The Role of Enzyme Loading on Starch and Cellulose Hydrolysis of Food Waste

2019 ◽  
Vol 10 (12) ◽  
pp. 3753-3762 ◽  
Author(s):  
Erfaneh Salimi ◽  
Konstantinos Saragas ◽  
Mir Edris Taheri ◽  
Jelica Novakovic ◽  
Elli Maria Barampouti ◽  
...  
2020 ◽  
Vol 8 (6) ◽  
pp. 915
Author(s):  
Regina Rettenmaier ◽  
Martina Schneider ◽  
Bernhard Munk ◽  
Michael Lebuhn ◽  
Sebastian Jünemann ◽  
...  

Bacterial hydrolysis of polysaccharides is an important step for the production of sustainable energy, for example during the conversion of plant biomass to methane-rich biogas. Previously, Hungateiclostridium thermocellum was identified as cellulolytic key player in thermophilic biogas microbiomes with a great frequency as an accompanying organism. The aim of this study was to physiologically characterize a recently isolated co-culture of H. thermocellum and the saccharolytic bacterium Defluviitalea raffinosedens from a laboratory-scale biogas fermenter. The characterization focused on cellulose breakdown by applying the measurement of cellulose hydrolysis, production of metabolites, and the activity of secreted enzymes. Substrate degradation and the production of volatile metabolites was considerably enhanced when both organisms acted synergistically. The metabolic properties of H. thermocellum have been studied well in the past. To predict the role of D. raffinosedens in this bacterial duet, the genome of D. raffinosedens was sequenced for the first time. Concomitantly, to deduce the prevalence of D. raffinosedens in anaerobic digestion, taxonomic composition and transcriptional activity of different biogas microbiomes were analyzed in detail. Defluviitalea was abundant and metabolically active in reactor operating at highly efficient process conditions, supporting the importance of this organism for the hydrolysis of the raw substrate.


2019 ◽  
Author(s):  
Jennifer Nill ◽  
Tina Jeoh

AbstractInterfacial enzyme reactions require formation of an enzyme-substrate complex at the surface of a heterogeneous substrate, but often multiple modes of enzyme binding and types of binding sites complicate analysis of their kinetics. Excess of heterogeneous substrate is often used as a justification to model the substrate as unchanging; but using the study of the enzymatic hydrolysis of insoluble cellulose as an example, we argue that reaction rates are dependent on evolving substrate interfacial properties. We hypothesize that the relative abundance of binding sites on cellulose where hydrolysis can occur (productive binding sites) and binding sites where hydrolysis cannot be initiated or is inhibited (non-productive binding sites) contribute to rate limitations. We show that the initial total number of productive binding sites (the productive binding capacity) determines the magnitude of the initial burst phase of cellulose hydrolysis, while productive binding site depletion explains overall hydrolysis kinetics. Furthermore, we show that irreversibly bound surface enzymes contribute to the depletion of productive binding sites. Our model shows that increasing the ratio of productive- to non-productive binding sites promotes hydrolysis, while maintaining an elevated productive binding capacity throughout conversion is key to preventing hydrolysis slowdown.


2015 ◽  
Vol 1113 ◽  
pp. 305-310
Author(s):  
Qadly Ameen Pahlawi ◽  
Nazlee Faisal Ghazali ◽  
Khairilanuar Mohd Hanim ◽  
Nik Azmi Nik Mahmood

A preliminary study was performed on enzymatic hydrolysis process for treating empty fruit bunch (EFB) fibre. The bioconversion of cellulose hydrolysis was carried out with soluble cellulase from Trichodermareesei as the biocatalyst. Crucial trends such as substrate and enzyme loading influencing the enzymatic reaction were also studied in order to enhance the cellulose conversion. The results indicate that as the enzyme loading was increased, the EFB conversion also increased until it reached 115.63 FPU/g of enzyme concentration, beyond this values, the reverse occurred. On the other hand, as the substrate loading was increased the conversion decreased. Inhibition of enzyme adsorption by hydrolysis products appear to be the main cause of the decreasing conversion at increasing enzyme loading and substrate loading.


Química Nova ◽  
2012 ◽  
Vol 35 (10) ◽  
pp. 1927-1930 ◽  
Author(s):  
Carlos Martín ◽  
George Jackson de Moraes Rocha ◽  
Julliana Ribeiro Alves dos Santos ◽  
Maria Carolina de Albuquerque Wanderley ◽  
Ester Ribeiro Gouveia

Author(s):  
Pan Hu ◽  
Huanan Li ◽  
Wenjing Xiao ◽  
Xiaohang Xie ◽  
Yuxian Yang ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2852
Author(s):  
Paul A. Foster

Steroid sulphatase (STS), involved in the hydrolysis of steroid sulphates, plays an important role in the formation of both active oestrogens and androgens. Since these steroids significantly impact the proliferation of both oestrogen- and androgen-dependent cancers, many research groups over the past 30 years have designed and developed STS inhibitors. One of the main contributors to this field has been Prof. Barry Potter, previously at the University of Bath and now at the University of Oxford. Upon Prof. Potter’s imminent retirement, this review takes a look back at the work on STS inhibitors and their contribution to our understanding of sulphate biology and as potential therapeutic agents in hormone-dependent disease. A number of potent STS inhibitors have now been developed, one of which, Irosustat (STX64, 667Coumate, BN83495), remains the only one to have completed phase I/II clinical trials against numerous indications (breast, prostate, endometrial). These studies have provided new insights into the origins of androgens and oestrogens in women and men. In addition to the therapeutic role of STS inhibition in breast and prostate cancer, there is now good evidence to suggest they may also provide benefits in patients with colorectal and ovarian cancer, and in treating endometriosis. To explore the potential of STS inhibitors further, a number of second- and third-generation inhibitors have been developed, together with single molecules that possess aromatase–STS inhibitory properties. The further development of potent STS inhibitors will allow their potential therapeutic value to be explored in a variety of hormone-dependent cancers and possibly other non-oncological conditions.


1983 ◽  
Vol 258 (22) ◽  
pp. 13673-13679 ◽  
Author(s):  
A Gómez-Puyou ◽  
G Ayala ◽  
U Muller ◽  
M Tuena de Gómez-Puyou

2016 ◽  
Vol 199 ◽  
pp. 49-58 ◽  
Author(s):  
Shaoni Sun ◽  
Shaolong Sun ◽  
Xuefei Cao ◽  
Runcang Sun

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