

Applied and Environmental Microbiology ◽

10.1128/aem.00243-17 ◽

2017 ◽

Vol 83 (9) ◽

Cited By ~ 8

Author(s):

Anita Mac Rygaard ◽

Mariane Schmidt Thøgersen ◽

Kristian Fog Nielsen ◽

Lone Gram ◽

Mikkel Bentzon-Tilia

Keyword(s):

Marine Bacteria ◽

Incubation Temperature ◽

Amplicon Sequencing ◽

Signaling Molecules ◽

Medium Composition ◽

Gellan Gum ◽

Gelling Agent ◽

Marine Microorganisms ◽

Medium Components ◽

Cell Counts

ABSTRACT Only 1% of marine bacteria are currently culturable using standard laboratory procedures, and this is a major obstacle for our understanding of the biology of marine microorganisms and for the discovery of novel microbial natural products. Therefore, the purpose of this study was to investigate if improved cultivation conditions, including the use of an alternative gelling agent and supplementation with signaling molecules, improve the culturability of bacteria from seawater. Replacing agar with gellan gum improved viable counts 3- to 40-fold, depending on medium composition and incubation conditions, with a maximum of 6.6% culturability relative to direct cell counts. Through V4 amplicon sequencing we found that culturable diversity was also affected by a change in gelling agent, facilitating the growth of orders not culturable on agar-based substrates. Community analyses showed that communities grown on gellan gum substrates were significantly different from communities grown on agar and that they covered a larger fraction of the seawater community. Other factors, such as incubation temperature and time, had less obvious effects on viable counts and culturable diversity. Supplementation with acylated homoserine lactones (AHLs) did not have a positive effect on total viable counts or a strong effect on culturable diversity. However, low concentrations of AHLs increased the relative abundance of sphingobacteria. Hence, with alternative growth substrates, it is possible to significantly increase the number and diversity of cultured marine bacteria. IMPORTANCE Serious challenges to human health, such as the occurrence and spread of antibiotic resistance and an aging human population in need of bioactive pharmaceuticals, have revitalized the search for natural microbial products. The marine environment, representing the largest ecosystem in the biosphere, harbors an immense and virtually untapped microbial diversity producing unique bioactive compounds. However, we are currently able to cultivate only a minute fraction of this diversity. The lack of cultivated microbes is hampering not only bioprospecting efforts but also our general understanding of marine microbes. In this study, we present a means to increase the number and diversity of cultured bacteria from seawater, showing that relatively simple changes to medium components may facilitate the isolation and growth of hitherto unknown bacterial orders.

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Mechanistic Insight into TrimethylamineN-Oxide Recognition by the Marine Bacterium Ruegeria pomeroyi DSS-3

Journal of Bacteriology ◽

10.1128/jb.00542-15 ◽

2015 ◽

Vol 197 (21) ◽

pp. 3378-3387 ◽

Cited By ~ 10

Author(s):

Chun-Yang Li ◽

Xiu-Lan Chen ◽

Xuan Shao ◽

Tian-Di Wei ◽

Peng Wang ◽

...

Keyword(s):

Nitrous Oxide ◽

Substrate Specificity ◽

Nitrogen Source ◽

Marine Bacteria ◽

Substrate Binding ◽

Marine Microorganisms ◽

Binding Mechanism ◽

Content Type ◽

Ruegeria Pomeroyi ◽

Substrate Binding Protein

ABSTRACTTrimethylamineN-oxide (TMAO) is an important nitrogen source for marine bacteria. TMAO can also be metabolized by marine bacteria into volatile methylated amines, the precursors of the greenhouse gas nitrous oxide. However, it was not known how TMAO is recognized and imported by bacteria.Ruegeria pomeroyiDSS-3, a marineRoseobacter, has an ATP-binding cassette transporter, TmoXWV, specific for TMAO. TmoX is the substrate-binding protein of the TmoXWV transporter. In this study, the substrate specificity of TmoX ofR. pomeroyiDSS-3 was characterized. We further determined the structure of the TmoX/TMAO complex and studied the TMAO-binding mechanism of TmoX by biochemical, structural, and mutational analyses. A Ca2+ion chelated by an extended loop in TmoX was shown to be important for maintaining the stability of TmoX. Molecular dynamics simulations indicate that TmoX can alternate between “open” and “closed” states for binding TMAO. In the substrate-binding pocket, four tryptophan residues interact with the quaternary amine of TMAO by cation-π interactions, and Glu131 forms a hydrogen bond with the polar oxygen atom of TMAO. The π-π stacking interactions between the side chains of Phe and Trp are also essential for TMAO binding. Sequence analysis suggests that the TMAO-binding mechanism of TmoX may have universal significance in marine bacteria, especially in the marineRoseobacterclade. This study sheds light on how marine microorganisms utilize TMAO.IMPORTANCETrimethylamineN-oxide (TMAO) is an important nitrogen source for marine bacteria. The products of TMAO metabolized by bacteria are part of the precursors of the greenhouse gas nitrous oxide. It is unclear how TMAO is recognized and imported by bacteria. TmoX is the substrate-binding protein of a TMAO-specific transporter. Here, the substrate specificity of TmoX ofRuegeria pomeroyiDSS-3 was characterized. The TMAO-binding mechanism of TmoX was studied by biochemical, structural, and mutational analyses. Moreover, our results suggest that the TMAO-binding mechanism may have universal significance in marine bacteria. This study sheds light on how marine microorganisms utilize TMAO and should lead to a better understanding of marine nitrogen cycling.

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Gene Cluster Analysis of Marine Bacteria Seeking for Natural Anticancer Products

Jundishapur Journal of Natural Pharmaceutical Products ◽

10.5812/jjnpp.104665 ◽

2021 ◽

Vol In Press (In Press) ◽

Author(s):

Ashraf Mohamadkhani

Keyword(s):

Natural Products ◽

Marine Bacteria ◽

Chemical Engineering ◽

Biological Activities ◽

Bacterial Species ◽

Bacterial Genome ◽

Gene Clusters ◽

Marine Microorganisms ◽

Genome Database ◽

Anti Cancer

Background: In the past decade, metabolites of marine microorganisms have been increasingly used for their various biological activities. An intense effort has been dedicated to assessing the therapeutic efficacy of the marine natural products and metabolites obtained from marine bacteria in cancer therapy. Fast and reliable analytical bacterial genome sequencing provides specialized bioinformatic tools to identify potential gene clusters in bacteria for obtaining secondary metabolites. Objectives: This study aimed to analyze the genome sequences of marine bacteria to recognize bioactive compounds with anti-cancer properties. Methods: Marine bacteria with the genomic sequences registered in the National Center for Biotechnology Information (NCBI) genome database were used in this study. The genome was analyzed for proteins, tRNAs, and rRNAs from GenBank entries by Feature Extract 1.2L Server. The Anti-SMASH webserver was used for the analysis of unique marine bacterial metabolites of the marine bacterial genome, available from the NCBI database. Results: A number of marine bacterial species, including Salinispora arenicola, Salinispora tropica, Crocosphaera watsonii, and Blastopirellula marina encoded metabolites belonging to the polyketide and nonribosomal peptide (NRP) families, showing anti-cancer properties. Among the marine species described, S. tropica and S. arenicola are richer in the genes encoding polyketide and NRP with potential antitumor activities. Conclusions: Marine bacteria are an excellent and exceptional source of anti-cancer compounds. In silico genome analysis of marine bacteria provided an opportunity to evaluate gene clusters for known natural products. Like this chemical engineering approaches for pharmaceutical application are useful in clinical evaluation of cancer treatment.

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Advances in cultivation, wastewater treatment application, bioactive components of Caulerpa lentillifera and their biotechnological applications

10.7287/peerj.preprints.27231v1 ◽

2018 ◽

Author(s):

Xiaolin Chen ◽

Yuhao Sun ◽

Hong Liu ◽

Song Liu ◽

Yukun Qin ◽

...

Keyword(s):

Fatty Acids ◽

Wastewater Treatment ◽

Unsaturated Fatty Acids ◽

Saturated Fatty Acids ◽

Algal Growth ◽

Stress Factors ◽

Nutrient Concentrations ◽

Bioactive Components ◽

Edible Seaweed ◽

Caulerpa Lentillifera

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Efficiency of Marine Bacteria and Yeasts on the Biocontrol Activity of Pythium ultimum in Ancho-Type Pepper Seedlings

Agronomy ◽

10.3390/agronomy10030408 ◽

2020 ◽

Vol 10 (3) ◽

pp. 408 ◽

Cited By ~ 1

Author(s):

Liliana Lara-Capistran ◽

Ramon Zulueta-Rodriguez ◽

Thelma Castellanos-Cervantes ◽

Juan J. Reyes-Perez ◽

Pablo Preciado-Rangel ◽

...

Keyword(s):

Marine Bacteria ◽

Growth Parameters ◽

Debaryomyces Hansenii ◽

Pythium Ultimum ◽

Cryptococcus Laurentii ◽

Marine Microorganisms ◽

Alternative Source ◽

Pepper Plants

Ancho-type pepper (Capsicum annuum L.) is a crop susceptible to Pythium ultimum, which has already been controlled with synthetic fungicide applications; however, marine antagonist microorganisms could be an alternative source of control. The efficiency in vitro and in vivo of marine bacteria and yeasts was determined against P. ultimum. The inhibition of the radial growth of P. ultimum was quantified in vitro by the bacteria Stenotrophomonas rhizophila KM01 and KM02; Bacillus subtilis RBM01 and RBM02, B. amyloliquefaciens 2RLBF and 3R4CF; and Pseudomonas spp. 2R6BF and 2RE9CF, as well as the yeasts Debaryomyces hansenii 1R11AB, 1R11CB, and LL01 and Cryptococcus laurentii 2R3BF and 2R1CB. The β-1,3-glucanase activity of the marine microorganisms was quantified in the presence of the phytopathogen. The disease index (DI), growth parameters, and colony forming units (CFU) were determined in ancho-type pepper plants inoculated with marine bacteria, yeasts, and P. ultimum. The radial zone of the phytopathogen was inhibited by 80% and 75% by S. rhizophila KM01 and C. laurentii 2R1CB, respectively. D. hansenii LL01 and S. rhizophila KM02 showed the highest activity of β-1,3-glucanase, with 6060 U/mL and 47 U/mL, respectively. B. subtilis RBM02 protected 100% of the plants from the oomycete, and an increase was quantified in all the growth parameters and CFU. The use of these marine bacteria and yeasts are, therefore, an option for P. ultimum biocontrol in ancho-type pepper plants, thereby minimizing the application of synthetic fungicides.

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The Unusual Lipid A Structure and Immunoinhibitory Activity of LPS from Marine Bacteria Echinicola pacifica KMM 6172T and Echinicola vietnamensis KMM 6221T

Microorganisms ◽

10.3390/microorganisms9122552 ◽

2021 ◽

Vol 9 (12) ◽

pp. 2552

Author(s):

Molly Dorothy Pither ◽

Giuseppe Mantova ◽

Elena Scaglione ◽

Chiara Pagliuca ◽

Roberta Colicchio ◽

...

Keyword(s):

Marine Bacteria ◽

Lipid A ◽

Fatty Acid Content ◽

Membrane System ◽

Marine Microorganisms ◽

Gram Negative ◽

Structural Modifications ◽

Chemical Structures ◽

Marine Habitats ◽

Lipid A Structure

Gram-negative bacteria experiencing marine habitats are constantly exposed to stressful conditions dictating their survival and proliferation. In response to these selective pressures, marine microorganisms adapt their membrane system to ensure protection and dynamicity in order to face the highly mutable sea environments. As an integral part of the Gram-negative outer membrane, structural modifications are commonly observed in the lipopolysaccharide (LPS) molecule; these mainly involve its glycolipid portion, i.e., the lipid A, mostly with regard to fatty acid content, to counterbalance the alterations caused by chemical and physical agents. As a consequence, unusual structural chemical features are frequently encountered in the lipid A of marine bacteria. By a combination of data attained from chemical, MALDI-TOF mass spectrometry (MS), and MS/MS analyses, here, we describe the structural characterization of the lipid A isolated from two marine bacteria of the Echinicola genus, i.e., E. pacifica KMM 6172T and E. vietnamensis KMM 6221T. This study showed for both strains a complex blend of mono-phosphorylated tri- and tetra-acylated lipid A species carrying an additional sugar moiety, a d-galacturonic acid, on the glucosamine backbone. The unusual chemical structures are reflected in a molecule that only scantly activates the immune response upon its binding to the LPS innate immunity receptor, the TLR4-MD-2 complex. Strikingly, both LPS potently inhibited the toxic effects of proinflammatory Salmonella LPS on human TLR4/MD-2.

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