Two mathematical models for the development of a single microbial pellet

Meyerhoff, J.; Tiller, V.; Bellgardt, K.‐H.

doi:10.1007/bf00369507

Cited by 24 publications

(16 citation statements)

References 15 publications

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“…In silico models have been developed to better understand mycelial growth (389)(390)(391), although many were primarily based on physiological and nutritional parameters. Helped by the strong increase in computing power in the modern era, new models were developed recently (392,393).…”

Section: Correlation Between Growth and Antibiotic Productionmentioning

confidence: 99%

Taxonomy, Physiology, and Natural Products of Actinobacteria

Barka

Vatsa

Sanchez

et al. 2016

Microbiol Mol Biol Rev

1,592

1,048

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SUMMARYActinobacteriaare Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla, and they are ubiquitously distributed in both aquatic and terrestrial ecosystems. ManyActinobacteriahave a mycelial lifestyle and undergo complex morphological differentiation. They also have an extensive secondary metabolism and produce about two-thirds of all naturally derived antibiotics in current clinical use, as well as many anticancer, anthelmintic, and antifungal compounds. Consequently, these bacteria are of major importance for biotechnology, medicine, and agriculture.Actinobacteriaplay diverse roles in their associations with various higher organisms, since their members have adopted different lifestyles, and the phylum includes pathogens (notably, species ofCorynebacterium,Mycobacterium,Nocardia,Propionibacterium, andTropheryma), soil inhabitants (e.g.,MicromonosporaandStreptomycesspecies), plant commensals (e.g.,Frankiaspp.), and gastrointestinal commensals (Bifidobacteriumspp.).Actinobacteriaalso play an important role as symbionts and as pathogens in plant-associated microbial communities. This review presents an update on the biology of this important bacterial phylum.

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Section: Correlation Between Growth and Antibiotic Productionmentioning

confidence: 99%

Taxonomy, Physiology, and Natural Products of Actinobacteria

Barka

Vatsa

Sanchez

et al. 2016

Microbiol Mol Biol Rev

1,592

1,048

View full text Add to dashboard Cite

show abstract

“…In order to proceed towards a better understanding of influencing factors for growth and product formation of Penicillium chrysogenum in the presence of pellets, Meyerhoff et al [63] developed a detailed model for the growth of single hyphae up to mycelia flocs and pellets. The model adopted the basic concepts of Yang et al [64,65] for the growth of Streptomyces tendae.…”

Section: A Detailed Model For Growth Of Penicillium Chrysogenurn Pelletsmentioning

confidence: 99%

“…The model was aimed at the early phases of growth beginning with a single spore and does not consider effects of transport limitation. For the simulation of pellets under more realistic conditions, terms for growth limitation by space, substrate and oxygen, cell inactivation and lysis under starvation condition (e. g. in the center of pellets) and cut-off of hyphae at the surface of pellets were introduced by Meyerhoff et al [63]. In the following the model is briefly outlined.…”

Section: A Detailed Model For Growth Of Penicillium Chrysogenurn Pelletsmentioning

confidence: 99%

“…Similar expressions for the other types of compartments can be derived [63], but are not repeated here. After being grown to a sufficient size, the events of septation and branching can occur.…”

Section: A Detailed Model For Growth Of Penicillium Chrysogenurn Pelletsmentioning

confidence: 99%

“…Breakage events are basically of a stochastic nature although the actual state of the pellet with respect to the cell density profile, the size and age will influence the breakage probability. The model provides this information, but as a first step, a simple linear correlation of the breakage probability in a given time interval, PBr, with respect to the intensity of the shear forces and the entire biomass, Cx, was assumed to be valid for all pellets: At PBr = KBr)kShear Cx 0.2h (31) The microkinetics of hyphal growth were adopted from Tiller et al [63] with slight modifications. The production of penicillin in this model was related to the morphology by dt qp x-~d~px -k h P -D P where qp= .…”

Section: Integrated Process Modelmentioning

confidence: 99%

See 2 more Smart Citations

Proces models for production of β-lactam antibiotics

Bellgardt

1998

Relation Between Morphology and Process Performances

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Great progress has been made in the modelling of biotechnical processes using filamentous microorganisms. This paper deals with cultivations of Penicillium chrysogenum for the production of Penicillin and of Acrernonium chrysogenum for the production of Cephalosporin C. The properties of the processes and the existing models are reviewed. Models are presented for both processes that consider aspects which are important for industrial cultivation. The process model for Penicillin production is based on a detailed morphological description of growth of hyphal filaments and pellets. The model allows for simulation of the production process including the preculture and considering the inhomogenous pellet population. It opens new possibilities for understanding the complex kinetics of the process and improvement of its control. The structured segregated model for Cephalosporin C production considers soy oil as second carbon source besides sugar. The application of the model for dynamic optimization of feeding strategies by Iterative Dynamic Programming is demonstrated. As an alternative approach, modelling of the Cephalosporin production by an artificial neural network is discussed.

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Oxygen profiles and biomass distribution in biopellets of Aspergillus niger

Hille

Neu

Hempel

et al. 2005

Biotech & Bioengineering

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Morphology of fungal pellets has a significant influence on mass transfer and turnover processes in submerged cultures. There are many reports in literature that biomass is not distributed homogeneously over the pellet radius, yet quantitative data is rare. This study presents a method for the quantification of fungal pellet structure (Aspergillus niger). Confocal laser scanning microscopy (CLSM) is used in combination with image analysis freeware (Image J). Hyphal distribution is resolved spatially in radial direction. Quantitative morphological parameters are derived from digital images especially from the peripheral regions of the pellet that are not oxygen limited. This morphological information is combined with data of microelectrode measurements in the same pellets. Results show that the morphological parameters obtained can describe the impact of pellet structure on oxygen gradients much better than average biomass density. It is concluded that CLSM and image analysis are powerful tools not only to generate valuable data for quantitative description of pellet morphology. In addition, this data may be used in mathematical models to improve predictions of mass transfer and substrate conversion in mycelial aggregates.

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Two mathematical models for the development of a single microbial pellet

Cited by 24 publications

References 15 publications

Taxonomy, Physiology, and Natural Products of Actinobacteria

Taxonomy, Physiology, and Natural Products of Actinobacteria

Proces models for production of β-lactam antibiotics

Oxygen profiles and biomass distribution in biopellets of Aspergillus niger

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