IN VITRO THERMAL REQUIREMENTS OF TWO ISOLATES OF METARHIZIUM ANISOPLIAE METCH.) SOROK. UNDER CONSTANT CONDITIONS

2021 ◽  
Vol 14 ◽  
pp. 70-74
Author(s):  
Cristina-Maria Lumînare ◽  
Daniel Nicolae Cojanu ◽  
Mihaela-Monica Dinu ◽  
Ana-Cristina Fătu

"The effect of temperature on the mycelial growth of two isolates of Metarhizium anisopliae (Metch.) Sorok. (Hypocreales, Clavicipitaceae) was evaluated in vitro on PDA growth medium, by measuring the diameter of the fungal colonies, at the following temperature values: 5, 10, 15, 20, 25, 30, 35 and 40 °C, over 14 days under constant conditions. The data obtained were used for the calculation of the growth rate (mm/day) using linear regression. The representation of the values corresponding to the minimum, optimal and maximum temperature of vegetative growth was made by a curve described by a mathematical function, a modified beta (ß) function. The lowest temperatures at which growth occurs are 7 and 10°C, the highest is 35.7°C; temperature at which the most growth occurs, as indicated by the measurements, was distributed over a range of temperatures from 22.9 to 31°C."

Parasitology ◽  
2020 ◽  
pp. 1-9
Author(s):  
Summia Perveen ◽  
Yuhua Lei ◽  
Fei Yin ◽  
Chunlin Wang

Abstract Mesanophrys sp. is a newly identified parasitic ciliate infecting farmed swimming crab. To demonstrate the correlation between parasite development and environmental conditions, this study aimed to investigate the effect of temperature, salinity, pH and frequency of passage of parasite on survival, growth and body size of Mesanophrys sp. in vitro. The results revealed that survival, population density and growth rate of the parasite were highest at 12°C and decreased with increasing temperature from 16 to 26°C. In addition, the survival, population density and growth rate of Mesanophrys sp. were high at 20‰. When salinity was adjusted to levels lower (0–10‰) and higher (40–60‰) than 20‰, the parasite's survival and growth rate gradually declined. The optimal pH for parasite survival was 8.0, whereas its survival was inhibited at <4.5 or >9.5. Our result also showed that parasite body proportions (length:width) were significantly smaller at the highest temperature compared to the lower temperature, whereas different salinities had no significant effect. Furthermore, we introduced dynamic parasite culture systems in vitro where Mesanophrys sp. was cultured in medium-containing culture plates through continually reducing and halving the old medium into fresh. Application of this optimized dilution timing technique with fresh medium and sub-cultured enabled a continuous culture of parasites. Under this optimized condition, the highest population density and exponential growth rate of the parasite were achieved than that of a control group. This study will help to understand the ciliated parasite infection dynamics and provides new possibilities for in vitro parasite-associated studies.


2020 ◽  
Vol 83 (9) ◽  
pp. 1495-1504
Author(s):  
TERESA SANDOVAL-CONTRERAS ◽  
MARICARMEN IÑIGUEZ-MORENO ◽  
LUIS GARRIDO-SÁNCHEZ ◽  
JUAN ARTURO RAGAZZO-SÁNCHEZ ◽  
JOSÉ ALBERTO NARVÁEZ-ZAPATA ◽  
...  

ABSTRACT Colletotrichum species are the most important postharvest spoilage fungi of papaya fruit. The objective of this research was to evaluate the effect of temperature and relative humidity on growth rate and time for growth to become visible of five strains of Colletotrichum gloeosporioides isolated from papaya fruit in a complex medium. As a primary model, the radial growth rates were estimated using the Baranyi and Roberts model in papaya agar. The Solver MS Excel function was used to obtain the time to visible mycelium (tv). Secondary models obtained with the Rosso et al. cardinal model of inflection were applied to describe the effect of temperature on the growth rate (μ). The Arrhenius-Davey model was used to model tv. The obtained models seem to be satisfactory for describing both μ and tv. The relative humidity had an effect on μ and tv for all tested C. gloeosporioides isolates, but no model accurately described the behavior of the fungus. External validation of models was performed with papaya fruit. Growth models were developed with the same models used in vitro. The bias and the accuracy factors as indices for performance evaluation of predictive models in food microbiology as a function of temperature and RH were 1.22 and 1.33, respectively, for μ and 1.18 and 1.62, respectively, for tv, indicating accurate predictions. The supply chain of papaya is complex and requires constant conditions, and poor conditions can result in damage to the fruit. Knowledge of the behavior of C. gloeosporioides on papaya fruit and application of the developed models in the supply chain will help to establish transport control strategies to combat these fungi. This research has contributed to development of the first models of growth for C. gloeosporioides in Mexico. HIGHLIGHTS


2021 ◽  
Vol 13 (4) ◽  
pp. 120
Author(s):  
Karla Danielle Nogueira Cardoso ◽  
Maria Josiane Martins ◽  
Thaisa Aparecida Neres de Souza ◽  
Isabelle Carolyne Cardoso ◽  
Patrícia Nirlane da Costa Souza ◽  
...  

Phomopsis sojae and Sclerotinia sclerotiorum are responsible for stem and pod dryness and white mold in soybean. These pathologies directly affect the quality of seeds/grains and compromise the entire plant. The use of extracts from different plants has been the subject of research for the control of several phytopathogens. Calotropis procera is among botanical species that synthesize efficient compounds for biocontrol. In this context, the aim of this study was to evaluate the in vitro effect of C. procera aqueous extract on P. sojae and S. sclerotiorum. The experiment was carried out in completely randomized blocks in a 2 &times; 5 factorial scheme (two fungi and five extract concentrations 0%, 5%, 10%, 15% and 20%) with 4 replicates. C. procera aqueous extract concentrations were added to Petri dishes containing PDA. After 48 hours, the mycelial growth rate was evaluated. After seven days of incubation, the fungal colony area, sporulation, and germination of P. sojae and S. sclerotiorum were evaluated. There was significant interaction between fungi &times; extract concentrations (p &lt; 0.05) for all variables analyzed. The mycelial growth rate of P. sojae was lower than that of S. sclerotiorum. The diameter of the P. sojae fungal colony was smaller than that of S. sclerotiorum when concentrations of 5%, 10% and 15% were used. As the extract concentration increased, fungi sporulation and germination reduced.


2019 ◽  
Vol 11 (17) ◽  
pp. 167
Author(s):  
Vanessa P. Gonçalves ◽  
Cândida R. J. de Farias ◽  
Victoria Moreira-Nunêz ◽  
Renata Moccellin ◽  
Viviana Gaviria-Hernández ◽  
...  

The objective of this work was to evaluate the fungitoxic effect of the agrochemicals used in the cultivation of soybean and irrigated rice on entomopathogenic fungi such as Beauveria bassiana and Metarhizium anisopliae by means of the mycelial growth, sporulation and spore germination. The isolates were inoculated in potato-dextrose-agar (PDA) medium containing the pesticides and exposed to spraying with the products. It was observed that chlorantraniliprole produced the best results regarding and was compatible with the two methods of contact of the product with the fungi. Flubendiamide it&rsquo;s very toxic to fungi, producing 100% inhibition when incorporated into the medium, when by spraying, the fungus M. anisopliae got mycelial growth. Etofenprox and thiamethoxam changed their toxity classification according to the method of contact with product, was moderately compatible to B. bassiana and compatible to M. anisopliae and spinosad showed more compatibility with M. anisopliae than B. bassiana and was classified as compatible. Among fungicides the tricyclazole was the only compatible with the fungus by the spray method. The results showed that in vitro agrochemicals such as tricyclazole, thiamethoxam, flubendiamide and etofenprox are harmful to fungi. It was found that environmental interference could minimize the effects on organisms, especially when the chemicals are applied by spraying.


2019 ◽  
Vol 74 (11-12) ◽  
pp. 811-818 ◽  
Author(s):  
Lingling Fan ◽  
Bilan Luo ◽  
Zhongfu Luo ◽  
Li Zhang ◽  
Judi Fan ◽  
...  

AbstractIn order to obtain novel bioactive compounds with significant antifungal activities, two series of 3-substituted phthalide derivatives were designed and synthesized via reduction, bromine substitution, and etherification. In addition, the antifungal activities of all target compounds against nine phytopathogenic fungi in vitro were tested by using the mycelial growth rate method at the concentration of 50 μg mL−1. Preliminary bioassay tests showed that some compounds exhibited more potent antifungal activities as compared with hymexazol. The preliminary structure-activity relationships (SARs) of all target compounds were also investigated.


1961 ◽  
Vol 59 (4) ◽  
pp. 457-470 ◽  
Author(s):  
H. S. Bedson ◽  
K. R. Dumbell

The ‘ceiling temperature’ of a pox virus has been defined as the maximum temperature (to the nearest 0·5° C.) of incubation at and below which that virus will grow and produce pocks on the chorioallantois of 12-day-old chick embryos, and above which no pocks appear.Ceiling temperatures have been estimated for: alastrim (2 strains), 37·5° C.; variola major (2 strains), 3·8° C.; ectromelia (3 strains) and monkey pox (1 strain), 39°C.; cowpox (2 strains), 40°C. Five strains of vaccinia and two of rabbit pox were all capable of pock formation at 40·5° C. Above this temperature difficulty was encountered because many embryos died. But the ceiling temperature for two strains of vaccinia and one strain of rabbit pox was probably 41° C. The Utrecht strain of rabbit pox produced some lesions at 41·5° C.—the highest temperature used.The ceiling temperatures of the viruses used were not correlated with their thermal stabilities at 55°C.in vitro. Thus vaccinia strain, Lederle-7 N, had a high ceiling temperature and a low thermal stability, while variola major had a low ceiling temperature and a high thermal stability. For this reason ceiling temperatures and thermal stability are regarded as distinct characters.In experiments with twelve of the seventeen viruses of which the ceiling temperatures had been determined, the virulence for the chick embryo was then measured. It was found that, in general, the higher the ceiling temperature of a virus the greater was its virulence for the chick embryo.The presentation of these results is followed by a brief discussion of their significance and potential use.


2020 ◽  
Author(s):  
Bhavin Vasavada

UNSTRUCTURED Aim of the study: Aim of he study was to analyse correlation of daily maximum temperature on corona virus daily growth rate as well as effect of lockdown on daily growth rate of cases. Materials and Methods: All the data regarding new cases of covid 19 Pandemic in Gujarat was collected from Gujarat health department website., Temperature details were collected from www.accuweather.com. Growth rate was calculated as a percent increase of new cases daily compared to previous day active cases. Relations between trends were calculated from correlation and regression studies. MANNOVA analysis was performed. Results: Total 6625 cases, 4729 active cases and 380 deaths were reported as on 6th May 2020 in Gujarat. Daily maximum temperature was significantly correlated inversely with daily growth rate. (p value= 0.010) with Pearson correlation coefficient =-0.363. Correlation between time since lock down to daily case growth rate was non significant. (p=0.123). Phases of lockdown and growth rates showed significant inverse correlation. (p=0.002). Multivariate ANOVA showed there was statistical significant difference in case growth rate based on daily temperature [p= 0.006 F=4.71] and progression of phases of lockdown (p=0.018, F=3.55). Conclusion: Conclusion increase in temperature has inverse relationship in growth rate in covid 19 pandemic. Lockdown may be useful in decreasing growth.


2016 ◽  
Vol 10 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Esmat Ebrahimi ◽  
Alireza Salarzadeh

Salinity and temperature are two of the major factors controlling the growth rate of microalgae. In this study, the effect of salinity and temperature on the growth of marine microalgae; Chlorella capsulata and Skeletonema costatum were investigated to optimize the microalgal biomass production. These species were cultured at different salinities (20, 25 and 30 ‰) and temperatures (20, 25 and 30°C). Skeletonema costatum and Chlorella capsulata had significantly higher (p<0.05) growth rate when cultured at salinities of 30 and 25 ‰, respectively. In terms of temperature, the highest (p<0.05) growth rate was observed in Skeletonema costatum and Chlorella capsulata cultivated at temperatures of 30 and 25°C, respectively. This study indicated that Skeletonema costatum was suitable to marine condition, whereas Chlorella capsulata showed optimum growth at lower salinity and temperature. In addition, can be concluded, Chlorella capsulata and Skeletonema costatum can be considered as suitable species for large outdoor micro algal cultivation.International Journal of Life Sciences 10 (1) : 2016; 40-44


2020 ◽  
Vol 19 (5) ◽  
pp. 71-79
Author(s):  
Barbara Anna Abramczyk ◽  
Ewa Dorota Król ◽  
Ewa Dorota Zalewska ◽  
Beata Zimowska

The purpose of this experiment was to determine the influence of temperature and fungi colonizing fruit plants on Diaporthe, a pathogenic fungus in Poland. The biotic series method was used to test in vitro the effects of the fungi colonizing fruit trees on isolates of Diaporthe. Among the 13 fungal species tested, six inhibited the growth and development of Diaporthe; while another two species were neutral and the rest showed the lack of limiting impact in relation to the pathogen. Fungi present in the shoots of fruit plants was able to limit the growth and development of Diaporthe spp., both in chemically-protected and non-protected orchards. Studies on the effect of temperature indicated that the optimum temperature for vegetative growth of isolates of Diaporthe ranged from 20°C to 30°C, and for conidial sporulation from 25°C to 30°C. However, the ability of Diaporthe sp. to survive at extreme temperature (–20°C and +35°C) enables their vegetative growth in climatic conditions worldwide.


Author(s):  
Y. Arana-Gabriel ◽  
C. Burrola-Aguilar ◽  
A. Alcalá-Adán ◽  
C. Zepeda-Gómez ◽  
M.E. Estrada-Zúñiga

Objectives: To evaluate mycelial growth and biomass production of F. luteovirens in different culture mediums and pH values.Design/methods/approach: The study was carried out in two stages. In the first stage, the amount of biomass produced and growth rate was measured in five generalist culture mediums. During the second stage, the pH was adjusted to 4, 5, and 6 in three of the five mediums, in order to increase biomass and growth speed shown in the first stage.Results: pH is an influential factor in the availability of nutrients needed by the fungus, which is shown by the increase or inhibition of mycelial growth and biomass production. During the first stage, coconut and malt extract agar were the most favorable for mycelial development, while corn meal agar was the least favorable. When the pH was modified, malt extract agar with a pH of 4 was the most efficient in terms of growth rate, while coconut agar demonstrated the most biomass production regardless of pH.Study limitations and implications: The growth of cultures in vitro is slow when compared with other mushrooms species.Findings/Conclusions: Floccularia luteovirens cultivation represents an alternative to obtain food with a high nutritionalvalue, safeguard germplasm, and increase and diversify species cultivated; since it is edible, with high nutritional contentand has medicinal properties.


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