Growth responses of oligotrophic and heterotrophic marine bacteria in various substrate concentrations, and taxonomic studies on them

1980 ◽  
Vol 26 (7) ◽  
pp. 800-806 ◽  
Author(s):  
Y. Akagi ◽  
U. Simidu ◽  
N. Taga
Keyword(s):  
Marine Bacteria ◽  
Heterotrophic Bacteria ◽  
Bacterial Flora ◽  
Relative Proportion ◽  
Sampling Station ◽  
Growth Responses ◽  
Oligotrophic Bacteria ◽  
The Media ◽  
Taxonomic Studies ◽  
Substrate Concentrations

Growth responses of oligotrophic bacteria to substrate concentrations have been investigated in comparison with those of heterotrophic bacteria. The results suggested that oligotrophs were the group which could grow and produce a perceptible turbidity in the media containing less than 10 mg peptone C/L of medium.Taxonomic studies indicated that the most abundant group in the oligotrophic bacterial flora was consistent with that in the heterotrophic bacterial flora at each sampling station. However, the relative proportion of pseudomonads in the oligotrophs was higher than that in the heterotrophs (at stations H-24, H-28, H-29, Ab-1, Ab-2, and O-4), while the relative proportion of Vibrio in the former was lower than that in the latter (at stations H-24, H-28, H-29, O-4, and O-9).

scholarly journals Transcriptional Control in Marine Copiotrophic and Oligotrophic Bacteria with Streamlined Genomes

2016 ◽  
Vol 82 (19) ◽  
pp. 6010-6018 ◽  
Author(s):  
Matthew T. Cottrell ◽  
David L. Kirchman
Keyword(s):  
Marine Bacteria ◽  
Environmental Conditions ◽  
Transcriptional Control ◽  
Heterotrophic Bacteria ◽  
Content Type ◽  
Oligotrophic Bacteria ◽  
Protein Encoding ◽  
Culture Growth ◽  
Ruegeria Pomeroyi ◽  
And Shifts

ABSTRACTBacteria often respond to environmental stimuli using transcriptional control, but this may not be the case for marine bacteria such as “CandidatusPelagibacter ubique,” a cultivated representative of the SAR11 clade, the most abundant organism in the ocean. This bacterium has a small, streamlined genome and an unusually low number of transcriptional regulators, suggesting that transcriptional control is low inPelagibacterand limits its response to environmental conditions. Transcriptome sequencing during batch culture growth revealed that only 0.1% of protein-encoding genes appear to be under transcriptional control inPelagibacterand in another oligotroph (SAR92) whereas >10% of genes were under transcriptional control in the copiotrophsPolaribactersp. strain MED152 andRuegeria pomeroyi. When growth levels changed, transcript levels remained steady inPelagibacterand SAR92 but shifted in MED152 andR. pomeroyi. Transcript abundances per cell, determined using an internal RNA sequencing standard, were low (<1 transcript per cell) for all but a few of the most highly transcribed genes in all four taxa, and there was no correlation between transcript abundances per cell and shifts in the levels of transcription. These results suggest that low transcriptional control contributes to the success ofPelagibacterand possibly other oligotrophic microbes that dominate microbial communities in the oceans.IMPORTANCEDiverse heterotrophic bacteria drive biogeochemical cycling in the ocean. The most abundant types of marine bacteria are oligotrophs with small, streamlined genomes. The metabolic controls that regulate the response of oligotrophic bacteria to environmental conditions remain unclear. Our results reveal that transcriptional control is lower in marine oligotrophic bacteria than in marine copiotrophic bacteria. Although responses of bacteria to environmental conditions are commonly regulated at the level of transcription, metabolism in the most abundant bacteria in the ocean appears to be regulated by other mechanisms.

Substrate Affinity of Oligotrophic Bacteria in Biofilm Reactors

1989 ◽  
Vol 21 (8-9) ◽  
pp. 779-790 ◽  
Author(s):  
K. Nakamura ◽  
M. Shibata ◽  
Y. Miyaji
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Bacterial Flora ◽  
Biofilm Reactor ◽  
Substrate Affinity ◽  
Biofilm Reactors ◽  
Oligotrophic Bacteria ◽  
The Media ◽  
Media Volume

Several biofilm reactors were operated to investigate the substrate affinity of oligotrophic bacteria in the biofilm reactor. The attached oligotrophs were removed from reactors, and substrate affinity was determined in dispersed form. The saturation constant (Ks) of attached oligotrophs for acetate was less than 10 µg-C/l. The apparent Ks (Ksa) values of reactors were also determined to evaluate the performance of reactors,and the effect of specific surface area of packed media on Ksa was investigated at a loading of 0.006 mg-C per cm3-apparent media volume per hour. Larger specific surface area led to smaller Ksa, and 6.9 µg-C/l of Ksa for acetate was obtained with the media having 340 cm2 -surface area per cm -apparent media volume of specific surface area. The bacterial flora in the oligotrophic biofilm was examined, and Pseudomonas was found to be dominant.

A medium, solidified with gellan gum, for determining the Na+ requirement of Vibrio species

1993 ◽  
Vol 39 (8) ◽  
pp. 804-808 ◽  
Author(s):  
Lisa D. Noble ◽  
John A. Gow
Keyword(s):  
Marine Bacteria ◽  
Solid Medium ◽  
Specific Growth ◽  
Basal Medium ◽  
Gellan Gum ◽  
Growth Responses ◽  
Prolonged Incubation ◽  
Low Sodium ◽  
Growth Requirements ◽  
Lag Period

Until now there has not been a satisfactory solid medium for determining the growth responses, to Na+, of marine and other bacteria that have specific growth requirements for Na+. A solid medium would be useful to investigators who would like to take advantage of the efficiency of multipoint inoculation when testing for a Na+ requirement. By using 1% gellan gum (Gel-GroTM) as the solidifying agent a medium was formulated that had a contaminating level of Na+ of slightly less than 2 mM in the basal medium. Two species of Aeromonas, which do not require Na+ for growth, and 31 species of Vibrio, which require Na+, were tested for their growth responses to Na+ on this medium. The Aeromonas strains grew well, within 24 h, at all of the Na+ concentrations tested. Approximately 75% of the Vibrio strains did not grow on the basal medium even after a prolonged incubation period. The remaining species were able to grow on the basal medium, but not without a lag period. These lag periods were as short as 36 h for two of the species and in some instances as long as 312 h. These lag periods were of sufficient duration to determine that Na+ stimulated the growth of the Vibrio strains that were able to grow on the basal medium. Approximately 75% of the strains, representing most species of Vibrio, were able to grow if as little as 25 mM Na+ was present in the medium.Key words: low-sodium medium, Na+ requirement, gellan gum, agar substitute, marine bacteria.

scholarly journals Use of Microautoradiography Combined with Fluorescence In Situ Hybridization To Determine Dimethylsulfoniopropionate Incorporation by Marine Bacterioplankton Taxa

2004 ◽  
Vol 70 (8) ◽  
pp. 4648-4657 ◽  
Author(s):  
Maria Vila ◽  
Rafel Simó ◽  
Ronald P. Kiene ◽  
Jarone Pinhassi ◽  
José M. González ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Gulf Of Mexico ◽  
Fluorescence In Situ Hybridization ◽  
Marine Bacteria ◽  
Heterotrophic Bacteria ◽  
Phytoplankton Bloom ◽  
Mediterranean Coast ◽  
Marine Bacterioplankton ◽  
Significant Uptake

ABSTRACT The fraction of planktonic heterotrophic bacteria capable of incorporating dissolved dimethylsulfoniopropionate (DMSP) and leucine was determined at two coastal sites by microautoradioagraphy (AU). In Gulf of Mexico seawater microcosm experiments, the proportion of prokaryotes that incorporated sulfur from [35S]DMSP ranged between 27 and 51% of 4′,6-diamidino-2-phenylindole (DAPI)-positive cells, similar to or slightly lower than the proportion incorporating [3H]leucine. In the northwest Mediterranean coast, the proportion of cells incorporating sulfur from [35S]DMSP increased from 5 to 42% from January to March, coinciding with the development of a phytoplankton bloom. At the same time, the proportion of cells incorporating [3H]leucine increased from 21 to 40%. The combination of AU and fluorescence in situ hybridization (FISH) revealed that the Roseobacter clade (α-proteobacteria) accounted for 13 to 43% of the microorganisms incorporating [35S]DMSP at both sampling sites. Significant uptake of sulfur from DMSP was also found among members of the γ-proteobacteria and Cytophaga-Flavobacterium groups. Roseobacter and γ-proteobacteria exhibited the highest percentage of DAPI-positive cells incorporating 35S from DMSP (around 50%). Altogether, the application of AU with [35S]DMSP combined with FISH indicated that utilization of S from DMSP is a widespread feature among active marine bacteria, comparable to leucine utilization. These results point toward DMSP as an important substrate for a broad and diverse fraction of marine bacterioplankton.

Bovine distal pulmonary arterial media is composed of a uniform population of well-differentiated smooth muscle cells with low proliferative capabilities

2003 ◽  
Vol 285 (4) ◽  
pp. L819-L828 ◽  
Author(s):  
Leopold Stiebellehner ◽  
Maria G. Frid ◽  
John T. Reeves ◽  
Robert B. Low ◽  
Meena Gnanasekharan ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Pulmonary Circulation ◽  
Main Pulmonary Artery ◽  
Muscle Cells ◽  
Hypoxic Exposure ◽  
Growth Responses ◽  
The Media ◽  
Well Differentiated ◽  
Uniform Population

The media of the normal bovine main pulmonary artery (MPA) is composed of phenotypically heterogeneous smooth muscle cells (SMC) with markedly different proliferative capabilities in response to serum, mitogens, and hypoxia. Little, however, is known of the SMC phenotype in distal pulmonary arteries (PA), particularly in arterioles, which regulate the pulmonary circulation. With a panel of muscle-specific antibodies against α-smooth muscle (SM)-actin, SM-myosin heavy chains (SM-MHC), SM-MHC-B isoform, desmin, and meta-vinculin, we demonstrate a progressive increase in phenotypic uniformity and level of differentiation of SMC along the proximal-to-distal axis of normal adult bovine pulmonary circulation so that the media of distal PA (1,500- to 100-μm diameter) is composed of a phenotypically uniform population of “well-differentiated” SMC. Similarly, when isolated and assessed in vitro, distal PA-SMC is composed of a single, uniform population of differentiated SMC that exhibited minimal growth responses to a variety of mitogens while their cell size increased substantially in response to serum. Their growth was inhibited by hypoxic exposure under all conditions tested. Distal PA-SMC also differed from MPA-SMC by exhibiting a distinct pattern of DNA synthesis in response to serum and mitogens. Thus, in contrast to the MPA, distal PA media is composed of an apparently uniform population of well-differentiated SMC that are proliferation resistant and have a substantial capacity to hypertrophy in response to growth-promoting stimuli. We thus speculate that distinct SMC phenotypes present in distal vs. proximal PA may confer different response mechanisms during remodeling in conditions such as hypertension.

Bacterial flora of phyto- and zoo-plankton in the inshore water of Japan

1971 ◽  
Vol 17 (9) ◽  
pp. 1157-1160 ◽  
Author(s):  
U. Simidu ◽  
K. Ashino ◽  
E. Kaneko
Keyword(s):  
Heterotrophic Bacteria ◽  
Bacterial Flora ◽  
Marine Organisms ◽  
Inshore Water ◽  
Generic Composition

Generic composition of aerobic bacterial flora of plankton was compared with that of seawater. More than 70% of the heterotrophic bacteria from most of the plankton samples were Vibrio and Aeromonas, while the percentage of occurrence of these genera in the seawater flora was about 45%. The assumption that some Vibrio and Aeromonas are closely associated with marine organisms was discussed.

scholarly journals The organosulfur compound dimethylsulfoniopropionate (DMSP) is utilized as an osmoprotectant by Vibrio species

2020 ◽  
pp. AEM.02235-20
Author(s):  
Gwendolyn J. Gregory ◽  
Katherine E. Boas ◽  
E. Fidelma Boyd
Keyword(s):  
Marine Bacteria ◽  
Heterotrophic Bacteria ◽  
Turgor Pressure ◽  
Organosulfur Compound ◽  
Marine Species ◽  
Sulfur Cycle ◽  
Marine Phytoplankton ◽  
Growth Defect ◽  
Choline Transport ◽  
Coral Mucus

Dimethylsulfoniopropionate (DMSP), a key component of the global geochemical sulfur cycle, is a secondary metabolite produced in large quantities by marine phytoplankton and utilized as an osmoprotectant, thermoprotectant and antioxidant. Marine bacteria can use two pathways to degrade and catabolize DMSP, a demethylation pathway and a cleavage pathway that produces the climate active gas dimethylsulfide (DMS). Whether marine bacteria can also accumulate DMSP as an osmoprotectant to maintain the turgor pressure of the cell in response to changes in external osmolarity has received little attention. The marine halophile Vibrio parahaemolyticus, contains at least six osmolyte transporters, four betaine carnitine choline transport (BCCT) carriers BccT1-BccT4 and two ABC-family ProU transporters. In this study, we showed that DMSP is used as an osmoprotectant by V. parahaemolyticus and several other Vibrio species including V. cholerae and V. vulnificus. Using a V. parahaemolyticus proU double mutant, we demonstrated that these ABC transporters are not required for DMSP uptake. However, a bccT null mutant lacking all four BCCTs had a growth defect compared to wild type in high salinity media supplemented with DMSP. Using mutants possessing only one functional BCCT in growth pattern assays, we identified two BCCT-family transporters, BccT1 and BccT2, which are carriers of DMSP. The only V. parahaemolyticus BccT homolog that V. cholerae and V. vulnificus possess is BccT3 and functional complementation in Escherichia coli MKH13 showed V. cholerae VcBccT3 could transport DMSP. In V. vulnificus strains, we identified and characterized an additional BCCT family transporter, which we named BccT5 that was also a carrier for DMSP.Importance DMSP is present in the marine environment, produced in large quantities by marine phytoplankton as an osmoprotectant, and is an important component of the global geochemical sulfur cycle. This algal osmolyte has not been previously investigated for its role in marine heterotrophic bacterial osmotic stress response. Vibrionaceae are marine species, many of which are halophiles exemplified by V. parahaemolyticus, a species that possesses at least six transporters for the uptake of osmolytes. Here, we demonstrated that V. parahaemolyticus and other Vibrio species can accumulate DMSP as an osmoprotectant and show that several BCCT family transporters uptake DMSP. These studies suggest that DMSP is a significant bacterial osmoprotectant, which may be important for understanding the fate of DMSP in the environment. DMSP is produced and present in coral mucus and Vibrio species form part of the microbial communities associated with them. The function of DMSP in these interactions is unclear, but could be an important driver for these associations allowing Vibrio proliferation. This work suggests that DMSP likely has an important role in heterotrophic bacteria ecology than previously appreciated.

scholarly journals Characterization of the interactive effects of labile and recalcitrant organic matter on microbial growth and metabolism

2019 ◽  
Author(s):  
Lauren N. M. Quigley ◽  
Abigail Edwards ◽  
Andrew D. Steen ◽  
Alison Buchan
Keyword(s):  
Organic Matter ◽  
Marine Bacteria ◽  
Interactive Effects ◽  
Specific Substrate ◽  
Growth Responses ◽  
Metabolic Potential ◽  
Labile Organic Matter ◽  
Casamino Acids ◽  
Geochemical Models ◽  
Species Specific

AbstractGeochemical models typically represent organic matter (OM) as consisting of multiple, independent pools of compounds, each accessed by microorganisms at different rates. However, recent findings indicate that organic compounds can interact within microbial metabolisms. The relevance of interactive effects within marine systems is debated and a mechanistic understanding of its complexities, including microbe-substrate relationships, is lacking. As a first step toward uncovering mediating processes, the interactive effects of distinct pools of OM on the growth and respiration of marine bacteria, individual strains and a simple, constructed community of Roseobacter lineage members were tested. Isolates were provided with natural organic matter (NOM) and different concentrations (1, 4, 40, 400 μM-C) and forms of labile organic matter (acetate, casamino acids, tryptone, coumarate). The microbial response to the mixed substrate regimes was assessed using viable counts and respiration in two separate experiments. Two marine bacteria and a six-member constructed community were assayed with these experiments. Both synergistic and antagonistic growth responses were evident for all strains, but all were transient. The specific substrate conditions promoting a response, and the direction of that response, varied amongst species. These findings indicate that the substrate conditions that result in OM interactive effects are both transient and species-specific and thus influenced by both the composition and metabolic potential of a microbial community.

The effect of chromic oxide (Cr2O3) on aerobic bacterial populations associated with the intestinal epithelial mucosa of Arctic charr, Salvelinus alpinus (L.)

1993 ◽  
Vol 39 (12) ◽  
pp. 1169-1173 ◽  
Author(s):  
Einar Ringø
Keyword(s):  
Heterotrophic Bacteria ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Bacterial Flora ◽  
Chromic Oxide ◽  
Intestinal Epithelial ◽  
Gram Positive ◽  
Bacterial Populations ◽  
Gram Negative ◽  
Attachment Sites

Populations of aerobic heterotrophic bacteria present in the gastrointestinal tract of healthy Arctic charr, Salvelinus alpinus (L.), were estimated using the dilution plate technique. The gastrointestinal bacterial flora of fish fed an unsupplemented diet was dominated by Gram-negative bacteria of the genera Acinetobacter, Aeromonas, Agrobacterium, Alcaligenes, Cytophaga, Flavobacterium, Pseudomonas, and Vibrio, and Gram-positive bacteria of the genera Arthrobacter, Brevibacterium, Corynebacterium, Kurthia, Lactobacillus, Microbacterium, Micrococcus, Staphylococcus, and Streptococcus. The composition of the indigenous aerobic bacterial flora in the digestive tract, and especially the microorganisms isolated from the midgut and hindgut regions, was affected by inclusion of 1% chromic oxide (Cr2O3) in the diet. Many of the Gram-negative bacterial genera and some of the Gram-positive bacterial genera were not detectable in the Cr2O3-fed fish. The midgut and hindgut regions in the Cr2O3-fed fish were dominated by Gram-positive microorganisms of the genera Lactobacillus and Streptococcus. It is suggested that the increased accumulation of Cr2O3 in the alimentary tract, as dietary compounds are removed, affects the attachment sites for the gastrointestinal microflora or affects the gut epithelium directly.Key words: chromic oxide, aerobic bacterial flora, Arctic charr.

Sign in / Sign up

Export Citation Format

Share Document