Influence of ultrasound amplitude and duty cycle on fungal morphology and broth rheology of Aspergillus terreus

Herrán, N. Sainz; López, J.L. Casas; Pérez, J.A. Sánchez; Chisti, Yusuf

doi:10.1007/s11274-010-0315-9

Cited by 11 publications

(9 citation statements)

References 21 publications

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“…and Wickerhamomyces anomalus and found that power was the most significant parameter. On the other hand, Sainz Herrán et al ( 2010 ) studied the effects of US on Aspergillus terreus and observed that US affected fungal morphology but not the growth rate at any power.…”

Section: Resultsmentioning

confidence: 99%

Using homogenization, sonication and thermo-sonication to inactivate fungi

Campaniello

Bevilacqua

Sinigaglia

et al. 2016

PeerJ

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Ultrasound (US), Thermo-sonication (TS) and High Pressure Homogenization (HPH) were studied as tools to inactivate the spores of Penicillium spp. and Mucor spp. inoculated in distilled water. For US, the power ranged from 40% to 100%, pulse from 2 to 10 s, and duration of the treatment from 2 to 10 min. TS was performed combining US (40–80% of power, for 8 min and pulse of 2 s) with a thermal treatment (50, 55 and 60°C at 4, 8 and 12 min). Homogenization was done at 30–150 MPa for 1, 2 and 3 times. Power was the most important factors to determine the antifungal effect of US and TS towards the conidia of Penicillium spp.; on the other hand, in US treatments Mucor spp. was also affected by pulse and time. HPH exerted a significant antifungal effect only if the highest pressures were applied for 2–3 times.

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Section: Resultsmentioning

confidence: 99%

Using homogenization, sonication and thermo-sonication to inactivate fungi

Campaniello

Bevilacqua

Sinigaglia

et al. 2016

PeerJ

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“…As expected, K L a increased with the gas flow rate, but no significant variation of K L a values with temperature was found in the range tested, which amply covers the operating conditions expected for the culture of microorganisms. In previous works, the temperature was controlled at 28 °C in all sonicated fermentations. , Therefore, it is ensured that the temperature changes caused by ultrasound application have no effect on the K L a measurement.…”

Section: Resultsmentioning

confidence: 99%

“…This consequence is mainly attributed to the metabolite secretion mode, which usually takes place with pellet morphology. At the same time, the ultrasound application cycle was proven to be the most influential parameter. , …”

Section: Introductionmentioning

confidence: 99%

Gas–liquid Mass Transfer in Sonicated Bubble Columns. Effect of Reactor Diameter and Liquid Height

Herrán

López

Pérez

2012

Ind. Eng. Chem. Res.

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The enhancing effects of ultrasound on different aspects of bioprocesses have been repeatedly reported in the literature. These have usually been attributed to the mass transfer increase induced by sonication in fermentation processes. However, until now, this has not been analyzed in detail. In this work, the influence of ultrasonication on the overall gas−liquid oxygen transfer coefficient, K L a, has been studied as a function of reactor geometry and liquid height. Bubble columns ranging from 0.5 to 20 L were used. The effect of temperature on K L a was checked and no significant variation was observed between 25 and 45 °C. Therefore, the temperature changes caused by the application of ultrasound had no effect on the K L a measurement. The effects of ultrasonication were only significant when applied to small volumes resulting in power densities above 400 kW•m −3 , which are two orders higher than the standard mechanical power density supplied for mixing in fermentation (1−2 kW•m −3 ). Additionally, the enhancement obtained from ultrasound depended on the superficial gas velocity and the height/diameter ratio (H/D). Sonication only enhanced K L a at H/D ratios lower than 1, which corresponds more to the geometry of an ultrasonic bath than to a bubble column. Regardless of the ultrasound supply, when the H/D ratio increased from 0.3 to 3, the K L a significantly decreased regardless of the Ug value. However, for H/D ratios higher than 3, no influence of the H/D ratio on K L a was observed.

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“…In the past, extensive experimental investigations for the rheological characterisation of pellet‐based cultivations were carried out [15,42,43,103–112]. Although it is important to determine the viscous properties of a cultivation medium in order to estimate the power input of a process, it is not possible to conclude on the mechanical stress of an individual pellet or its influence on the pellet morphology without making major system assumptions [92,113].…”

Section: Experimental Investigations For the Micromechanical Charactementioning

confidence: 99%

Challenges of influencing cellular morphology by morphology engineering techniques and mechanical induced stress on filamentous pellet systems—A critical review

Böl

Schrinner

Tesche

et al. 2020

Engineering in Life Sciences

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Filamentous microorganisms are main producers of organic acids, enzymes, and pharmaceutical agents such as antibiotics and other active pharmaceutical ingredients. With their complex cell morphology, ranging from dispersed mycelia to dense pellets, the cultivation is challenging. In recent years, various techniques for tailor‐made cell morphologies of filamentous microorganisms have been developed to increase product formation and have been summarised under the term morphology engineering. These techniques, namely microparticle‐enhanced cultivation, macroparticle‐enhanced cultivation, and alteration of the osmolality of the culture medium by addition of inorganic salts, the salt‐enhanced cultivation, are presented and discussed in this review. These techniques have already proven to be useful and now await further proof‐of‐concept. Furthermore, the mechanical behaviour of individual pellets is of special interest for a general understanding of pellet mechanics and the productivity of biotechnological processes with filamentous microorganisms. Correlating them with substrate uptake and finally with productivity would be a breakthrough not to be underestimated for the comprehensive characterisation of filamentous systems. So far, this research field is under‐represented. First results on filamentous pellet mechanics are discussed and important future aspects, which the filamentous expert community should deal with, will be presented and critically discussed.

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Influence of ultrasound amplitude and duty cycle on fungal morphology and broth rheology of Aspergillus terreus

Cited by 11 publications

References 21 publications

Using homogenization, sonication and thermo-sonication to inactivate fungi

Using homogenization, sonication and thermo-sonication to inactivate fungi

Gas–liquid Mass Transfer in Sonicated Bubble Columns. Effect of Reactor Diameter and Liquid Height

Challenges of influencing cellular morphology by morphology engineering techniques and mechanical induced stress on filamentous pellet systems—A critical review

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