Abstract：
:The possibility of using thermostable inulinases from Aspergillus ficuum in place of invertase for sucrose hydrolysis was explored. The commercial inulinases preparation was immobilized onto porous glass beads by covalent coupling using activation by a silane reagent and glutaraldehyde before adding the enzyme. The immobilization steps were optimized resulting in a support with 5,440 IU/g of support (sucrose hydrolysis) that is 77% of the activity of the free enzyme. Enzymatic properties of the immobilized inulinases were similar to those of the free enzymes with optimum pH near pH 5.0. However, temperature where the activity was maximal was shifted of 10 degrees C due to better thermal stability after immobilization with similar activation energies. The curve of the effect of sucrose concentration on activity was bi-phasic. The first part, for sucrose concentrations lower than 0.3 M, followed Michaelis-Menten kinetics with apparent K(M) and Vm only slightly affected by immobilization. Substrate inhibition was observed at values from 0.3 to 2 M sucrose. Complete sucrose hydrolysis was obtained for batch reactors with 0.3 and 1 M sucrose solutions. In continuous packed-bed reactor 100% (for 0.3 M sucrose), 90% (1 M sucrose) or 80% sucrose conversion were observed at space velocities of 0.06-0.25 h(-1). The operational half-life of the immobilized inulinases at 50 degrees C with 2 M sucrose was 350 days.
journal_name
Enzyme Microb Technoljournal_title
Enzyme and microbial technologyauthors
Ettalibi M,Baratti JCdoi
10.1016/s0141-0229(00)00342-2keywords:
subject
Has Abstractpub_date
2001-05-07 00:00:00pages
596-601issue
7-8eissn
0141-0229issn
1879-0909pii
S0141022900003422journal_volume
28pub_type
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pub_type： 杂志文章
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journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2018.12.001
更新日期：2019-03-01 00:00:00
abstract：:'Candidatus Liberibacter asiaticus' ('Ca. L. asiaticus'), the suspected causative agent of citrus greening disease, is one of many phloem-restricted plant pathogens that have not been isolated and grown in an axenic culture. In this study, infected Asian citrus psyllids were used to prepare a host-free source of 'Ca. ...
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