scholarly journals Invertebrate Grazing on Live Turtlegrass (Thalassia testudinum): A Common Interaction That May Facilitate Fungal Growth

2022 ◽  
Vol 8 ◽  
Author(s):  
Anjali D. Boyd ◽  
Nia S. Walker ◽  
Stephanie R. Valdez ◽  
Y. Stacy Zhang ◽  
Andrew H. Altieri ◽  
...  
Keyword(s):  
Coastal Wetlands ◽  
Microbial Growth ◽  
Fungal Growth ◽  
Thalassia Testudinum ◽  
Microbial Infection ◽  
Simulated Herbivory ◽  
Feeding Trials ◽  
The Caribbean ◽  
Invertebrate Grazing ◽  
Initial Survey

In coastal wetlands and tropical reefs, snails can regulate foundation species by feeding on marsh grasses and hard corals. In many cases, their impacts are amplified because they facilitate microbial infection in grazer-induced wounds. Whether snails commonly graze live plants and facilitate microbial growth on plants in tropical seagrass systems is less explored. On a Belizean Caye, we examined patterns in snail-generated grazer scars on the abundant turtlegrass (Thalassia testudinum). Our initial survey showed the occurrence of snail-induced scarring on live turtlegrass blades was common, with 57% of live leaves scarred. Feeding trials demonstrated that two of five common snails (Tegula fasciata–smooth tegula and Smaragdia viridis–emerald nerite) grazed unepiphytized turtlegrass blades and that smooth tegula abundance had a positive relationship with scarring intensity. Subsequent surveys at three Caribbean sites (separated by >150 km) also showed a high occurrence of snail-induced scars on turtlegrass blades. Finally, simulated herbivory experiments and field observations of a turtlegrass bed in Florida, United States suggests that herbivore damage could facilitate fungal growth in live seagrass tissue through mechanical opening of tissue. Combined, these findings reveal that snail grazing on live turtlegrass blades in the Caribbean can be common. Based on these results, we hypothesize that small grazers could be exerting top-down control over turtlegrass growth directly via grazing and/or indirectly by facilitating microbial infection in live seagrass tissue. Further studies are needed to determine the generality and relative importance of direct and indirect effects of gastropod grazing on turtlegrass health.

Effects of simulated herbivory on nitrogen enzyme levels, assimilation and allocation in Thalassia testudinum

2004 ◽  
Vol 79 (3) ◽  
pp. 235-255 ◽  
Author(s):  
John F Valentine ◽  
E Fennel Blythe ◽  
S Madhavan ◽  
Timothy D Sherman
Keyword(s):  
Thalassia Testudinum ◽  
Simulated Herbivory

scholarly journals Microbial Agents Causing Infective Corneal Ulcer and their Anti-microbial Susceptibility pattern

2019 ◽  
Vol 47 (2) ◽  
pp. 1-6
Author(s):  
Azima Aktar Jhuma ◽  
Md Moynul Haque ◽  
Jamil Ahmed ◽  
Shantanu Das ◽  
Tarun Kanti Paul ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Staphylococcus Epidermidis ◽  
Microbial Growth ◽  
Corneal Ulcer ◽  
Bacterial Pathogen ◽  
Fungal Growth ◽  
Penicillium Species ◽  
Corneal Ulcers ◽  
Microbial Agents ◽  
Susceptibility Patterns

This study was designed to identify the microbial agents causing infective corneal ulcer and to carry out the antimicrobial susceptibility patterns of isolated bacteria causing infective corneal ulcer. Out of 80 samples, 67 (83.75%) cases were positive by microscopy and culture. This study showed pure fungal growth in 39 (48.75%) cases, pure bacterial growth in 8 (10%) cases, mixed microbial growth (both fungi and bacteria) in 20 (25%) cases and no growth was observed in 13 (16.25%) cases. Among the fungal isolates, Aspergillus species was the leading agent detected in 37(46.3%) cases followed by Penicillium species in 7 (8.8%) instances. Pseudomonas aeruginosa was the most common bacterial pathogen found in 11 (13.8%) cases followed by Staphylococcus epidermidis present in 9 (11.3%) cases. Gentamicin, Ciprofloxacin and Levofloxacin were found to be better efficacious drugs against most of the bacterial pathogens noted in antimicrobial susceptibility test. This study showed that infective corneal ulcers are caused by both bacterial and fungal agents but fungal agents are more common. The findings of this study would help the ophthal- mologists in evidence based management of their patients of infective corneal ulcer. Bangladesh Med J. 2018 May; 47 (2): 1-6

scholarly journals Multicenter Clinical Evaluation of BacT/Alert Virtuo Blood Culture System

2017 ◽  
Vol 55 (8) ◽  
pp. 2413-2421 ◽  
Author(s):  
Michael R. Jacobs ◽  
Tony Mazzulli ◽  
Kevin C. Hazen ◽  
Caryn E. Good ◽  
Ayman M. Abdelhamed ◽  
...  
Keyword(s):  
Blood Culture ◽  
Culture System ◽  
Microbial Growth ◽  
Fungal Growth ◽  
Detection Algorithm ◽  
Blood Culture System ◽  
Gram Negative ◽  
Time To Detection ◽  
Clinically Significant ◽  
Organism Group

ABSTRACTBacT/Alert Virtuo is an advanced, automated blood culture system incorporating improved automation and an enhanced detection algorithm to shorten time to detection. A multicenter study of the investigational Virtuo system (bioMérieux, Inc., Durham, NC) compared to BacT/Alert 3D (BTA3D) for detection of bacteremia/fungemia in four bottle types, SA and FA Plus (aerobic) and SN and FN Plus (anaerobic), was performed in a clinical setting with patient samples in a matched system design clinical trial. Blood was added to paired aerobic or anaerobic bottles, with the volume in each bottle in each pair required to be ≤10 ml and with the volumes required to be within 30% of each other. Of 5,709 bottle sets (52.5% aerobic pairs and 47.5% anaerobic pairs), 430 (7.5%) were positive for bacterial or fungal growth, with 342 (6.0%) clinically significant and 83 (1.5%) contaminated. A total of 3,539 sets (62.0%) were volume compliant, with 203 sets (5.7%) clinically significant. The positivity rates for volume-compliant bottle pairs determined by the two systems were comparable, with 68.7% of clinically significant isolates detected by both instruments, 15.7% by Virtuo only, and 15.7% by BTA3D only. Virtuo detected microbial growth nearly 2 h sooner overall than BTA3D (mean, 15.9 h versus 17.7 h). Shorter time to detection by Virtuo was related to organism group, with the time to detection being significantly shorter for enteric Gram-negative bacilli and enterococci (means, 3.6 h and 2.3 h shorter, respectively). This large clinical study demonstrated that the Virtuo blood culture system produced results comparable to those seen with the long-established BTA3D system, with significantly shorter time to detection.

scholarly journals MARINE VEGETATION FROM A LOCALITY OF THE CONTINENTAL PLATFORM OF LA GUAJIRA (COLOMBIAN CARIBBEAN)

2016 ◽  
Vol 29 ◽  
Author(s):  
Guillermo Díaz Pulido
Keyword(s):  
Continental Shelf ◽  
Thalassia Testudinum ◽  
Leaf Biomass ◽  
Green Macroalgae ◽  
Marine Macrophytes ◽  
Dry Biomass ◽  
The Caribbean

A list of 46 species of marine macrophytes (44 algae and 2 seagrasses) collected between 5 to 36 m depth off Riohacha, on the continental shelf of the peninsula La Guajira (Colombian Caribbean) is presented. 22 species of algae were not previously known from this area. A total of 149 apecies are now registered from the area of La Guajira. Three types of macrophyte asociations were found: (1) dominated by the seagrass Thalassia testudinum with a dry leaf biomass between 27 and 40 gm-2 at 5 m depth. (2) established at -17 m and also dominated by T. testudinum, but with a lower dry leaf biomass (14 gm-2) and a more scattered distribution; green rhizophytic macroalgae (Caulerpa spp.) are quite common. (3) dominated by red and green macroalgae with a total dry biomass of 14 gm-2 at -36 m. 92 % of the species found occurs also in the Santa Marta region, located 160 km far W-SW from the study area. In general, the species found are widely distributed in the Caribbean.

Limiting factors for soil microbial growth in climate change simulation treatments in the Subarctic

2020 ◽  
Author(s):  
Mingyue Yuan ◽  
Meng Na ◽  
Lettice Hicks ◽  
Johannes Rousk
Keyword(s):  
Climate Change ◽  
Bacterial Growth ◽  
N Mineralization ◽  
Microbial Growth ◽  
Fungal Growth ◽  
Plant Productivity ◽  
Limiting Factors ◽  
Limiting Factor ◽  
Soil Microbial ◽  
C Limitation

<p>Soil microorganisms play a crucial role in the regulation of nutrient cycling, and are thought to be either limited by low nutrient availability, or by labile carbon supplied by nutrient limited plant productivity. It remains unknown how climate change will affect the rate-limiting resources for decomposer microorganisms in the Arctic, rendering feedbacks to climate change highly uncertain. In this study, we focused on the responses of soil microbial community processes to simulated climate change in a subarctic tundra system in Abisko, Sweden, using litter additions to represent arctic greening and inorganic N fertilizer additions to represent a faster nutrient cycling due to arctic warming. We hypothesized that 1) the plant community would shift and plant productivity would increase in response to N fertilization, 2) microbial process rates would be stimulated by both plant litter and fertilizer additions, and 3) the growth limiting factors for decomposer microorganisms would shift toward nutrient limitation in response to higher plant material input, and towards C-limitation in response to N-fertilizer additions.</p><p> </p><p>We assessed the responses of the plant community composition (vegetation surveys) and productivity (NDVI), microbial processes (bacterial growth, fungal growth, C and N mineralization) along with an assessment of the limiting factors for fungal and bacterial growth. The growth-limiting factors were determined by full factorial additions of nutrients (C, N, P), with measurement of microbial growth and respiration following brief incubations in the laboratory. We found that plant productivity was ca. 15% higher in the N fertilized plots. However, field-treatments had limited effects on bacterial growth, fungal growth and the fungal-to-bacterial growth ratio in soils. Field-treatments also had no significant effect on the rate of soil C mineralization, but did affect rates of gross N mineralization. Gross N mineralization was twice as high in N fertilized plots compared to the control. In control soils, bacterial growth increased 4-fold in response to C, indicating that bacterial growth was C limited. Bacterial growth remained C limited in soils from all field-treatments. However, in the N fertilized soils, the C limitation was 1.8-times greater than the control, while in soils with litter input, the C limitation was 0.83-times the control, suggesting that the N fertilized soils were moving towards stronger C-limitation and the litter addition soils were becoming less C-limited. The limiting factor for fungal growth was difficult to resolve. We presumed that the competition of fungi with bacteria decreased our resolution to detect the limiting factor. Therefore, factorial nutrient addition were combined with low amount of bacterial specific inhibitors.</p>

Storage of Prepackaged Fresh “Green” Peanuts

1974 ◽  
Vol 1 (2) ◽  
pp. 50-52
Author(s):  
M. W. Hoover ◽  
Norman C. Miller
Keyword(s):  
Microbial Growth ◽  
Hot Water ◽  
Water Bath ◽  
Microbial Infection ◽  
Surface Moisture

Abstract Raw ‘green’ peanuts were treated with combinations of hot water and fungicides. Portions of the variously treated peanuts were surface dried in 110°F. moving air for 10 minutes prior to packaging. The visible microbial infection of the packaged peanuts was greatly reduced by treating the raw, washed product in a 120°F. water bath containing 500 ppm of either Botran or benomyl. Treating the raw peanuts by submerging them in 120°F. water for 2.5 to 5 minutes was effective in retarding microbial growth; however, this was greatly improved by the addition of Botran or Benomyl. Reducing the surface moisture of the peanuts in 110°F. moving air for 10 minutes enhanced the effectiveness of all treatments.

Is microbial resilience to drying-rewetting driven by selection for quick colonizers?

2020 ◽  
Author(s):  
Lettice Hicks ◽  
Simon Lin ◽  
Johannes Rousk
Keyword(s):  
Bacterial Growth ◽  
Growth Response ◽  
Microbial Growth ◽  
Fungal Growth ◽  
Growth Responses ◽  
Labile C ◽  
Lag Period ◽  
Selection For ◽  
Resilient Response ◽  
Pre Treatment

<p>Climate change is exposing terrestrial ecosystems to more extreme drought and rainfall events, resulting in an increased frequency and intensity of drying-rewetting (D/RW) events in soils. Rewetting a dry soil induces enormous dynamics in both microbial growth and biogeochemistry, including a large pulse of CO<sub>2 </sub>release to the atmosphere. Upon D/RW, two different microbial growth responses have been identified; a more resilient response where bacteria start growing immediately with a quick recovery after rewetting and a less resilient response where there is a lag-period of up to 30 hours of near-zero growth before bacteria start to grow. The resilience of microbial growth following D/RW has important implications for the ecosystem C budget, since an extended lag-period of no growth during a time of high CO<sub>2 </sub>release will result in net soil C loss. In natural systems, it has been found that a legacy of drought led to a more resilient bacterial growth response upon rewetting, with a reduced lag-period before the onset of growth. Exposing soils to repeated cycles of D/RW in the laboratory has also been shown to shift bacterial growth responses to a more resilient type. We hypothesised that this shift in response is explained by selection for a microbial community which is quick at colonizing the labile C resources made available upon D/RW.  </p><p>In order to test our hypothesis, we pre-treated soils by exposing them to either (i) three cycles of D/RW, (ii) three pulses of glucose addition or (iii) three pulses of litter addition. The substrate additions were used to simulate the labile C release in soils during D/RW, thereby enabling us to investigate if the colonization of new substrate is the causal mechanism explaining the observed shift in bacterial resilience in soils with a history of D/RW. The pre-treated soils – along with an unamended control soil – were then exposed to the same D/RW event, with bacterial growth, fungal growth and respiration responses measured at high temporal resolution over 4 days. As previously reported, exposing the soil to a series of D/RW events resulted in a more resilient bacterial growth response, with the lag-period reduced from ca. 30 hours to an immediate initiation of growth. Pre-treating the soils with glucose reduced the lag-period before the onset of bacterial growth by ca. 50% whereas pre-treatment with litter induced only a marginally (< 10%) more resilient bacterial growth response to D/RW. Interestingly, pre-treatment of the soils with glucose and litter both induced a more resilient fungal growth response, with the responses resembling the shift in fungal resilience induced by exposing the soils to repeated cycles of D/RW. Overall, our results show that selection for quick colonizers partly explains the shift to more resilient microbial growth in soils exposed to repeated D/RW events, but further investigation is required to identify additional factors contributing to the shift in resilience.</p>

scholarly journals Use of hydrogen peroxide, citric acid and sodium hypochlorite as sanitizer for minimally processed table grapes

2018 ◽  
Vol 33 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Muharrem Ergun ◽  
Ezgi Dogan
Keyword(s):  
Hydrogen Peroxide ◽  
Citric Acid ◽  
Sodium Hypochlorite ◽  
Microbial Growth ◽  
Tap Water ◽  
Fungal Growth ◽  
Table Grape ◽  
Minimally Processed ◽  
Table Grapes ◽  
Grape Cultivars

The objective of this study was to explore two local table grape cultivars, one is white and the other one red colored, as a minimally processed produce, and to identify the most effective sanitizers (hydrogen peroxide, citric acid or sodium hypochlorite) to control microbial growth. The table grape cultivars indigenous to Elazig province of Turkey ‘Agin Beyazi’ and ‘Agin Kirmizisi’ were tested in the present experiment. Grape clusters were washed by dipping in tap water as control, in citric acid (20 g/L), with sodium hypochlorite (50 mg/L), or with hydrogen peroxide (20 g/L), solutions for 1 minute. Grape berries were then placed into PET clamshells and kept at 4 °C for 10 days. The berries were subject to quality assessments during the storage, and to total aerobic microbial and fungal count at the end. Washing with hydrogen peroxide- or sodium hypochlorite-diluted water was very effective controlling both aerobic microbial and fungal growth. Citric acid treatment however represented no significant effect on microbial growth. It is concluded that both hydrogen peroxide and sodium hypochlorite are strong sanitizers for table grapes tested, with no detection of undesirable effects.

scholarly journals Antimicrobial solid media for screening non-sterile Arabidopsis thaliana seeds

2019 ◽  
Author(s):  
James B. Y. H. Behrendorff ◽  
Guillem Borràs-Gas ◽  
Mathias Pribil
Keyword(s):  
Arabidopsis Thaliana ◽  
Microbial Growth ◽  
Microbial Contamination ◽  
Marker Gene ◽  
Fungal Growth ◽  
Rapid Screening ◽  
Screening Methods ◽  
Surface Sterilization ◽  
Solid Media ◽  
Low Efficiency

AbstractBackgroundStable genetic transformation of plants is a low-efficiency process, and identification of positive transformants usually relies on screening for expression of a co-transformed marker gene. Often this involves germinating seeds on solid media containing a selection reagent. Germination on solid media requires surface sterilization of seeds and careful aseptic technique to prevent microbial contamination, but surface sterilization techniques are time consuming and can cause seed mortality if not performed carefully. We developed an antimicrobial cocktail that can be added to solid media to inhibit bacterial and fungal growth without impairing germination, allowing us to bypass the surface sterilization step.ResultsAdding a combination of terbinafine (1 µM) and timentin (200 mg/L) to solid media delayed the onset of observable microbial growth and did not affect germination of non-sterile seeds from ten different wild-type and mutant Arabidopsis thaliana accessions. The method was also compatible with Nicotiana tabacum germination. Seedlings sown in non-sterile conditions could be maintained on antimicrobial media for up to a week without observable contamination. The antimicrobial cocktail was compatible with rapid screening methods for hygromycin B, phosphinothricin (BASTA) and nourseothricin resistance genes, meaning that positive transformants can be identified from non-sterile seeds in as little as four days after stratification and transferred to soil before the onset of visible microbial contamination.ConclusionThe antimicrobial cocktail presented here delays microbial growth for long enough to permit germination of non-sterile Arabidopsis thaliana seedlings on solid media and it is compatible with rapid screening methods. We were able to select genetic transformants on solid media without seed surface sterilization, eliminating a tedious and time-consuming step.

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