Regio- and Stereoselective Fungal Oxyfunctionalisation of Limonenes

Selective transformations of limonene by asco- and basidiomycetes were investigated. On the shake flask scale, Penicillium citrinum hydrated R-(+)-limonene to α-terpineol [83% regioselectivity (rs), more than 80 mg 1-1 product yield], and Gongronella butleri catalysed the terminal oxidation to yield perillyl alcohol (60% rs, 16 mg 1-1). On the laboratory bioreactor scale, Penicillium digitatum produced a peak concentration of 506 mg α-terpineol 1-1 in the fed-batch mode, equivalent to a theoretical yield of 67%, and no volatile by-products were found. Fusarium proliferatum transformed R-(+)-limonene enantiospecifically to cis-(+)- carveol (98.6% ee, more than 35 mg 1-1 product yield) and S-(-)-limonene predominantly to trans-(-)-carveol (96.3% ee). Pleurotus sapidus selectively dehydrogenised the accumulating trans-(-)-carveol to the corresponding enantiopure R-(-)-carvone. The results show that a careful selection of strain and bioprocess parameters may improve both the yield and the optical purity of a desired product.

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Production of 2,3-Butanediol from Sucrose by Klebsiella pneumoniae NRRL B199 in Batch and Fed-Batch Reactors

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89131998000300009 ◽

1998 ◽

Vol 41 (3) ◽

pp. 329-334 ◽

Cited By ~ 7

Author(s):

Mauricio M. Silveira ◽

M. Berbert-Molina ◽

A. M. R. Prata ◽

W. Schmidell

Keyword(s):

Klebsiella Pneumoniae ◽

Consumption Rate ◽

Substrate Inhibition ◽

Product Yield ◽

Batch Reactors ◽

Process Rate ◽

Fed Batch ◽

Sucrose Consumption ◽

Batch Mode ◽

Transfer Rates

In batch mode, Klebsiella pneumoniae growth and 2,3-butanediol/acetoin formation are increasingly inhibited by initial sucrose concentrations (S0) over 60 g/L. At non inhibitory conditions, a maximum sucrose consumption rate of 1,5 g/L/h was measured. With S0=204 g/L however, this rate decreased to 0.15 g/L/h. K. pneumoniae fermented 204 g/L sucrose to produce 84.3 g/L of a mixture 2,3-butanediol/acetoin with a yield of 0.41 g/g and a productivity of 1.06 g/L/h. Higher oxygen transfer rates improved the overall process rate but the product yield was reduced. Avoiding substrate inhibition, by performing the fermentation in fed-batch mode, a final 2,3-butanediol/acetoin concentration of 80.0 g/L was achieved. In this case, a productivity of 2.63 g/L/h and a product yield of 0.37 g/g were calculated.

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Enhanced co-generation of cellulosic ethanol and methane with the starch/sugar-rich waste mixtures and Tween 80 in fed-batch mode

Biotechnology for Biofuels ◽

10.1186/s13068-019-1562-0 ◽

2019 ◽

Vol 12 (1) ◽

Cited By ~ 2

Author(s):

Meishan Fan ◽

Jun Li ◽

Guican Bi ◽

Guangying Ye ◽

Hongdan Zhang ◽

...

Keyword(s):

Cellulosic Ethanol ◽

Ethanol Concentration ◽

Ethanol Yield ◽

Tween 80 ◽

Fed Batch ◽

Mixed Fermentation ◽

Batch Mode ◽

Mixture Ratio ◽

Theoretical Yield ◽

Solids Loading

Abstract Background The mixed-feedstock fermentation is a promising approach to enhancing the co-generation of cellulosic ethanol and methane from sugarcane bagasse (SCB) and molasses. However, the unmatched supply of the SCB and molasses remains a main obstacle built upon binary feedstock. Here, we propose a cellulose–starch–sugar ternary waste combinatory approach to overcome this bottleneck by integrating the starch-rich waste of Dioscorea composita Hemls. extracted residue (DER) in mixed fermentation. Results The substrates of the pretreated SCB, DER and molasses with varying ratios were conducted at a relatively low solids loading of 12%, and the optimal mixture ratio of 1:0.5:0.5 for the pretreated SCB/DER/molasses was determined by evaluating the ethanol concentration and yield. Nevertheless, it was found that the ethanol yield decreased from 79.19 ± 0.20 to 62.31 ± 0.61% when the solids loading increased from 12 to 44% in batch modes, regardless of the fact that the co-fermentation of three-component feedstock was performed under the optimal condition defined above. Hence, different fermentation processes such as fed-batch and fed-batch + Tween 80 were implemented to further improve the ethanol concentration and yield at higher solids loading ranging between 36 and 44%. The highest ethanol concentration of 91.82 ± 0.86 g/L (69.33 ± 0.46% of theoretical yield) was obtained with fed-batch + Tween 80 mode during the simultaneous saccharification and fermentation at a high solids loading of 44%. Moreover, after the ethanol recovery, the remaining stillage was digested for biomethane production and finally yielded 320.72 ± 6.98 mL/g of volatile solids. Conclusions Integrated DER into the combination of SCB and molasses would be beneficial for ethanol production. The co-generation of bioethanol and biomethane by mixed cellulose–starch–sugar waste turns out to be a sustainable solution to improve the overall efficacy in biorefinery.

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Afterword

The Oxford Handbook of Social Media and Music Learning ◽

10.1093/oxfordhb/9780190660772.013.41 ◽

2020 ◽

pp. 680-683

Author(s):

Janice L. Waldron ◽

Stephanie Horsley ◽

Kari K. Veblen

Keyword(s):

Social Media ◽

Media Use ◽

Careful Selection ◽

Social Media Use ◽

Pedagogical Tools ◽

The Future ◽

User Data ◽

Selection Of ◽

Data Surface

We all feel the implications of the force of social media—for good and for ill—in our lives and in our professional world. At the time of this writing, Facebook continues with its struggle to “clean up its act” as more revelations surrounding breaches of trust and hacked user data surface in the news and various countries attempt to hold Facebook to account. Despite this, social media use continues to grow exponentially, and the potential for responsible, ethical, and transparent social media to transform the ways in which we interact with and learn from each other increase with it. As we wait to see what the future holds for social media in society, we are reminded once again that it is the careful selection of pedagogical tools such as social media, as well the guided awareness of the challenges and benefits of those tools, that remains constant, even as tools may change, disappear, or fall out of fashion.

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Screening for optimal protease producing Bacillus licheniformis strains with polymer-based controlled-release fed-batch microtiter plates

Microbial Cell Factories ◽

10.1186/s12934-021-01541-2 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Tobias Habicher ◽

Tobias Klein ◽

Jacqueline Becker ◽

Andreas Daub ◽

Jochen Büchs

Keyword(s):

Controlled Release ◽

Bacillus Licheniformis ◽

Protease Activity ◽

Microtiter Plate ◽

Fed Batch ◽

Batch Mode ◽

Screening Process ◽

Microtiter Plates ◽

Batch Fermenter ◽

Production Conditions

Abstract Background Substrate-limited fed-batch conditions have the favorable effect of preventing overflow metabolism, catabolite repression, oxygen limitation or inhibition caused by elevated substrate or osmotic concentrations. Due to these favorable effects, fed-batch mode is predominantly used in industrial production processes. In contrast, screening processes are usually performed in microtiter plates operated in batch mode. This leads to a different physiological state of the production organism in early screening and can misguide the selection of potential production strains. To close the gap between screening and production conditions, new techniques to enable fed-batch mode in microtiter plates have been described. One of these systems is the ready-to-use and disposable polymer-based controlled-release fed-batch microtiter plate (fed-batch MTP). In this work, the fed-batch MTP was applied to establish a glucose-limited fed-batch screening procedure for industrially relevant protease producing Bacillus licheniformis strains. Results To achieve equal initial growth conditions for different clones with the fed-batch MTP, a two-step batch preculture procedure was developed. Based on this preculture procedure, the standard deviation of the protease activity of glucose-limited fed-batch main culture cultivations in the fed-batch MTP was ± 10%. The determination of the number of replicates revealed that a minimum of 6 parallel cultivations were necessary to identify clones with a statistically significant increased or decreased protease activity. The developed glucose-limited fed-batch screening procedure was applied to 13 industrially-relevant clones from two B. licheniformis strain lineages. It was found that 12 out of 13 clones (92%) were classified similarly as in a lab-scale fed-batch fermenter process operated under glucose-limited conditions. When the microtiter plate screening process was performed in batch mode, only 5 out of 13 clones (38%) were classified similarly as in the lab-scale fed-batch fermenter process. Conclusion The glucose-limited fed-batch screening process outperformed the usual batch screening process in terms of the predictability of the clone performance under glucose-limited fed-batch fermenter conditions. These results highlight that the implementation of glucose-limited fed-batch conditions already in microtiter plate scale is crucial to increase the precision of identifying improved protease producing B. licheniformis strains. Hence, the fed-batch MTP represents an efficient high-throughput screening tool that aims at closing the gap between screening and production conditions.

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Screening and selection of camptothecin producing endophytes from Nothapodytes nimmoniana

Scientific Reports ◽

10.1038/s41598-021-90778-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

I. A. H. Khwajah Mohinudeen ◽

Saumya Pandey ◽

Hemalatha Kanniyappan ◽

Vignesh Muthuvijayan ◽

Smita Srivastava

Keyword(s):

Natural Habitat ◽

Product Yield ◽

Study Strategies ◽

Selective Agent ◽

Nothapodytes Nimmoniana ◽

Time Consumption ◽

Potential Alternative ◽

Plant Metabolite ◽

Produce Plant ◽

Selection Of

AbstractEndophytic fungi with the ability to produce plant based secondary metabolites are a potential alternative for producing the host plant metabolite and to prevent natural plants from extinction. To isolate a high metabolite yielding endophytic strain from plants, hundreds of endophytic strains are screened and tested for product yield separately under axenic state, before shortlisting the potential endophyte, which involves huge time consumption. In this study, strategies for screening and selection of high camptothecin yielding endophytes from their natural habitat were proposed. A correlation was built between the camptothecin yield in the explants and the endophytes isolated from them. In addition, camptothecin yield was compared between the endophytes isolated from young and matured plants. Further, camptothecin producers and non-producers strains were compared for their tolerance toward camptothecin. The study indicates that high camptothecin yielding endophytes were isolated from high yielding explants and younger plants and they were more tolerant to camptothecin in comparison to non-camptothecin yielding endophytes. Thus, choosing a young and high yielding explant for endophyte isolation, and use of camptothecin as a selective agent in the growth medium, can be instrumental in screening and selection of high camptothecin yielding endophytes from nature in relatively less time.

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Catacomb culture wagons of the Eurasian steppes

Antiquity ◽

10.1017/s0003598x00101061 ◽

2014 ◽

Vol 88 (340) ◽

pp. 378-394 ◽

Cited By ~ 2

Author(s):

N.I. Shishlina ◽

D.S. Kovalev ◽

E.R. Ibragimova

Keyword(s):

Stable Isotope ◽

Isotope Analysis ◽

Burial Mound ◽

Careful Selection ◽

Southern Russia ◽

The Subject ◽

The Individual ◽

Wheeled Vehicles ◽

Selection Of ◽

Catacomb Culture

The origin and development of wheeled vehicles continues to fascinate today no less than when Stuart Piggott (1974) first wrote about the subject inAntiquity40 years ago. A growing number of examples from the steppes of southern Russia and Ukraine are providing new insights into the design and construction of these complex artefacts. A recent example from the Ulan IV burial mound illustrates the techniques employed and the mastery of materials, with careful selection of the kinds of wood used for the wheels, axles and other elements. Stable isotope analysis of the individual interred in this grave showed that he had travelled widely, emphasising the mobility of steppe populations.

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The Effects of Landscape Elements on the Breeding Sites of Bloodsucking Midge

Sustainability ◽

10.3390/su13052863 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2863

Author(s):

Kaowen Grace Chang ◽

Hungju Chien

Keyword(s):

Ground Surface ◽

Preventive Strategies ◽

Careful Selection ◽

Public Concern ◽

Breeding Sites ◽

Algae Growth ◽

Potential Habitats ◽

Landscape Factors ◽

The Relationship ◽

Selection Of

Forcipomyia taiwana, a bloodsucking midge that is one of the most irritating biting pests in Taiwan, has raised widespread public concern. However, we have little information about the extent to which landscape factors affect their potential habitats. As a result, landscape professionals do not have enough information to implement preventive strategies to control midges. The purpose of this study is to investigate the relationship between landscaping and algae growth for larval breeding sites of Forcipomyia taiwana. The intent is to determine the environmental strategies that make the planned landscape unsuitable for midges to breed. GIS based on data collected from 16 constructed landscape sites (317,187 m2 in total) was utilized to spatially examine the relationship between the occurrence of the algae for midge breeding sites and the ground surface types and planting characteristics in each landscape. The results revealed that the potential midge habitats can be controlled through careful selection of the ground surface, the improvement of the site drainage, and choosing plants with the appropriate characteristics. Apart from choosing the appropriate type of paving surface, the integrity of the paving installation and the coverage of the ecological surface also influence prevention efficacy.

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WEIGHT GAINS IN THE FIRST FOUR WEEKS OF INFANCY: A COMPARISON OF THREE DIETS

PEDIATRICS ◽

10.1542/peds.18.3.362 ◽

1956 ◽

Vol 18 (3) ◽

pp. 362-368

Author(s):

Ruth T. Gross ◽

Lincoln E. Moses

Keyword(s):

Human Milk ◽

Statistical Methods ◽

Full Term ◽

Clinical Judgement ◽

Careful Selection ◽

Term Infants ◽

Weight Gains ◽

The Many ◽

Selection Of

Four hundred seven healthy, full-term infants were divided into three groups and fed, respectively, a formula of evaporated milk and water with 5% carbohydrate; human milk; and a special modified evaporated milk designed to simulate human milk. No other foods were added to the diet. A comparison of the three groups was made, based on weight gains from birth to the end of the first 4 weeks. The conclusions refer only to weight gains; no attempt was made to determine the superiority of any particular diet. The data show no significant differences in the 4-week weight gains among the three groups of infants, although sensitive statistical methods could be validly applied to the problem. These methods are explained. The authors wish to emphasize the many variables which must be taken into account in a study of this sort; the necessity for careful selection of valid statistical methods; the importance of critical clinical judgement in the evaluation of the results.

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The Design for Assembly Guidelines Transform a Product Innovation From a Loser to a Winner

Volume 4: 3rd Design for Manufacturing Conference ◽

10.1115/detc98/dfm-5715 ◽

1998 ◽

Author(s):

David H. Myszka

Keyword(s):

Product Innovation ◽

Computer Models ◽

Design For Assembly ◽

Careful Selection ◽

Significant Cost ◽

Success Stories ◽

Modeling Process ◽

Design Activities ◽

Manual Review ◽

Selection Of

Abstract Several manufacturer’s are witnessing soaring profits as a result of cost reductions derived from Design for Manufacturing and Assembly (DFMA) analyses. These successes are prompting others to turn to more refined computer models of product assemblies. However, much can be gained from a very routine analysis, using nothing more than the basic Design for Assembly (DFA) guidelines. These gains can be realized at a mere fraction of the resources needed for the computer models. This method of analysis is especially appealing to engineers whose time constraints require careful selection of design activities. This paper argues that DFMA analysis does not need to be an elaborate modeling process to produce significant cost improvements. This point is illustrated with an example of a redesign of a cooking range door. A manual review of the DFA guidelines turned a design innovation from a loser into a winner. Success stories from such informal analyses should promote greater implementation across industries that are hesitant in adopting DFMA practices.

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Automated and Adaptive Geometry Preparation for AR/VR-Applications

10.1115/detc2021-66731 ◽

2021 ◽

Author(s):

Maximilian Peter Dammann ◽

Wolfgang Steger ◽

Ralph Stelzer

Keyword(s):

Software Tool ◽

Product Structure ◽

Preparation Process ◽

Data Preparation ◽

Batch Mode ◽

Computing Power ◽

Time Savings ◽

Automatic Preparation ◽

Target Platform ◽

Selection Of

Abstract Product visualization in AR/VR applications requires a largely manual process of data preparation. Previous publications focus on error-free triangulation or transformation of product structure data and display attributes for AR/VR applications. This paper focuses on the preparation of the required geometry data. In this context, a significant reduction in effort can be achieved through automation. The steps of geometry preparation are identified and examined with respect to their automation potential. In addition, possible couplings of sub-steps are discussed. Based on these explanations, a structure for the geometry preparation process is proposed. With this structured preparation process it becomes possible to consider the available computing power of the target platform during the geometry preparation. The number of objects to be rendered, the tessellation quality and the level of detail can be controlled by the automated choice of transformation parameters. We present a software tool in which partial steps of the automatic preparation are already implemented. After an analysis of the product structure of a CAD file, the transformation is executed for each component. Functions implemented so far allow, for example, the selection of assemblies and parts based on filter options, the transformation of geometries in batch mode, the removal of certain details and the creation of UV maps. Flexibility, transformation quality and time savings are described and discussed.

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